bluuebunny/crossref_metadata_2025 huggingface dataset:
Adopting the Position of Error: Space and Speculation in the Exploratory Significance of Milieu Formulations
Authors: O'Grady Nathaniel
Published: April 2013

As Foucault's writing on the role of population in managing societies through security would attest, the term milieu is not primarily a tool for analysing primary data. Instead, it is a means to model data on population according to specific spatial parameters, and a means of structuring examination of populations in a particular way. The importance of space is also apparent in Canguilhem's work on the notion of milieu in his writings on bacteriology and organism development. Although the contexts in which the term is deployed are different, both thinkers show how the notion of milieu allows observation of heterogeneous elements in relation to one another, in terms of the movement of elements studied and what possible points of intersection may be forged between elements. In spite of the different research contexts in which each author uses the term, both can be seen to share an understanding of the milieu according to its epistemological qualities. What is stressed in both Foucault's and Canguilhem's accounts is an indication of the structural parameters which characterise the milieu. These parameters work to enframe the circulation of that which is being observed. From this structure, particular forms of knowledge concerning that which is examined are produced by the milieu model. In this paper I argue that both Foucault and Canguilhem show how the milieu facilitates thinking, and produces knowledge, that is speculative. As such, the paper can explore how, through their understanding of the milieu, the authors make claims which describe speculative thinking in its practice.
Influence of culture regime on arsenic cycling by the marine phytoplankton Dunaliella tertiolecta and Thalassiosira pseudonana
Authors: Duncan Elliott G. , Maher William A. , Foster Simon D. , Krikowa Frank
Published: April 2013

Environmental context Phytoplankton form the base of marine food-webs, and hence they have been proposed as the likely source of many arsenic compounds found in marine animals. Because of the difficulties associated with field experiments with phytoplankton, attempts to test this hypothesis have relied mainly on laboratory experiments. This study assesses the environmental validity of this research approach by investigating the influence of the culturing experimental protocol on the uptake, accumulation and biotransformation of arsenic by marine phytoplankton. Abstract Arsenic cycling by the marine phytoplankton Dunaliella tertiolecta and the marine diatom Thalassiosira pseudonana was influenced by culture regime. Arsenic was associated with the residue cell fractions of batch cultured phytoplankton (D. tertiolecta and T. pseudonana), due to the accumulation of dead cells within batch cultures. Greater arsenic concentrations were associated with water-soluble and lipid-soluble cell fractions of continuously cultured phytoplankton. Arsenoribosides (as glycerol (Gly-), phosphate (PO4-) and sulfate (OSO3-)) were ubiquitous in D. tertiolecta (Gly- and PO4- only) and T. pseudonana (all three species). Additionally, arsenobetaine (AB) was not detected in any phytoplankton tissues, illustrating that marine phytoplankton themselves are not an alternate source of AB. Arsenic species formation was influenced by culture regime, with PO4-riboside produced under nutrient rich conditions, whereas Dimethylarsenoacetate (DMAA) was found in old (>42 days old) batch cultures, with this arsenic species possibly produced by the degradation of arsenoribosides-arsenolipids from decomposing cells rather than by biosynthesis. Nutrient availability, hence culture regime was thus influential in directly and indirectly influencing arsenic cycling and the arsenic species produced by D. tertiolecta and T. pseudonana. Future research should thus utilise continuous culture regimes to study arsenic cycling as these are far more analogous to environmental processes.
Supplementation of culture medium with L-carnitine improves development and cryotolerance of bovine embryos produced in vitro
Authors: Takahashi Toshikiyo , Inaba Yasushi , Somfai Tamas , Kaneda Masahiro , Geshi Masaya , Nagai Takashi , Manabe Noboru
Published: April 2013

High lipid content in embryos is associated with low freezing tolerance. This study assessed the effects of exogenous l-carnitine, an enhancer of lipid metabolism, on the in vitro development and freezing survival of bovine embryos. Also, effects on metabolic activity, reactive oxygen species (ROS) and apoptosis were investigated. Supplementation of embryo culture medium with 1.518 mM or 3.030 mM l-carnitine significantly increased the rates of zygote development to the blastocyst stage and blastocyst cell numbers whereas 6.072 mM of this compound did not improve embryo development. Survival rates after slow freezing of blastocysts were significantly higher when embryos were cultured in the presence of 1.518 mM or 3.030 mM l-carnitine compared with the control. A lower density of lipid droplets was detected in l-carnitine-treated blastocysts compared with the control. l-carnitine significantly reduced ROS levels in 2-cell embryos but did not reduce ROS levels at later stages. The apoptotic cell rate was not different between control and l-carnitine-treated blastocysts. l-carnitine significantly increased ATP levels in 2-cell embryos but not at the 8-cell or blastocyst stages. l-carnitine increased the expression of metabolism-related ATP6 and COX1 genes in blastocysts. In conclusion, l-carnitine supplementation enhanced lipid metabolism in embryos resulting in improved development and cryotolerance of bovine blastocysts produced in vitro.
Actin nucleator Arp2/3 complex is essential for mouse preimplantation embryo development
Authors: Sun Shao-Chen , Wang Qing-Ling , Gao Wei-Wei , Xu Yong-Nan , Liu Hong-Lin , Cui Xiang-Shun , Kim Nam-Hyung
Published: April 2013

The Arp2/3 complex is a critical actin nucleator, which promotes actin assembly and is widely involved in a diverse range of actin-related processes such as cell locomotion, phagocytosis and the establishment of cell polarity. Previous studies showed that the Arp2/3 complex regulates spindle migration and asymmetric division during mouse oocyte maturation; however, the role of the Arp2/3 complex in early mouse embryo development is still unknown. The results of the present study show that the Arp2/3 complex is critical for cytokinesis during mouse embryo development. The Arp2/3 complex was concentrated at the cortex of each cell at the 2- to 8-cell stage and the peripheral areas of the morula and blastocyst. Inhibition of the Arp2/3 complex by the specific inhibitor CK666 at the zygote stage caused a failure in cell division; mouse embryos failed to undergo compaction and lost apical–basal polarity. The actin level decreased in the CK666-treated group, and two or more nuclei were observed within a single cell, indicating a failure of cell division. Addition of CK666 at the 8-cell stage caused a failure of blastocyst formation, and CDX2 staining confirmed the loss of embryo polarity and the failure of trophectoderm and inner cell mass formation. Taken together, these data suggest that the Arp2/3 complex may regulate mouse embryo development via its effect on cell division.
Microtubule organisation, pronuclear formation and embryonic development of mouse oocytes after intracytoplasmic sperm injection or parthenogenetic activation and then slow-freezing with 1,2-propanediol
Authors: Li Dun-Gao , Zhu Yan , Xing Feng-Ying , Li Shan-Gang , Chen Xue-Jin , Jiang Man-Xi
Published: April 2013

The goal of this study was to investigate the effect of cryopreservation on oocytes at different times after intracytoplasmic sperm injection (ICSI) and parthenogenetic activation. The study was performed in mouse oocytes fertilised by ICSI, or in artificially-activated oocytes, which were cryopreserved immediately, one hour or five hours later through slow-freezing. After thawing, the rates of survival, fertilisation–activation, embryonic development of oocytes–zygotes and changes in the cytoskeleton and ploidy were observed. Our results reveal a significant difference in survival rates of 0-, 1- and 5-h cryopreserved oocytes following ICSI and artificial activation. Moreover, significant differences in two pronuclei (PN) development existed between the 0-, 1- and 5-h groups of oocytes frozen after ICSI, while the rates of two-PN development of activated oocytes were different between the 1-h and 5-h groups. Despite these initial differences, there was no difference in the rate of blastocyst formation from two-PN zygotes following ICSI or artificial activation. However, compared with ICSI or artificially-activated oocytes cryopreserved at 5 h, many oocytes from the 0- and 1-h cryopreservation groups developed to zygotes with abnormal ploidy; this suggests that too little time before cryopreservation can result in some activated oocytes forming abnormal ploidy. However, our results also demonstrate that spermatozoa can maintain normal fertilisation capacity in frozen ICSI oocytes and the procedure of freeze–thawing did not affect the later development of zygotes.
TRPM8 activation attenuates inflammatory responses in mouse models of colitis
Authors: Ramachandran Rithwik , Hyun Eric , Zhao Liena , Lapointe Tamia K. , Chapman Kevin , Hirota Christina L. , Ghosh Subrata , McKemy David D. , Vergnolle Nathalie , Beck Paul L. , Altier Christophe , Hollenberg Morley D.
Published: April 2013

Transient Receptor Potential Melastatin–8 (TRPM8), a recently identified member of the transient receptor potential (TRP) family of ion channels, is activated by mild cooling and by chemical compounds such as the supercooling agent, icilin. Since cooling, possibly involving TRPM8 stimulation, diminishes injury-induced peripheral inflammation, we hypothesized that TRPM8 activation may also attenuate systemic inflammation. We thus studied the involvement of TRPM8 in regulating colonic inflammation using two mouse models of chemically induced colitis. TRPM8 expression, localized immunohistochemically in transgenic
TRPM8

GFP

mouse colon, was up-regulated in both human- and murine-inflamed colon samples, as measured by real-time PCR. Wild-type mice (but not TRPM8-nulls) treated systemically with the TRPM8 agonist, icilin showed an attenuation of chemically induced colitis, as reflected by a decrease in macroscopic and microscopic damage scores, bowel thickness, and myeloperoxidase activity compared with untreated animals. Furthermore, icilin treatment reduced the 2,4,6-trinitrobenzenesulfonic acid–induced increase in levels of inflammatory cytokines and chemokines in the colon. In comparison with wild-type mice, Dextran Sodium Sulfate (DSS)-treated TRPM8 knockout mice showed elevated colonic levels of the inflammatory neuropeptide calcitonin-gene–related peptide, although inflammatory indices were equivalent for both groups. Further, TRPM8 activation by icilin blocked capsaicin-triggered calcitonin-gene–related peptide release from colon tissue ex vivo and blocked capsaicin-triggered calcium signaling in Transient Receptor Potential Vaniloid-1 (TRPV1) and TRPM8 transfected HEK cells. Our data document an anti-inflammatory role for TRPM8 activation, in part due to an inhibiton of neuropeptide release, pointing to a novel therapeutic target for colitis and other inflammatory diseases.
Molecular view of an electron transfer process essential for iron–sulfur protein biogenesis
Authors: Banci Lucia , Bertini Ivano , Calderone Vito , Ciofi-Baffoni Simone , Giachetti Andrea , Jaiswal Deepa , Mikolajczyk Maciej , Piccioli Mario , Winkelmann Julia
Published: April 2013

Biogenesis of iron–sulfur cluster proteins is a highly regulated process that requires complex protein machineries. In the cytosolic iron–sulfur protein assembly machinery, two human key proteins—NADPH-dependent diflavin oxidoreductase 1 (Ndor1) and anamorsin—form a stable complex in vivo that was proposed to provide electrons for assembling cytosolic iron–sulfur cluster proteins. The Ndor1–anamorsin interaction was also suggested to be implicated in the regulation of cell survival/death mechanisms. In the present work we unravel the molecular basis of recognition between Ndor1 and anamorsin and of the electron transfer process. This is based on the structural characterization of the two partner proteins, the investigation of the electron transfer process, and the identification of those protein regions involved in complex formation and those involved in electron transfer. We found that an unstructured region of anamorsin is essential for the formation of a specific and stable protein complex with Ndor1, whereas the C-terminal region of anamorsin, containing the [2Fe-2S] redox center, transiently interacts through complementary charged residues with the FMN-binding site region of Ndor1 to perform electron transfer. Our results propose a molecular model of the electron transfer process that is crucial for understanding the functional role of this interaction in human cells.
X-ray snapshots of possible intermediates in the time course of synthesis and degradation of protein-bound Fe
4
S
4
clusters
Authors: Nicolet Yvain , Rohac Roman , Martin Lydie , Fontecilla-Camps Juan C.
Published: April 2013

Fe
4
S
4
clusters are very common versatile prosthetic groups in proteins. Their redox property of being sensitive to O
2
-induced oxidative damage is, for instance, used by the cell to sense oxygen levels and switch between aerobic and anaerobic metabolisms, as exemplified by the fumarate, nitrate reduction regulator (FNR). Using the hydrogenase maturase HydE from
Thermotoga maritima
as a template, we obtained several unusual forms of FeS clusters, some of which are associated with important structural changes. These structures represent intermediate states relevant to both FeS cluster assembly and degradation. We observe one Fe
2
S
2
cluster bound by two cysteine persulfide residues. This observation lends structural support to a very recent Raman study, which reported that Fe
4
S
4
-to-Fe
2
S
2
cluster conversion upon oxygen exposure in FNR resulted in concomitant production of cysteine persulfide as cluster ligands. Similar persulfide ligands have been observed in vitro for several other Fe
4
S
4
cluster-containing proteins. We have also monitored FeS cluster conversion directly in our protein crystals. Our structures indicate that the Fe
4
S
4
-to-Fe
2
S
2
change requires large structural modifications, which are most likely responsible for the dimer–monomer transition in FNR.
A public health approach to preventing child abuse in low‐ and middle‐income countries: A call for action
Authors: Skeen Sarah , Tomlinson Mark
Published: April 2013

Violence against children is prevalent across all countries and cultures, with the burden of child injury and violence heaviest in low‐ and middle‐income (LAMI) settings. There are several types of program to prevent child abuse, with family‐based approaches to prevention being the most comprehensively researched and successful interventions in high‐income settings. In LAMI countries, however, there is very little research evidence for the prevention of child abuse. We conducted a systematic search of relevant databases for studies published between 1995 and 2011 and the search revealed only one relevant study. There is thus a need for research into child maltreatment prevention in LAMI settings, taking account of local resources and contexts. In the light of the lack of evidence, we focus on two case studies that document the use of home visiting by community health workers perinatally to improve maternal and child outcomes. We propose four areas for action moving forward, including increased investment in early intervention and prevention programs, development of a research agenda that prioritizes prevention research, integration of implementation research into efforts to scale up interventions, and improving systematically collected information on child maltreatment.
Differentiating between child protection and family support in the Canadian child welfare system's response to intimate partner violence, corporal punishment, and child neglect
Authors: Trocmé Nico , Fallon Barbara , Sinha Vandna , Van Wert Melissa , Kozlowski Anna , MacLaurin Bruce
Published: April 2013

Rates of reported child maltreatment nearly doubled in Canada over the period 1998–2003, an increase that reflects growing awareness of the harmful effects of an expanding array of parental behaviors, including corporal punishment, lack of supervision, and exposure to intimate partner violence (IPV). Some of these situations may benefit from voluntary family support programs outside of the child welfare system. Analyzing a sample of 11,807 investigations, this paper compares cases where the sole concern is exposure to IPV, or hitting a child, or neglect, or other forms of investigated maltreatment. Situations where exposure to IPV or potentially abusive hitting were the sole reason for investigation presented with fewer risk factors and were less likely to lead to ongoing child welfare interventions compared to other maltreatment investigations. While situations involving alleged neglect presented a higher risk profile and elicited a more intensive child welfare response than did exposure to IPV or hitting, opportunities for alternative services were nevertheless identified. The study also found that visible minority families were overrepresented in cases involving hitting and that Aboriginal families were overrepresented in cases involving neglect. Overall the findings support the development of alternative response programs in Canada.
Writing sociology in the Arab world: knowledge production through Idafat, The Arab Journal of Sociology
Authors: Hanafi Sari
Published: April 2013

This article analyses the 18 issues of Idafat, The Arab Journal of Sociology, published from 2008 to 2012, including some specific variables (submission data, author nationality, article keywords, use of references). While all published materials are analysed, only 120 articles written by Arab authors are scrutinized. The objective is to unfold the way Arab sociologists produce knowledge in sociology. A special focus will be placed on the language of citations and references. This article argues that some institutional settings in addition to the economy of knowledge production make the balanced use of references in Arabic and foreign languages difficult. What are the resources upon which they rely? To answer to this question, the article presents the results of an online 27-question survey about the use of references by researchers who hold a master’s or a PhD degree from any university in the Arab world or who have dealt with a topic related to the Arab world.
Sustained Savings from a Longitudinal Cost Analysis of an Internet-Based Preapproval Antimicrobial Stewardship Program
Authors: Sick Anna C. , Lehmann Christoph U. , Tamma Pranita D. , Lee Carlton K. K. , Agwu Allison L.
Published: April 2013

Objective.

To evaluate an internet-based preapproval antimicrobial stewardship program for sustained reduction in antimicrobial prescribing and resulting cost savings.

Design.

Retrospective cohort study and cost analysis.

Methods.

Review of all doses and charges of antimicrobials dispensed to patients over 6 years (July 1, 2005–June 30, 2011) at a tertiary care pediatric hospital.

Results.

Restricted antimicrobials account for 26% of total doses but 81% of total antimicrobial charges. Winter months (November–February) and the oncology and infant and toddler units were associated with the highest antimicrobial charges. Five restricted drugs accounted for the majority (54%) of charges but only 6% of doses. With an average approval rate of 91.5% (95% confidence interval [CI], 91.1%–91.9%), the preapproval antibiotic stewardship program saved $103,787 (95% CI, $98,583–$109,172) per year, or $14,156 (95% CI, $13,446–$14,890) per 1,000 patient-days.

Conclusions.

A preapproval antimicrobial stewardship program effectively reduces the number of doses and subsequent charges due to restricted antimicrobials years after implementation. Hospitals with reduced resources for implementing postprescription review may benefit from a preapproval antimicrobial stewardship program. Targeting specific units, drugs, and seasons may optimize preapproval programs for additional cost savings.
National Estimates of Central Line–Associated Bloodstream Infections in Critical Care Patients
Authors: Wise Matthew E. , Scott R. Douglas , Baggs James M. , Edwards Jonathan R. , Ellingson Katherine D. , Fridkin Scott K. , McDonald L. Clifford , Jernigan John A.
Published: April 2013

Objective.

Recent studies have demonstrated that central line-associated bloodstream infections (CLABSIs) are preventable through implementation of evidence-based prevention practices. Hospitals have reported CLABSI data to the Centers for Disease Control and Prevention (CDC) since the 1970s, providing an opportunity to characterize the national impact of CLABSIs over time. Our objective was to describe changes in the annual number of CLABSIs in critical care patients in the United States.

Design.

Monte Carlo simulation.

Setting.

US acute care hospitals.

Patients.

Nonneonatal critical care patients.

Methods.

We obtained administrative data on patient-days for nearly all US hospitals and applied CLABSI rates from the National Nosocomial Infections Surveillance and the National Healthcare Safety Network systems to estimate the annual number of CLABSIs in critical care patients nationally during the period 1990–2010 and the number of CLABSIs prevented since 1990.

Results.

We estimated that there were between 462,000 and 636,000 CLABSIs in nonneonatal critical care patients in the United States during 1990–2010. CLABSI rate reductions led to between 104,000 and 198,000 fewer CLABSIs than would have occurred if rates had remained unchanged since 1990. There were 15,000 hospital-onset CLABSIs in nonneonatal critical care patients in 2010; 70% occurred in medium and large teaching hospitals.

Conclusions.

Substantial progress has been made in reducing the occurrence of CLABSIs in US critical care patients over the past 2 decades. The concentration of critical care CLABSIs in medium and large teaching hospitals suggests that a targeted approach may be warranted to continue achieving reductions in critical care CLABSIs nationally.
Trafficking of the Menkes copper transporter ATP7A is regulated by clathrin-, AP-2–, AP-1–, and Rab22-dependent steps
Authors: Holloway Zoe G. , Velayos-Baeza Antonio , Howell Gareth J. , Levecque Clotilde , Ponnambalam Sreenivasan , Sztul Elizabeth , Monaco Anthony P.
Published: April 2013

The transporter ATP7A mediates systemic copper absorption and provides cuproenzymes in the trans-Golgi network (TGN) with copper. To regulate metal homeostasis, ATP7A constitutively cycles between the TGN and plasma membrane (PM). ATP7A trafficking to the PM is elevated in response to increased copper load and is reversed when copper concentrations are lowered. Molecular mechanisms underlying this trafficking are poorly understood. We assess the role of clathrin, adaptor complexes, lipid rafts, and Rab22a in an attempt to decipher the regulatory proteins involved in ATP7A cycling. While RNA interference (RNAi)–mediated depletion of caveolin 1/2 or flotillin had no effect on ATP7A localization, clathrin heavy chain depletion or expression of AP180 dominant-negative mutant not only disrupted clathrin-regulated pathways, but also blocked PM-to-TGN internalization of ATP7A. Depletion of the μ subunits of either adaptor protein-2 (AP-2) or AP-1 using RNAi further provides evidence that both clathrin adaptors are important for trafficking of ATP7A from the PM to the TGN. Expression of the GTP-locked Rab22aQ64Lmutant caused fragmentation of TGN membrane domains enriched for ATP7A. These appear to be a subdomain of the mammalian TGN, showing only partial overlap with the TGN marker golgin-97. Of importance, ATP7A remained in the Rab22aQ64L-generated structures after copper treatment and washout, suggesting that forward trafficking out of this compartment was blocked. This study provides evidence that multiple membrane-associated factors, including clathrin, AP-2, AP-1, and Rab22, are regulators of ATP7A trafficking.
CellH5: a format for data exchange in high-content screening
Authors: Sommer Christoph , Held Michael , Fischer Bernd , Huber Wolfgang , Gerlich Daniel W.
Published: April 2013

Summary: High-throughput microscopy data require a diversity of analytical approaches. However, the construction of workflows that use algorithms from different software packages is difficult owing to a lack of interoperability. To overcome this limitation, we present CellH5, an HDF5 data format for cell-based assays in high-throughput microscopy, which stores high-dimensional image data along with inter-object relations in graphs. CellH5Browser, an interactive gallery image browser, demonstrates the versatility and performance of the file format on live imaging data of dividing human cells. CellH5 provides new opportunities for integrated data analysis by multiple software platforms.

Availability: Source code is freely available at www.github.com/cellh5 under the GPL license and at www.bioconductor.org/packages/release/bioc/html/rhdf5.html under the Artistic-2.0 license. Demo datasets and the CellH5Browser are available at www.cellh5.org. A Fiji importer for cellh5 will be released soon.

Contact:  daniel.gerlich@imba.oeaw.ac.at or christoph.sommer@imba.oeaw.ac.at

Supplementary information:  Supplementary data are available at Bioinformatics online.
The Emergence of Political Accountability*
Authors: Bidner Chris , Francois Patrick
Published: April 2013

When and how do democratic institutions deliver accountable government? In addressing this broad question, we focus on the role played by political norms—specifically, the extent to which leaders abuse office for personal gain and the extent to which citizens punish such transgressions. We show how qualitatively distinct political norms can coexist because of a dynamic complementarity, in which citizens’ willingness to punish transgressions is raised when they expect such punishments to be used in the future. We seek to understand the emergence of accountability by analysing transitions between norms. To do so, we extend the analysis to include the possibility that, at certain times, a segment of voters are (behaviorally) intolerant of transgressions. Our mechanism highlights the role of leaders, offering an account of how their actions can instigate enduring change, within a fixed set of formal institutions, by disrupting prevailing political norms. We show how such changes do not depend on “sun spots” to trigger coordination, and are asymmetric in effect—a series of good leaders can (and eventually will) improve norms, whereas bad leaders cannot damage them.
Cognitive Changes after Saline or Plasmalyte Infusion in Healthy Volunteers
Authors: Story David A. , Lees Lucy , Weinberg Laurence , Teoh Soon-Yee , Lee Katherine J. , Velissaris Sarah , Bellomo Rinaldo , Wilson Sarah J.
Published: April 2013

Background:

In an incidental finding, during a study of plasma chemistry after crystalloid infusion, participants reported subjective cognitive changes, particularly slower thinking, after saline but not Hartmann’s (Ringer’s lactate) solution. The authors tested the hypothesis that saline infusion would produce greater adverse cognitive changes than Plasmalyte infusion.

Methods:

The authors conducted a randomized, cross-over, multiple blinded study of healthy adult volunteers. On separate days, participants received 30 ml/kg over 1 h of either 0.9% saline or Plasmalyte with the order randomly allocated. Plasma chemistry was tested on venous samples. As part of a battery of cognitive tests our primary endpoint was the reaction time index after infusion.

Results:

The authors studied 25 participants. Plasma chloride was greater after saline than after Plasmalyte: mean difference 5.4 mM (95% CI, 4.1–6.6 mM; P < 0.001). Saline was also associated with greater metabolic acidosis: base-excess 2.5 mM more negative (95% CI, 1.9–3.0 mM more negative; P < 0.001). There was no evidence of a difference in the reaction time index between the two interventions: mean reaction time index 394 ms (SD, 72) after saline versus 385 ms (SD, 55) after Plasmalyte. Difference: saline 9 ms slower (95% CI, 30 ms slower to 12 ms faster; P = 0.39). There were minimal differences in the other cognitive and mood tests.

Conclusions:

Despite expected differences in plasma chemistry, the authors found that measures of cognition did not differ after infusions of Plasmalyte or saline.
Changes in Blood Pressure and Cardiac Output during Cesarean Delivery
Authors: Rosseland Leiv Arne , Hauge Tor Hugo , Grindheim Guro , Stubhaug Audun , Langesæter Eldrid
Published: April 2013

Background:

Little is known about maternal hemodynamics after Cesarean delivery. Uterine contractions may increase cardiac output. Oxytocin is the first-line treatment for uterine atony, although the effects of the long-acting oxytocin analogue carbetocin are comparable with that of oxytocin. The authors analyzed the effects of i.v. oxytocin 5 U, carbetocin 100 µg, and placebo on hemodynamics, uterine tone, adverse events, and blood loss after Cesarean delivery.

Methods:

This was a randomized, double-blinded, placebo-controlled, parallel-group comparison of carbetocin and oxytocin after elective Cesarean delivery of singletons under spinal anesthesia (n = 76). Continuously measured invasive systolic arterial pressure was the primary outcome measure.

Results:

The mean systolic arterial pressure decrease was 28 mmHg (95% CI, 22–34) after oxytocin and 26 mmHg (95% CI, 20–31) after carbetocin. The decrease was greatest after 80 (95% CI, 71–89) and 63 s (95% CI, 55–72), respectively (P = 0.006). The differences were nearly undetectable after 2.5 min, although the effect of carbetocin was slightly greater than placebo (P < 0.001). The group differences in systolic arterial pressure decreased over 5 min and were gone at 1 h. Heart rate and cardiac output increased in all three groups. Stroke volume increased after oxytocin and carbetocin but was unchanged after placebo.

Conclusions:

The hemodynamic side effects of oxytocin 5 U and carbetocin 100 µg were comparable. The lack of an increase in stroke volume in the placebo group challenges the theory that uterine contraction causes autotransfusion of uterine blood, leading to an increase in preload.
Higher Frequency Ventilation Attenuates Lung Injury during High-frequency Oscillatory Ventilation in Sheep Models of Acute Respiratory Distress Syndrome
Authors: Liu Songqiao , Yi Yang , Wang Maohua , Chen Qiuhua , Huang Yingzi , Liu Ling , Xie Jianfeng , Zhou Dunyuan , Qiu Haibo
Published: April 2013

Background:

High-frequency oscillatory ventilation (HFOV) at higher frequencies minimizes the tidal volume. However, whether increased frequencies during HFOV can reduce ventilator-induced lung injury remains unknown.

Methods:

After the induction of acute respiratory distress syndrome in the model by repeated lavages, 24 adult sheep were randomly divided into four groups (n = 6): three HFOV groups (3, 6, and 9 Hz) and one conventional mechanical ventilation (CMV) group. Standard lung recruitments were performed in all groups until optimal alveolar recruitment was reached. After lung recruitment, the optimal mean airway pressure or positive end-expiratory pressure was determined with decremental pressure titration, 2 cm H2O every 10 min. Animals were ventilated for 4 h.

Results:

After lung recruitment, sustained improvements in gas exchange and compliance were observed in all groups. Compared with the HFOV-3 Hz and CMV groups, the transpulmonary pressure and tidal volumes were statistically significantly lower in the HFOV-9 Hz group. The lung injury scores and wet/dry weight ratios were significantly reduced in the HFOV-9 Hz group compared with the HFOV-3 Hz and CMV groups. Expression of interleukin-1β and interleukin-6 in the lung tissue, decreased significantly in the HFOV-9 Hz group compared with the HFOV-3 Hz and CMV groups. Malondialdehyde expression and myeloperoxidase activity in lung tissues in the HFOV-9 Hz group decreased significantly, compared with the HFOV-3 Hz and CMV groups.

Conclusion:

The use of HFOV at 9 Hz minimizes lung stress and tidal volumes, resulting in less lung injury and reduced levels of inflammatory mediators compared with the HFOV-3 Hz and CMV conditions.
MHJ_0125 is an M42 glutamyl aminopeptidase that moonlights as a multifunctional adhesin on the surface of
Mycoplasma hyopneumoniae
Authors: Robinson Mark W. , Buchtmann Kyle A. , Jenkins Cheryl , Tacchi Jessica L. , Raymond Benjamin B. A. , To Joyce , Roy Chowdhury Piklu , Woolley Lauren K. , Labbate Maurizio , Turnbull Lynne , Whitchurch Cynthia B. , Padula Matthew P. , Djordjevic Steven P.
Published: April 2013

Bacterial aminopeptidases play important roles in pathogenesis by providing a source of amino acids from exogenous proteins, destroying host immunological effector peptides and executing posttranslational modification of bacterial and host proteins. We show that MHJ_0125 from the swine respiratory pathogen
Mycoplasma hyopneumoniae
represents a new member of the M42 class of bacterial aminopeptidases. Despite lacking a recognizable signal sequence, MHJ_0125 is detectable on the cell surface by fluorescence microscopy and LC-MS/MS of (i) biotinylated surface proteins captured by avidin chromatography and (ii) peptides released by mild trypsin shaving. Furthermore, surface-associated glutamyl aminopeptidase activity was detected by incubation of live
M. hyopneumoniae
cells with the diagnostic substrate H-Glu-AMC. MHJ_0125 moonlights as a multifunctional adhesin, binding to both heparin and plasminogen. Native proteomics and comparative modelling studies suggest MHJ_0125 forms a dodecameric, homopolymeric structure and provide insight into the positions of key residues that are predicted to interact with heparin and plasminogen. MHJ_0125 is the first aminopeptidase shown to both bind plasminogen and facilitate its activation by tissue plasminogen activator. Plasmin cleaves host extracellular matrix proteins and activates matrix metalloproteases, generating peptide substrates for MHJ_0125 and a source of amino acids for growth of
M. hyopneumoniae
. This unique interaction represents a new paradigm in microbial pathogenesis.
A generalization of Nash's theorem with higher-order functionals
Authors: Hedges Julian
Published: April 2013

The recent theory of sequential games and selection functions by Escardó & Oliva is extended to games in which players move simultaneously. The Nash existence theorem for mixed-strategy equilibria of finite games is generalized to games defined by selection functions. A normal form construction is given, which generalizes the game-theoretic normal form, and its soundness is proved. Minimax strategies also generalize to the new class of games, and are computed by the Berardi–Bezem–Coquand functional, studied in proof theory as an interpretation of the axiom of countable choice.
Reexposure to the amnestic agent alleviates cycloheximide-induced retrograde amnesia for reactivated and extinction memories
Authors: Briggs James F. , Olson Brian P.
Published: April 2013

We investigated whether reexposure to an amnestic agent would reverse amnesia for extinction of learned fear similar to that of a reactivated memory. When cycloheximide (CHX) was administered immediately after a brief cue-induced memory reactivation (15 sec) and an extended extinction session (12 min) rats showed retrograde amnesia for both memories. CHX did not produce amnesia for a moderate extinction session (6 min). Re-administering CHX before testing reversed the amnestic effect for both memories (i.e., the memories were recovered). These results are discussed using a modified state dependent model of retrograde amnesia.
Activation of β2-adrenoceptor enhances synaptic potentiation and behavioral memory via cAMP-PKA signaling in the medial prefrontal cortex of rats
Authors: Zhou Hou-Cheng , Sun Yan-Yan , Cai Wei , He Xiao-Ting , Yi Feng , Li Bao-Ming , Zhang Xue-Han
Published: April 2013

The prefrontal cortex (PFC) plays a critical role in cognitive functions, including working memory, attention regulation, behavioral inhibition, as well as memory storage. The functions of PFC are very sensitive to norepinephrine (NE), and even low levels of endogenously released NE exert a dramatic influence on the functioning of the PFC. Activation of β-adrenoceptors (β-ARs) facilitates synaptic potentiation and enhances memory in the hippocampus. However, little is known regarding these processes in the PFC. In the present study, we investigate the role of β2-AR in synaptic plasticity and behavioral memory. Our results show that β2-AR selective agonist clenbuterol facilitates spike-timing-dependent long-term potentiation (tLTP) under the physiological conditions with intact GABAergic inhibition, and such facilitation is prevented by co-application with the cAMP inhibitor Rp-cAMPS. Loading postsynaptic pyramidal cells with Rp-cAMPS, the PKA inhibitor PKI5-24, or the G protein inhibitor GDP-β-S significantly decreases, but does not eliminate, the effect of clenbuterol. Clenbuterol suppresses the GABAergic transmission, while blocking GABAergic transmission by the GABAA receptor blocker partially mimics the effect of clenbuterol. In behavioral tests, a post-training infusion of clenbuterol into mPFC enhances 24-h trace fear memory. In summary, we observed that prefrontal cortical β2-AR activation by clenbuterol facilitates tLTP and enhances trace fear memory. The mechanism underlying tLTP facilitation involves stimulating postsynaptic cAMP-PKA signaling cascades and suppressing GABAergic circuit activities.
Functional Redundancy and Divergence within the Arabidopsis RETICULATA-RELATED Gene Family
Authors: Pérez-Pérez José Manuel , Esteve-Bruna David , González-Bayón Rebeca , Kangasjärvi Saijaliisa , Caldana Camila , Hannah Matthew A. , Willmitzer Lothar , Ponce María Rosa , Micol José Luis
Published: April 2013

A number of Arabidopsis (Arabidopsis thaliana) mutants exhibit leaf reticulation, having green veins that stand out against paler interveinal tissues, fewer cells in the interveinal mesophyll, and normal perivascular bundle sheath cells. Here, to examine the basis of leaf reticulation, we analyzed the Arabidopsis RETICULATA-RELATED (RER) gene family, several members of which cause leaf reticulation when mutated. Although transcripts of RE, RER1, and RER3 were mainly detected in the bundle sheath cells of expanded leaves, functional RER3:GREEN FLUORESCENT PROTEIN was visualized in the chloroplast membranes of all photosynthetic cells. Leaf reticulation in the re and rer3 loss-of-function mutants occurred, along with accumulation of reactive oxygen species, in a photoperiod-dependent manner. A comparison of re and rer3 leaf messenger RNA expression profiles showed more than 200 genes were similarly misexpressed in both mutants. In addition, metabolic profiles of mature leaves revealed that several biosynthetic pathways downstream of pyruvate are altered in re and rer3. Double mutant analysis showed that only re rer1 and rer5 rer6 exhibited synergistic phenotypes, indicating functional redundancy. The redundancy between RE and its closest paralog, RER1, was confirmed by overexpressing RER1 in re mutants, which partially suppressed leaf reticulation. Our results show that RER family members can be divided into four functional modules with divergent functions. Moreover, these results provide insights into the origin of the reticulated phenotype, suggesting that the RER proteins functionally interconnect photoperiodic growth, amino acid homeostasis, and reactive oxygen species metabolism during Arabidopsis leaf growth.
Synergistic lubrication of MoS2 particles with different morphologies in liquid paraffin
Authors: Hu Kunhong , Cai Yongkui , Hu Xianguo , Xu Yufu
Published: April 2013

Purpose

The purpose of this paper is to explore the synergistic lubrication of MoS2 particles with different morphologies.

Design/methodology/approach

The synergistic lubrication of MoS2 particles with different morphologies is evaluated using a four‐fall tribometer in liquid paraffin.

Findings

Results show that the morphology of MoS2 has an influence on the tribological properties of MoS2. Both MoS2 nano‐balls and nano‐platelets function as lubrication additives in liquid paraffin better than MoS2 micro‐platelets do. It is also found that there is a synergistic lubrication between two different morphologies of MoS2. The composite MoS2 additives with different morphologies can improve the wear resistance and friction reduction of liquid paraffin more than each of them singly does. The synergistic lubrication between two different MoS2 morphologies results from the cooperation of their different lubrication mechanism.

Originality/value

The paper reveals a synergistic lubrication between two different MoS2 structures. It is very advantageous and practical to partly displace nano‐MoS2 with micro‐MoS2.
Analysis of fluorinated interactions in plain ZDDP and fully formulated oils using design of experiment (DOE) and chemistry characterization of tribofilms in boundary lubrication under extreme loading conditions
Authors: Nehme Gabi
Published: April 2013

Purpose

The purpose of this paper is to describe very reproducible boundary lubrication tests, conducted as part of design of experiment (DOE) to study the behavior of fluorinated catalyst mixed with polutetrafluoroethylene or Teflon (PTFE) in developing environmentally friendly (reduced P and S) anti‐wear additives for future engine oil formulations. The paper presents both the statistical and experimental solution to the fluorinated interactions in fully formulated (F‐fully formulated) and plain ZDDP (F‐plain) oils.

Design/methodology/approach

The wear performance of fluorinated additive in combination with conventional commercial oil and ZDDP plain oil were investigated using DOE software. Several chemistry combinations were prepared and tested under extreme boundary lubrication (385 N with maximum Hertzian contact pressure of 2.72 GPa). Wear and frictional properties were evaluated using DOE and the interactions of fluorinated mix with minimum phosphorus were studied and compared with respect to fully formulated and plain ZDDP oils.

Findings

The optimized desirability shows the best condition that leads to more consistency in the breakdown of the tribofilm for a fixed contact load and fixed amount of fully formulated ZDDP oil. The influence of catalyst and PTFE fluorinated mix were examined. Scanning electron microscopy with chemistry analysis was developed. Hardness of the tribofilms, X‐ray of the wear track and Auger spectroscopy confirm the present of fluorine and phosphorus.

Originality/value

To ensure the reliability of the model, two original tests were conducted on the fully formulated and plain oil with minimum fluorinated mix.
Wear behaviour of aluminium/alumina/graphite hybrid metal matrix composites using Taguchi's techniques
Authors: Radhika N. , Subramaniam R.
Published: April 2013

Purpose

Recent advances in modern technology have generated the need to develop newer materials for better antifriction and wear properties. The objective is to analyse the significance of design parameters that significantly affects the dry sliding wear.

Design/methodology/approach

The tribological behaviour of aluminium alloy (Al‐Si10Mg) reinforced with alumina and graphite produced by liquid metallurgy is studied using pin‐on‐disc wear test apparatus under dry sliding condition. Experiments are conducted based on the plan of experiments generated through Taguchi technique. A L27 Orthogonal array is selected for analysis of the data. Influence of applied load, sliding speed and weight percentage of reinforcements on wear rate as well as the coefficient of friction during wearing process is studied using analysis of variance technique and regression equations for each response are developed. Finally, confirmation tests are carried out to verify the experimental results.

Findings

Mechanical property such as hardness has been evaluated and it was found that the hardness increases as reinforcement content increases. The wear rate and coefficient of friction increases by increasing load and decreases by increasing sliding speed and weight percentage of reinforcements. Results from analysis of variance reveals that the applied load has the highest influence on both wear rate and coefficient of friction, followed by sliding speed and weight percentage of reinforcement.

Practical implications

Aluminium hybrid metal matrix composites showing ample success in improving strength and wear resistance by utilising the optimal process condition.

Originality/value

The results obtained by this method are useful in improving the dry sliding wear resistance.
Optimize aluminum's surface roughness in rolling lubrication process
Authors: Sun Jianlin , Ying Huang , Lu Mingyu
Published: April 2013

Purpose

The purpose of this paper is to conduct a comprehensive experimental study to achieve optimal surface roughness of aluminum rolled with freshly ground rollers of two high rolling mills.

Design/methodology/approach

Various rolling oils and processing conditions are applied in the rolling process. Resultant surface roughness is measured with a profilometer; and surface topography of aluminum after rolling is observed under scanning electron microscope. In order to examine the oil film thickness (the most critical factor in rolling process), a planimeter is used to measure the area of oil patch resulting from a precisely controlled oil droplet, which in turn allows calculation of outlet oil film thickness as an approximation to inlet oil film thickness in the deformation region.

Findings

The experimental results indicate that two major factors have dominant impacts on aluminum's surface roughness in the rolling lubrication process: reduction of roller; and viscosity of lubrication oil. Based upon analysis of the experimental data, optimal roller reduction is found to be within range (23%, 30%) and optimal oil viscosity should be chosen, such that the ratio between inlet oil film thickness in the deformation region and the combined surface roughness is around 1.

Originality/value

According to the authors' observations, the above parameter choices generally assure excellent surface quality of aluminum after rolling.