bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stress‐related predictors of optimism in breast cancer survivors
Authors: Karademas Evangelos C. , Karvelis Spyridoula , Argyropoulou Katerina 
Published: February 2007

AbstractOptimism is a key variable for adjustment in aversive conditions. The purpose of this study was to examine whether optimism is predicted by two stress‐related variables which represent information about self and the environment (i.e. illness‐related stress and self‐efficacy), in a sample of breast cancer survivors. Ninety‐two women who had undergone a mastectomy participated in the study (minimum time elapsed since diagnosis = 3 years). Most participants (51 per cent) reported that at least one of four illness‐related concerns had been quite or very stressful in the past 6 months. Analyses showed that illness‐related stress exerted influence on optimism through coping, whereas self‐efficacy exerted influence both directly and through coping. Stress was predicted by two medical variables (time since diagnosis and time since mastectomy). These findings confirmed our hypothesis that knowledge about personal abilities, as well as about environment difficulties can predict the way a person evaluates future outcomes. This study has significant implications for clinical practice with patients. Copyright © 2007 John Wiley & Sons, Ltd.
Alignment of a Conjugated Polymer onto Amyloid‐like Protein Fibrils
Authors: Herland Anna , Björk Per , Hania P. Ralph , Scheblykin Ivan G. , Inganäs Olle 
Published: February 2007

AbstractThe amyloid‐like fibril is a biomolecular nanowire template of very high stability. Here we describe the coordination of a conjugated polyelectrolyte, poly(thiophene acetic acid) (PTAA), to bovine insulin fibrils with widths of <10 nm and lengths of up to more than 10 μm. Fibrils complexed with PTAA are aligned on surfaces through molecular combing and transfer printing. Single‐molecule spectroscopy techniques are applied to chart spectral variation in the emission of these wires. When these results are combined with analysis of the polarization of the emitted light, we can conclude that the polymer chains are preferentially aligned along the fibrillar axis.
Nanogoniometry with Scanning Force Microscopy: A Model Study of CdTe Thin Films
Authors: Palacios‐Lidón Elisa , Guanter Luis , Zúñiga‐Pérez Jesús , Muñoz‐Sanjosé Vicente , Colchero Jaime 
Published: February 2007

AbstractIn this paper scanning force microscopy is combined with simple but powerful data processing to determine quantitatively, on a sub‐micrometer scale, the orientation of surface facets present on crystalline materials. A high‐quality scanning force topography image is used to determine an angular histogram of the surface normal at each image point. In addition to the known method for the assignment of Miller indices to the facets appearing on the surface, a quantitative analysis is presented that allows the characterization of the relative population and morphological quality of each of these facets. Two different CdTe thin films are used as model systems to probe the capabilities of this method, which enables further information to be obtained about the thermodynamic stability of particular crystallographic facets. The method, which is referred to as nanogoniometry, will be a powerful tool to study in detail the surface of crystalline materials, particularly thin films, with sub‐micrometer resolution.
Power control and channel allocation for real‐time applications in cellular networks
Authors: Li Xiaochen , Wu Dapeng 
Published: February 2007

AbstractThe next‐generation packet‐based wireless cellular network will provide real‐time services for delay‐sensitive applications. To make the next‐generation cellular network successful, it is critical that the network utilizes the resource efficiently while satisfying quality of service (QoS) requirements of real‐time users. In this paper, we consider the problem of power control and dynamic channel allocation for the downlink of a multi‐channel, multi‐user wireless cellular network. We assume that the transmitter (the base‐station) has the perfect knowledge of the channel gain. At each transmission slot, a scheduler allots the transmission power and channel access for all the users based on the instantaneous channel gains and QoS requirements of users. We propose three schemes for power control and dynamic channel allocation, which utilize multi‐user diversity and frequency diversity. Our results show that compared to the benchmark scheme, which does not utilize multi‐user diversity and power control, our proposed schemes substantially reduce the resource usage while explicitly guaranteeing the users' QoS requirements. Copyright © 2007 John Wiley & Sons, Ltd.
Bovine Brain Diacylglycerol Lipase: Substrate Specificity and Activation by Cyclic AMP‐dependent Protein Kinase
Authors: Rosenberger Thad A. , Farooqui Akhlaq A. , Horrocks Lloyd A. 
Published: February 2007

AbstractDiacylglycerol lipase (EC 3.1.1.3) was purified from bovine brain microsomes using multiple column chromatographic techniques. The purified enzyme migrates as a single band on SDS‐PAGE and has an apparent molecular weight of 27 kDa. Substrate specificity experiments using mixed molecular species of 1,2‐diacyl‐sn‐glycerols indicate that low concentrations of Ca2+ and Mg2+ have no direct effect on enzymic activity and 1,2‐diacyl‐sn‐glycerols are the preferred substrate over 1,3‐diacyl‐sn‐glycerols. The enzyme hydrolyzes stearate in preference to palmitate from the sn‐1 position of 1,2‐diacyl‐sn‐glycerols. 1‐O‐Alkyl‐2‐acyl‐sn‐glycerols are not a substrate for the purified enzyme. The native enzyme had a Vmax value of 616 nmol/min mg protein. Phosphorylation by cAMP‐dependent protein kinase resulted in a threefold increase in catalytic throughput (Vmax = 1,900 nmol/min mg protein). The substrate specificity and catalytic properties of the bovine brain diacylglycerol lipase suggest that diacylglycerol lipase may regulate protein kinase C activity and 2‐arachidonoyl‐sn‐glycerol levels by rapidly altering the intracellular concentration of diacylglycerols.
Intestinal Epithelial Cells Absorb γ‐Tocotrienol Faster than α‐Tocopherol
Authors: Tsuzuki Wakako , Yunoki Ritsuko , Yoshimura Hiroyuki 
Published: February 2007

AbstractTo elucidate the transepithelial transport characteristics of lipophilic compounds, the cellular uptake of tocopherol and tocotrienol isomers were investigated in Caco2 cell monolayer models. These vitamin E isomers formed mixed micelles consisting of bile salts, lysophospholipids, free fatty acid, and 2‐monoacylglycerols, then the micelles were supplied to Caco2 cells. The initial accumulation of tocotrienol isomers in Caco2 cells was larger than those of corresponding tocopherol isomers. There was little difference among the cellular accumulations of four tocopherol isomers. These findings suggested that the difference between the molecular structures of the C16 hydrocarbon chain tail in tocopherol and tocotrienol was strongly responsible for the rapid epithelial transport into the Caco2 cells membranes rather than the difference in the molecular structures of their chromanol head groups. Furthermore, the secretion of α‐tocopherol and γ‐tocotrienol from Caco2 cells was investigated using Caco2 cells plated on a transwell. The time courses of their secretions from Caco2 cells showed that the initial secretion rate of γ‐tocotrienol was also larger than that of α‐tocopherol. To investigate the intestinal uptake of α‐tocopherol and γ‐tocotrienol in vivo, the mice were fed single doses of α‐tocopherol or γ‐tocotrienol with triolein. The γ‐tocotrienol responded faster in plasma than α‐tocopherol, although the maximal level of γ‐tocotrienol was lower than that of α‐tocopherol. This suggested that the intestinal uptake properties of administered α‐tocopherol and γ‐tocotrienol would characterize their plasma level transitions in mice.
Sinomenine inhibits primary CD4+ T‐cell proliferation via apoptosis
Authors: Shu Luan , Yin Wu , Zhang Jing , Tang Bo , Kang Yuan‐Xi , Ding Fan , Hua Zi‐Chun 
Published: February 2007

AbstractSinomenine is an active component isolated from Sinomenium acutum and is widely used as an immunosuppressive drug for treating autoimmune diseases. CD4+ T‐cell population plays a key role in adaptive immune response and is related to some autoimmune diseases. In this study, we investigated the possible immunosuppressive effect of sinomenine on CD4+ T cells and its underlying mechanism. Our data demonstrated that sinomenine remarkably suppressed the proliferation of CD4+ T cells, blocked the cell cycle progression from G0/G1 phase to S plusG2/M phases. Finally, the immunosuppressive activity elicited by sinomenine in CD4+ primary lymphocytes was found to be largely accounted for by caspase 3‐dependent cells apoptosis. Sinomenine did not significantly alter the expression of bcl‐2 in activated CD4+ primary T cells, suggesting that bcl‐2 might not be involved in sinomenine‐induced T cells apoptosis. In sum, this study proposes a novel mechanism for the immunosuppressive function of sinomenine on primary mouse CD4+ T cells.
Stratigraphic constraints on late Pleistocene glacial erosion and deglaciation of the Chukchi margin, Arctic Ocean
Authors: Polyak Leonid , Darby Dennis A. , Bischof Jens F. , Jakobsson Martin 
Published: February 2007

AbstractAt least two episodes of glacial erosion of the Chukchi margin at water depths to ∼ 450 m and 750 m have been indicated by geophysical seafloor data. We examine sediment stratigraphy in these areas to verify the inferred erosion and to understand its nature and timing. Our data within the eroded areas show the presence of glaciogenic diamictons composed mostly of reworked local bedrock. The diamictons are estimated to form during the last glacial maximum (LGM) and an earlier glacial event, possibly between OIS 4 to 5d. Both erosional events were presumably caused by the grounding of ice shelves originating from the Laurentide ice sheet. Broader glaciological settings differed between these events as indicated by different orientations of flutes on eroded seafloor. Postglacial sedimentation evolved from iceberg-dominated environments to those controlled by sea-ice rafting and marine processes in the Holocene. A prominent minimum in planktonic foraminiferal δ18O is identified in deglacial sediments at an estimated age near 13,000 cal yr BP. This δ18O minimum, also reported elsewhere in the Amerasia Basin, is probably related to a major Laurentide meltwater pulse at the Younger Dryas onset. The Bering Strait opening is also marked in the composition of late deglacial Chukchi sediments.
Effects of chelating agents during freeze-drying of boar spermatozoa on DNA fragmentation and on developmental abilityin vitroandin vivoafter intracytoplasmic sperm head injection
Authors: Nakai M. , Kashiwazaki N. , Takizawa A. , Maedomari N. , Ozawa M. , Noguchi J. , Kaneko H. , Shino M. , Kikuchi K. 
Published: February 2007

SUMMARYSuccessful offspring production after intracytoplasmic injection of freeze-dried sperm has been reported in laboratory animals but not in domesticated livestock, including pigs. The integrity of the DNA in the freeze-dried sperm is reported to affect embryogenesis. Release of endonucleases from the sperm is one of the causes of induction of sperm DNA fragmentation. We examined the effects of chelating agents, which inhibit the activation of such enzymes, on DNA fragmentation in freeze-dried sperm and on thein vitroandin vivodevelopmental ability of porcine oocytes following boar sperm head injection. Boar ejaculated sperm were sonicated, suspended in buffer supplemented with (1) 50 mM EGTA, (2) 50 mM EDTA, (3) 10 mM EDTA, or (4) no chelating agent and freeze-dried. A fertilization medium (Pig-FM) was used as a control. The rehydrated spermatozoa in each group were then incubated in Pig-FM at room temperature. The rate of DNA fragmentation in the control group, as assessed by the TUNEL method, increased gradually as time after rehydration elapsed (2.8% at 0 min to 12.2% at 180 min). However, the rates in all experimental groups (1–4) did not increase, even at 180 min (0.7–4.1%), which were all significantly lower (p< 0.05) than that of the control group. The rate of blastocyst formation after the injection in the control group (6.0%) was significantly lower (p< 0.05) than those in the 50 mM EGTA (23.1%) and 10 mM EDTA (22.6%) groups incubated for 120–180 min. The average number of blastocyst cells in the 50 mM EGTA group (33.1 cells) was significantly higher (p< 0.05) than that in the 10 mM EDTA group (17.8 cells). Finally, we transferred oocytes from 50 mM EGTA or control groups incubated for 0–60 min into estrous-synchronized recipients. The two recipients of the control oocytes became pregnant and one miscarried two fetuses on day 39.The results suggested that fragmentation of DNA in freeze-dried boar sperm is one of the causes of decreasedin vitrodevelopmental ability of injected oocytes to the blastocyst stage. Supplementation with EGTA in a freeze-drying buffer improves this ability.
Body mass index, physical activity and dietary behaviours among adolescents in the Kingdom of Tonga
Authors: Smith BJ , Phongsavan P , Havea D , Halavatau V , Chey T ,   and Members of the Health Behaviour and Lifestyle of Pacific Youth Survey Collaborating Group and Tonga Core Survey Team
Published: February 2007

AbstractObjectivesTo compare the prevalence of overweight and obesity among adolescents using international and ethnic-specific cut-off points and to examine patterns of physical activity and dietary behaviours.DesignCross-sectional analytical study.SettingSchools on Tongatapu, Vava'u and Hapa'ai islands in the Kingdom of Tonga.SubjectsA total of 443 school students aged 11–16 years underwent anthropometric measures of height and weight and provided self-reported measures of physical activity and dietary behaviours.ResultsMean body mass index (BMI) was higher among girls than boys (23.7 kg m− 2vs. 21.8 kg m− 2) and tended to increase with age. A total of 36.0% of boys and 53.8% of girls were overweight or obese using the international cut-off points, whereas 25.0% of boys and 37.6% of girls were classified in this way using Polynesian-specific cut-off points. Tinned mutton or beef was the food that most participants (56.9%) reported eating once or more per day. Over half of the young people did not eat taro, fruit or vegetables at least once per day. Regular physical activity outside of school hours was reported by 20.7% of respondents, and 58.2% watched 1 h or more of television per day. Physical activity participation was the only behaviour independently associated with a lower risk of overweight or obesity.ConclusionsUsing Polynesian-specific cut-off points for overweight and obesity the prevalence of these conditions was still among the highest found in adolescents. The prevalence of physical inactivity and poor dietary habits indicate that risk factors for chronic disease are well established during adolescence in Tonga.
Association of key foods and beverages with obesity in Australian schoolchildren
Authors: Sanigorski Andrea M , Bell A Colin , Swinburn Boyd A 
Published: February 2007

AbstractObjectiveTo examine the pattern of intake of key foods and beverages of children aged 4–12 years and the association with weight status.Design and settingA computer-assisted telephone interview was used to determine the intake of fruit, vegetables, packaged snacks, fast foods and sweetened drinks ‘yesterday’ and ‘usually’ as reported by parents/guardians of a representative sample of 2184 children from the Barwon South-Western region of Victoria, Australia.ResultsChildren who consumed >2–3, >3–4 and >4 servings of fruit juice/drinks ‘yesterday’ were, respectively, 1.7 (95% confidence interval (CI) 1.2–2.2), 1.7 (95% CI 1.2–2.5) and 2.1 (95% CI 1.5–2.9) times more likely to be overweight/obese compared with those who had no servings of fruit juice/drink ‘yesterday’, adjusted for age, gender and socio-economic status (SES). Further, children who had ≥ 3 servings of soft drink ‘yesterday’ were 2.2 (95% CI 1.3–3.9) times more likely to be overweight/obese compared with those who had no servings of soft drink ‘yesterday’, adjusted for age, gender and SES. In addition, children who ‘usually’ drank fruit juice/drinks twice or more per day were 1.7 (95% CI 1.2–2.4) times more likely to be overweight/obese compared with those who drank these beverages once or less per week, adjusted for age, gender and SES. Although fast foods and packaged snacks were regularly eaten, there were no associations between weight status and consumption of these foods.ConclusionsIntake of sweetened beverages was associated with overweight and obesity in this population of Australian schoolchildren and should be a target for intervention programmes aimed at preventing unhealthy weight gain in children.
Accelerated Clone Selection for Recombinant CHO Cells Using a FACS‐Based High‐Throughput Screen
Authors: DeMaria Christine T. , Cairns Victor , Schwarz Cordula , Zhang Jin , Guerin Megan , Zuena Erin , Estes Scott , Karey Kenneth P. 
Published: February 2007

AbstractFlow cytometry was partnered with a nonfluorescent reporter protein for rapid, early stage identification of clones producing high levels of a therapeutic protein. A cell surface protein, not normally expressed on CHO cells, is coexpressed, as a reporter, with the therapeutic protein and detected using a fluorescently labeled antibody. The genes encoding the reporter protein and the therapeutic protein are linked by an IRES, so that they are transcribed in the same mRNA but are translated independently. Since they each arise from a common mRNA, the reporter proteinapos;s expression level accurately predicts the relative expression level of the therapeutic protein for each clone. This method provides an effective process for generating recombinant cell lines producing high levels of therapeutic proteins, with the benefits of rapid and accurate 96‐well plate clone screening and elimination of unstable clones at an earlier stage in the development process. Furthermore, because this method does not rely on the availability of an antibody specific for the therapeutic protein being expressed, it can be easily implemented into any cell line development process.
Severity of gastritis determines glandular stomach carcinogenesis in Helicobacter pylori‐infected Mongolian gerbils
Authors: Cao Xueyuan , Tsukamoto Tetsuya , Nozaki Koji , Tanaka Harunari , Cao Liyu , Toyoda Takeshi , Takasu Shinji , Ban Hisayo , Kumagai Toshiko , Tatematsu Masae 
Published: February 2007

Helicobacter pylori (H. pylori) infection causes chronic gastritis and is also related to gastric carcinoma. The present study focused on severity of H. pylori‐induced gastritis as a determinant of carcinogenesis. Seven‐week‐old male Mongolian gerbils were inoculated with H. pylori at experimental weeks 0, 12, or 18, then given N‐methyl‐N‐nitorosourea (MNU) from weeks 20–40. At week 70, stomachs were then excised for histological examination 70, 58, or 52 weeks after H. pylori inoculation, respectively (Groups A, B, and C for long‐, middle‐, and short‐term). The respective incidences of glandular stomach adenocarcinomas were 65.0% (13/20), 20.0% (2/10), and 23.0% (3/13) (P < 0.05). Higher scores of infiltration of inflammatory cells, hyperplasia, intestinal metaplasia and mucosal bromodeoxyuridine (BrdU) labeling index in antrum and corpus mucosa, were seen in group A than B or C (P < 0.05) and serum anti‐H. pylori IgG titer and gastrin levels were also significantly higher, along with mRNA levels for mucosal interleukin‐1β (IL‐1β), tumor necrosis factor‐α (TNF‐α), cyclooxygenase‐2 (COX‐2), and inducible nitric oxide synthase (iNOS). The results demonstrated the term and severity of H. pylori infection to play important roles in gastric carcinogenesis, with essential involvement of chronic inflammation, especially increased rates of cell proliferation, in H. pylori‐associated carcinogenesis. (Cancer Sci 2007; 98: 478–483)
Intrinsic, inter‐specific competition between egg, egg–larval, and larval parasitoids of plusiine loopers
Authors: YAMAMOTO DAISUKE , HENDERSON RUTH , CORLEY LAURA S. , IWABUCHI KIKUO 
Published: February 2007

Abstract 1. Intrinsic, inter‐specific competition between parasitoid wasp species is a key factor in ecological community dynamics and is particularly important for application in biological control. Here three parasitoid wasp species with overlapping host ranges and differing life history strategies were chosen to examine parasitoid–parasitoid interactions: the egg parasitoid Trichogramma pretiosum, the egg–larval, polyembryonic parasitoid wasp Copidosoma floridanum, and the gregarious larval parasitoid Glyptapanteles pallipes, with the plusiine loopers Acanthoplusia agnata and Trichoplusia ni as hosts.2. Copidosoma floridanum has been shown to be an intrinsically superior competitor against larval parasitoids because of their production and increased investment in a soldier larval caste during development, but little is known of their interactions with egg parasitoid species. Trichogramma pretiosum completely dominated intrinsic competition with C. floridanum regardless of oviposition order or sex of the C. floridanum egg.3. Competition between C. floridanum and G. pallipes, however, depended on the host stage at which parasitism occurred, the sex of the C. floridanum egg, and parasitoid development time. Copidosoma floridanum outcompeted G. pallipes overall, despite the fact that G. pallipes injects a polyDNA virus into the host.4. The sex of the C. floridanum egg was a significant factor in its ability to shift caste ratios to produce more soldiers in response to G. pallipes competition.5. Only developing female C. floridanum responded to competition with G. pallipes by increasing the ratio of soldier to reproductive larvae, and this happened only when multiparasitism occurred in the host’s 1st and 2nd instar.
Chemical mediation and niche partitioning in non‐pollinating fig‐wasp communities
Authors: PROFFIT MAGALI , SCHATZ BERTRAND , BORGES RENÉE M. , HOSSAERT‐MCKEY MARTINE 
Published: February 2007

Summary

The parasitic chalcidoid wasps associated with the species‐specific and obligatory pollination mutualisms between Ficus spp. and their agaonid wasp pollinators provide a good model to study the functional organization of communities.
However, communities of non‐pollinating fig wasps (NPFWs) remain little characterized, and their functioning and evolutionary dynamics are still poorly understood.
We studied the communities of NPFWs associated with the monoecious F. racemosa and the dioecious F. hispida. Associated with these two fig species are a total of seven wasp species belonging to three genera. These species present contrasts in life history traits and in timing of oviposition. The species studied are thus broadly representative of the communities of NPFWs associated specifically with fig–pollinator mutualisms.
In our study systems, there is temporal segregation of oviposition time among members of NPFW communities.
We tested the role of volatile chemicals in the attraction of NPFWs associated with these two fig species, and tried to determine if chemical mediation can explain the organization of the communities.
We conducted odour choice tests using a Y‐tube olfactometer. All the NPFWs studied were shown to use volatile chemicals produced by the fig to locate their host. Furthermore, the signals used by each species depended on the phenological stage of the fig they exploit.
Results demonstrated that the pattern of oviposition results from the utilization of volatile signals produced by figs that vary in their composition at different stages of fig development. Thus, chemical mediation allows resource partitioning in the NPFW communities associated with fig–pollinator mutualisms, and suggests hypotheses to explain coexistence in other parasite communities.