bluuebunny/crossref_metadata_2025_split huggingface dataset:
Responses of a California annual grassland to litter manipulation
Authors: Amatangelo Kathryn L. , Dukes Jeffrey S. , Field Christopher B. 
Published: April 2008

AbstractQuestion:What are the physical and chemical effects of plant litter on annual grassland community composition, above‐ground net primary production (ANPP), and density?Location:California annual grassland.Methods:We manipulated litter and light levels independently and in concert. Litter removal and litter addition treatments tested both the physical and chemical impacts of litter's presence. We additionally simulated the effect of litter physical shading by using shade cloth, and added powdered litter to test for the chemical impacts of decomposing litter.Results:Increased whole litter and shading decreased grass germination and establishment, but not that of forbs or legumes. Species shifts occurred within all groups across treatments, including a transition from small‐seeded to large‐seeded grass and legume species with increased shading. ANPP was highest in control plots (473 ± 59 g/m2), and species richness was highest in litter removal plots. While the physical effects of litter via shading were significant, the chemical effects of adding powdered litter were negligible.Conclusions:This work suggests that over one growing season, the physical impacts of litter are more important than chemical impacts in shaping community structure and ANPP in annual grasslands. Changes in light availability with altered litter inputs drive shifts in species and functional group composition. Litter feedbacks to ANPP and species composition of local patches may help maintain diversity and stabilize ANPP in this grassland.
Electronically controlled multiphase sinusoidal oscillators using current amplifiers
Authors: Souliotis George , Psychalinos Costas 
Published: April 2008

AbstractA novel current‐mode multiphase oscillator topology is introduced in this letter. This is realized by employing current amplifiers and only grounded capacitors. Attractive characteristics offered by the new topology are the electronic adjustment of the oscillation frequency, the absence of passive resistors, and the requirement of only grounded capacitors. Comparison with the corresponding already published current follower based structure shows that the proposed topology has better performance in terms of the number of required active elements, the employment of passive resistors, and the ability for electronic adjustment of the oscillation frequency. Copyright © 2008 John Wiley & Sons, Ltd.
Immunologic features of HIV‐1‐infected women on HAART at delivery
Authors: Ono Erika , dos Santos Amélia M. N. , Machado Daisy M. , Succi Regina C. de M. , Amed Abes M. , Salomão Reinaldo , Kallás Esper G. , de Moraes‐Pinto M. Isabel 
Published: April 2008

AbstractBackground:The conjoint effect of HIV infection and pregnancy on the immune system of women submitted to the prophylactic antiretroviral therapy presently recommended is still poorly understood.Methods:We evaluated 44 HIV‐infected women (HIV) and 45 HIV‐negative women (CT) at parturition and we compared them to 20 healthy nonpregnant women (NP). Immunophenotyping of lymphocytes was done by four‐color flow cytometry.Results:All HIV‐infected women received HAART during pregnancy and 56.8% had viral load <50 copies/mL at delivery. CD4+T cells/mm3 were lower in HIV (447) than CT (593) and NP (738) (P < 0.05). CD8+T cells/mm3 were higher in HIV (799) than CT (384) and NP (395) (P < 0.05). NK cells/mm3 were lower in HIV (146) than in CT (253) and NP (198) (P < 0.05). CD38 expression on CD4+T and on CD8+T cells was higher in HIV (CD4:12.1; CD8:14.9) than in CT(CD4:9.2; CD8:10.2) and NP(CD4:8.6; CD8:6.0) (P < 0.05). However, CD56 expression on CD8+T cells (a marker of cytolytic effector function) was lower in HIV(7%) than in CT(12%) and NP(9%) (P < 0.05).Conclusions:Even with low levels of viremia, HIV‐infected women at delivery showed a different immunologic profile from both healthy non‐HIV‐infected women in the puerperium and nonpregnant women, with lower CD4+T and higher CD8+T cells, high levels of CD38 expression, but low CD56 expression on CD8+T cells and low NK cell numbers. © 2008 Clinical Cytometry Society
The genetics of essential metal homeostasis during development
Authors: Kambe Taiho , Weaver Benjamin P. , Andrews Glen K. 
Published: April 2008

AbstractThe essential metals copper, zinc, and iron play key roles in embryonic, fetal, and postnatal development in higher eukaryotes. Recent advances in our understanding of the molecules involved in the intricate control of the homeostasis of these metals and the availability of natural mutations and targeted mutations in many of the genes involved have allowed for elucidation of the diverse roles of these metals during development. Evidence suggests that the ability of the embryo to control the homeostasis of these metals becomes essential at the blastocyst stage and during early morphogenesis. However, these metals play unique roles throughout development and exert pleiotropic, metal‐specific, and often cell‐specific effects on morphogenesis, growth, and differentiation. Herein, we briefly review the major players known to be involved in the homeostasis of each of these essential metals and their known roles in development. genesis 46:214–228, 2008. © 2008 Wiley‐Liss, Inc.
On‐line cell lysis and DNA extraction on a microfluidic biochip fabricated by microelectromechanical system technology
Authors: Chen Xing , Cui Da Fu , Liu Chang Chun 
Published: April 2008

AbstractIntegrating cell lysis and DNA purification process into a micrototal analytical system (μTAS) is one critical step for the analysis of nucleic acids. On‐chip cell lysis based on a chemical method is realized by sufficient blend of blood sample and the lyzing reagent. In this paper two mixing models, T‐type mixing model and sandwich‐type mixing model, are proposed and simulation of those models is conducted. Result of simulation shows that the sandwich‐type mixing model with coiled channel performs best and this model is further used to construct the microfluidic biochip for on‐line cell lysis and DNA extraction. The result of simulation is further verified by experiments. It asserts that more than 80% mixing of blood sample and lyzing reagent which guarantees that completed cell lysis can be achieved near the inlet location when the cell/buffer velocity ratio is less than 1:5. After cell lysis, DNA extraction by means of a solid‐phase method is implemented by using porous silicon matrix which is integrated in the biochip. During continuous flow process in the microchip, rapid cell lysis and PCR‐amplifiable genomic DNA purification can be achieved within 20 min. The potential of this microfluidic biochip is illustrated by pretreating a whole blood sample, which shows the possibility of integration of sample preparation, PCR, and separation on a single device to work as portable point‐of‐care medical diagnostic system.
Numerical analysis of thermal lens effect for sensitive detection on microchips
Authors: Anraku Ryo , Mawatari Kazuma , Tokeshi Manabu , Nara Masatoshi , Asai Takahiro , Hattori Akihiko , Kitamori Takehiko 
Published: April 2008

AbstractThermal lens microscope (TLM) is a sensitive detection method for nonfluorescent molecules and widely applied to detection in a capillary or on a microchip. In this paper, we developed a flexible design tool for TLM systems to meet various applications utilizing a microspace. The TL effect was modeled, including signal processing, and calculated by combining fluidic dynamics and wave optics software. The coincidence of the calculations and experiments was investigated by measuring the effects of optical path length or focus positions of the excitation beams on TL signals which are quite difficult to calculate by a conventional method. Good agreement was shown and the applicability of the TLM design tool was verified.
Study of a novel sample injection method (floating electrokinetic supercharging) for high‐performance microchip electrophoresis of DNA fragments
Authors: Hirokawa Takeshi , Takayama Yoichi , Arai Akihiro , Xu Zhongqi 
Published: April 2008

AbstractAiming to achieve high‐performance analysis of DNA fragments using microchip electrophoresis, we developed a novel sample injection method, which was given the name of floating electrokinetic supercharging (FEKS). In the method, electrokinetic injection (EKI) and ITP preconcentration of samples was performed in a separation channel, connecting two reservoir ports (P3 and P4) on a cross‐geometry microchip. At these two stages, side channels, crossing the separation channel, and their ports (P1 and P2) were electrically floated. After the ITP‐stacked zones passed the cross‐part, they were eluted for detection by using leading ions from P1 and P2 that enabled electrophoresis mode changing rapidly from ITP to zone electrophoresis (ZE). Possible sample leakage at the cross‐part toward P1 and P2 was studied in detail on the basis of computer simulation using a CFD‐ACE+ software and real experiments, through which it was validated that the analyte recovery to the separation channel was almost complete. The FEKS method successfully contributed to higher resolution and shorter analysis time of DNA fragments on the cross‐microchip owing to more rapid switching from ITP status to ZE separation in comparison with our previous EKS procedure realized on a single‐channel microchip. Without any degradation of resolution, the achieved LODs were on average ten times better than using conventional pinched injection.
Mitochondrial dysfunction by complex II inhibition delays overall cell cycle progression via reactive oxygen species production
Authors: Byun Hae‐Ok , Kim Hee Young , Lim Jin J. , Seo Yong‐Hak , Yoon Gyesoon 
Published: April 2008

AbstractMitochondrial complex II defect has recently been implicated in cellular senescence and in the ageing process of which a critical phenotype is retardation and arrest of cellular growth. However, the underlying mechanisms of how complex II defect affects cellular growth, remain unclear. In this study, we investigated the effect of complex II inhibition using a subcytotoxic dose (400 µM) of 2‐thenoyltrifluoroacetone (TTFA), a conventional complex II inhibitor, on cell cycle progression. TTFA (400 µM) directly decreased KCN‐sensitive cellular respiration rate to 67% of control and disrupted the mitochondrial membrane potential. In contrast to other respiratory inhibitors such as rotenone, antimycin A, and oligomycin, TTFA prolonged the duration of each phase of the cell cycle (G1, S, and G2/M) equally, thereby delaying overall cell cycle progression. This delay was accompanied by a biphasic increase of reactive oxygen species (ROS) and concurrent glutathione oxidation, in addition to a slight decrease in the cellular ATP level. Finally, the delay in cell cycle progression caused by TTFA was proved to be mainly due to ROS overproduction and subsequent oxidative stress, as evidenced by its reversal following pretreatment with antioxidants. Taken together, these results suggest that an overall delay in cell cycle progression due to complex II defects may contribute to ageing and degenerative diseases via inhibition of cellular growth and proliferation without arrest at any specific phase of the cell cycle. J. Cell. Biochem. 104: 1747–1759, 2008. © 2008 Wiley‐Liss, Inc.
c‐Myc represses FOXO3a‐mediated transcription of the gene encoding the p27Kip1 cyclin dependent kinase inhibitor
Authors: Chandramohan Vidyalakshmi , Mineva Nora D. , Burke Brian , Jeay Sébastien , Wu Min , Shen Jian , Yang William , Hann Stephen R. , Sonenshein Gail E. 
Published: April 2008

AbstractThe p27Kip1 (p27) cyclin‐dependent kinase inhibitor and c‐Myc oncoprotein play essential roles in control of cell cycle progression and apoptosis. Induction of p27 (CDKN1B) gene transcription by Forkhead box O proteins such as FOXO3a leads to growth arrest and apoptosis. Previously, we observed that B cell receptor (surface IgM) engagement of WEHI 231 immature B lymphoma cells with an anti‐IgM antibody results in activation of FOXO3a, growth arrest and apoptosis. As ectopic c‐Myc expression in these cells prevented anti‐IgM induction of p27 and cell death, we hypothesized that c‐Myc represses FOXO3a‐mediated transcription. Here we show that c‐Myc inhibits FOXO3a‐mediated activation of the p27 promoter in multiple cell lines. The mechanism of this repression was explored using a combination of co‐immunoprecipitation, oligonucleotide precipitation, and chromatin immunoprecipitation experiments. The studies demonstrate a functional association of FOXO3a and c‐Myc on a proximal Forkhead binding element in the p27 promoter. This association involves the Myc box II domain of c‐Myc and the N‐terminal DNA‐binding portion of FOXO3a. Analysis of publicly available microarray datasets showed an inverse pattern of c‐MYC and p27 RNA expression in primary acute myeloid leukemia, prostate cancer and tongue squamous cell carcinoma samples. The inhibition of FOXO3a‐mediated activation of the p27 gene by the high aberrant expression of c‐Myc in many tumor cells likely contributes to their uncontrolled proliferation and invasive phenotype. J. Cell. Biochem. 104: 2091–2106, 2008. © 2008 Wiley‐Liss, Inc.
A novel butyrolactone derivative inhibited smooth muscle cell migration and proliferation and maintained endothelial cell functions through selectively affecting Na, K‐ATPase activity and mitochondria membrane potential during in vitro angiogenesis
Authors: Meng Ning , Zhao Jing , Zhao BaoXiang , Cheng Yizhe , Wang Weiwei , Zhang Yun , Zhang ShangLi , Miao JunYing 
Published: April 2008

AbstractWe have found that 3‐benzyl‐5‐((2‐nitrophenoxy) methyl)–dihydrofuran ‐2(3H)‐one (3BDO), could effectively suppress human umbilical vascular endothelial cell (HUVEC) apoptosis induced by deprivation of fibroblast growth factor‐2 and serum. Here, our purpose was to investigate whether 3BDO could modulate angiogenesis and its possible acting mechanism. The effect of 3BDO on angiogenesis was investigated by capillary‐like tubule formation and rat aortic ring assay. Proliferation and migration of cells were detected by counting living cell number and scraping cell monolayer, respectively. Na, K‐ATPase activity was measured spectrophotometrically. Mitochondrial membrane potential was analyzed using tetramethylrhodamine methylester fluorescence by confocal microscopy. Our results showed that 3BDO inhibited migration and proliferation of vascular smooth muscle cells (VSMCs), but maintained migration and tubule formation of HUVECs. In HUVECs, 3BDO inhibited Na, K‐ATPase activity, but had no effect on mitochondria membrane potential. In VSMCs, it did not affect Na, K‐ATPase activity, but depressed mitochondria membrane potential obviously. The data showed that 3BDO had selective effects on HUVECs and VSMCs, it might perform its role through the selective effects on the activity of Na, K‐ATPase and the mitochondria membrane potential in HUVECs and VSMCs. J. Cell. Biochem. 104: 2123–2130, 2008. © 2008 Wiley‐Liss, Inc.
Process regulation via genealogical decision trees
Authors: Ikonen E. , Gomez‐Ramirez E. , Najim K. 
Published: April 2008

AbstractThis paper deals with regulation control on the basis of genealogical decision trees (GDTs). GDTs are a population‐based random search technique for solving sequential multimodal and multivariable trajectory tracking problems, when gradient information is not available or does not exist. A direct application of GDT results in an open‐loop control. In this paper, feedback regulation based on GDT is considered. In the proposed scheme, GDTs are used for solving off‐line a number of predictive control problems; a finite set of initial states is then constructed from these simulations, for each of which an optimal control sequence has been computed. Natural handling of missing state vector measurements is provided. Numerical examples dealing with the van der Vusse CSTR illustrate the feasibility and the efficiency of this feedback control algorithm. A discussion on alternative approaches and a numerical comparison with the Markov‐decision‐process‐based optimal policy are provided. Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of six widely‐used dense gas dispersion models for three recent chlorine railcar accidents
Authors: Hanna Steven , Dharmavaram Seshu , Zhang John , Sykes Ian , Witlox Henk , Khajehnajafi Shah , Koslan Kay 
Published: April 2008

AbstractSix widely‐used dense gas dispersion models (ALOHA, HGSYSTEM, SLAB, SCIPUFF, PHAST, and TRACE) were used to calculated downwind chlorine gas concentrations following three railcar accidents. The accidents, where as much as 60 tons of chlorine were released, were located at Festus, MO (release from a ruptured 1‐in. line while offloading), and Macdona, TX, and Graniteville, SC (release from a large hole due to an accident). Public sources such as National Transportation Safety Board (NTSB) reports were used to develop input data. Source emissions rates were refined based on source modeling with PHAST and TRACE and derivations using fundamental thermodynamic equations. No chlorine removal mechanisms, such as photolysis, chemical reactions, or deposition were accounted for. Given the same source emissions rates, the models' simulations of 10‐min averaged cloud centerline concentration, at downwind distances ranging from 0.1 to 10 km, agree with each other within plus and minus a factor of two most of the time. For a very large release (Graniteville), the 2,000, 400, and 20 ppm contours are predicted to extend downwind about 1.3, 3.1, and 14 km, respectively, from the source. There is also agreement among the models simulations of the plume widths and heights to the 2,000, 400, and 20 ppm contours. A major conclusion of the study is that estimation of the source or release term is important for reliable results, since the calculated chlorine concentrations are approximately proportional to the mass release rate. It must also be stressed that observed concentrations would be expected to be less than those calculated here, because removal by dry deposition at the surface and by chemical reactions in the plume have not been accounted for. © 2008 American Institute of Chemical Engineers Process Saf Prog, 2008
The confirmation of accurate combination of functional and basis set for transition‐metal dimers: Fe2, Co2, Ni2, Ru2, Rh2, Pd2, Os2, Ir2, and Pt2
Authors: Du Jiguang , Sun Xiyuan , Wang Hongyan 
Published: April 2008

AbstractEight kinds of density functionals named B3LYP, PBE1PBE, B1B95, BLYP, BP86, G96PW91, mPWPW91, and SVWN along with two different valence basis sets (LANL2DZ and CEP‐121g) are employed to study the transition‐metal dimers for the elements of group VIII. By comparing the equilibrium bond distances, vibrational frequencies, and dissociation energies of the ground state of these dimers with the available experimental values and theoretical data, we show that the “pure” DFT methods (G96PW91, BLYP, and BP86) with great‐gradient approximation always give better results relative to the hybrid HF/DFT schemes (B3LYP, PBE1PBE, and B1B95). The striking case found by us is that the G96PW91 functional, which is not tested in previous systemic studies, always predicts the dissociation energy to be well. The Ru2 and Os2 dimers are sensitive to not only the functionals employed but also the valence basis sets adopted. The natural bond orbital population is analyzed, and the molecular orbitals of the unpaired electrons are determined. Furthermore, our results indicate that the s and d orbitals of these dimers always hybridize with each other except for Rh2 and Pt2 molecules. And by analyzing the electron configuration of the bonding atom, the dissociation limit of the ground state is obtained. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
Introduction to computers and their development
Authors: Brown James E. 
Published: April 2008

AbstractA data processing system can be a calculator, a bookkeeping machine, or a computer. Computers are based upon these five basic elements: a control unit, an arithmetic unit, memory unit, input unit, and output unit. Historically, first generation systems were physically large, able to be programmed only by bit manipulation machine language, very slow, and required extensive air conditioning and atmospheric control. Second generation computers saw the transition from electronic tubes to transistorized circuits speeding up internal processing. High levels compilers and assemblers were introduced, enabling programs to be written on a one‐for‐one assembly language basis, or on a two‐to‐one, three‐to‐one or more basis by using a compiler. Third generation systems saw significant improvements in utilization of microminiaturized circuits and interrupt handling that permitted development of complex operating systems including extensive progress in the area of time sharing and communications uses. Additional computers, first introduced in 1960, are the minicomputers. These minicomputers usually function in a dedicated environment and have many characteristics originally found in the third generation systems as well as many unique qualities of their own. Characteristics that categorize a computer as being a “mini” include purchase price of less than $25,000 at introduction, a memory size of 4000 bytes or more, minimal system configuration, and, usually, outright purchase. Minicomputer manufacturers are finding a large market for their product with dedicated applications and the original equipment manufacturer. The minicomputer may be the basis for still another generation of computers.
Applications of nonlinear programming to detergent formulations
Authors: Steinle Edmund C. , Hendrix Charles D. , Fields Robert R. 
Published: April 2008

AbstractDesigned experiments have been used to secure orthogonal data in a typical light duty liquid detergent system. Regression analyses of the data have provided prediction equations relating composition to performance and physical properties for formulations in this system. The use of these equations in a nonlinear programming computer optimization program is described, illustrated by examples taken from a limited subsystem wherein two of the six components are held constant. Costs, types and uses of such optimization procedures are considered.
A computer approach toward automation of a chemical services laboratory: II. Management information
Authors: Munson A. W. , Schneider E. L. 
Published: April 2008

AbstractA Real Time Information Management System is described which is based on several interacting data bases. Fifteen dynamic files are accessed by 70 chemists and microbiologists through the use of computer terminals and more than 25 programs. The System provides for real time work scheduling for a chemical laboratory and the generation of all reports. The System also handles accounting, billing, summarization, analysis and distribution of all laboratory functions. The system is open ended, and therefore, expandable. There is no dependency to a particular computer but rather only the need for a computer that can handle terminals and dynamic files.
Postulated scheme forβ crystal structures of mixed palmitic‐stearic triglycerides
Authors: Lutton E. S. 
Published: April 2008

AbstractA structural scheme is proposed forβ phases of the six palmitic‐stearic triglycerides, based on known configurations of tricaprin and 2‐11‐bromoundecanoyl‐1,1′‐dicaprin. The scheme receives some support from short spacing and binary system data.