bluuebunny/crossref_metadata_2025 huggingface dataset:
The Lam/Mpi Checkpoint/Restart Framework: System-Initiated Checkpointing
Authors: Sankaran Sriram , Squyres Jeffrey M. , Barrett Brian , Sahay Vishal , Lumsdaine Andrew , Duell Jason , Hargrove Paul , Roman Eric
Published: November 2005

As high performance clusters continue to grow in size and popularity, issues of fault tolerance and reliability are becoming limiting factors on application scalability. To address these issues, we present the design and implementation of a system for providing coordinated checkpointing and rollback recovery for MPI-based parallel applications. Our approach integrates the Berkeley Lab BLCR kernel-level process checkpoint system with the LAM implementation of MPI through a defined checkpoint/restart interface. Checkpointing is transparent to the application, allowing the system to be used for cluster maintenance and scheduling reasons as well as for fault tolerance. Experimental results show negligible communication performance impact due to the incorporation of the checkpoint support capabilities into LAM/MPI.
A Partitioner-Centric Model for Structured Adaptive Mesh Refinement Partitioning Trade-Off Optimization: Part I
Authors: Steensland Johan , Ray Jaideep
Published: November 2005

Optimal partitioning of structured adaptive mesh applications necessitates dynamically determining and optimizing for the most time-inhibiting factor, such as load imbalance and communication volume. However, any trivial monitoring of an application evaluates the current partitioning rather than the inherent properties of the grid hierarchy. We present an analytical model that given a structured adaptive grid determines, ab initio, to what extent the partitioner should focus on optimizing load imbalance or communication volume to reduce execution time. This model contributes to the meta-partitioner, able to select and configure the optimal partitioner based on the mesh configuration, the simulation and computer characteristics. We validate the predictions of this model by comparing them with actual measurements (via traces) from four different adaptive simulations. The results show that the proposed model generally captures the inherent optimization-need in structured adaptive mesh refinement applications. We conclude that our model is a useful contribution, since tracking and adapting to the dynamic behavior of such applications potentially lead to a large decrease in execution times.
Manufacturing Parties
Authors: Manacsa Rodelio Cruz , Tan Alexander C.
Published: November 2005

In this article we reassess the thesis of Lipset and Rokkan in a non-European context and thereby seek to contribute to the understanding of the relationship between social divisions and party creation. Political parties are usually generated by the politicization of social cleavages that exist within societies. The critical question is why certain divisions become politicized and others do not. Using the Philippines as a case study, we seek to explain how acute social dissensions could fail to give rise to competitive political parties. We contend that certain institutional forms could significantly influence whether social conflicts are translated into political form.
Narrative in Social Work
Authors: Riessman Catherine Kohler , Quinney Lee
Published: November 2005

We examine how the concept of narrative has entered social work over the past 15 years, with special emphasis on research applications. Approaching our task from distinctive standpoints and locations, the article reviews definitions of narrative, criteria for ‘good’ enough narrative research, and patterns in social work journals. Our evaluation uncovered few studies, in contrast to the volume of narrative research in education, nursing and other practicing professions. Three exemplars of narrative inquiry - model research completed by social workers - show the knowledge for practice that can be produced with careful application of narrative methods, in all their diversity. Drawing on our respective locations and experiences, we cautiously suggest some reasons for the paucity of quality research in the USA, and greater representation in Europe.
Making a Case in Social Work
Authors: Urek Mojca
Published: November 2005

The central focus of the article is a case study in which the author highlights the ways in which social workers and other helping professionals constructed a mother, her daughter and their own realities through the use of authorial devices such as moral characterization, point of view, and other techniques. This analysis is made on the basis of oral and written accounts available in this case and focuses primarily on some of the narrative strategies underpinning interventions in the case. These, it is maintained, served social workers in making their representations persuasive for various publics. Moreover, this analysis shows that social work accounts are also deeply moral narrative strategies. The narrative materials examined here about a mother illustrate how the character of a morally unsuitable woman and parent are constructed in social work accounts. The analysis also demonstrates that such moral constructions then serve as the basis for interventions requiring justification when presented to important professional audiences.
Research capability in doctoral training
Authors: Mcvicar Andrew , Caan Woody
Published: November 2005

Rationale:Doctoral training should provide insight into the evolution of research capability in nursing.

Methods:Research designs were evaluated from abstracts of 204 theses extracted from the ASLIB database, 1983–2002. Most were from PhD/DPhil degrees, but a few were Professional Doctorates.

Findings:‘Educational’ and ‘organisational’ settings dominated, indicating their sustained popularity. A total of 11 methodological frameworks were noted, with ‘Ethnography’, ‘Social history’, ‘Work environment’ and ‘Grounded theory’ being the most popular. ‘Interviews’ with individuals and ‘Questionnaire survey’ were easily the most popular of 28 different research tools/techniques.

Comparing abstracts from 1997–2002 with those from 1983–1996 identified significant changes in methodologies and methods used. The frequency of ‘Phenomenology’, ‘Work environment’ and ‘Grounded theory’ methodologies increased. The ‘Patient led’ framework appeared for the first time, albeit in just a few theses. The incidence of ‘Ethnography’ declined. Some methods only appeared for the first time during the 1990s, e.g. ‘Focus groups’. Of the methods, ‘Interviews’ increased substantially but ‘Questionnaires’ decreased slightly. In terms of developing clinical research, we noted an increased frequency of ‘All experimental’ methods. Multiple methods, used in 71% of theses overall, increased in incidence during the late 1990s, a change that was significantly associated with ‘post-1992’ universities. Over time, there was a significant increase in the number of methodologies and methods used, per thesis.

Conclusions:This study documents the breadth of research designs used by students researching nursing. It provides evidence for an evolution of designs with an increasing diversity that indicates a growing maturity of nursing research culture.
Pathogenic anti-β2-glycoprotein I antibodies recognize domain I of β2-glycoprotein I only after a conformational change
Authors: de Laat Bas , Derksen Ronald H. W. M. , van Lummel Menno , Pennings Maarten T. T. , de Groot Philip G.
Published: November 2005

Recently, we published the existence of 2 populations of anti-β2-glycoprotein I (β2-GPI) IgG antibodies. Type A antibodies recognize epitope G40-R43 in domain I of β2-GPI and are strongly associated with thrombosis. Type B antibodies recognize other parts of β2-GPI and are not associated with thrombosis. In this study we demonstrate that type A antibodies only recognize plasma-purified β2-GPI when coated onto a negatively charged surface and not when coated onto a neutrally charged surface. The affinity of type B antibodies toward plasma-purified β2-GPI was independent of the charge of the surface to which β2-GPI was coated. Type A antibodies did not recognize plasma-purified β2-GPI in solution, whereas they did recognize recombinant β2-GPI both in solution and coated onto a neutrally charged plate. When the carbohydrate chains were removed from plasma-purified β2-GPI, we found that type A antibodies did recognize the protein in solution. This supports the hypothesis that the difference in recognition of plasma-purified and recombinant β2-GPI is caused by the difference in glycosylation and that epitope G40-R43 of plasma-purified β2-GPI is covered by a carbohydrate chain. Type A anti-β2-GPI antibodies can only recognize this epitope when this carbohydrate chain is displaced as a result of a conformational change. This finding has major implications both for the detection of pathogenic anti-β2-GPI antibodies and the comprehension of the pathophysiology of the antiphospholipid syndrome.
CD4+/CD8+ macrophages infiltrating at inflammatory sites: a population of monocytes/macrophages with a cytotoxic phenotype
Authors: Baba Tomohisa , Ishizu Akihiro , Iwasaki Sari , Suzuki Akira , Tomaru Utano , Ikeda Hitoshi , Yoshiki Takashi , Kasahara Masanori
Published: November 2005

We found a population of nonlymphoid cells expressing both CD4 and CD8 in peripheral blood mononuclear cells (PBMCs) of human T-cell leukemia virus type-I pX transgenic rats with autoimmune diseases. These cells, which showed a monocytic phenotype, were also found in wild-type rats, and their number increased by adjuvant-assisted immunization. GM-CSF increased the number of these double-positive (DP) monocytes in PBMCs. Consistent with the idea that DP monocytes differentiate into DP macrophages at sites of inflammation, we found infiltration of DP macrophages at the site of myosin-induced myocarditis in wild-type rats; these cells exhibited a T-helper 1 (Th1)-type cytokine/chemokine profile and expressed high levels of Fas ligand, perforin, granzyme B, and NKR-P2 (rat orthologue of human NKG2D). Adoptive transfer of GFP-positive spleen cells confirmed hematogenous origin of DP macrophages. DP monocytes had a cytotoxic phenotype similar to DP macrophages, indicating that this phenotypic specialization occurred before entry into a tissue. In line with this, DP monocytes killed tumor cells in vitro. Combined evidence indicates that certain inflammatory stimuli that induce GM-CSF trigger the expansion of a population of DP monocytes with a cytotoxic phenotype and that these cells differentiate into macrophages at inflammatory sites. Interestingly, human PBMCs also contain DP monocytes.
CXCR4: a key receptor in the crosstalk between tumor cells and their microenvironment
Authors: Burger Jan A. , Kipps Thomas J.
Published: November 2005

Signals from the microenvironment have a profound influence on the maintenance and/or progression of hematopoietic and epithelial cancers. Mesenchymal or marrow-derived stromal cells, which constitute a large proportion of the non-neoplastic cells within the tumor microenvironment, constitutively secrete the chemokine stromal cell-derived factor-1 (SDF-1/CXCL12). CXCL12 secretion by stromal cells attracts cancer cells, acting through its cognate receptor, CXCR4, which is expressed by both hematopoietic and nonhematopoietic tumor cells. CXCR4 promotes tumor progression by direct and indirect mechanisms. First, CXCR4 is essential for metastatic spread to organs where CXCL12 is expressed, and thereby allows tumor cells to access cellular niches, such as the marrow, that favor tumor-cell survival and growth. Second, stromal-derived CXCL12 itself can stimulate survival and growth of neoplastic cells in a paracrine fashion. Third, CXCL12 can promote tumor angiogenesis by attracting endothelial cells to the tumor microenvironment. CXCR4 expression is a prognostic marker in various types of cancer, such as acute myelogenous leukemia or breast carcinoma. Promising results in preclinical tumor models indicate that CXCR4 antagonists may have antitumor activity in patients with various malignancies. Collectively, these observations reveal that CXCR4 is an important molecule involved in the spread and progression of a variety of different tumors. As such, CXCR4 antagonists, although initially developed for treatment of AIDS, actually may become effective agents for the treatment of neoplastic disease.
Why do snails have hairs? A Bayesian inference of character evolution
Authors: Pfenninger Markus , Hrabáková Magda , Steinke Dirk , Dèpraz Aline
Published: November 2005

Background

Costly structures need to represent an adaptive advantage in order to be maintained over evolutionary times. Contrary to many other conspicuous shell ornamentations of gastropods, the haired shells of several Stylommatophoran land snails still lack a convincing adaptive explanation. In the present study, we analysed the correlation between the presence/absence of hairs and habitat conditions in the genusTrochulusin a Bayesian framework of character evolution.

Results

Haired shells appeared to be the ancestral character state, a feature most probably lost three times independently. These losses were correlated with a shift from humid to dry habitats, indicating an adaptive function of hairs in moist environments. It had been previously hypothesised that these costly protein structures of the outer shell layer facilitate the locomotion in moist habitats. Our experiments, on the contrary, showed an increased adherence of haired shells to wet surfaces.

Conclusion

We propose the hypothesis that the possession of hairs facilitates the adherence of the snails to their herbaceous food plants during foraging when humidity levels are high. The absence of hairs in someTrochulusspecies could thus be explained as a loss of the potential adaptive function linked to habitat shifts.
Effects of screening and brief intervention training on resident and faculty alcohol intervention behaviours: a pre- post-intervention assessment
Authors: Seale J Paul , Shellenberger Sylvia , Boltri John M , Okosun IS , Barton Barbara
Published: November 2005

Background

Many hazardous and harmful drinkers do not receive clinician advice to reduce their drinking. Previous studies suggest under-detection and clinician reluctance to intervene despite awareness of problem drinking (PD). The Healthy Habits Project previously reported chart review data documenting increased screening and intervention with hazardous and harmful drinkers after training clinicians and implementing routine screening. This report describes the impact of the Healthy Habits training program on clinicians' rates of identification of PD, level of certainty in identifying PD and the proportion of patients given advice to reduce alcohol use, based on self-report data using clinician exit questionnaires.

Methods

28 residents and 10 faculty in a family medicine residency clinic completed four cycles of clinician exit interview questionnaires before and after screening and intervention training. Rates of identifying PD, level of diagnostic certainty, and frequency of advice to reduce drinking were compared across intervention status (pre vs. post). Findings were compared with rates of PD and advice to reduce drinking documented on chart review.

Results

1,052 clinician exit questionnaires were collected. There were no significant differences in rates of PD identified before and after intervention (9.8% vs. 7.4%, p = .308). Faculty demonstrated greater certainty in PD diagnoses than residents (p = .028) and gave more advice to reduce drinking (p = .042) throughout the program. Faculty and residents reported higher levels of diagnostic certainty after training (p = .039 and .030, respectively). After training, residents showed greater increases than faculty in the percentage of patients given advice to reduce drinking (p = .038), and patients felt to be problem drinkers were significantly more likely to receive advice to reduce drinking by all clinicians (50% vs. 75%, p = .047). The number of patients receiving advice to reduce drinking after program implementation exceeded the number of patients felt to be problem drinkers. Recognition rates of PD were four to eight times higher than rates documented on chart review (p = .028).

Conclusion

This program resulted in greater clinician certainty in diagnosing PD and increases in the number of patients with PD who received advice to reduce drinking. Future programs should include booster training sessions and emphasize documentation of PD and brief intervention.
Transformation of human bronchial epithelial cells alters responsiveness to inflammatory cytokines
Authors: Loewen Gregory M , Tracy Erin , Blanchard Frédéric , Tan Dongfeng , Yu Jihnhee , Raza Sameera , Matsui Sei-Ichi , Baumann Heinz
Published: November 2005

Background

Inflammation is commonly associated with lung tumors. Since inflammatory mediators, including members of the interleukin-6 (IL-6) cytokine family, suppress proliferation of normal epithelial cells, we hypothesized that epithelial cells must develop mechanisms to evade this inhibition during the tumorigenesis. This study compared the cytokine responses of normal epithelial cells to that of premalignant cells.

Methods

Short-term primary cultures of epithelial cells were established from bronchial brushings. Paired sets of brushings were obtained from areas of normal bronchial epithelium and from areas of metaplastic or dysplastic epithelium, or areas of frank endobronchial carcinoma. In 43 paired cultures, the signalling through the signal transducer and activator of transcription (STAT) and extracellular regulated kinase (ERK) pathways and growth regulation by IL-6, leukemia inhibitory factor (LIF), oncostatin M (OSM), interferon-γ (IFNγ) or epidermal growth factor (EGF) were determined. Inducible expression and function of the leukemia inhibitory factor receptor was assessed by treatment with the histone deacetylase inhibitor depsipeptide.

Results

Normal epithelial cells respond strongly to OSM, IFNγ and EGF, and respond moderately to IL-6, and do not exhibit a detectable response to LIF. In preneoplastic cells, the aberrant signaling that was detected most frequently was an elevated activation of ERK, a reduced or increased IL-6 and EGF response, and an increased LIF response. Some of these changes in preneoplastic cell signaling approach those observed in established lung cancer cell lines. Epigenetic control of LIF receptor expression by histone acetylation can account for the gain of LIF responsiveness. OSM and macrophage-derived cytokines suppressed proliferation of normal epithelial cells, but reduced inhibition or even stimulated proliferation was noted for preneoplastic cells. These alterations likely contribute to the supporting effects that inflammation has on lung tumor progression.

Conclusion

This study indicates that during the earliest stage of premalignant transformation, a modified response to cytokines and EGF is evident. Some of the altered cytokine responses in primary premalignant cells are comparable to those seen in established lung cancer cell lines.
Characterization of the metabolic shift between oxidative and fermentative growth in Saccharomyces cerevisiae by comparative 13C flux analysis
Authors: Frick Oliver , Wittmann Christoph
Published: November 2005

Background

One of the most fascinating properties of the biotechnologically important organism Saccharomyces cerevisiae is its ability to perform simultaneous respiration and fermentation at high growth rate even under fully aerobic conditions. In the present work, this Crabtree effect called phenomenon was investigated in detail by comparative 13C metabolic flux analysis of S. cerevisiae growing under purely oxidative, respiro-fermentative and predominantly fermentative conditions.

Results

The metabolic shift from oxidative to fermentative growth was accompanied by complex changes of carbon flux throughout the whole central metabolism. This involved a flux redirection from the pentose phosphate pathway (PPP) towards glycolysis, an increased flux through pyruvate carboxylase, the fermentative pathways and malic enzyme, a flux decrease through the TCA cycle, and a partial relocation of alanine biosynthesis from the mitochondrion to the cytosol. S. cerevisiae exhibited a by-pass of pyruvate dehydrogenase in all physiological regimes. During oxidative growth this by-pass was mainly provided via pyruvate decarboxylase, acetaldehyde dehydrogenase, acetyl-CoA synthase and transport of acetyl-CoA into the mitochondrion. During fermentative growth this route, however, was saturated due to limited enzyme capacity. Under these conditions the cells exhibited high carbon flux through a chain of reactions involving pyruvate carboxylase, the oxaloacetate transporter and malic enzyme. During purely oxidative growth the PPP alone was sufficient to completely supply NADPH for anabolism. During fermentation, it provided only 60 % of the required NADPH.

Conclusion

We conclude that, in order to overcome the limited capacity of pyruvate dehydrogenase, S. cerevisiae possesses different metabolic by-passes to channel carbon into the mitochondrion. This involves the conversion of cytosolic pyruvate either into acetyl CoA or oxaloacetate followed by intercompartmental transport of these metabolites. During oxidative growth mainly the NAD specific isoforms of acetaldehyde dehydrogenase and isocitrate dehydrogenase catalyze the corresponding reactions in S. cerevisiae, whereas NADPH supply under fermentative conditions involves significant contribution of sources other than the PPP such as e. g. NADPH specific acetaldehyde dehydrogenase or isocitrate dehydrogenase.
Evaluation of KO-Tab 1-2-3®: a wash-resistant 'dip-it-yourself' insecticide formulation for long-lasting treatment of mosquito nets
Authors: Yates Alison , N'Guessan Raphael , Kaur Harparkash , Akogbéto Martin , Rowland Mark
Published: November 2005

Introduction

Insecticide-treated nets (ITN) are an important method of preventing malaria. To remain effective, they need to be re-treated with pyrethroid insecticide at approximately yearly intervals. Systems for re-treating nets in Africa are limited, and the vast majority of nets in use have never been treated or were treated only once. Bayer Environmental Science (BES) has developed a long-lasting formulation 'KO-Tab 1-2-3®' which can be applied to the net post-manufacture, under field conditions, and renders the insecticide wash-resistant.

Methods

The performance of polyester nets treated with three kinds of BES long-lasting formulations, a conventional ITN (treated with standard KO-Tab) and PermaNet 2.0 were evaluated after washing samples of treated netting up to 30 times using standard WHO procedures. Performance was measured using 'three-minute exposure' and 'median time to knockdown' bioassay tests and by measuring the levels of deltamethrin using high-pressure liquid chromatography.

Results

The conventional ITN was largely stripped of deltamethrin within 5–10 washes and insecticidal efficacy in bioassay declined to suboptimal levels. With PermaNet and KO-Tab 1-2-3 the loss of deltamethrin was much slower: insecticide content halved within 20 washes and there was no loss of biological efficacy in three-minute exposure bioassays in WHO cylinders even after 30 washes. After 30 washes there remained on the netting 16% (4.4 mg/m2) of the loading dose of KO-Tab 1-2-3 and 28% (18.8 mg/m2) of the loading dose of PermaNet.

Conclusion

KO-Tab 1-2-3 was confirmed to be a long-lasting insecticide formulation. This finding raises the prospect of conventional polyester nets being converted into long-lasting insecticidal nets through simple dipping in the community or at home. This single development, if widely adopted, could transform the malaria control landscape in Africa and have a major impact on malaria.
The Bradford Hill considerations on causality: a counterfactual perspective
Authors: Höfler Michael
Published: November 2005

Bradford Hill's considerations published in 1965 had an enormous influence on attempts to separate causal from non-causal explanations of observed associations. These considerations were often applied as a checklist of criteria, although they were by no means intended to be used in this way by Hill himself. Hill, however, avoided defining explicitly what he meant by "causal effect".

This paper provides a fresh point of view on Hill's considerations from the perspective of counterfactual causality. I argue that counterfactual arguments strongly contribute to the question of when to apply the Hill considerations. Some of the considerations, however, involve many counterfactuals in a broader causal system, and their heuristic value decreases as the complexity of a system increases; the danger of misapplying them can be high. The impacts of these insights for study design and data analysis are discussed. The key analysis tool to assess the applicability of Hill's considerations is multiple bias modelling (Bayesian methods and Monte Carlo sensitivity analysis); these methods should be used much more frequently.
Pulse contour analysis after normothermic cardiopulmonary bypass in cardiac surgery patients
Authors: Sander Michael , von Heymann Christian , Foer Achim , von Dossow Vera , Grosse Joachim , Dushe Simon , Konertz Wolfgang F , Spies Claudia D
Published: November 2005

Introduction

Monitoring of the cardiac output by continuous arterial pulse contour (COPiCCOpulse) analysis is a clinically validated procedure proved to be an alternative to the pulmonary artery catheter thermodilution cardiac output (COPACtherm) in cardiac surgical patients. There is ongoing debate, however, of whether the COPiCCOpulse is accurate after profound hemodynamic changes. The aim of this study was therefore to compare the COPiCCOpulse after cardiopulmonary bypass (CPB) with a simultaneous measurement of the COPACtherm.

Methods

After ethical approval and written informed consent, data of 45 patients were analyzed during this prospective study. During coronary artery bypass graft surgery, the aortic transpulmonary thermodilution cardiac output (COPiCCOtherm) and the COPACtherm were determined in all patients. Prior to surgery, the COPiCCOpulse was calibrated by triple transpulmonary thermodilution measurement of the COPiCCOtherm. After termination of CPB, the COPiCCOpulse was documented. Both COPACtherm and COPiCCOtherm were also simultaneously determined and documented.

Results

Regression analysis between COPACtherm and COPiCCOtherm prior to CPB showed a correlation coefficient of 0.95 (P < 0.001), and after CPB showed a correlation coefficient of 0.82 (P < 0.001). Bland-Altman analysis showed a mean bias and limits of agreement of 0.0 l/minute and -1.4 to +1.4 l/minute prior to CPB and of 0.3 l/minute and -1.9 to +2.5 l/minute after CPB, respectively. Regression analysis of COPiCCOpulse versus COPiCCOtherm and of COPiCCOpulse versus COPACtherm after CPB showed a correlation coefficient of 0.67 (P < 0.001) and 0.63 (P < 0.001), respectively. Bland-Altman analysis showed a mean bias and limits of agreement of -1.1 l/minute and -1.9 to +4.1 l/minute versus -1.4 l/minute and -4.8 to +2.0 l/minute, respectively.

Conclusion

We observed an excellent correlation of COPiCCOtherm and COPACtherm measurement prior to CPB. Pulse contour analysis did not yield reliable results with acceptable accuracy and limits of agreement under difficult conditions after weaning from CPB in cardiac surgical patients. The pulse contour analysis thus should be re-calibrated as soon as possible, to prevent false therapeutic consequences.
Review of atmospheric water-soluble ionic species in Asia during 1998-2001
Authors: Fang Guor-Cheng , Wu Yuh-Shen , Rau Jui-Yeh , Huang Shih-Han
Published: November 2005

Anthropogenic acid precursor emissions in Asia are increasing at a significant rate and this is expected to continue for the next several years. This paper comprises of studies that included sulfate, nitrate and ammonium around Asian countries (China, Korea, Japan and Taiwan) in recent years. The paper also provides the water-soluble ionic fine and coarse particulate concentrations in these Asian countries in recent years. Fine and coarse particulates in Taiwan (Kaohsiung and Talchung) and China (Nanjing and Shanghai) were found to have higher sulfate (average 18.68 and 15.75 mg/m3) and nitrate (average 12.77 and 7.71 mg/m3) concentrations than any other Asian country. The average sulfate concentrations for Japan and Korea were 7.31 and 5.84 mg/m3, respectively. The average nitrate concentrations for Japan and Korea were 6.73 and 4.65 mg/m3, respectively during the years 1998-2001. The different sample collection devices, analysis methods and pollutant concentrations are discussed in this study. The purpose of this study is to arrange the atmospheric water-soluble ionic species (SO/2- 4 and NO /-3) investigations in the Asian region. The data obtained here can also help to understand the sources, concentrations, phase distribution and health impact of atmospheric water-soluble ionic species (SO42- and NO-3) in other Asian regions.
Effect of water-soluble metal working fluid aerosols on respiratory system after 13 weeks of repeated inhalation exposure in F344 rats
Authors: Lim Cheol-Hong , Yu Il Je , Kim Hyeon-Young , Lee Seung-Bae , Marshak Daniel R , Lee Ji Hyun , Kim Kwang Jong
Published: November 2005

Three groups of male F344 rats were exposed to a water-soluble metal working fluid (MWF) aerosol at concentrations of 20, 60 or 180 mg/m3 for 6 h/day, five days a week, for 13 weeks in inhalation chambers. The aerosol particles were normally distributed and the mass median aerodynamic diameter was 1.56 mm. Despite the absence of clinical findings or significant changes in body weight during the 13-week exposure period, the numbers of white blood cells and lung weights were significantly higher at the end of the 13-week exposure period. Exposure to 20 mg/m3 of the MWF aerosol was found to have an effect on the respiratory system, including an accumulation of foamy macrophages in the bronchoalveolar lavage (BAL) fluid and thickening of the alveolar walls in the histopathology. The level of histamine and number of polymorphonuclear (PMN) cells were also higher in the BAL fluid from the rats exposed to 60 mg/m3 of the MWF aerosol, while the respiratory inflammation was most pronounced in the rats exposed to 180 mg/m3 of the MWF aerosol, including the accumulation of PMNs and foamy macrophages in the BAL cells, lung weight increase and thickening of the alveolar walls. Immunoglobulin IgG2a level was also lower in the sera from the rats exposed to 180 mg/m3 of the MWF aerosol. Therefore, even though no clinical symptoms were observed in the rats exposed to the high MWF concentration, respiratory inflammation was still induced by a relatively low concentration of the MWF, while the immune system was affected by the high MWF concentration.
Effect of 2,4-dichlorophenoxyacetic acid on the activities of some metabolic enzymes for generating pyridine nucleotide pool of cells from mouse liver
Authors: Yilmaz H Ramazan , Yuksel Esref
Published: November 2005

2,4-Dichlorophenoxyacetic acid (2,4-D), which is a plant auxin analogue, is lethal to broad leaved weeds within days at high dosages and is considered as having low toxicity to mammals. Some studies have reported that exposure to this compound may cause damage to organs such as liver. The aim of this study was to investigate the effects of 2,4-D in mouse liver on chromosomes as well as hexokinase (HK), glucose-6-phosphate dehydrogenase (G6PD), 6-phosphogluconate dehydrogenase (6PGD), lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) which are required for the generation of the pyridine nucleotide pool. The experiments were carried out with a 2,4-D group, an ethanol control for 2,4-D, and saline group for ethanol control group on three generations of mice. Only female parents were given 2,4-D during the gestation period, lactation period and for 33 days following the lactation period. In females of the first cross, 2,4-D caused a significant increase in the activity of LDH, and ethanol alone caused a significant increase in the activities of HK and LDH. In the male offspring of the first cross maternal, 2,4-D caused a significant increase in the activity of LDH, and ethanol alone caused a significant decrease in the activity of 6PGD. In the female offspring of the first cross maternal, ethanol caused a significant increase in the activities of G6PD and MDH. In the female offsprings of the third cross maternal, 2,4-D caused a significant increase in the activity of MDH. No gross morphological changes were observed in internal organs, such as liver, kidney and spleen of the affected animals. Also, a chromosomal study from bone marrow cells indicated no anomalies in chromosomal sets and structures. As a result, 2,4-D had an effect on the first cross maternal and their offsprings. The compound did not affect the parameters studied except MDH enzyme activity in the second and third generation of mice.
Hyperstimulation and a Gonadotropin-Releasing Hormone Agonist Modulate Ovarian Vascular Permeability by Altering Expression of the Tight Junction Protein Claudin-5
Authors: Kitajima Yoshimitsu , Endo Toshiaki , Nagasawa Kunihiko , Manase Kengo , Honnma Hiroyuki , Baba Tsuyoshi , Hayashi Takuhiro , Chiba Hideki , Sawada Norimasa , Saito Tsuyoshi
Published: November 2005

We investigated the mechanism by which a GnRH agonist (GnRHa) affects ovarian vascularity, vascular permeability, and expression of the tight junction protein claudin-5 in a rat model of ovarian hyperstimulation syndrome (OHSS). Hyperstimulated rats received excessive doses of pregnant mare serum gonadotropin (PMSG; 50 IU/d) for 4 consecutive days, from d 25 to 28 of life, followed by 25 IU human chorionic gonadotropin (hCG) on d 29. Control rats received 10 IU PMSG on d 27 of life, followed by 10 IU hCG on d 29. GnRHa (leuprolide 100 μg/kg·d) was administered to some hyperstimulated rats either on d 29 and 30 (short-term GnRHa treatment) or from d 25 to 30 (long-term GnRHa treatment). Ovarian vascular density (vessels per 10 mm2) and vessel endothelial area (percent) were assessed by immunohistochemical analysis of the distribution of von Willebrand factor, whereas vascular permeability was evaluated based on leakage of Evans blue. High doses of PMSG and hCG significantly increased ovarian weight, vascular permeability, vascular density, and the vessel endothelial area and significantly reduced expression of claudin-5 protein and mRNA. All of these effects were significantly and dose-dependently inhibited by administration of GnRHa. This suggests that reduced expression of claudin-5 plays a crucial role in the increased ovarian vascular permeability seen in OHSS and that its expression can be modulated by GnRHa treatment. Indeed, preventing redistribution of tight junction proteins in endothelial cells and the resultant loss of endothelial barrier architecture might be the key to protecting patients against massive extravascular fluid accumulation in cases of OHSS.
Null Mutation in Transforming Growth Factor β1 Disrupts Ovarian Function and Causes Oocyte Incompetence and Early Embryo Arrest
Authors: Ingman Wendy V. , Robker Rebecca L. , Woittiez Karen , Robertson Sarah A.
Published: November 2005

TGFβ1 is implicated in regulation of ovarian function and the events of early pregnancy. We have investigated the effect of null mutation in the Tgfβ1 gene on reproductive function in female mice. The reproductive capacity of TGFβ1 null mutant females was severely impaired, leading to almost complete infertility. Onset of sexual maturity was delayed, after which ovarian function was disrupted, with extended ovarian cycles, irregular ovulation, and a 40% reduction in oocytes ovulated. Serum FSH and estrogen content were normal, but TGFβ1 null mutant mice failed to display the characteristic proestrus surge in circulating LH. Ovarian hyperstimulation with exogenous gonadotropins elicited normal ovulation rates in TGFβ1 null mutant mice. After mating with wild-type stud males, serum progesterone content was reduced by 75% associated with altered ovarian expression of mRNAs encoding steroidogenic enzymes 3β-hydroxysteroid dehydrogenase-1 and P450 17 α-hydroxylase/C17–20-lyase. Embryos recovered from TGFβ1 null mutant females were developmentally arrested in the morula stage and rarely progressed to blastocysts. Attempts to rescue embryos by exogenous progesterone administration and in vitro culture were unsuccessful, and in vitro fertilization and culture experiments demonstrated that impaired development is unlikely to result from lack of maternal tract TGFβ1. We conclude that embryo arrest is due to developmental incompetence in oocytes developed in a TGFβ1-deficient follicular environment. This study demonstrates that TGFβ1 is a critical determinant of normal ovarian function, operating through regulation of LH activity and generation of oocytes competent for embryonic development and successful initiation of pregnancy.
Year-round recordings of behavioural and physiological parameters reveal the survival strategy of a poorly insulated diving endotherm during the Arctic winter
Authors: Grémillet David , Kuntz Grégoire , Woakes Anthony J. , Gilbert Caroline , Robin Jean-Patrice , Le Maho Yvon , Butler Patrick J.
Published: November 2005

Warm-blooded diving animals wintering in polar regions are expected to show a high degree of morphological adaptation allowing efficient thermal insulation. In stark contrast to other marine mammals and seabirds living at high latitudes, Arctic great cormorants Phalacrocorax carbo have very limited thermal insulation because of their partly permeable plumage. They nonetheless winter in Greenland, where they are exposed to very low air and water temperatures. To understand how poorly insulated diving endotherms survive the Arctic winter, we performed year-round recordings of heart rate,dive depth and abdominal temperature in male great cormorants using miniature data loggers. We also examined the body composition of individuals in the spring. Abdominal temperatures and heart rates of birds resting on land and diving showed substantial variability. However, neither hypothermia nor significantly lower heart rate levels were recorded during the winter months. Thus our data show no indication of general metabolic depression in great cormorants wintering in Greenland. Furthermore, great cormorants did not reduce their daily swimming time during the coldest months of the year to save energy; they continued to forage in sub-zero waters for over an hour every day. As birds spent extended periods in cold water and showed no signs of metabolic depression during the Arctic winter, their theoretical energy requirements were substantial. Using our field data and a published algorithm we estimated the daily food requirement of great cormorants wintering in Greenland to be 1170±110 g day-1. This is twice the estimated food requirement of great cormorants wintering in Europe. Great cormorants survive the Arctic winter but we also show that they come close to starvation during the spring, with body reserves sufficient to fast for less than 3 days. Lack of body fuels was associated with drastically reduced body temperatures and heart rates in April and May. Concurrent, intense feeding activity probably allowed birds to restore body reserves. Our study is the first to record ecophysiological parameters in a polar animal on a year-round basis. It challenges the paradigm that efficient thermal insulation is a prerequisite to the colonization of polar habitats by endotherms.
Thermally induced changes in lipid composition of raft and non-raft regions of hepatocyte plasma membranes of rainbow trout
Authors: Zehmer John K. , Hazel Jeffrey R.
Published: November 2005

In poikilotherms, increases in plasma membrane (PM) cholesterol and an increase in the degree of lipid acyl chain saturation commonly accompany an increase in growth temperature. This has typically been interpreted in terms of membrane fluidity/order homeostasis, but these changes would also be expected to stabilize the structure of PM rafts against thermal perturbation. Rafts are microdomains that organize the molecules of many signaling cascades and are formed as a result of interactions between lipids with saturated acyl chains and cholesterol. No study to date has examined the thermally induced compositional changes of raft and non-raft regions of the PM separately. In this study we have measured the phospholipid class composition and fatty acid composition of raft-enriched (raft) and raft-depleted PM (RDPM) of hepatocytes from trout Oncorhynchus mykiss acclimated to 5°C and 20°C. In the raft, warm acclimation was associated with a reduction in the proportion of phosphatidylcholine from 56% to 30% while phosphatidylserine and phosphatidylinositol each increased from 8% to approximately 20% of the total phospholipid. Additionally, there were significantly fewer unsaturated fatty acids in the raft lipids from warm-acclimated (61%) than from the cold-acclimated trout (68%). In contrast, there were no significant changes in phospholipid class or acyl chain unsaturation in the RDPM. These data suggest that changes in raft lipid composition, rather than the PM as a whole, are particularly important during thermal acclimation.
Time course of osmoregulatory and metabolic changes during osmotic acclimation in Sparus auratus
Authors: Sangiao-Alvarellos Susana , Arjona Francisco J. , del Río María P. Martín , Míguez Jesús M. , Mancera Juan M. , Soengas José L.
Published: November 2005

Changes in different osmoregulatory and metabolic parameters over time were assessed in gills, kidney, liver and brain of gilthead sea bream Sparus auratus transferred either from seawater (SW, 38 p.p.t.) to hypersaline water (HSW, 55 p.p.t.) or from SW to low salinity water (LSW, 6 p.p.t.) for 14 days. Changes displayed by osmoregulatory parameters revealed two stages during hyperosmotic and hypo-osmotic acclimation: (i) an adaptive period during the first days of acclimation (1–3 days), with important changes in these parameters, and (ii) a chronic regulatory period (after 3 days of transfer) where osmotic parameters reached homeostasis. From a metabolic point of view, two clear phases can also be distinguished during acclimation to hyperosmotic or hypo-osmotic conditions. The first one coincides with the adaptive period and is characterized by enhanced levels of plasma metabolites(glucose, lactate, triglycerides and protein), and use of these metabolites by different tissues in processes directly or indirectly involved in osmoregulatory work. The second stage coincides with the chronic regulatory period observed for the osmoregulatory parameters and is metabolically characterized in HSW-transferred fish by lower energy expenditure and a readjustment of metabolic parameters to levels returning to normality,indicative of reduced osmoregulatory work in this stage. In LSW-transferred fish, major changes in the second stage include: (i) decreased glycolytic potential, capacity for exporting glucose and potential for amino acid catabolism in liver; (ii) enhanced use of exogenous glucose through glycolysis, pentose phosphate and glycogenesis in gills; (iii) increased glycolytic potential in kidney; and (iv) increased glycogenolytic potential and capacity for use of exogenous glucose in brain.
Desert ants compensate for navigation uncertainty
Authors: Wolf Harald , Wehner Rüdiger
Published: November 2005

During foraging trips, desert ants Cataglyphis fortis do not rely only on their well-studied path integration system, they also use olfactory cues when approaching a familiar food source. When a wind is blowing from a constant direction, as is characteristic of their desert habitat, the ants do not approach the feeder directly. They rather steer some distance downwind of the food source to pick up odour filaments emanating from the food. They follow this odour trail upwind, and find the source quickly and reliably.

This approach behaviour was examined in more detail in order to identify the underlying orientation strategy. First, the ants may employ a `goal expansion strategy', using odour spread as a spatially limited indicator for the presence of food. In that case, the distance steered downwind of the feeder should be determined by the range of the odour plume (and, for instance, wind speed). It should be independent of the distance between nest and feeder. Second, the ants may apply an `error compensation strategy', using odour filaments as a guideline towards the food source. Steering downwind by a margin just exceeding their maximum navigation error will lead the ants safely across the odour guide. In that case, the distance steered downwind of the feeder should increase more or less linearly with the nest-feeder distance.

Our results unambiguously support the second strategy. When feeders were established at distances of 5-75 m from the nest, the distances steered downwind of the food increased from 0.7 m to 3.4 m in a linear fashion. This result was independent of wind speed or wind direction. It translates into an ant's estimate of its navigation error within a range of 3° to 8°.
Neural plasticity of mushroom body-extrinsic neurons in the honeybee brain
Authors: Menzel Randolf , Manz Gisela
Published: November 2005

Central interneurons exiting the alpha lobe of the mushroom bodies were studied with respect to their plasticity by electrically stimulating their presynaptic inputs, the Kenyon cells. Special attention was given to the analysis of a single, identified neuron, the PE1. Three stimulation protocols were tested: double pulses, tetanus (100 Hz for 1 s), and tetanus paired with intracellular de- or hyper-polarization of the recorded cell. Double-pulse stimulations revealed short-term facilitation and depression, tuning the responses of these interneurons to frequencies in the range of 20–40 Hz. The tetanus may lead to augmentation of responses to test stimuli lasting for several minutes, or to depression followed by augmentation. Associative long-term potentiation (LTP) was induced in the PE1 neuron by pairing a presynaptic tetanus with depolarization. This is the first time that associative LTP has been found in an interneuron of the insect nervous system. These data are discussed in the context of spike tuning in the output of the mushroom body, and the potential role of associative LTP in olfactory learning. It is concluded that the honeybee mushroom body output neurons are likely to contribute to the formation of olfactory memory.
Design of Reconfigurable Flight Control System Using Adaptive Sliding Mode Control: Actuator Fault
Authors: Shin D , Moon G , Kim Y
Published: November 2005

This article presents the reconfigurable flight controller using an adaptive sliding mode control scheme for actuator fault case. Sliding mode controller, which has good performance for the systems with various uncertainties, is used to deal with the actuator faults. Actuator fault can be considered as a disturbance or an unexpected parameter change, which degrades the system performance and may destabilize the system. In this study, the adaptive sliding mode control technique is adopted to compensate the effects of the disturbance generated by actuator faults. Lyapunov stability theory is used to derive the adaptive rule, and the closed-loop system stability analysis is performed. To demonstrate the effectiveness of the proposed controller, numerical simulation is performed for aircraft having redundant control surfaces.