bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infilling of the Younger Kathmandu–Banepa intermontane lake basin during the Late Quaternary (Lesser Himalaya, Nepal): a sedimentological study
Authors: Dill H. G. , Khadka D. R. , Khanal R. , Dohrmann R. , Melcher F. , Busch K. 
Published: January 2003

AbstractThe Kathmandu and Banepa Basins, Central Nepal, are located in a large syncline of the Lesser Himalayas. The Older Kathmandu Lake evolved during the Pliocene and early Pleistocene; the Younger Kathmandu Lake, which is the focus of this study, is infilled with late Quaternary sediments. Three formations, arranged in stratigraphical order, the Kalimati, Gokarna and Thoka Formations formed during the infilling stage of this lacustrine basin. Structural and textural sedimentological analyses, a chemical survey across the basin and mineralogical investigations of fine‐grained sediments form the basis of this palaeogeographical study. The basin under investigation was covered by a perennial freshwater lake before 30 000 yr BP. The lake was infilled with alluvial and fluvial sediments delivered mainly from the mountains north of the basin. A fairly low gradient was favourable for the formation of diatomaceous earths, carbonaceous mudstones and siltstones, which were laid down in the centre of the lake and in small ponds. Towards the basin edge, lacustrine sediments gave way to deltaic deposits spread across the delta plain. Crevasse splays and anastomosing rivers mainly delivered suspended load for the widespread siltstones and mudstones. The proximal parts of the alluvial–fluvial sedimentary wedge contain debris flows that interfinger with fine‐grained floodplain deposits. Three highstands of the water‐level (>30 000 yr BP, 28 000–19 000 yr BP, 11 000–4000 yr BP (?)) have been recognised in the sedimentary record of the younger Kathmandu Lake in the Late Quaternary. Second‐order water‐level fluctuations are assumed to be triggered by local processes (damming by tectonically induced landslides). First‐order water‐level fluctuations are the result of climatic changes. Copyright © 2003 John Wiley & Sons, Ltd.
Pollen‐ and diatom based environmental history since the Last Glacial Maximum from the Andean core Fúquene‐7, Colombia
Authors: Vélez Maria Isabel , Hooghiemstra Henry , Metcalfe Sarah , Martínez Ignacio , Mommersteeg Herman 
Published: January 2003

AbstractThe late Pleistocene–Holocene ecological and limnological history of Lake Fúquene (2580 m a.s.l.), in the Colombian Andes, is reconstructed on the basis of diatom, pollen and sediment analyses of the upper 7 m of the core Fúquene‐7. Time control is provided by 11 accelerator mass spectrometry (AMS) 14C dates ranging from 19 670 ± 240 to 6040 ± 60 yr BP. In this paper we present the evolution of the lake and its surroundings. Glacial times were cold and dry, lake‐levels were low and the area was surrounded by paramo and subparamo vegetation. Late‐glacial conditions were warm and humid. The El Abra Stadial, a Younger Dryas equivalent, is reflected by a gap in the sedimentary record, a consequence of the cessation of deposition owing to a drop in lake‐level. The early Holocene was warm and humid; at this time the lake reached its maximum extension and was surrounded by Andean forest. The onset of the drier climate prevailing today took place in the middle Holocene, a process that is reflected earlier in the diatom and sediment records than in the pollen records. In the late Holocene human activity reduced the forest and transformed the landscape.Climate patterns from the Late‐glacial and throughout the Holocene, as represented in our record, are similar to other records from Colombia and northern South America (the Caribbean, Venezuela and Panama) and suggest that the changes in lake‐level were the result of precipitation variations driven by latitudinal shifts of the Intertropical Convergence Zone. Copyright © 2003 John Wiley & Sons, Ltd.
Xanthates as Chain‐Transfer Agents in Controlled Radical Polymerization (MADIX): Structural Effect of the O‐Alkyl Group
Authors: Destarac Mathias , Bzducha Wojciech , Taton Daniel , Gauthier‐Gillaizeau Isabelle , Zard Samir Z. 
Published: January 2003

AbstractThe capability of three chain‐transfer agents, O‐alkyl‐S‐(1‐ethoxycarbonyl)ethyl xanthates (CH3CHCO2C2H5)S(CS)OZ′, to control the free‐radical polymerization of styrene and ethyl acrylate by the MADIX process was examined. The reactivity of the xanthates varied according to the following trend: Z′  CH2CH3 < CH2CF3 < CH[P(O)(OEt)2]CF3. This change in reactivity allowed a lowering of the polydispersity index from 2.0 for Z′  CH2CH3 to 1.15 for Z′  CH[P(O)(OEt)2]CF3 in the case of the polymerization of styrene.
Evolution of Mw/Mn with conversion during the polymerization of ethyl acrylate in the presence of xanthates X1, X2 and X3. Reaction conditions: [EA]0 = 4.6 M, [X]0 = 5.75 × 10−2 M, [AIBN]0 = 1.72 × 10−3 M ; T = 80 °C ; solvent: toluene.magnified imageEvolution of Mw/Mn with conversion during the polymerization of ethyl acrylate in the presence of xanthates X1, X2 and X3. Reaction conditions: [EA]0 = 4.6 M, [X]0 = 5.75 × 10−2 M, [AIBN]0 = 1.72 × 10−3 M ; T = 80 °C ; solvent: toluene.
Effects of tellington touch in healthy adults awaiting venipuncture
Authors: Cecilia Wendler M. 
Published: January 2003

AbstractMany natural‐healing modalities administered by professional nurses are provided without adequate scientific scrutiny. Tellington touch (TTouch), a form of gentle physical touch originally developed for the calming of horses, is an emerging nursing intervention. However, the safety and efficacy of human TTouch has not yet been established. The purpose of this study, which used a pretest, posttest repeated‐measures control group design, was to identify patterns of mean blood pressure (MBP), heart rate (HR), state anxiety (SA), and procedural pain (PP) in healthy adults receiving a 5‐min intervention of TTouch (n = 47) just before venipuncture versus a no‐touch control group (n = 46). There were statistically and clinically significant decreases in the TTouch group in MBP and HR. There were no significant differences between groups in SA and PP. Further research is essential to determine the safety and efficacy of this modality for acutely or critically ill patients. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:40–52, 2003
Methods to document semantic equivalence of a translated scale
Authors: Beck Cheryl Tatano , Bernal Henrietta , Froman Robin D. 
Published: January 2003

AbstractTo ensure the semantic equivalence of the Postpartum Depression Screening Scale (PDSS)–Spanish Version, multiple methods were used, including back‐translation, the committee approach, pretest techniques, and alternate forms equivalence. The back‐translation process involved eight translators who represented the four predominant Hispanic groups in the United States. In the committee approach the Hispanic translators convened together to discuss the results of the back‐translations and to come to group consensus on problematic items. In pretesting the PDSS–Spanish Version was field‐tested with five Hispanic mothers, and it was determined that it accurately captured the connotative meanings of the screening scale. Alternate forms equivalence of the two language versions of the PDSS was assessed with a sample of 30 bilingual Hispanic mothers. Alpha reliability estimates ranged from 0.94 to 0.99. Though lengthy, this systematic procedure was needed to guarantee the production of a fully equivalent linguistic version of the PDSS. © 2003 Wiley Periodicals, Inc. Res Nurs Health 26:64–73, 2003
Pd(0)‐catalyzed polyaddition of bifunctional vinyloxiranes with phenol derivatives: The synthesis of polymers containing an allyl aryl ether moiety in the main chain
Authors: Koizumi Toshio , Imai Takao , Endo Takeshi 
Published: January 2003

AbstractThe palladium(0)‐catalyzed polyaddition of bifunctional vinyloxiranes [1,4‐bis(2‐vinylepoxyethyl)benzene (1a) and 1,4‐bis(1‐methyl‐2‐vinylepoxyethyl)benzene (1b)] with oxygen nucleophiles such as hydroquinone and bisphenol A gave new unsaturated polyethers containing an allyl aryl ether moiety and pendant hydroxy groups. The polyaddition with 1a was largely affected by the phosphine ligands employed and the reaction temperature. The polyaddition with hydroquinone and bisphenol A was conducted at room temperature for 24 h in tetrahydrofuran in the presence of PPh3 and gave the desired polyethers in good yields, the number‐average molecular weights (Mn) of which were 5700 and 7700, respectively. 1,2‐Bis(diphenylphosphino)ethane (dppe) was not effective in the polyaddition with 1a. The polyaddition of 1b with hydroquinone and bisphenol A gave the corresponding polyethers despite the kinds of ligands employed (PPh3 and dppe), contrary to the polyaddition with 1a. The polyaddition of 1b with 4,4′‐biphenol was also carried out in the presence of Pd2(dba)3 · CHCl3/dppe as a catalyst (where dba is dibenzylideneacetone) and afforded the expected polyether with a high Mn value (Mn = 24,900). In addition, vinyloxirane 1b could reacted with racemic 1,1′‐bi‐2‐naphthol to give the corresponding polyether in a good yield. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 476–482, 2003
Possible structural effect of a′,b′‐dihydroxyacetophenone units in the preformed oligoesters upon copolycondensation with isomeric c′,d′‐dihydroxyacetophenones by TsCl/dimethylformamide/pyridine
Authors: Higashi Fukuji , Koshio Masato 
Published: January 2003

AbstractA two‐stage copolycondensation of a mixture of equal parts of isophthalic acid and terephthalic acid first with a′,b′‐dihydroxyacetophenone (a′,b′‐DHAP) and then with isomeric c′,d′‐DHAP was examined at 60 and 80 °C. A structurally selective reaction was observed. At 80 °C, the preformed oligomers from symmetrically substituted 2′,6′‐DHAP reacted better with similarly substituted 2′,6′‐ or 3′,5′‐DHAP to give the copolymers of significantly higher inherent viscosity values than from the reaction with asymmetrically substituted 2′,4′‐DHAP, whereas at 60 °C they did almost equally well with any c′,d′‐DHAP. Similarly, the reaction of oligomers from 2′,4′‐DHAP with asymmetrically substituted 2′,4′‐DHAP or 2,4‐dihydroxybenzophenone yielded better results than those from the reaction with 2′,6′‐ or 3′,5′‐DHAP at both temperatures. The copolycondensations with comonomers of the structure independent of DHAPs were not affected by the preformed oligomers from DHAPs. The results are discussed in terms of the distributions of resulting oligomers determined by gel permeation chromatography. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 616–623, 2003
Electrospun nanofibers: Internal structure and intrinsic orientation
Authors: Dersch R. , Liu Taiqi , Schaper A. K. , Greiner A. , Wendorff J. H. 
Published: January 2003

AbstractElectrospinning gives rise to polymer nanofibers. The spinning process is characterized by strong deformations of the polymer material taking place during the spinning process and a very rapid structure formation process happening within milliseconds. We were interested in the influence of the peculiar spinning process on the structures of nanofibers. For this purpose, we analyzed the internal structures of nanofibers spun from polyamide‐6 and polylactide with an average diameter of about 50 nm. The fibers were partially crystalline, with degrees of crystallinity not significantly smaller than those found for less rapidly quenched and much thicker melt‐extruded fibers. The annealing of polyamide fibers at elevated temperatures resulted in a transformation from the disordered γ modification to the more highly ordered α modification, and this again was in close agreement with the response of melt‐extruded fibers. The orientation of the crystals along the fiber axis was strongly inhomogeneous: it was, on average, very weak, yet it could be quite pronounced locally. Small elongations of approximately 10% resulted in well‐developed homogeneous crystal orientations. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 545–553, 2003
Crosslinking polymerization leading to interpenetrating polymer network formation. I. Polyaddition crosslinking reactions of poly(methyl methacrylate‐co‐2‐methacryloyloxyethyl isocyanate)s with ethylene glycol resulting in polyurethane networks
Authors: Kiguchi Tadahiro , Aota Hiroyuki , Matsumoto Akira 
Published: January 2003

AbstractAt the start of our research program concerned with the elucidation of the crosslinking polymerization mechanism leading to interpenetrating polymer network (IPN) formation, in which IPNs consist of both polymethacrylates and polyurethane (PU) networks, this article deals with the polyaddition crosslinking reaction leading to PU network formation. Therefore, 2‐methacryloyloxyethyl isocyanate (MOI) was radically copolymerized with methyl methacrylate (MMA) in the presence of CBr4 as a chain‐transfer agent. The resulting poly(MMA‐co‐MOI)s, having pendant isocyanate (NCO) groups as novel multifunctional polyisocyanates, were used for polyaddition crosslinking reactions with ethylene glycol as a typical diol. The second‐order rate constants depended on both the functionality of poly(MMA‐co‐MOI) and the NCO group concentration. The actual gel points were compared with the theoretical ones calculated according to Macosko's equation; the deviation of the actual gel point from the theoretical value became more remarkable for a greater functionality of poly(MMA‐co‐MOI) and at a lower NCO group concentration or at a lower poly(MMA‐co‐MOI) concentration. These are discussed mechanistically, with consideration given to the significance of intramolecular cyclization and intramolecular crosslinking reactions leading to the shrinkage of the molecular size of the prepolymer, along with the data of the intrinsic viscosities of resulting prepolymers and the swelling ratios of resulting gels. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 606–615, 2003
Ground and excited states of one‐dimensional self‐interacting nonlinear oscillators through time‐dependent quantum mechanics
Authors: Wadehra Amita , Roy Amlan K. , Deb B. M. 
Published: January 2003

AbstractEnergy eigenvalues, probability densities, and 〈x2r〉 values (r = 1 to 6) of one‐dimensional self‐interacting nonlinear oscillators have been obtained by evolving the time‐dependent Schrödinger equation in imaginary time, coupled with the minimization of energy expectation values. For excited states, the orthogonality constraint with lower states is maintained. Probability density plots for the ground and first three excited states are presented. A comparison of energy eigenvalues and probability densities plots is also made between oscillators with and without self‐interaction. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2003
A dynamic model of work quality in a government oversight organization
Authors: Trost Christopher S. 
Published: January 2003

AbstractManagement of a government organization responsible for the oversight of contractor work is a sensitive and challenging task. One such organization is the Supervisor of Shipbuilding (SUPSHIP), Groton, a unit of the U.S. Navy, whose engineering department is responsible for oversight of submarine designs from General Dynamics' Electric Boat Division. Management of the SUPSHIP Engineering Department is further complicated by a high cost of mistakes and a significant lag between the time a mistake is made and when it is discovered in production. Recent defense cutbacks led to a reorganization of the department with significantly fewer personnel and periodic variations in workload have raised questions about the department's ability to maintain a desired level of quality in its design reviews. Quality in this context refers to work done without errors—errors that could affect the final product if they are not caught by supervisors or higher up the chain of command. To understand and explore these issues better, a system dynamics model that integrates the structural elements of the engineering department's workload and workforce was developed. Using the model to analyze expected performance during future peaks and valleys in the workload, as well as expected retirements and new hiring, allowed management to develop policies that keep quality at acceptable levels. Copyright © 2002 John Wiley & Sons, Ltd.
All models are wrong: reflections on becoming a systems scientist
Authors: Sterman John D. 
Published: January 2003

AbstractThoughtful leaders increasingly recognize that we are not only failing to solve the persistent problems we face, but are in fact causing them. System dynamics is designed to help avoid such policy resistance and identify high‐leverage policies for sustained improvement. What does it take to be an effective systems thinker, and to teach system dynamics fruitfully? Understanding complex systems requires mastery of concepts such as feedback, stocks and flows, time delays, and nonlinearity. Research shows that these concepts are highly counterintuitive and poorly understood. It also shows how they can be taught and learned. Doing so requires the use of formal models and simulations to test our mental models and develop our intuition about complex systems. Yet, though essential, these concepts and tools are not sufficient. Becoming an effective systems thinker also requires the rigorous and disciplined use of scientific inquiry skills so that we can uncover our hidden assumptions and biases. It requires respect and empathy for others and other viewpoints. Most important, and most difficult to learn, systems thinking requires understanding that all models are wrong and humility about the limitations of our knowledge. Such humility is essential in creating an environment in which we can learn about the complex systems in which we are embedded and work effectively to create the world we truly desire. The paper is based on the talk the author delivered at the 2002 International System Dynamics Conference upon presentation of the Jay W. Forrester Award. Copyright © 2002 John Wiley & Sons, Ltd.
Maternal and perinatal outcome in rheumatic heart disease
Authors: Sawhney H. , Aggarwal N. , Suri V. , Vasishta K. , Sharma Y. , Grover A. 
Published: January 2003

AbstractObjectives: To study the maternal and perinatal outcome of pregnancies complicated by rheumatic heart disease. Methods: A retrospective study was carried out in the cardio‐obstetric clinic of the Postgraduate Institute of Medical Education and Research, Chandigarh (India) over a period of 13 years (1987–1999) involving 486 pregnant patients with rheumatic heart disease. Maternal and perinatal outcome was reviewed. Results: Three hundred and four patients (63.3%) had single valve involvement and mitral stenosis was the most predominant lesion (89.2%). One hundred and seventy one (38.6%) patients had undergone surgical correction prior to the onset of pregnancy. One hundred and thirteen patients (22.6%) were identified as NYHA class III–IV. Mitral valvotomy was performed during pregnancy in 48 patients. The incidence of preterm birth and small for gestational age newborns was 12% and 18.2%, respectively. There were 10 maternal deaths, of which eight patients were NYHA III and IV. Conclusions: Rheumatic heart disease in pregnancy is associated with significant maternal and perinatal morbidity in NYHA class III–IV patients.
Birthweight‐specific neonatal mortality in developing countries and obstetric practices
Authors: Straughn H.K. , Goldenberg R.L. , Tolosa J.E. , Daly S. , de Codes J. , Festin M.R. , Limpongsanurak S. , Lumbiganon P. , Paul V.K. , Peedicayil A. , Purwar M. , Sabogal J.C. , Shenoy S. 
Published: January 2003

AbstractObjectives: To evaluate birthweight‐specific neonatal mortality and perinatal interventions in major medical centers in developed and developing countries. Methods: A survey was developed and electronically mailed to 13 medical centers participating in the Global Network for Perinatal and Reproductive Health (GNPRH). The ability of a center to provide requested data was assessed. The mortality rates and use of specific perinatal interventions in centers in developing countries were compared with developed countries. Results: Nine centers in developing countries responded to the survey, and three centers in developed countries were used for comparison. Data collection was highly variable. Most developing country centers were able to provide data by birthweight but not by gestational age. The differences in mortality rates between developing and developed countries were more pronounced at lower gestational ages and birthweights. A difference was found in perinatal interventions between developing and developed countries. In the former, viability was generally considered 28 weeks, and the gestational age at which cesarean sections were usually performed for the sake of the fetus at preterm gestations varied from 26 to 37 weeks. Most centers did not routinely induce for pPROM; only five out of nine centers used antibiotics to prolong latency. Most centers used tocolysis beginning at 26–28 weeks through 32–37 weeks, and a variety of tocolytic agents were used. Most centers routinely used corticosteroids for preterm infants, and all centers employed repeat weekly steroid dosing if undelivered. Conclusions: Despite the fact that the GNPRH centers included in this study represent some of the best health care available in these countries, they lag far behind centers in developed countries in neonatal mortality rates and their use of various obstetric practices. Furthermore, incomplete and inconsistent data collection complicates the evaluation of the factors contributing to high neonatal mortality rates.
Risk factors as the basis for triage in low‐resource cervical cancer screening programs
Authors: Gaffikin L. , Ahmed S. , Chen Y.Q. , McGrath J.M. , Blumenthal P.D. 
Published: January 2003

AbstractObjectives: Several studies have shown impressive sensitivity and specificity of visual inspection using acetic acid wash (VIA) in detecting cervical dysplasia. This study examines how risk‐factor based triage, using clinical history‐taking to limit the testing to those at highest risk of disease, improves the clinical utility of VIA. Methods: The study population included 2206 woman aged 25–56 from peri‐urban primary care clinics in Zimbabwe. Three risk factors variables [age, lifetime number of sexual partners and history of a sexually transmitted infection (STI)] were selected as the basis for computer‐simulated patient triage. Criteria for selecting risk factors were biological relevance, programmatic feasibility, historical evidence in the scientific literature as a risk factor for cervical cancer and a significant (P<0.05) predictor of dysplasia in this study population. Predictive values for VIA were calculated on subgroups of women with combinations of the three risk factors and then compared with the predictive value of VIA calculated on the full study population. Results: The positive predictive value (PPV) among women with all three risk factors (30.2%) was 1.6 times higher than that of all study women and 4.5 times higher than women with none of the three risk factors (4.1%). Additionally, the PPV was slightly (30%) higher than that obtained from computer‐simulated serial testing using VIA as the primary test followed by HPV testing (27.4%). Conclusion: Clinical history‐taking could provide the basis for patient triage to increase the clinical utility of VIA. Such an approach could also serve to prioritize who gets tested first in low‐resource countries with high disease prevalence that are struggling to strengthen national cervical cancer prevention programs.