bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mid-Pleistocene Change in Large Mammal Faunas of East Africa
Authors: Potts Richard , Deino Alan 
Published: October 2002

AbstractSingle-crystal40Ar/39Ar age estimates of 392,000 ± 4000 to 330,000 ± 6000 yr from Lainyamok, a middle Pleistocene fossil locality in the southern Kenya rift, document the oldest evidence from sub-Saharan Africa of a diverse, large mammal fauna consisting entirely of extant species. The inferred age of this fauna implies an upper limit for extinction of species that characterize well-calibrated, mid-Pleistocene fossil assemblages in East Africa. For its age and species richness, the Lainyamok fauna is surprising for its lack of extinct forms (e.g., the bovinePelorovis) well documented in later faunal assemblages of East and South Africa. Definitive presence of the South African blesbok(Damaliscus dorcas)is also unexpected, especially as this alcelaphine bovid is the dominant large mammal in the Lainyamok fauna. These age estimates and the faunal composition at Lainyamok indicate that geographic ranges and taxonomic associations of extant largebodied mammals were susceptible to wide fluctuations in sub-Saharan Africa over the past 330,000 yr. This inference is consistent with the hypothesis of nonanalogue, or ephemeral, biotas believed to characterize late Quaternary ecosystems of northern continents.
Glacial Meltwater in Lake Huron during Early Postglacial Time as Inferred from Single-Valve Analysis of Oxygen Isotopes in Ostracodes
Authors: Dettman David L. , Smith Alison J. , Rea David K. , Moore Theodore C. , Lohmann Kyger C. 
Published: October 2002

Abstractδ18O measurements of benthic ostracodes are used to reconstruct the δ18O history of Lake Huron and Georgian Bay water between 10,600 and 760014C yr B.P. This δ18O record was calibrated using a comparison of the δ18O values of modern ostracodes and Lake Huron water, where a fractionation of 1.0358 was measured between the oxygen isotope ratios of the most isotopically positive ostracodeCandona subtriangulataand lake water. The most positive shell δ18O value was used because it is precipitated in the cold (0° to 2°C) water common to both deep and shallow environments. The δ18O of Lake Huron water reflects a large glacial meltwater component for much of its history before 760014C yr B.P. Times of low lake level correlate with the highest ratio of glacial meltwater to local precipitation in the basin (most negative δ18O values). Georgian Bay water was more negative in δ18O than Lake Huron water of the same age; this reflects a higher proportion of glacial meltwater in Georgian Bay and its separation from Lake Huron during times of low lake level.
Uranium-Series Dating of Carbonate (Tufa) Deposits Associated with Quaternary Fluctuations of Pyramid Lake, Nevada
Authors: Szabo Barney J. , Bush Charles A. , Benson Larry V. 
Published: October 2002

AbstractUranium-series dating of dense tufa deposited in a small cave, at former lake margins, and in large tufa mounds clarifies the timing of lake-level variation during the past 400,000 yr in the Pyramid Lake basin. A moderate-sized lake occasionally overflowed the Emerson Pass sill at elevation of ∼1207 m between ca. 400,000 and 170,000 and from ca. 60,000 to 20,000 yr B.P., as shown by 230Th/234U ages of the cave samples, 230Th-excess ages of tubular tufas, and average isochron-plot ages of shoreline-deposited tufas. (By comparison, modern Pyramid Lake is ∼50 m below this sill). There is a lack of tufa record during the intervening period from ca. 170,000 to 60,000 yr B.P. After ca. 20,000 yr, Pyramid Lake underwent abrupt changes in level and, based on previous 14C ages, reached its highest elevation (ca 1335 m) at ca. 14,000 yr B.P. The youngest uranium-series ages are comparable with previously reported 14C ages.
Calibration, Review, and Geomorphic Implications of Postglacial Radiocarbon Ages in Southeastern Alberta, Canada
Authors: Campbell Celina , Campbell Ian A. 
Published: October 2002

AbstractCalibration of radiocarbon dates of postglacial geomorphic events in southeastern Alberta, Canada, reveals a strong association between type of geomorphic event and seasonality of insolation. The late glacial and postglacial periods can be divided into four major episodes: glaciation, ca. >20,000 cal yr B.P.; deglaciation, ca. 20,000–12,000 cal yr B.P.; landscape stability, ca. 12,000–10,000 cal yr B.P.; and landscape instability, ca. 10,000–0 cal yr B.P. This indicates that there was significantly more time than previously thought (12,000–13,000 yr) for postglacial processes. Glaciation, deglaciation, maximum landscape stability (indicating maximum aridity), and landscape instability did not lag behind minimum, increasing, maximum, and decreasing seasonality of insolation, respectively.
Paleoclimatic Reconstruction Using Mutual Climatic Range on Terrestrial Mollusks
Authors: Moine Olivier , Rousseau Denis-Didier , Jolly Dominique , Vianey-Liaud Marc 
Published: October 2002

AbstractTerrestrial mollusks, easily identified in Quaternary sediments, represent a reliable tool for quantitative estimates of environmental parameters. Our study, comparing the species distribution with meteorological parameters in Europe, shows that mean temperature of the coldest month and annual thermal magnitude are the most important forcing parameters. This survey allows us to adapt the mutual climatic range (MCR) method to terrestrial mollusk assemblages following two main steps. A set of assemblages from different European regions (northern Norway to southern France) is used to apply the method to present-day mollusks. The reconstructed values describe the latitudinal temperature gradient prevailing over Europe. However, the comparison between the reconstructed and the measured values indicates a shift, similar to that observed, with the same method applied to beetle assemblages. Thus, estimates must be calculated after the reconstruction is tuned with the observations. The results from the modern mollusk assemblages indicate that the MCR method can be safely applied to reconstructing temperatures from terrestrial mollusk assemblages in any worldwide Quaternary sequence. A trial application is made on Late Pleistocene assemblages from Achenheim (Alsace, France).
Sediment-Color Record from the Northeast Atlantic Reveals Patterns of Millennial-Scale Climate Variability during the Past 500,000 Years
Authors: Helmke Jan P. , Schulz Michael , Bauch Henning A. 
Published: October 2002

AbstractA 500,000-yr-long deep-sea sediment-color record from the Northeast Atlantic was investigated to reconstruct the evolution of late Pleistocene climate variability on millennial time scales. Variations of the red–green color intensity are probably caused by climatically induced changes in the ice-rafted input of red-colored iron-bearing terrigenous material to the core site. The resolution of the age model impedes the detection of distinct spectral features at sub-Milankovitch periodicities. Hence, millennial-scale climate variability is quantified as time-dependent variance of the high-pass filtered color time series. The course of the estimated variance shows distinct patterns, which can be linked to continental ice mass. During the past 500,000 yr, large-amplitude millennial-scale climate variability occurs only if continental ice mass exceeds a threshold level, equivalent to sea level at approximately 40% of the lowering during the last glacial maximum.
Generalised Stream X-Machines and Cooperating Distributed Grammar Systems
Authors: Gheorghe Marian 
Published: October 2002

Abstract.

Stream X-machines are a general and powerful computational model. By coupling the control structure of a stream X-machine with a set of formal grammars a new machine called a
generalised stream X-machine with underlying distributed grammars
, acting as a translator, is obtained. By introducing this new mechanism a hierarchy of computational models is provided. If the grammars are of a particular class, say regular or context-free, then finite sets are translated into finite sets, when ?
k
, =
k
derivation strategies are used, and regular or context-free sets, respectively, are obtained for ?
k
, * and
terminal
derivation strategies. In both cases, regular or context-free grammars, the regular sets are translated into non-context-free languages. Moreover, any language accepted by a Turing machine may be written as a translation of a regular set performed by a generalised stream X-machine with underlying distributed grammars based on context-free rules, under =
k
derivation strategy. On the other hand the languages generated by some classes of cooperating distributed grammar systems may be obtained as images of regular sets through some X-machines with underlying distributed grammars. Other relations of the families of languages computed by generalised stream X-machines with the families of languages generated by cooperating distributed grammar systems are established. At the end, an example dealing with the specification of a scanner system illustrates the use of the introduced mechanism as a formal specification model.
Misleading postevent information and working memory capacity: an individual differences approach to eyewitness memory
Authors: Jaschinski Uta , Wentura Dirk 
Published: October 2002

AbstractThe present study examines how individual differences in working memory capacity relate to the effect of misleading postevent information on memory for the original event. Participants were shown a film of a crime event and were then asked to unscramble a narrative that included misinformation regarding some of the film's details. Additionally, the working memory capacity of the participants was measured using the operation‐word span task. Finally, in a free recall test, participants recalled fewer correct details in the misinformation condition compared to the control condition. This effect was negatively correlated with working memory capacity. Copyright © 2002 John Wiley & Sons, Ltd.
Pre‐arrangement of solvability, complexity, stability and quality of GPC systems
Authors: Suchomski Piotr , Kowalczuk Zdzisław 
Published: October 2002

AbstractA design problem of generalized predictive control (GPC) of plants characterized by discrete‐time models with a non‐zero transportation‐delay is considered. Conditions for the existence of the solution of the problem in terms of relevant design parameters (tuning knobs) are proposed and the system characteristics are discussed. Several design hints suitable for such plant models are proposed. Consequently, it is shown that by a suitable choice of the GPC tuning knobs a definite pre‐arrangement of the solvability, complexity, stability and quality (including robustness) of the resultant GPC control systems can be achieved. Some numerical examples are also given to illustrate the design problem and proposed methodology. Copyright © 2002 John Wiley & Sons, Ltd.
Virtual reference feedback tuning for two degree of freedom controllers
Authors: Lecchini A. , Campi M.C. , Savaresi S.M. 
Published: October 2002

AbstractThe virtual reference feedback tuning (VRFT) is a data‐based method for the design of feedback controllers. In the original formulation, the VRFT method gives a solution to the degree of freedom model‐reference control problem in which the objective is to shape the input–output transfer function of the control system. In this paper, the extension of the method to the design of 2 d.o.f. controllers is presented and discussed. Copyright © 2002 John Wiley & Sons, Ltd.
Iterative feedback tuning—an overview
Authors: Hjalmarsson Håkan 
Published: October 2002

AbstractAdaptive and iterative control algorithms based on explicit criterion minimization are briefly reviewed and an overview of one such algorithm, iterative feedback tuning (IFT), is presented. The basic IFT algorithm is reviewed for both single‐input/single‐output and multi‐input/multi‐output systems. Subsequently the application to non‐linear systems is discussed. Stability and robustness aspects are covered. A survey of existing extensions, applications and related methods is also provided. Copyright © 2002 John Wiley & Sons, Ltd.
Follow‐up examinations including sequential bone marrow biopsies in essential thrombocythemia (ET): A retrospective clinicopathological study of 120 patients
Authors: Thiele Juergen , Kvasnicka Hans Michael , Schmitt‐Graeff Annette , Zankovich Rudolph , Diehl Volker 
Published: October 2002

AbstractDiagnosis of essential thrombocythemia (ET) has been usually established by regarding the criteria of the Polycythemia Vera Study Group. Accordingly, a retrospective clinicopathological study was performed on 120 patients with a follow‐up ranging between 5 and 13 years and repeated bone marrow trephine examinations. Following the new WHO classification, at presentation patients revealed three distinctive patterns of bone marrow (BM) features: (true) ET in 43 patients, prefibrotic idiopathic myelofibrosis (IMF) in 50 patients, and early IMF in 27 patients. Heterogeneity of morphological features was associated with correspondingly expressed laboratory data. Contrasting initial and early IMF, patients with true ET displayed an about 80% probability to lack splenomegaly, anemia, and increase in the LDH and LAP values and also failed to show any myeloblasts or erythroblasts on the peripheral blood films. Follow‐up examinations including sequential BM biopsies (mean interval 39 ± 31 months) disclosed that of the 43 patients with true ET only one developed an increase in reticulin. On the other hand, 65 of 77 patients with prefibrotic and early IMF evolved into overt myelofibrosis–osteosclerosis. Moreover, survival analysis demonstrated significant differences in our patients. A neglectable proportion of life loss according to a sex‐ and age‐matched general population was found in true ET (less than 11%) opposed to IMF without or mild fibrosis (range 21% to 32%). Am. J. Hematol. 70:283–291, 2002. © 2002 Wiley‐Liss, Inc.
Silent brain infarcts are rare in Kuwaiti children with sickle cell disease and high Hb F
Authors: Adekile A.D. , Yacoub F. , Gupta R. , Sinan T. , Haider M.Z. , Habeeb Y. , Al‐Bloushi M. , Moosa A. 
Published: October 2002

AbstractOvert stroke is rare among sickle cell disease (SCD) patients in Kuwait. However, there are no previous studies of silent cerebral infarcts, which have been described in up to 20% of American children with Hb SS. We have carried out a prospective brain MRI study among otherwise normal SCD patients, who were consecutive patients seen in a 1‐year period to document the prevalence of silent cerebral infarcts in children with sickle cell disease in Kuwait. Any patient with a previous seizure or other neurological abnormality was excluded. MRI was done with a 1.5 Tesla unit with super‐conducting magnet. T1‐ and T2‐weighted sagittal and axial sections and proton density axial images were obtained in 5‐mm thick sections. The study group consisted of 30 (23 SS and 7 Sβ0Thal) patients—19 males and 11 females—whose ages ranged from 6 to 17 (mean of 9.8 ± 3.5) years. Hb F ranged from 11% to 35% with a mean of 22.8% ± 5.7%. Only one patient, a 10‐and‐a‐half‐year‐old boy with Hb SS, showed hyperintense signals in the parietal white matter, consistent with small infarcts, thus giving a prevalence of 3.3%. Silent brain infarcts are uncommon in our patients, and the protective factors remain to be fully elucidated. Am. J. Hematol. 70:228–231, 2002. © 2002 Wiley‐Liss, Inc.
Body mass index, overweight and obesity in married and never married men and women in Poland
Authors: Lipowicz Anna , Gronkiewicz Stanislaw , Malina Robert M. 
Published: October 2002

AbstractThe study examined the relationship between marital status and the body mass index (BMI) and the prevalence of overweight and obesity in the Polish population. The sample included 2,266 men and 4,122 women, 25–60 years of age, who were occupationally active inhabitants of Wroclaw, in southwestern Poland. Marital status was defined by two categories: never married and presently married, and two groups in each category were established on the basis of educational level: well‐educated (12 or more years in school) and poorly educated (less than 12 years in school). The subjects were also divided into four age groups: 25–30, 31–40, 41–50, and 51–60 years. Height and weight were measured and the BMI was calculated. Three categories of the BMI were established: normal, BMI < 25.0 kg/m2, overweight, BMI ≥ 25 < 30 kg/m2, and obese, BMI ≥ 30 kg/m2. In each age and educational group, married individuals had a higher BMI than those who were never married. With the exception of well‐educated males 51–60 years, differences in the BMI between married and never married individuals increased with age. In general, married men and women were more likely to be overweight and obese than never married individuals. The results indicated a significant association (P < 0.001) between marital status and the BMI in both sexes. After age, marital status was the most important predictor of overweight/obesity among men (P < 0.001), whereas educational level did not have a significant role. Among women, age, marital status, and education were significantly (P < 0.001) related to the BMI. Am. J. Hum. Biol. 14:468–475, 2002.© 2002 Wiley‐Liss, Inc.
Seasonal variation in the dietary adequacy of highland Pwo and Sgaw Karen (Thailand)
Authors: Omori Kinuko , Greksa Lawrence P. 
Published: October 2002

AbstractThe present report describes seasonal variability (postharvest, preharvest, harvest) in the dietary adequacy of highland Karen farmers (38 Pwo and 51 Sgaw mother‐weaned child pairs) in Thailand. Both the Pwo and Sgaw exhibit little functionally significant seasonal variation in either energy or protein intakes, although there is significant seasonal variation in other nutrients. Sgaw Karen mothers and their weaned children had significantly higher intakes of energy, protein, and seven nutrients than their Pwo counterparts during all three study seasons. The cause of this difference appears to be related to the better socioeconomic status of the Sgaw, as well as to differences in belief systems that result in a greater utilization of wild resources by the Sgaw. There were no significant differences in energy intakes between mothers and their children in either ethnic group, while children tended to have significantly greater intakes of protein but significantly lower intakes of other nutrients. These differences in dietary patterns appear to be due to differences in dietary density and dietary preferences, rather than to foods being differentially directed towards adults. Am. J. Hum. Biol. 14:519–531, 2002. © 2002 Wiley‐Liss, Inc.
Occupational determinants of bone and blood lead levels in middle aged and elderly men from the general community: The Normative Aging Study
Authors: Elmarsafawy Sahar F. , Tsaih Shirng‐Wern , Korrick Susan , Dickey Jefferson H. , Sparrow David , Aro Antonio , Hu Howard 
Published: October 2002

AbstractBackgroundFew studies of the general population have investigated risk factors for elevated levels of lead in bone in relation to occupation.MethodsSix hundred and fifty six community‐exposed men had their bone and blood lead levels measured (by K‐X‐ray fluorescence). Based on their occupational histories, participants were categorized into those who worked in white‐collar (WC) occupations (59%) or blue‐collar (BC) occupations (41%). No subjects had worked in a primary lead industry (e.g., smelting).ResultsIn multivariate regression models that adjusted for age, race, education, smoking, alcohol ingestion and retirement status, BC subjects had tibia and patella lead concentrations that were 5.5 (95% CI: 3.2–7.8) and 6.5 (95% CI: 3.1–9.8) μg/g higher than WC subjects, respectively. Interaction terms pairing race with occupational status indicated that in non‐white BC subjects, tibia and patella lead levels were higher still by 11.3 (95% CI: −2 to 24.5) and 20.5 (95% CI: 1.2–39.8) μg/g, respectively. Blood lead levels were low for these mostly retired men (mean [SD]: 6.1 [3.9] μg/g) and in multivariate regression models, occupational status was not a significant predictor of blood lead levels; however, an interaction between race and occupational status was also suggested, with non‐white BC subjects having blood lead levels that were predicted to be higher by 4.5 (95% CI: 0.3–8.7) μg/dl.ConclusionsBone lead levels are higher in the men who worked in BC occupations even if they have not worked in primary lead‐exposed occupations. This effect is markedly stronger in non‐white BC workers and suggests an interaction between occupational exposures and race/ethnicity with respect to cumulative exposure to lead. A similar interaction was suggested by models of blood lead levels. Am. J. Ind. Med. 42:38–49, 2002. © 2002 Wiley‐Liss, Inc.
Respiratory protection: Associated factors and effectiveness of respirator use among underground coal miners
Authors: Li Hongfei , Wang Mei‐Lin , Seixas Noah , Ducatman Alan , Petsonk Edward Lee 
Published: October 2002

AbstractBackgroundWe investigated factors associated with the use of respiratory protection and explored the effectiveness of respirators among coal miners.MethodsBetween 1987 and 1992, respiratory symptoms, smoking, lung function, and dust exposures were assessed longitudinally among 185 underground bituminous coal miners. Self‐reported use of respiratory protection was expressed as mean percent time wearing a respirator.ResultsMiners' respirator use increased with mean dust concentration, but decreased with tobacco consumption. Increasing age was associated with greater respirator use. Miners who had respiratory symptoms at the initial survey subsequently reported greater use of respirators. A significant protective association was found between the miners' respirator use and FEV1 levels at both the initial and follow‐up surveys.ConclusionsThese results provide additional evidence that respirator use is protective of lung health. When respiratory protection programs are developed, factors that may affect respirator use behavior, such as age, smoking, and respiratory symptoms, should be considered. Future studies of respiratory health will need to consider workers' use of respiratory protection. Am. J. Ind. Med. 42:55–62, 2002. Published 2002 Wiley‐Liss, Inc.
Induction of ferritin and lipid peroxidation by coal samples with different prevalence of coal workers' pneumoconiosis: Role of iron in the coals
Authors: Zhang Qi , Huang Xi 
Published: October 2002

AbstractBackgroundDifferences in levels of bioavailable iron (BAI) in coal may be responsible for the observed regional differences in the prevalence and severity of coal workers' pneumoconiosis (CWP).MethodsTwenty‐nine coal samples from three coal mine regions were tested in human lung epithelial Type II A549 cells. They were from Utah (UT), West Virginia (WV), and Pennsylvania (PA) with a prevalence of CWP of 4, 10, and 26%, respectively.ResultsLow molecular weight (LMW) chelators bound iron, a fraction of BAI in the cells released from coals, ferritin, and lipid peroxidation were significantly higher in cells treated with various coals than in control cells, with an increasing order of UT < WV < PA, in parallel to the prevalence of CWP in these coal mine regions. Deferoxamine (DFO), a specific iron chelator, was used to distinguish effects of BAI from those of other transition metals. Our results indicate that BAI in the coals of WV and UT is the main metal species in inducing ferritin and lipid peroxidation. In contrast, biological effects of PA coals are not only from BAI, but from other transition metals as well.ConclusionsBased on a large number of coal samples from various seams, the findings of this study provide further evidence that metals, particularly iron, play important roles in coal dust‐induced cellular damage, ultimately leading to the development of CWP and contributing to the regional differences in the prevalence of the disease. Am. J. Ind. Med. 42:171–179, 2002. © 2002 Wiley‐Liss, Inc.