bluuebunny/crossref_metadata_2025_split huggingface dataset:
The importance of learning to make assumptions
Authors: Fortus David 
Published: June 2008

AbstractMaking assumptions is an important step in solving many real‐world problems. This study investigated whether participants who could solve well‐defined physics problems could also solve a real‐world physics problem that involved the need to make assumptions. The participants, who all had at least a BA in physics, were videotaped “thinking aloud” while solving three well‐defined and one real‐world problem and then interviewed about the problem‐solving process. All the problems dealt with the same scientific content. The recordings were analyzed to identify similarities and differences in the ways the problems were solved and to see which steps in the solution of the problems posed the greatest cognitive difficulty for each participant. Results indicate that (a) the process of making the constraining assumptions needed to convert the real‐world problem into a well‐defined one was the most difficult step for all, and (b) only the participants who had prior experience making constraining assumptions were able to make the needed assumptions and solve the real‐world problem. These findings suggest a need to support physics students develop this important skill. © 2008 Wiley Periodicals, Inc. Sci Ed 93:86–108, 2009
Reproductive parameters in captive hand‐reared black‐bellied sandgrouse
Authors: Aourir M. , Znari M. , El Abbassi A. , Radi M. , Melin J‐M. 
Published: June 2008

AbstractFlock breeders of black‐bellied sandgrouse originated from wild‐laid eggs collected in west central Morocco in 2003 and 2004, were hatched, and hand‐reared in captivity in the framework of a reinforcement population program. Three to five pairs of different ages were housed in an aviary. Egg‐pulling procedure was used and eggs incubated artificially. Breeding parameters, hatchability, and posthatching mortality were recorded. The black‐bellied sandgrouse showed a seasonal breeding pattern with a laying period extending from 7 to12 weeks. The clutch frequency varied from 3 to 7 clutches per female per season. The mean clutch size was 2.66±0.47 eggs, and the mean interclutch interval was 10±2.7 days. The average total egg production was 12±5.83 eggs per female varying with age from 8 to18 eggs per female. Egg hatchability of incubated eggs increased with age and varied from 37.5 to 72.2%. Chick mortality occurred only in the first week after hatching, averaging 60.5%. The obtained results showed that black‐bellied sandgrouse can be successfully bred in captivity and opened the possibility of controlling, managing, and maximizing their production for the reinforcement of the local declining wild populations. Zoo Biol 27:269–281, 2008. © 2008 Wiley‐Liss, Inc.
Converting Layered Zinc Acetate Nanobelts to One-dimensional Structured ZnO Nanoparticle Aggregates and their Photocatalytic Activity
Authors: Zhang Ye , Zhu Feng , Zhang Junxi , Xia Lingli 
Published: June 2008

Abstract
We were successful in synthesizing periodic layered zinc acetate nanobelts through a hydrothermal solution process. One-dimensional structured ZnO nanoparticle aggregate was obtained by simple thermal annealing of the above-mentioned layered ZnO acetate nanobelts at 300 °C. The morphology, microstructure, and composition of the synthesized ZnO and its precursors were characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD), and infrared spectroscopy, respectively. Low angle X-ray diffraction spectra reveal that as-synthesized zinc acetate has a layered structure with two interlayer d-spacings (one is 1.32 nm and the other is 1.91 nm). SEM and TEM indicate that nanobelt precursors were 100–200 nm in width and possesses length up to 30 μm. Calcination of precursor in air results in the formation of one-dimensional structured ZnO nanoparticle aggregates. In addition, the as-prepared ZnO nanoparticle aggregates exhibit high photocatalytic activity for the photocatalytic degradation of methyl orange (MO).
Identification of Tumor-Associated Proteins in Well Differentiated Laryngeal Squamous Cell Carcinoma by Proteomics
Authors: Zhou Jian-rong , Fu Zhong-xue , Li Jie , Wei Lian-zhi , Li Jun-cai 
Published: June 2008

Abstract

Introduction
This study established two-dimensional gel electrophoresis (2-DE) profiles for human well-differentiated laryngeal squamous cell carcinoma tissue and paired normal mucosa epithelia tissue and identified proteins with different expressions. Well-resolved and reproducible 2-DE patterns of well-differentiated laryngeal squamous cell carcinoma and adjacent normal mucosa were obtained.

Results
Thirteen proteins were preliminarily identified, among which ten proteins including cofilin-1, nuclear body protein SP140, GRP94, HSP 90, GSTP1-1, superoxide dismutase [Mn], cyclophilin A, proteasome activator complex subunit 2, apolipoprotein A-I precursor, and CaM-like protein were upregulated and three proteins including fatty acid-binding protein (E-FABP), calgranulin A, and calgranulin B were downregulated in laryngeal cancer tissue. The different expressions of cyclophilin A and MRP8 were confirmed by Western blotting.

Discussion
We first identified 13 proteins that might be associated with the tumorigenesis of the laryngeal squamous cell carcinoma. Some proteins were the products of oncogenes and apoptosis and others were related to signal transduction and immune defense. These extensive protein variations indicated that multiple protein molecules were simultaneously involved in the oncogenesis of laryngeal cancer, which in turn is a basis for the rational designs of diagnostic and therapeutic methods.
Effect of repeated intracoronary injection of bone marrow cells in patients with ischaemic heart failure☆ The Danish Stem Cell study—Congestive Heart Failure trial (DanCell‐CHF)
Authors: Diederichsen Axel C.P. , Møller Jacob E. , Thayssen Per , Junker Anders B. , Videbæk Lars , Sækmose Susanne G. , Barington Torben , Kristiansen Malthe , Kassem Moustapha 
Published: June 2008

AbstractBackground:It has been suggested that myocardial regeneration may be achieved by a single intracoronary bone marrow derived stem cell infusion in selected patients with ischaemic heart disease. The effect is uncertain in patients with chronic ischaemic heart failure and it is not known whether repeated infusions would have additional positive effects.Aims:To assess whether two treatments of intracoronary infusion of bone marrow stem cells, administered 4 months apart, could improve left ventricular (LV) systolic function in patients with chronic ischaemic heart failure.Methods:The study was prospective and non‐randomised, comprising an observational baseline period of 4 months followed by an interventional period of 12 months. Intracoronary bone marrow cell infusion was performed at the end of the baseline period and repeated 4 months later.Results:32 patients were included. LV ejection fraction remained unchanged (33±9% vs. 34±10% after 8 months, p=0.30). Likewise, there was no significant change in LV end‐systolic volume, wall motion score index (WMSI) or contractile reserve. At 12 months, a decrease in target vessel WMSI was seen (2.17±0.34 vs. 2.06±0.46, p=0.02). Furthermore, NYHA class improved (p<0.0001). No deaths were observed.Conclusion:In this non‐randomised study, no change in LV ejection fraction could be demonstrated after repeated intracoronary bone marrow stem cell treatment in patients with chronic ischaemic heart failure.
A Brief Review of Bone Adaptation to Unloading
Authors: Zhang Ping , Hamamura Kazunori , Yokota Hiroki 
Published: June 2008

Abstract
Weight-bearing bone is constantly adapting its structure and function to mechanical environments. Loading through routine exercises stimulates bone formation and prevents bone loss, but unloading through bed rest and cast immobilization as well as exposure to weightlessness during spaceflight reduces its mass and strength. In order to elucidate the mechanism underlying unloading-driven bone adaptation, ground-based in vitro and in vivo analyses have been conducted using rotating cell culturing and hindlimb suspension. Focusing on gene expression studies in osteoblasts and hindlimb suspension studies, this minireview introduces our recent understanding on bone homeostasis under weightlessness in space. Most of the existing data indicate that unloading has the opposite effects to loading through common signaling pathways. However, a question remains as to whether any pathway unique to unloading (and not to loading) may exist.
Gene Expression Profiling of Human Epidermal Keratinocytes in Simulated Microgravity and Recovery Cultures
Authors: Clement Jade Q. , Lacy Shareen M. , Wilson Bobby L. 
Published: June 2008

Abstract
Simulated microgravity (SMG) bioreactors and DNA microarray technology are powerful tools to identify “space genes” that play key roles in cellular response to microgravity. We applied these biotechnology tools to investigate SMG and post-SMG recovery effects on human epidermal keratinocytes by exposing cells to SMG for 3, 4, 9, and 10 d using the high aspect ratio vessel bioreactor followed by recovery culturing for 15, 50, and 60 d in normal gravity. As a result, we identified 162 differentially expressed genes, 32 of which were “center genes” that were most consistently affected in the time course experiments. Eleven of the center genes were from the integrated stress response pathways and were coordinately down-regulated. Another seven of the center genes, which are all metallothionein MT-I and MT-II isoforms, were coordinately up-regulated. In addition, HLA-G, a key gene in cellular immune response suppression, was found to be significantly up-regulated during the recovery phase. Overall, more than 80% of the differentially expressed genes from the shorter exposures (≤4 d) recovered in 15 d; for longer (≥9 d) exposures, more than 50 d were needed to recover to the impact level of shorter exposures. The data indicated that shorter SMG exposure duration would lead to quicker and more complete recovery from the microgravity effect.
Transcriptional Analysis of Normal Human Fibroblast Responses to Microgravity Stress
Authors: Liu Yongqing , Wang Eugenia 
Published: June 2008

Abstract
To understand the molecular mechanism(s) of how spaceflight affects cellular signaling pathways, quiescent normal human WI-38 fibroblasts were flown on the STS-93 space shuttle mission. Subsequently, RNA samples from the space-flown and ground-control cells were used to construct two cDNA libraries, which were then processed for suppression subtractive hybridization (SSH) to identify spaceflight-specific gene expression. The SSH data show that key genes related to oxidative stress, DNA repair, and fatty acid oxidation are activated by spaceflight, suggesting the induction of cellular oxidative stress. This is further substantiated by the up-regulation of neuregulin 1 and the calcium-binding protein calmodulin 2. Another obvious stress sign is that spaceflight evokes the Ras/mitogen-activated protein kinase and phosphatidylinositol-3 kinase signaling pathways, along with up-regulating several G1-phase cell cycle traverse genes. Other genes showing up-regulation of expression are involved in protein synthesis and pro-apoptosis, as well as pro-survival. Interactome analysis of functionally related genes shows that c-Myc is the “hub” for those genes showing significant changes. Hence, our results suggest that microgravity travel may impact changes in gene expression mostly associated with cellular stress signaling, directing cells to either apoptotic death or premature senescence.
Increased Filamentous Growth of Candida Albicans in Simulated Microgravity
Authors: Altenburg Sara D. , Nielsen-Preiss Sheila M. , Hyman Linda E. 
Published: June 2008

Abstract
Knowledge of simulated microgravity (SMG)-induced changes in the pathogenicity of microorganisms is important for success of long-term spaceflight. In a previous study using the high aspect ratio vessel bioreactor, we showed that the yeast species Saccharomyces cerevisiae underwent a significant phenotypic response when grown in modeled microgravity, which was reflected in the analysis of gene expression profiles. In this study, we establish that Candida albicans responds to SMG in a similar fashion, demonstrating that there is a conserved response among yeast to this environmental stress. We also report that the growth of C. albicans in SMG results in a morphogenic switch that is consistent with enhanced pathogenicity. Specifically, we observed an increase in filamentous forms of the organism and accompanying changes in the expression of two genes associated with the yeast-hyphal transition. The morphological response may have significant implications for astronauts’ safety, as the fungal pathogen may become more virulent during spaceflight.
Diversity and Stability Study on Rice Mutants Induced in Space Environment
Authors: Lu Wei-Hong , Wang Xin-Zhu , Zheng Qi , Guan Shuang-Hong , Xin Ping , Sun Ye-Qing 
Published: June 2008

Abstract
To further study the characteristics of changes on the molecular level of rice mutants induced in space environment, we analyzed proteins in leaves and seeds of four rice mutants (two high-tillering and two low-tillering) in the 8th and 9th generations after a 15-day spaceflight, and compared with their ground controls by two-dimentional polyacrylamide gel electrophoresis and reverse phase liquid chromatography (RPLC). In addition, the albumin, globulin, prolamine, glutelin, and amylose of the mutant seeds were analyzed by RPLC and ultra-violet spectrometry. The results showed that the low-abundance proteins of leaves in the peak tillering stage are more likely to be induced compared with their corresponding controls. The albumin, globulin, and prolamine of the mutant seeds revealed changes when compared with their controls, and the characteristics of changes in different mutants were stably inherited in the 8th and 9th generations, suggesting that they can be used as biomarkers to identity the mutants induced by spaceflight. Moreover, two proteins (SSP9111 and SSP6302) were found to be expressed with high intensity (two-fold change) in different mutants, which were both correlated with photosystem according to mass spectrometry and database searching.
Molecular phylogeny of Pemphiginae (Hemiptera: Aphididae) inferred from nuclear gene EF-1α sequences
Authors: Zhang H.C. , Qiao G.X. 
Published: June 2008

AbstractThree traditional tribes of Fordini, Pemphigini and Eriosomatini comprise Pemphiginae, and there are two subtribes in Fordini and Pemphigini, respectively. Most of the species in this subfamily live heteroecious holocyclic lives with distinct primary host specificity. The three tribes of Pemphigini (except Prociphilina), Eriosomatini and Fordini use three families of plants, Salicaceae (Populus), Ulmaceae (Ulums) and Anacardiaceae (PistaciaandRhus), as primary hosts, respectively, and form galls on them. Therefore, the Pemphigids are well known as gall makers, and their galls can be divided into true galls and pseudo-galls in type. We performed the first molecular phylogenetic study of Pemphiginae based on molecular data (EF-1α sequences). Results show that Pemphiginae is probably not a monophylum, but the monophyly of Fordini is supported robustly. The monophyly of Pemphigini is not supported, and two subtribes in it, Pemphigina and Prociphilina, are suggested to be raised to tribal level, equal with Fordini and Eriosomatini. The molecular phylogenetic analysis does not show definite relationships among the four tribes of Pemphiginae, as in the previous phylogenetic study based on morphology. It seems that the four tribes radiated at nearly the same time and then evolved independently. Based on this, we can speculate that galls originated independently four times in the four tribes, and there is no evidence to support that true galls are preceded by pseudo-galls, as in the case of thrips and willow sawflies.
Reproductive Interference between the Common Ground-hopper Tetrix undulata and the Slender Ground-hopper Tetrix subulata (Orthoptera, Tetrigidae)
Authors: Hochkirch A. , Bücker A. , Gröning J. 
Published: June 2008

AbstractThe coexistence of closely related species is often hampered by resource competition or reproductive interference (interspecific sexual interactions). Species utilising similar signal channels might face substantial problems when they co-occur. It has, therefore, been suggested that reinforcement might drive signal evolution in narrow suture zones of secondary contact. However, species with large overlapping ranges are usually not believed to interact sexually. The Slender Ground-hopper, Tetrix subulata, and the Common Ground-hopper, Tetrix undulata (Orthoptera: Tetrigidae) are sister species, which occur sympatrically in large parts of western and Central Europe, but rarely share the same habitat. It has been hypothesized that reproductive interference might account for their missing coexistence. Here, we test experimentally whether these two species interact sexually. Our results suggest an incomplete premating isolation of these ground-hoppers, as we recorded heterospecific courtship, mating attempts and mating. The number of conspecific copulations and mating attempts of T. subulata decreased substantially in the presence of T. undulata, whereas the latter species was not negatively affected. Males of both species preferred to approach females of T. undulata, whereas females of both species did not discriminate against heterospecific males. Further studies on the reproductive success are needed to clarify whether reproductive interference might influence habitat partitioning between these species.
40Ar–39Ar biotite and hornblende geochronology from the Oskarshamn area, SE Sweden: discerning multiple Proterozoic tectonothermal events
Authors: SÖDERLUND PIA , PAGE LAURENCE M. , SÖDERLUND ULF 
Published: June 2008

AbstractTwelve40Ar–39Ar biotite and four hornblende age determinations have been carried out to constrain the cooling history of the Proterozoic bedrock near Oskarshamn, SE Sweden, an area identified as a possible site for long-term nuclear waste storage. The bedrock hostsc.1.80 Ga granites and diorites of the Transscandinavian Igneous Belt and two 1.45–1.44 Ga granite intrusions, the Götemar and Uthammar plutons. Biotite was selected from three surface samples, representing both the older rocks and the younger granites, and from three cored boreholes at nine different depth levels. Hornblende was extracted from samples at the top and bottom of one borehole and at two sub-surface levels of another borehole. Three age groups were distinguished: ≥1.62 Ga, 1.51–1.47 Ga and 1.43–1.42 Ga. In the first group, two hornblende analyses yielded ages of 1799±4 Ma and 1773±13 Ma, which indicate initial fast cooling after emplacement of 1.80 Ga rocks of the Transscandinavian Igneous Belt. Two biotite ages of 1618±7 Ma and 1621±3 Ma are interpreted to date final cooling, through 300 °C, after the youngest suite (1.68–1.67 Ga) of the Transscandinavian Igneous Belt in south-central Sweden. Seven biotite ages, in the range 1.51–1.47 Ga, are enigmatic to interpret but largely coincide in age with the end of widespread rapakivi magmatism in Fennoscandia and the initiation of the Danopolonian event. The 1.43–1.42 Ga biotite and hornblende ages reflect cooling after thermal heating from the 1.45–1.44 Ga Götemar and Uthammar plutons. Later events thermally affected the bedrock in the Oskarshamn area as indicated by a poorly defined biotite age of 928±6 Ma and other disturbed40Ar–39Ar ages of samples bordering a complex deformation zone.
The diagnostics of density distribution for inhomogeneous dense DT plasmas using fast protons
Authors: Li X.-M. , Shen B.-F. , Zhang X.-M. , Jin Z.-Y. , WANG F.-C. 
Published: June 2008

AbstractThe density distribution of inhomogeneous dense deuterium-tritium plasmas in laser fusion is revealed by the energy loss of fast protons going through the plasma. In our simulation of a plasma density diagnostics, the fast protons used for the diagnostics may be generated in the laser-plasma interaction. Dividing a two-dimensional area into grids and knowing the initial and final energies of the protons, we can obtain a large linear and ill-posed equation set for the densities of all grids, which is solved with the Tikhonov regularization method. We find that the accuracy of the set plan with four proton sources is better than those of the set plans with less than four proton sources. Also we have done the density reconstruction especially for four proton sources with and without assuming circularly symmetrical density distribution, and find that the accuracy is better for the reconstruction assuming circular symmetry. The error is about 9% when no noise is added to the final energy for the reconstruction of four proton sources assuming circular symmetry. The accuracies for different random noises to final proton energies with four proton sources are also calculated.
Quasi-monoenergetic electron beams generated from 7 TW laser pulses in N2 and He gas targets
Authors: Chen Z.L. , Unick C. , Vafaei-Najafabadi N. , Tsui Y.Y. , Fedosejevs R. , Naseri N. , Masson-Laborde P.-E. , Rozmus W. 
Published: June 2008

AbstractQuasi-monoenergetic electron beams of energies 12 MeV to over 200 MeV are generated from both nitrogen and helium gas targets with 7TW laser pulses. Typically nitrogen gas interactions lead to electron bunches in the range of 12 to 50 MeV varying from shot to shot. Helium gas leads to higher energy electron bunches from 25 to 100 MeV. Occasionally exceptionally high energy bunches of electrons up to 200 MeV are observed from nitrogen and helium. Initial full two-dimensional simulations indicate the production of 20–30 MeV electron energy bunches for the typical interaction conditions as the electrons are injected from wave breaking in the plasma wake behind the laser pulse and injected into the strong electric field gradient propagating with the optical pulse. This is consistent with the experimental observations from the majority of shots. Pulse compression during propagation in the high density plasma does not allow the threshold conditions for the full bubble regime to be reached. However, the electric acceleration field in the wakefield cavity is still sufficient to lead to the formation of a bunch of electrons with an energy peak in the range of 20 to 30 MeV. In order to explain the occasional high energy shots most likely a lower density channel created by the laser prepulse may occasionally form a natural low density electron guide channel giving ideal conditions for acceleration over much longer lengths leading to the high energies observed.
Simulations of shock generation and propagation in laser-plasmas
Authors: Lebo I.G. , Lebo A.I. , Batani D. , Dezulian R. , Benocci R. , Jafer R. , Krousky E. 
Published: June 2008

AbstractWe analyze the results of a recent experiment performed at the PALS laboratory and concerning ablation pressure at 0.44 µm laser wavelength measured at irradiance up to 2 × 1014 W/cm2. Using the code “ATLANT,” we have performed two-dimensional (2D) hydrodynamics simulations. Results show that 2D effects did not affect the experiment and also give evidence of the phenomenon of delocalized absorption of laser light.