bluuebunny/crossref_metadata_2025_split huggingface dataset:
Late Holocene Vegetation Change in the Sierra Madre Oriental of Central Mexico
Authors: Conserva Maria Elena , Byrne Roger 
Published: September 2002

AbstractPast vegetation and climate changes reconstructed from a sediment core from Laguna Atezca, Molango, Mexico, provide new insights into the environmental and cultural histories of the Sierra Madre Oriental during the last 1700 yr. Pollen, microscopic charcoal, sediment chemistry, loss on ignition, and magnetic susceptibility indicate that three phases of human occupation, deforestation, and erosion (ca. A.D. 280–890, ca. A.D. 1030–1420, and ca. A.D. 1680–present) alternate with two phases of abandonment (ca. A.D. 890–1030 and ca. A.D. 1420–1680). Forest composition of the two abandonment phases differed, with cloud forest taxa (Liquidambar, Ostrya/Carpinus, Ulmus, etc.) dominating the pollen record during the first phase, andQuercusandPinuspollen characterizing phase two. These differences may reflect a climate change in which the second phase was drier than the first; Alternatively, the increase inPinusandQuercusmay have been caused by a human-induced decline in soil fertility. The Laguna Atezca record also differs from several other Mesoamerican paleoenvironmental records in that it shows no evidence of drought at the end of the Classic Period, ca. A.D. 900.
Paleoenvironmental Changes in the Semiarid Coast of Chile (∼32°S) during the Last 6200 cal Years Inferred from a Swamp–Forest Pollen Record
Authors: Maldonado Antonio , Villagrán Carolina 
Published: September 2002

AbstractPollen analysis of two sediment records from a coastal swamp forest site in the Chilean semiarid region (31°50′S; 71°28′W) shows an alternation of dry and wet phases during the past ∼6100 cal yr B.P. The most prominent vegetation changes occur at ∼4200 cal yr B.P., with the expansion of the swamp forest taxa Luma chequen and Escallonia sp., followed by a regression of the forest beginning at ∼3200 cal yr B.P. and ending with its replacement by a xerophytic scrub, between ∼1800 and 1300 cal yr B.P. The swamp forest reexpanded after ∼1300 cal yr B.P. and persisted, with minor variation, until the present. We interpret the establishment of the swamp forest at the study site to be the result of a rising watertable in response to increased rainfalls from ∼4200 cal yr B.P. onward. Our results indicate that in north-central Chile the second half of the Holocene was climatically more variable than previously thought, suggesting significant changes in the position and/or intensity of the westerlies wind belt and possibly in the frequency of El Niño–Southern Oscillation events.
A Test of “Annual Resolution” in Stalagmites Using Tree Rings
Authors: Betancourt Julio L. , Grissino-Mayer Henri D. , Salzer Matthew W. , Swetnam Thomas W. 
Published: September 2002

AbstractSo-called annual banding has been identified in a number of speleothems in which the number of bands approximates the time interval between successive U-series dates. The apparent annual resolution of speleothem records, however, remains largely untested. Here we statistically compare variations in band thickness from a late Holocene stalagmite in Carlsbad Cavern, Southern New Mexico, USA, with three independent tree-ring chronologies form the same region. We found no correspondence. Although there may be various explanations for the discordance, this limited exercise suggests that banded stalagmites should be held to the same rigorous standards in chronology building and climatic inference as annually resolved tree rings, corals, and ice cores.
Implications of Water Supply for Indigenous Americans during Holocene Aridity Phases on the Southern High Plains, USA
Authors: Wood Warren W. , Stokes Stephen , Rich Julie 
Published: September 2002

AbstractSprings in the 40 to 50 large lake basins (>15 km2) on the southern portion of the Southern High Plains (SHP) were active during periods of aridity in the Holocene when there may have been human habitation of the area. Eolian erosion of the lake floors and lunette accretion occurred as groundwater levels declined in response to decreased groundwater recharge. The declining lake floor associated with eolian erosion allowed groundwater evaporative discharge to continue, thus maintaining a groundwater gradient toward the lake. This hydrologic condition was favorable for a relatively continuous spring discharge to the lake, independent of the elevation of the lake floor. To evaluate the postulated dynamic equilibrium critical to this conclusion, 17 optically stimulated ages were determined from a 17.7-m deep core of a lunette adjacent to Double Lakes, Texas (33°13′15″N, 101°54′08″W). The core yielded sediment accumulation dates of 11,500±1100, 6500±700, and 4900±500 yr B.P., corresponding broadly with periods of aridity known from other evidence. Based on analysis of this lunette, it is concluded that springs in Double Lakes basin probably existed throughout the Holocene with discharges similar to those observed historically. We assumed that similar dynamic equilibrium existed in the other large lake basins in the SHP and that these springs could have provided a continuous source of water for indigenous peoples during periods of prolonged aridity. The dynamic equilibrium that is proposed in this study is applicable not only to other arid and semiarid geographic areas with wind-erodible material but also over different geologic times.
Zooarchaeological Evidence of Prairie Taxa in Central Missouri during the Mid-Holocene
Authors: Wolverton Steve 
Published: September 2002

AbstractPrevious studies report that remains of prairie taxa are common in western Missouri archaeological sites. There is no reported evidence of prairie taxa, such as Bos bison, from sites within the northern Ozark Highlands of Missouri. New data indicate that prairie taxa inhabited the area during the warm and dry mid-Holocene (8500–5000 14C yr B.P.). Evidence suggests prairie taxa were farther east and south than previously documented in central Missouri and underscores the importance of biogeographic data in studies of prehistoric environments.
Early to Mid-Holocene Aridity in Central Chile and the Southern Westerlies: The Laguna Aculeo Record (34°S)
Authors: Jenny Bettina , Valero-Garcés Blas L. , Villa-Martínez Rodrigo , Urrutia Roberto , Geyh Mebus , Veit Heinz 
Published: September 2002

AbstractCentral Chile (32–35°S) lies at the northern border of strong Westerly influence and thus exhibits a steep precipitation gradient. Therefore, the palaeoclimatic archives in the region are suitable for detecting past moisture changes. The study of Laguna Aculeo (33°50'S, 70°54'W) presents a multiproxy Holocene lake record including sedimentology, geochemistry, mineralogy, pollen, diatoms, and radiocarbon dating (17 dates). Results indicate an arid early to mid-Holocene period (about 9500–5700 cal yr B.P.). After 5700 cal yr B.P. effective moisture increased progressively and around 3200 cal yr B.P., modern humid conditions were established. Numerous intercalated clastic layers reflect flood deposition during rainy winters. A fluvial unit was deposited shortly before 9000 cal yr B.P. Subsequently, flood events were absent until 5700 but have become frequent since 3200 cal yr B.P. The frequency of flood layers possibly points to weak or no El Niño activity during the early and mid-Holocene, with a subsequent increase during the late Holocene. During the early and mid-Holocene, the Westerlies were probably blocked and hence deflected southward by the subtropical high-pressure cell. Higher precipitation during the last 3200 yr seems strongly related to a weakened subtropical high-pressure cell with intensified Westerlies and possibly increased El Niño activity.
Hypogonadotropic hypogonadism: retrospective analysis of 19 cases
Authors: Moura M.D , Navarro P.A.A.S , Silva de Sá M.F , Ferriani R.A , Unzer S.M , Reis R.M 
Published: September 2002

AbstractObjectives: To survey the clinical data of patients with isolated gonadotropin deficiency. Methods: We retrospectively surveyed the medical records of 19 patients with isolated gonadotropin deficiency aged 16–31 years (mean: 20 years). The major complaint was primary amenorrhea in 100% of the patients, with 42.1% of them also reporting absence of secondary sex traits, and 10% reporting anosmia or hyposmia. Seventy‐four percent of the patients had been submitted to hormonal replacement therapy. Results: Bone densitometry was determined in 5 patients and revealed lumbar spine osteopenia in 3 patients and femoral osteopenia in 1. An association with urologic malformations was detected in 10.5% of cases and an association with gynecologic malformations was detected in 31.6%. Conclusions: Isolated gonadotropin deficiency can be easily diagnosed but requires early estrogen replacement therapy because of a higher risk of osteopenia and consequently of osteoporosis. Concomitant urogenital malformations are frequent and should be investigated.
Neurotic symptoms, stress, or deprivation: which is most closely associated with incidence of suicide? An ecological study of English Health Authorities
Authors: BARTLETT C. J. , GUNNELL D. , HARRISON G. , MOORE L. 
Published: September 2002

Background. Suicide rates, anxiety/depression scores and stress scores are routinely used as mental health indicators in populations, but their inter-relationships have not been explored. Our aim was to explore the association of suicide rates with anxiety/depression and stress scores, while also referring to deprivation scores, which are known to be linked to suicide rates.Methods. We undertook an ecological analysis of English Health Authorities, regressing suicide rates (1993–1994), on General Health Questionnaire and stress scores (1994), and also on Jarman deprivation scores (1991).Results. Overall, Jarman deprivation score was a better predictor of suicide rate than the psychological distress measures. There were no statistically significant associations between suicide rates and GHQ scores, although there was a weak association between suicide rate and mean stress level in women.Conclusions. Suicide rates, though important in themselves, are not reliable indicators of the levels of neurotic symptoms or stress in populations. Suicide rates are more strongly associated with area-based measures of social disadvantage, though a possible stress–suicide relationship in women could be investigated further.
Control and controllability: beliefs and behaviour in high and low expressed emotion relatives
Authors: HOOLEY JILL M. , CAMPBELL CHRISTINE 
Published: September 2002

Background. Expressed emotion (EE) is a measure of the family environment that is a well replicated psychosocial predictor of psychiatric relapse. Theoretical models of EE place heavy emphasis on the notion of control. We explored the extent to which high and low EE relatives made both attributions of control about patients and engaged in controlling behaviours.Methods. Trained raters who were blind to information about EE coded interviews with 35 relatives of patients with schizophrenia and 42 relatives of patients with unipolar depression. Relatives were rated on two reliable scales that assessed relatives' tendencies to make illness controllability attributions and relatives' efforts to exert direct behavioural control over patients.Results. In both the schizophrenia and depressed groups, high-EE relatives attributed more control to their ill family members than did low EE relatives. They also behaved in a more controlling manner. Examination of patients' clinical outcomes during a 9-month follow-up period revealed that high levels of behavioural control on the part of relatives significantly predicted relapse in patients with schizophrenia but not in patients with depression.Conclusions. These findings support the attribution-based model of EE. They further suggest that controlling behaviours on the part of relatives may mediate the EE-relapse link in schizophrenia. Such behaviours may be important targets for modification in family-based interventions for schizophrenia.
Progression to AIDS, a clinical AIDS condition and mortality: psychosocial and physiological predictors
Authors: LESERMAN J. , PETITTO J. M. , GU H. , GAYNES B. N. , BARROSO J. , GOLDEN R. N. , PERKINS D. O. , FOLDS J. D. , EVANS D. L. 
Published: September 2002

Background. The primary aim of this study is to examine prospectively the association of stressful life events, social support, depressive symptoms, anger, serum cortisol and lymphocyte subsets with changes in multiple measures of human immunodeficiency virus (HIV) disease progression.Methods. Ninety-six HIV-infected gay men without symptoms or anti-retroviral medication use at baseline were studied every 6 months for up to 9 years. Disease progression was defined in three ways using the Centers for Disease Control (CDC) classifications (e.g. AIDS, clinical AIDS condition and mortality). Cox regression models with time-dependent covariates were used, adjusting for control variables (e.g. race, age, baseline, CD4 T cells and viral load, number of anti-retroviral medications).Results. Higher cumulative average stressful life events and lower cumulative average social support predicted faster progression to both the CDC AIDS classification and a clinical AIDS condition. Higher anger scores and CD8 T cells were associated with faster progression to AIDS, and depressive symptoms were associated with faster development of an AIDS clinical condition. Higher levels of serum cortisol predicted all three measures of disease progression.Conclusions. These results suggest that stressful life events, dysphoric mood and limited social support are associated with more rapid clinical progression in HIV infection, with serum cortisol also exerting an independent effect on disease progression.
Age–period–cohort effects on inequalities in psychological distress, 1981–2000
Authors: SACKER AMANDA , WIGGINS RICHARD D. 
Published: September 2002

Background. In the closing decades of the twentieth century, changes in population sociodemographics took place that might be thought to have an adverse influence on the nation's psychological distress. Here, we examine the stability of social and gender inequalities in psychological distress throughout the 1980s and 1990s.Methods. The study uses data from the 1958 National Child Development Study and the 1970 British Cohort Study collected when the cohort members were aged between 23 and 42. Multilevel logistic regression models were used to examine the effects of social class, gender, age, period and cohort on psychological distress as measured by the Malaise Inventory.Results. We identify clear social inequalities in psychological distress during 1981–2000 that reduced in magnitude over this period. Non-linear age effects were observed: psychological distress improves in early adulthood but declines again on approaching mid-life. The 1970 cohort had poorer psychological distress than the 1958 cohort. Although women had higher rates of psychological distress than men, gender differences reduced in magnitude. Declining rates of women's psychological distress over time have not been matched in men. A reduction in social inequalities over time was also observed. Improvements in the psychological health of those in manual occupations were not equalled among those in non-manual occupations.Conclusions. Both social and gender inequalities have narrowed in the last two decades of the twentieth century.
Responses of tropical rainforest birds to abandoned plantations, edges and logged forest in the Western Ghats, India
Authors: Shankar Raman T. R. , Sukumar R. 
Published: September 2002

AbstractThis study examined the effects of alteration of tropical rainforest vegetation structure and composition on bird community structure and the influence of life‐history traits on species persistence in the Kalakad‐Mundanthurai Tiger Reserve, Western Ghats. Systematic sampling for vegetation and point count surveys for birds were carried out in cardamom plantations abandoned for 5 and 15 years, plantation‐rainforest edges, a selectively logged forest patch and adjoining undisturbed rainforest sites. Principal components analysis of vegetation variables revealed clear differences between undisturbed and altered sites in woody plant and cane densities, canopy cover and vertical stratification. Bird species richness was lowest in cardamom plantations abandoned for 5 years and highest in logged and undisturbed forest. Bird species richness and similarity with undisturbed forest were significantly positively related to the vegetation component representing woody plant and cane (Calamus spp.) densities. Sites that were more similar in tree species composition had more similar bird communities whereas similarity in foliage profile between sites did not influence bird community similarity. Birds that were rare, were large‐bodied and belonged to the carnivore, omnivore, bark‐surface feeder and terrestrial insectivore guilds were adversely affected by habitat alteration. Restoring woody plant and cane densities and rainforest floristic composition in disturbed habitats may be required for management and conservation of bird communities typical to the region.
A theoretical analysis of competitive exclusion in a Trans‐Himalayan large‐herbivore assemblage
Authors: Mishra Chardutt , Van Wieren Sipke E. , Heitkönig Ignas M. A. , Prins Herbert H. T. 
Published: September 2002

AbstractUnderstanding livestock grazing impacts on native wildlife is difficult when grazing is pervasive and has a long history. Spiti Valley in the Indian Trans‐Himalaya is characterized by overstocking of rangelands and a grazing history of over 3 millennia. An intriguing aspect of the wild large‐herbivore assemblage in Spiti Valley is its low diversity. In the present theoretical exploration, data on body masses of wild large‐herbivore species in the Trans‐Himalaya are examined against the backdrop of competition theory, to evaluate the possible role of competition in structuring the herbivore assemblage. The analysis is then expanded to include the livestock assemblage, and the possibility of the low wild herbivore diversity in Spiti Valley being a consequence of the high livestock diversity is explored. Null model analyses suggest that competitive interactions may have played a role in structuring the Trans‐Himalayan wild herbivore assemblage. This is reflected in a proportional regularity in species body masses, with each species, on average, being a constant proportion larger than the nearest smaller one. Such a proportional regularity is absent in the livestock assemblage. The analyses make a case for the competitive exclusion of at least four wild grazers in Spiti over the last 3 millennia. The present grazer assemblage conforms reasonably to the theoretical predictions ‐ these four species are among the six wild herbivores presently missing from Spiti. The implications of the analyses for conservation management in the Trans‐Himalaya are discussed.
Combined Antiviral-Antimediator Treatment for the Common Cold
Authors: Gwaltney Jack M. , Winther Birgit , Patrie James T. , Hendley J. Owen 
Published: September 2002

Abstract
A randomized, controlled, double-masked clinical trial was conducted with a combination antiviral-antimediator treatment for experimental rhinovirus colds. In all, 150 healthy men and women (aged 18–51 years) were randomly assigned to 1 of 3 groups: intranasal interferon (IFN)–α2b (6×106 U every 12 h × 3) plus oral chlorpheniramine (12 mg extended release) and ibuprofen (400 mg) every 12 h for 4.5 days (n=59 subjects); intranasal placebo plus oral chlorpheniramine and ibuprofen (n=61 subjects); or intranasal and oral placebos (n=30 subjects). Treatment was started 24 h after intranasal viral challenge. During the 4.5 days of treatment with IFN-α2b, chlorpheniramine, and ibuprofen, the daily mean total symptom score was reduced by 33%–73%, compared with placebo. Treatment reduced the severity of rhinorrhea, sneezing, nasal obstruction, sore throat, cough, and headache and reduced nasal mucus production, nasal tissue use, and virus concentrations in nasal secretions. IFN-α2b added to the effectiveness of chlorpheniramine and ibuprofen and was well tolerated
An Approach to an Analysis of the Arterial Pulse Wave I. Oscillations in an Attenuating Line
Authors: M G Taylor  
Published: September 2002

The Telegraph equations have been used to obtain expressions for the following quantities in an attenuating electric transmission line:1. the input impedance in terms of the length of an open-circuited line,2. the modulus of the voltage as a function of the distance along an open-circuited line,3. the ` apparent phase velocity at a point ' along a line, as a function of the distance from the origin and the nature of the termination,4. the ` apparent phase velocity over a finite interval ' for the same type of line,5. the modulus of the reflection coefficient in terms of (4).Numerical examples have been computed for (1)-(4) and are presented.The use of the attenuating electric line as a model in approaching an understanding of the dynamics of the arterial circulation is outlined, and the limitations discussed.
An analysis of gene-finding programs for Neurospora
crassa
Authors: Kraemer Eileen , Wang Jian , Guo Jinhua , Hopkins Samuel , Arnold Jonathan 
Published: September 2002

Abstract
Motivation: Computational gene identification plays an important role in genome projects. The approaches used in gene identification programs are often tuned to one particular organism, and accuracy for one organism or class of organism does not necessarily translate to accurate predictions for other organisms. In this paper we evaluate five computer programs on their ability to locate coding regions and to predict gene structure in Neurospora crassa. One of these programs (FFG) was designed specifically for gene-finding in N.crassa , but the model parameters have not yet been fully ‘tuned’, and the program should thus be viewed as an initial prototype. The other four programs were neither designed nor tuned for N.crassa.
Results: We describe the data sets on which the experiments were performed, the approaches employed by the five algorithms: GenScan, HMMGene, GeneMark, Pombe and FFG, the methodology of our evaluation, and the results of the experiments. Our results show that, while none of the programs consistently performs well, overall the GenScan program has the best performance on sensitivity and Missing Exons (ME) while the HMMGene and FFG programs have good performance in locating the exons roughly. Additional work motivated by this study includes the creation of a tool for the automated evaluation of gene-finding programs, the collection of larger and more reliable data sets for N.crassa , parameterization of the model used in FFG to produce a more accurate gene-finding program for this species, and a more in-depth evaluation of the reasons that existing programs generally fail for N.crassa.
Availability: Data sets, the FFG program source code, and links to the other programs analyzed are available at http://jerry.cs.uga.edu/~wang/genefind.html
Contact: eileen@cs.uga.edu
* To whom correspondence should be addressed.