bluuebunny/crossref_metadata_2025 huggingface dataset:
Can Novice Sonographers Accurately Locate an Endotracheal Tube With a Saline‐filled Cuff in a Cadaver Model? A Pilot Study
Authors: Uya Atim , Spear Dave , Patel Kalpesh , Okada Pam , Sheeran Paul , McCreight Audra
Published: March 2012

ACADEMIC EMERGENCY MEDICINE 2012; 19:361–364 © 2012 by the Society for Academic Emergency Medicine

Background:  No single confirmatory device can accurately distinguish between endotracheal, endobronchial, and esophageal intubation. Bedside ultrasound (US) shows promising potential for endotracheal tube (ETT) verification. Image acquisition depends on the approach used and the experience of the sonographer. Air within the trachea remains a challenge for interpretation of US images. Insufflation of the ETT cuff with saline helps overcome this difficulty and allows easy visualization of the cuff. This novel approach has not been studied in ETT verification among novice sonographers.

Objectives:  The objective was to evaluate the accuracy of novice sonographers in identifying proper ETT location and depth using US visualization of a saline‐filled cuff.

Methods:  Eight pediatric emergency medicine (PEM) fellows without prior training in airway bedside US participated in this prospective pilot study. Baseline US knowledge was assessed using a pretraining questionnaire. Fellows received a 20‐minute didactic training session focused on airway US, followed by a 30‐minute practice session. Using a linear US probe placed at the suprasternal notch, fellows identified the saline‐filled cuff of an ETT in both the trachea and the esophagus. Following training, the ETT was placed in either the esophagus or the trachea of the cadaver model by the principal investigator. ETT depth (adequacy) was confirmed by chest radiograph. Each PEM fellow, blinded to the placement of the ETT, used bedside US to determine ETT location and depth. If placement was determined to be tracheal, the fellow was asked to comment on adequacy of tube placement. Adequate placement was defined as complete visualization of the ETT cuff within the trachea at the suprasternal notch. This was used as a surrogate for correct depth. This study sequence was repeated five times for each trainee, following varying placement of the ETT in the trachea or esophagus.

Results:  The PEM fellows displayed limited baseline knowledge of US prior to receiving the training module (average score of 50% on pretest questionnaire). None had any prior airway bedside US experience. Following training, PEM fellows correctly identified ETT location in 39 of 40 scans, with a sensitivity of 96% (23 of 24) for identifying tracheal location. The tube depth was correctly identified in 22 of 23 scans identified as tracheal intubations.

Conclusions:  PEM fellows, lacking formal airway bedside US training, were able to identify the location and depth of a saline‐filled ETT above or at the suprasternal notch in an adult cadaver model following a 50‐minute teaching module. Filling the ETT cuff with saline allowed novice sonographers to accurately visualize the ETT within the trachea.
Maternal age and elective cesarean section in a low‐risk population
Authors: HERSTAD LINA , KLUNGSØYR KARI , SKJÆRVEN ROLV , TANBO TOM , EIDEM INGVILD , FORSÉN LISA , ÅBYHOLM THOMAS , VANGEN SIRI
Published: March 2012

Objective. To examine the association between maternal age and elective cesarean section in primiparous and para one women in a low‐risk population. Design. Population‐based registry study. Setting. Norway. Population. The source population was all mothers giving birth to their first or second child from 1 January 1999 to 31 December 2006. The final study population comprised 229 370 primiparous and para one low‐risk mothers. Methods. Data were extracted from the Medical Birth Registry of Norway. We constructed a low‐risk population by excluding pregnancies with medical conditions associated with elective cesarean section and maternal age. The association between maternal age and elective cesarean was analysed by relative‐risk models. Main outcome measures. Elective cesarean section. Results. In this low‐risk population, the proportion of cesarean section was 9%, and 27% of these were elective. Cesarean delivery increased substantially with increasing maternal age, especially elective cesarean section. In primipara, elective cesarean section increased from 0.6 to 7.5% of all deliveries, corresponding to a relative risk of 11.7 (95% confidence interval 8.9–15.4) in women ≥40 years relative to 20–24 years. When comparing women ≥40 years with those aged below 25 years, the relative risk in para one without previous cesarean section was 4.5 (95% confidence interval 3.5–5.8; the proportion increasing from 1.4 to 6.2%), while in para one with previous cesarean section it was 2.9 (95% confidence interval 2.4–3.6; the proportion increasing from 17.5 to 51.5%). Conclusions. We found a close association between maternal age and elective cesarean section in a low‐risk population.
MicroRNAs, new effectors and regulators of NF‐κB
Authors: Boldin Mark P. , Baltimore David
Published: March 2012

Summary:  Since its discovery 25 years ago, nuclear factor‐κB (NF‐κB) has emerged as a transcription factor that controls diverse biological functions, ranging from inflammation to learning and memory. Activation of NF‐κB initiates an elaborate genetic program. Some of the NF‐κB‐driven genes do not encode proteins but rather are precursors to microRNAs. These microRNAs play important roles in the regulation of the inflammatory process, some being inhibitory and others activating. Here, we discuss both the regulation of their expression and the function of some of these non‐coding RNA genes. We also include a personal discussion of how NF‐κB was first discovered.
Lessons from mathematically modeling the NF‐κB pathway
Authors: Basak Soumen , Behar Marcelo , Hoffmann Alexander
Published: March 2012

Summary:  Mathematical modeling has proved to be a critically important approach in the study of many complex networks and dynamic systems in physics, engineering, chemistry, and biology. The nuclear factor κB (NF‐κB) system consists of more than 50 proteins and protein complexes and is both a highly networked and dynamic system. To date, mathematical modeling has only addressed a small fraction of the molecular species and their regulation, but when employed in conjunction with experimental analysis has already led to important insights. Here, we provide a personal account of studying how the NF‐κB signaling system functions using mathematical descriptions of the molecular mechanisms. We focus on the insights gained about some of the key regulatory components: the control of the steady state, the signaling dynamics, and signaling crosstalk. We also discuss the biological relevance of these regulatory systems properties.
Dynamic roles for NF‐κB in HTLV‐I and HIV‐1 retroviral pathogenesis
Authors: Chan Jonathan K. , Greene Warner C.
Published: March 2012

Summary:  Viruses and hosts are involved in a continuing ‘arms race’. The body deploys multiple defenses; however, viruses utilize generally superior and more rapidly evolving tactics for negating host immune surveillance and viral clearance. In the case of the two major pathogenic human retroviruses, human immunodeficiency virus‐1 (HIV‐1) and human T‐lymphotrophic virus‐I (HTLV‐I), the nuclear factor‐κB (NF‐κB) transcription factor plays a key role in the host’s anti‐viral responses involving both the innate and adaptive arms of the immune response. Similarly, these retroviruses capably exploit NF‐κB for their replication, spread, and pathogenic functions. In this review, we discuss the dynamic and intimate interplay that occurs between NF‐κB and the HTLV‐I and HIV‐1 retroviral pathogens.
Regulation of cell death and autophagy by IKK and NF‐κB: critical mechanisms in immune function and cancer
Authors: Baldwin Albert S.
Published: March 2012

Summary:  The cellular response to survive or to undergo death is fundamental to the benefit of the organism, and errors in this process can lead to autoimmunity and cancer. The transcription factor nuclear factor κB (NF‐κB) functions to block cell death through transcriptional induction of genes encoding anti‐apoptotic and antioxidant proteins. This is essential for survival of activated cells of the immune system and for cells undergoing a DNA damage response. In Ras‐transformed cells and tumors as well as other cancers, NF‐κB functions to suppress apoptosis—a hallmark of cancer. Critical prosurvival roles for inhibitor of NF‐κB kinase (IKK) family members, including IKKε and TBK1, have been reported, which are both NF‐κB‐dependent and ‐independent. While the roles of NF‐κB in promoting cell survival in lymphocytes and in cancers is relatively clear, evidence has been presented that NF‐κB can promote cell death in particular contexts. Recently, IKK was shown to play a critical role in the induction of autophagy, a metabolic response typically associated with cell survival but which can lead to cell death. This review provides an historical perspective, along with new findings, regarding the roles of the IKK and NF‐κB pathways in regulating cell survival.
NF‐κB: where did it come from and why?
Authors: Gilmore Thomas D. , Wolenski Francis S.
Published: March 2012

Summary: The vast majority of research on nuclear factor κB (NF‐κB) signaling in the past 25 years has focused on its roles in normal and disease‐related processes in vertebrates, especially mice and humans. Recent genome and transcriptome sequencing efforts have shown that homologs of NF‐κB transcription factors, inhibitor of NF‐κB (IκB) proteins, and IκB kinases are present in a variety of invertebrates, including several in phyla simpler than Arthropoda, the phylum containing insects suchDrosophila. Moreover, many invertebrates also contain genes encoding homologs of upstream signaling proteins in the Toll‐like receptor signaling pathway, which is well‐known for its downstream activation of NF‐κB for innate immunity. This review describes what we now know or can infer and speculate about the evolution of the core elements of NF‐κB signaling as well as the biological processes controlled by NF‐κB in invertebrates. Further research on NF‐κB in invertebrates is likely to uncover information about the evolutionary origins of this key human signaling pathway and may have relevance to our management of the responses of ecologically and economically important organisms to environmental and adaptive pressures.
IκB kinase regulation of the TPL‐2/ERK MAPK pathway
Authors: Gantke Thorsten , Sriskantharajah Srividya , Sadowski Michael , Ley Steven C.
Published: March 2012

Summary:  Nuclear factor‐κB (NF‐κB) and mitogen‐activated protein kinase (MAPK) activation play central roles in the induction of gene expression in innate immune cells following pathogen recognition. TPL‐2 (tumor progression locus 2) is the MAP 3‐kinase component of an ERK‐1/2 (extracellular signal‐regulated kinase 1/2) MAPK pathway activated by Toll‐like receptor and tumor necrosis factor receptor family stimulation. In this review, we discuss results obtained from our laboratory and others that show that TPL‐2 signaling function is directly controlled by the inhibitor of NF‐κB (IκB) kinase (IKK) complex. Significantly, this means that IKK controls both NF‐κB and ERK activation. TPL‐2 is stoichiometrically complexed with the NF‐κB inhibitory protein, NF‐κB1 p105, and the ubiquitin‐binding protein ABIN‐2, both of which are required to maintain TPL‐2 protein stability. Binding to p105 also prevents TPL‐2 from phosphorylating MEK (MAPK/ERK kinase), its downstream target. Agonist stimulation releases TPL‐2 from p105‐inhibition by IKK‐mediated phosphorylation of p105, which triggers degradation of p105 by the proteasome. This facilitates TPL‐2 phosphorylation of MEK, in addition to liberating p105‐associated Rel subunits to translocate into the nucleus. We also examine evidence that TPL‐2 is critical for the induction of inflammation and may play a role in development and/or progression of certain types of cancer. Finally, we consider the potential of TPL‐2 as an anti‐inflammatory drug target for treatment of certain types of inflammatory disease and cancer.
Pathogenetic importance and therapeutic implications of NF‐κB in lymphoid malignancies
Authors: Lim Kian‐Huat , Yang Yibin , Staudt Louis M.
Published: March 2012

Summary:  Derangement of the nuclear factor κB (NF‐κB) pathway initiates and/or sustains many types of human cancer. B‐cell malignancies are particularly affected by oncogenic mutations, translocations, and copy number alterations affecting key components the NF‐κB pathway, most likely owing to the pervasive role of this pathway in normal B cells. These genetic aberrations cause tumors to be ‘addicted’ to NF‐κB, which can be exploited therapeutically. Since each subtype of lymphoid cancer utilizes different mechanisms to activate NF‐κB, several different therapeutic strategies are needed to address this pathogenetic heterogeneity. Fortunately, a number of drugs that block signaling cascades leading to NF‐κB are in early phase clinical trials, several of which are already showing activity in lymphoid malignancies.
IKK biology
Authors: Liu Fei , Xia Yifeng , Parker Aaron S. , Verma Inder M.
Published: March 2012

Summary:  The inhibitor of nuclear factor‐κB (IκB) kinase (IKK) complex is the master regulator of the NF‐κB signaling pathway. The activation of the IKK complex is a tightly regulated, highly stimulus‐specific, and target‐specific event that is essential for the plethora of functions attributed to NF‐κB. More recently, NF‐κB‐independent roles of IKK members have brought increased complexity to its biological function. This review highlights some of the major advances in the studies of the process of IKK activation and the biological roles of IKK family members, with a focus on NF‐κB‐independent functions. Understanding these complex processes is essential for targeting IKK for therapeutics.
Ubiquitination in signaling to and activation of IKK
Authors: Chen Zhijian J.
Published: March 2012

Summary:  A role for polyubiquitination in the activation of inhibitor of NF‐κB (IκB) kinase (IKK) through a proteasome‐independent mechanism was first reported in 1996, but the physiological significance of this finding was not clear until 2000 when TRAF6 was found to be a ubiquitin E3 ligase that catalyzes lysine‐63 (K63) polyubiquitination. Since then, several proteins known to regulate IKK have been linked to the ubiquitin pathway. These include the deubiquitination enzymes CYLD and A20 that inhibit IKK, and the ubiquitin binding proteins NEMO and TAB2 which are the regulatory subunits of IKK and TAK1 kinase complexes, respectively. Now accumulating evidence strongly supports a central role of K63 polyubiquitination in IKK activation by multiple immune and inflammatory pathways. Interestingly, recent research suggests that some alternative ubiquitin chains such as linear or K11 ubiquitin chains may also play a role in certain pathways such as the TNF pathway. Here I present a historical narrative of the discovery of the role of ubiquitin in IKK activation, review recent advances in understanding the role and mechanism of ubiquitin‐mediated IKK activation, and raise some questions to be resolved in future research.
The application of principal component analysis to quantify technique in sports
Authors: Federolf P. , Reid R. , Gilgien M. , Haugen P. , Smith G.
Published: March 2012

Analyzing an athlete's “technique,” sport scientists often focus on preselected variables that quantify important aspects of movement. In contrast, coaches and practitioners typically describe movements in terms of basic postures and movement components using subjective and qualitative features. A challenge for sport scientists is finding an appropriate quantitative methodology that incorporates the holistic perspective of human observers. Using alpine ski racing as an example, this study explores principal component analysis (PCA) as a mathematical method to decompose a complex movement pattern into its main movement components. Ski racing movements were recorded by determining the three‐dimensional coordinates of 26 points on each skier which were subsequently interpreted as a 78‐dimensional posture vector at each time point. PCA was then used to determine the mean posture and principal movements (PMk) carried out by the athletes. The first four PMk contained 95.5 ± 0.5% of the variance in the posture vectors which quantified changes in body inclination, vertical or fore‐aft movement of the trunk, and distance between skis. In summary, calculating PMk offered a data‐driven, quantitative, and objective method of analyzing human movement that is similar to how human observers such as coaches or ski instructors would describe the movement.
A WFC3 study of globular clusters in NGC 4150: an early-type minor merger
Authors: Kaviraj Sugata , Crockett R. Mark , Whitmore Bradley C. , Silk Joseph , O'Connell Robert W. , Windhorst Rogier A. , Mutchler Max , Rejkuba Marina , Yi Sukyoung , Frogel Jay A. , Calzetti Daniela
Published: March 2012

We combine near-ultraviolet (NUV; 2250 Å) and optical (U, B, V, I) imaging from the Wide Field Camera 3 (WFC3), on-board the Hubble Space Telescope (HST), to study the globular cluster (GC) population in NGC 4150, a sub-L* (MB∼−18.48 mag) early-type minor-merger remnant in the Coma I cloud. We use broad-band NUV—optical photometry from the WFC3 to estimate individual ages, metallicities, masses and line-of-sight extinctions [E(B−V)] for 63 bright (MV < −5 mag) GCs in this galaxy. In addition to a small GC population with ages greater than 10 Gyr, we find a dominant population of clusters with ages centred around 6 Gyr, consistent with the expected peak of stellar mass assembly in faint early types residing in low-density environments. The old and intermediate-age GCs in NGC 4150 are metal poor, with metallicities less than 0.1 Z⊙, and reside in regions of low extinction [E(B−V) < 0.05 mag]. We also find a population of young, metal-rich (Z > 0.3 Z⊙) clusters that have formed within the last Gyr and reside in relatively dusty [E(B−V) > 0.3 mag] regions that are coincident with the part of the galaxy core that hosts significant recent star formation. Cluster disruption models (in which ∼80–90 per cent of objects younger than a few ×108 yr dissolve every dex in time) suggest that the bulk of these young clusters are a transient population.
Characterizing Mathematics Classroom Practice: Impact of Observation and Coding Choices
Authors: Ing Marsha , Webb Noreen M.
Published: March 2012

Large‐scale observational measures of classroom practice increasingly focus on opportunities for student participation as an indicator of instructional quality. Each observational measure necessitates making design and coding choices on how to best measure student participation. This study investigated variations of coding approaches that may be feasible in large‐scale studies, and the ramifications of these variations for drawing inferences about instructional quality. Using data from classroom videos, we found that decisions about whether to keep track of individual students in the coding, observe multiple contexts in the classroom (e.g., whole‐class and small‐group discussions), and capture nuances of student participation changed the resulting characterizations of classroom practice. Most importantly, simplifying the coding approach did not fully capture and even misrepresented the level and nature of student participation in many classrooms.
Memorializing Colonial Power: The Death of Frank Paul
Authors: Razack Sherene H.
Published: March 2012

Through an analysis of an inquiry into the death of an Aboriginal man in custody, I argue that the contemporary colonial relationship between white settlers and those whom they have dispossessed is spatially and racially organized as one between modern subjects and those who must be assisted into modernity. Law, in the form of an inquiry, serves to confirm these arrangements. In Part One, Redemption, I begin with the inquiry's conclusion that Frank Paul was intrinsically vulnerable. In Part Two, Memorializing, I unravel Frank Paul's story, showing the imprinting of colonial power on his body. In Part Three, Cleansing, I show that the Aboriginal body must be repeatedly evicted from the civilized spaces of the settler. In Part Four, Abandonment, when the cleansing ritual proves lethal, death is declared comprehensible, given the body's incompatibility with modern life. In Part Five, Death Worlds, I suggest that the Downtown East Side of Vancouver, Canada where Frank Paul lived is maintained as a death world where humans are reduced to the status of the living dead. Throughout, I argue that Frank Paul must be understood and remembered as an Aboriginal man whose body bore the imprint of an ongoing colonialism.
Experts Judging Experts: The Role of Expertise in Reviewing Agency Decision Making
Authors: Miller Banks , Curry Brett
Published: March 2012

What role does judicial subject matter expertise play in the review of agency decisions? Using a data set of decisions in which the Board of Patent Appeals and Interferences (BPAI) is reviewed by the Court of Appeals for the Federal Circuit, we investigate this question and find that greater subject matter expertise does make it more likely that a judge will vote to reverse an agency decision.
Singapore's Culture War over Section 377A: Through the Lens of Public Choice and Multilingual Research
Authors: Chen Jianlin
Published: March 2012

The 2007 debate over the retention of Singapore's male sodomy law provision set off a vigorous and passionate public debate reminiscent of the US culture war. However, the Singapore government's final decision reflects an interesting compromise. The law was retained, but its moral content was severely curtailed. This article critically examines this episode and explores the political dynamics driving the compromise. Enriching public choice theory on interest group capture, this article argues that the ruling party's political dominance coupled with limited but real political competition is surprisingly effective in aligning the government's position with the preference of the majority despite concerted pressure from well-mobilized minority interest groups. Current legal scholarly work on this debate has focused on the “vigorous debate” in the English-language forums. In this article, the examination of the contemporaneous discourse in Chinese and Malay newspapers enables a more accurate and comprehensive appreciation of this culture war episode.
Poxvirus infection outbreak in common ringtails (Pseudocheirus peregrinus)
Authors: Vogelnest L , Stewart S , Sangster C
Published: March 2012

Viruses belonging to the Poxviridae family have long been recognised as pathogens of invertebrates and vertebrates alike. Poxvirus infection in Australian macropodids is well described, but few cases have been documented in marsupial species beyond this family. Only one instance has been previously reported in the common ringtail (Pseudocheirus peregrinus). This case report describes a poxvirus infection outbreak in a group of common ringtails held within a zoological collection in eastern Australia.
Canine vector‐borne disease pathogens in dogs from south‐east Queensland and north‐east Northern Territory
Authors: Hii SF , Kopp SR , Thompson MF , O'Leary CA , Rees RL , Traub RJ
Published: March 2012

Objectives  To determine the prevalence of canine vector‐borne diseases (CVBD: Babesia spp., Anaplasma spp., Ehrlichia spp., haemotropic mycoplasmas and Hepatozoon) in Australian dogs; namely, dogs from pounds in south‐east Queensland and an indigenous Aboriginal community in the north‐east of the Northern Territory.

Design and procedure  Blood samples were collected from 100 pound dogs and 130 Aboriginal community dogs and screened for the CVBD pathogens using polymerase chain reaction (PCR). All positive PCR products were sequenced for species confirmation.

Results  In total, 3 pound dogs and 64 Aboriginal community dogs were infected with at least one CVBD pathogen. Overall, B. vogeli was detected in 13 dogs, A. platys in 49, M. haemocanis in 23, Candidatus Mycoplasma haematoparvum in 3 and C. M. haemobos in 1 dog. Co‐infections were detected in 22 Aboriginal community dogs.

Conclusions  This study found B. vogeli, A. platys and haemotropic mycoplasma infections to be common in dogs in subtropical and tropical areas of Australia. This study also reports for the first time the prevalence and genetic characterisation of haemotropic mycoplasmas in dogs in Australia.
Qualia Compression
Authors: Decock Lieven , Douven Igor
Published: March 2012

Color qualia inversion scenarios have played a key role in various philosophical debates. Most notably perhaps, they have figured in skeptical arguments for the fundamental unknowability of other persons’ color experiences. For these arguments to succeed, it must be assumed that a person's having inverted color qualia may go forever unnoticed. This assumption is now generally deemed to be implausible. The present paper defines a variant of color qualia inversion—termed ‘‘color qualia compression’’—and argues that the possibility of undetectable color qualia compression is immune to the objections that have been levelled against color qualia inversion arguments, and that color qualia compression scenarios support full‐blown skepticism regarding other people's color experiences.
Belief, Credence, and Pragmatic Encroachment1
Authors: Ross Jacob , Schroeder Mark
Published: March 2012

This paper compares two alternative explanations of pragmatic encroachment on knowledge (i.e., the claim that whether an agent knows that p can depend on pragmatic factors). After reviewing the evidence for such pragmatic encroachment, we ask how it is best explained, assuming it obtains. Several authors have recently argued that the best explanation is provided by a particular account of belief, which we call pragmatic credal reductivism. On this view, what it is for an agent to believe a proposition is for her credence in this proposition to be above a certain threshold, a threshold that varies depending on pragmatic factors. We show that while this account of belief can provide an elegant explanation of pragmatic encroachment on knowledge, it is not alone in doing so, for an alternative account of belief, which we call the reasoning disposition account, can do so as well. And the latter account, we argue, is far more plausible than pragmatic credal reductivism, since it accords far better with a number of claims about belief that are very hard to deny.
Sonoclot® Evaluation of Single‐ and Multiple‐Dose Subcutaneous Unfractionated Heparin Therapy in Healthy Adult Dogs
Authors: Babski D.M. , Brainard B.M. , Ralph A.G. , Pittman J.R. , Koenig A.
Published: March 2012

Background

Heparin therapy is difficult to monitor due to variation in animal response. While laboratory measurements of activated partial thromboplasin time (aPTT) and Anti‐Xa activity (AXA) accurately describe heparin effect, their availability is limited.

Hypothesis

Sonoclot analysis would be as sensitive as AXA and aPTT to monitor effects of unfractionated heparin (UFH) in healthy adult dogs.

Animals

Six adult mixed‐breed dogs.

Methods

A prospective study design was employed. On day 1, baseline samples were collected (CBC, PT, aPTT, and Sonoclot), and UFH (300 U/kg SC) was administered to 6 dogs following an IV loading dose of 50 U/kg. Sonoclot and aPTT were performed hourly for 12 hours. AXA was assayed at hours 3, 6, 9, and 12. UFH (300 U/kg q8 h SC) was administered at 12 hours, and subsequently (q8 h) for 2 additional days. On day 4, a final dose of UFH was administered, and a sampling protocol identical to day 1 was performed.

Results

Sonoclot activated clotting time (ACT) and clot rate (CR) correlated with AXA (R = 0.69, R = 0.65, respectively, P < .001), although to a lesser degree than aPTT (R = 0.75, P < .001). Linear regression using ACT and CR as covariates indicated a stronger correlation with AXA (R = 0.73, P < .001). ACT values strongly correlated with aPTT (R = 0.87, P < .001).

Conclusions and Clinical Importance

Administration of UFH to healthy dogs results in progressive changes in Sonoclot values. AXA was correlated with a combination of ACT and CR and with aPTT. Sonoclot may play a role in monitoring UFH therapy; however, prospective studies evaluating its utility in clinical cases are warranted.
Hydroxyl scavenging activity accounts for differential antioxidant protection of Plantago major against oxidative toxicity in isolated rat liver mitochondria
Authors: Mello Joyce C , Guimarães Natalia S S , Gonzalez Mariano V D , Paiva Juliana S , Prieto Tatiana , Nascimento Otaciro R , Rodrigues Tiago
Published: March 2012

Objectives

The aim of this work was to study the effects of P. major against the oxidative damage of isolated rat liver mitochondria.

Methods

The extracts were obtained using methanol (MeOH), ethyl acetate (EAc), dichloromethane (DCM), and hexane (Hex) as solvents.

Key findings

Hex, DCM, and EAc totally, and MeOH partially, inhibited ROS generation and lipid peroxidation of membranes induced by Fe2+ or t-BOOH. However, only MeOH was able to prevent the t-BOOH-induced glutathione and NAD(P)H oxidation. All extracts chelated Fe2+ and reduced DPP Hradicals. EPR analysis revealed that P. major exhibited potent scavenger activity for hydroxyl radicals.

Conclusions

The potent antioxidant activity exhibited by P. major was able to prevent oxidative mitochondrial damage, contributing to the understanding of its hepatoprotective action against ROS-mediated toxicity.
Ajuga iva aqueous extract improves reverse cholesterol transport in streptozotocin-induced diabetic rat
Authors: Taleb-Senouci Douja , Lacaille-Dubois Marie A , Bouchenak Malika
Published: March 2012

Objectives

The aim of this study was to determine the effects of Ajuga iva aqueous extract on lecithin : cholesterol acyltransferase (LCAT) activity and amount and composition of high-density lipoprotein (HDL)2 and (HDL)3, in streptozotocin (STZ)-induced diabetic rats.

Methods

Diabetes was induced in male Wistar rats by intraperitoneal injection of STZ (60 mg/kg body weight). Diabetic rats (n = 12) were divided into two groups. The diabetic control group (D) received a 20% casein diet and the diabetic treated group received the same diet supplemented with A. iva aqueous extract (0.5 g/100 g diet) (DAi), for 4 weeks.

Key findings

Total cholesterol and HDL3-C were respectively decreased by 32% and 55% in the DAi group compared with the D group, whereas HDL2-C was increased by 30%. The amounts of HDL2 and HDL3, which were the sum of apolipoproteins, unesterified cholesterol (UC), cholesteryl esters (CEs), triacylglycerols (TGs) and phospholipids (PLs), showed no significant difference. A. iva treatment increased LCAT by 33% and its cofactor-activator, apolipoprotein A-I, by 58%. HDL3-PL (enzyme substrate) and HDL3-UC (acyl group acceptor) were respectively decreased by 70% and 57%, whereas HDL2-CE (product of LCAT reaction) was enhanced by 30%.

Conclusions

In STZ-induced diabetic rats, A. iva improves reverse cholesterol transport by enhancing LCAT activity, leading to anti-atherogenic effects.
The slice Burnside ring and the section Burnside ring of a finite group
Authors: Bouc Serge
Published: March 2012

This paper introduces two new Burnside rings for a finite group G, called the slice Burnside ring and the section Burnside ring. They are built as Grothendieck rings of the category of morphisms of G-sets and of Galois morphisms of G-sets, respectively. The well-known results on the usual Burnside ring, concerning ghost maps, primitive idempotents, and description of the prime spectrum, are extended to these rings. It is also shown that these two rings have a natural Green biset functor structure. The functorial structure of unit groups of these rings is also discussed.
Influence of Needle Insertion Speed on Backflow for Convection-Enhanced Delivery
Authors: Casanova Fernando , Carney Paul R. , Sarntinoranont Malisa
Published: March 2012

Fluid flow back along the outer surface of a needle (backflow) can be a significant problem during the direct infusion of drugs into brain tissues for procedures such as convection-enhanced delivery (CED). This study evaluates the effects of needle insertion speed (0.2 and 1.8 mm/s) as well as needle diameter and flow rate on the extent of backflow and local damage to surrounding tissues. Infusion experiments were conducted on a transparent tissue phantom, 0.6% (w/v) agarose hydrogel, to visualize backflow. Needle insertion experiments were also performed to evaluate local damage at the needle tip and to back out the prestress in the surrounding media for speed conditions where localized damage was not excessive. Prestress values were then used in an analytical model of backflow. At the higher insertion speed (1.8 mm/s), local insertion damage was found to be reduced and backflow was decreased. The compressive prestress at the needle-tissue interface was estimated to be approximately constant (0.812 kPa), and backflow distances were similar regardless of needle gauge (22, 26, and 32 gauge). The analytical model underestimated backflow distances at low infusion flow rates and overestimated backflow at higher flow rates. At the lower insertion speed (0.2 mm/s), significant backflow was measured. This corresponded to an observed accumulation of material at the needle tip which produced a gap between the needle and the surrounding media. Local tissue damage was also evaluated in excised rat brain tissues, and insertion tests show similar rate-dependent accumulation of tissue at the needle tip at the lower insertion speed. These results indicate that local tissue damage and backflow may be avoided by using an appropriate insertion speed.
Interactive Two-Stage Rendering Technique of Deformable Part Through Haptic Interface
Authors: Wang Zhaoguang , Dumont Georges
Published: March 2012

Virtual Reality technology has been widely applied in the background of industrial evaluation applications. However, a large majority of these applications are focusing on haptics-based assemblies which mainly deal with rigid-body dynamics. Here we concern the real-time haptic interaction with deformable mock-ups aiming at the industrial design evaluation of mechanical parts. The main challenge of this application is that a tradeoff between the deformation accuracy and the interaction performance has to be achieved. In this paper, we propose a two-stage method for a real-time deformation modelling by combining an off-line pre-computation phase and an on-line deformation interaction phase. The key contributions of this paper lie on two aspects. First, during off-line phase, we propose a mesh analysis method which allows us to pre-compute different deformation spaces by anticipating the evaluation scenarios. Moreover, a real-time switch among different deformation spaces is developed so that the on-line deformation computation can focus on degrees of freedom where necessary with respect to users’ interactions. Second, during on-line phase, we apply a division scheme to divide the deformation process into two separate modules which are implemented on different threads to ensure the haptic interaction performance. Experiments are carried out based on a prototype implementation concerning different models of growing complexity. The deformation accuracy and the real-time performance are discussed.
Do Observers Perceive Depth in Reaching Task Within Virtual Environments?
Authors: Naceri Abdeldjallil , Hoinville Thierry , Chellali Ryad , Ortiz Jesus , Hennig Shannon
Published: March 2012

The main objective of this paper is to investigate whether observers are able to perceive depth of virtual objects within virtual environments during reaching tasks. In other words, we tackled the question of observer immersion in a displayed virtual environment. For this purpose, eight observers were asked to reach for a virtual objects displayed within their peripersonal space in two conditions: condition one provided a small virtual sphere that was displayed beyond the subjects index finger as an extension of their hand and condition two provided no visual feedback. In addition, audio feedback was provided when the contact with the virtual object was made in both conditions. Although observers slightly overestimated depth within the peripersonal space, they accurately aimed for the virtual objects based on the kinematics analysis. Furthermore, no significant difference was found concerning the movement between conditions for all observers. Observers accurately targeted the virtual point correctly with regard to time and space. This suggests the virtual environment sufficiently simulated the information normally present in the central nervous system.
BREP Identification During Voxel-Based Collision Detection for Haptic Manual Assembly
Authors: Faas Daniela , Vance Judy M.
Published: March 2012

This paper presents a novel method to tie geometric boundary representation (BREP) to voxel-based collision detection for use in haptic manual assembly simulation. Virtual Reality, in particular haptics, has been applied with promising results to improve preliminary product design, assembly prototyping and maintenance operations. However, current methodologies do not provide support for low clearance assembly tasks, reducing the applicability of haptics to a small subset of potential situations. This paper discusses a new approach, which combines highly accurate CAD geometry (boundary representation) with voxel models to support a hybrid method involving both geometric constraint enforcement and voxel-based collision detection to provide stable haptic force feedback. With the methods presented here, BREP data can be accessed during voxel-based collision detection. This information can be used for constraint recognition and lead to constraint-guidance during the assembly process.
An Augmented Reality Based Application for Furnishing Configuration and Evaluation
Authors: Filippi Stefano , Barattin Daniela , Amato Marco , Tozzi Riccardo
Published: March 2012

Virtual reality as the way to display digital models and to interact with them has flourished in industrial contexts some years ago, both for design and marketing reasons. However, some specific sectors, e.g. furnishings and garments, would prefer to evaluate their products in a real environment, where their models could be easily placed, and where the interaction with them could take place in a natural way. These requirements suggested the design of an application, based on the augmented reality, which allows users placing digital models of pieces of furniture in real domestic environments, verifying their dimensional and aesthetic compatibility with the existing context, and interacting with them to test functional behavior and usability issues. Such a project would result interesting both for possible customers and for designers, because some important design hints could come from its adoption. An application prototype has been developed and tested in the field in a couple of case studies.
FunctionalDMU: Co-Simulation of Mechatronic Systems in a Virtual Environment
Authors: Wagner Mathias , Schneider Peter , Hinnerichs Andreas , Bruder Thomas , Stork Andre´
Published: March 2012

Digital Mock-up (DMU) is a widely introduced technology to virtually investigate geometrical and mechanical product properties. Functional Digital Mock-up (FunctionalDMU) is a combination of traditional DMU with behavioral simulation in mechatronics. Enhancing DMU with functional aspects, considerably more insight in product properties can be gained. To enable FunctionalDMU two main tasks have to be solved: a) simulators in the areas of mechanics, electronics, and software simulation have to talk to each other (coupling) and b) the simulation results have to be visualized in an interactive DMU environment. In this paper we present an independent and open approach to a FunctionalDMU framework including co-simulation. Starting with proprietary and natively given behavior and geometric models (in formats like JT), we wrap the behavior models into SysML to enable data exchange on an agreed and standardized format. The native behavior models still are executed in the corresponding simulators. The simulators are linked to the FunctionalDMU framework using a wrapping approach. Currently we support simulators such as Matlab/Simulink, Dymola, Saber, Rhapsody, SimPack, ANSYS with our framework. During simulation a simulator coupling algorithm controls the simulation processes. A dedicated visualization environment enables the user to interact with the simulation, i.e., to send simulation stimuli, change parameters, observe the simulation run etc. This paper introduces the components of the FunctionalDMU framework and illustrates the approach with an application example.
Design of Warning Delivery Strategies in Advanced Rider Assistance Systems
Authors: Valtolina Stefano , Vanzi Sara , Montanari Roberto , Minin Luca , Marzani Stefano
Published: March 2012

European statistics show that motorbikes road accidents are extremely high and the reduction of such accidents is one of the main concern for the European community. Advanced Driver Assistance Systems are safety electronic systems used to assist the driver in avoiding risks and road accidents, by means of warnings sent before the situation becomes critical. The use of such systems in motorcycle context is currently lacking due to numerous variables that it is necessary to consider for making sure the riding. This paper presents an innovative research for the safety improvement of Powered-Two-Wheelers (PTW) by means of the development of effective and rider-friendly interfaces and interaction elements for the on-bike assistance systems. In particular, the paper presents the experimental results on comfort and safety aspects of two advanced rider assistance systems: the Frontal Collision Warning (FCW) and the Lane Change Support (LCS). The study starts from analyzing results of motorcycle simulator tests performed in 3D Virtual Reality environments which aim is to find recursive rider’s behavior patterns in FCW and LCS situations according to different multimodal type of warnings (visual, audio and haptic). Afterward, the paper presents three different machine learning models, Hidden Markov Models, Support Vector Machines and Artificial Neural Networks, that have been considered for simulating the riders’ behavior patterns according to the reaction time needful for avoiding a front collision. These simulation behavior models enabled to design a warning delivery strategy for apprising the rider of possible dangerous situations due to front collisions. Finally, the paper describes how this warning delivery strategy has been implemented in a HMI (Human Machine Interface) installed on motorbikes. This HMI is thought to offer an effective FCW system based on an understandable but, at the same time, discreet and unobtrusive rider-friendly solution.
A Global Approach to the Design and Evaluation of Virtual Reality Medical Simulators
Authors: Bayona Sofia , Fernandez-Arroyo Jose Manuel , Bayona Pilar , Martin Isaac
Published: March 2012

VR Simulators are a powerful alternative to traditional educational techniques in many domains; and in particular, in surgery. Although they offer new possibilities for learning, training and assessment, they still found difficult to be accepted and integrated into hospitals. In this paper, we explain what we consider the key issues to create successful VR simulators, and we present two methodologies: the guidelines for the simulator design and the evaluation of their validity. Research on VR surgical simulators should be interdisciplinary. It involves medicine, educational psychology, computer science, and engineering. Optimal interdisciplinary communication is difficult, and most projects in surgical simulation are strongly influenced by the engineering perspective, with little or no contributions from the others. This unbalance often leads to a premature end of the project or to simulators which are less practical for surgeons. A design methodology should be used as a guide in the process of creating VR simulators. A thorough description of the problem, the simulator’s role, and an exhaustive task analysis will lead to the identification of the requirements. For the technical implementation, decisions will be taken related to the hardware interface and the interaction that users will have with the virtual world; which will determine collision detection and response algorithms, and the behaviour of the 3D models. In addition to the technical testing, it is necessary to prove the validity of the simulator and design procedures to measure the user performance. We explain a methodology to evaluate the validity (face, content, and criterion-related validity), reliability and transfer of skills from a VR simulator to the real environment in a structured and rigorous way. Following this methodology, an evaluation experiment involving 19 orthopaedic doctors using a VR arthroscopy simulator was carried out. Results prove face and content validities, and inform about the factors and measures that are considered important for arthroscopic surgery. In order to consolidate the research results, we encourage the establishment of an intersectorial consortium with agents from the academic, healthcare and industrial sectors to ensure the long-term sustainability of research lines, additional funding, and to guarantee that simulators, once validated, can be widely available in hospitals. This paper presents a global approach including relevant guidelines and methodologies for designing and evaluating VR simulators. It can provide a solid structure for other researchers when facing those processes and contribute to the successful integration of VR simulators within the educational curriculum.
Towards the Automatic Measurement of Human Performance in Virtual Environments for Industrial Safety
Authors: Colombo Simone , Manca Davide , Brambilla Sara , Totaro Roberto , Galvagni Remo
Published: March 2012

Human errors during operations, probably more clearly referred to as human or action failures, play an important role in causing industrial accidents. The assessment of human performance, through the identification and measurement of human failures, is a complicated, but essential, task to accomplish in real process plants. Virtual Reality (VR) provides a suitable mean to identify human failures, measure human performance and train field operators to risky situations. Nevertheless, not all the aspects relevant to Human Factors (HF) can be easily identified, assessed and reproduced in Virtual Environments (VE). Indeed, VR seems to be better suited to measure cognitive capabilities, such as Command, Control, and Communication capabilities (commonly referred to as C3 capabilities), rather than anthropometric ones like physical coordination, precision in manipulating and ability to reach. Actually, this is certainly not due to the intrinsic nature of VR but, rather, to its current state of development. Industrial environments, if properly recreated in VR, can allow anticipating people behavior, thus enabling to identify whether critical actions have been identified and to measure human performance. Further, by changing in real-time those experiment parameters, such as weather conditions (e.g., wind speed, direction, intensity) and process variables (e.g., pressure, flow rate, heat duties), the strength of environmental stressors, singularly or in a combined fashion, on cognitive capabilities such as recognition, anticipation, prioritization, and planning, can be suitably measured and assessed. The consequences of actions performed by operators can even be experienced instantly, thus allowing for an incisive and persistent training effect. The manuscript presents an integrated approach to step towards the use of VR to (a) verify whether the identified human failure types are all of those that might occur in reality, (b) identify additional human failure types that might affect plant safety, (c) measure the influence of environmental stressors on human performance. Further, the approach presents a way to collect automatically HF data to be used and manipulated for giving rise to Human Performance Indexes (HPI). Eventually, HPI can then be of real help in supporting decision-making processes for industrial safety.