bluuebunny/crossref_metadata_2025 huggingface dataset:
The mechanical and tribological properties of MAH-grafted HDPE filled SiO2/PMMA composite
Authors: Fu Yuan-fei , Li Jing , Zhang Fu-qiang , Xu Kan
Published: March 2012

Maleic anhydride–grafted high-density polyethylene (HDPE; PE- g-MAH) was used to fill the interphase layer of silicon dioxide (SiO2)/polymethyl methacrylate (PMMA) composites. The mechanical, friction and wear properties of SiO2/PMMA/HDPE composites were investigated on a ring-on-ring friction and wear tester with AISI 1045 steel metallic ring counterface under dry friction conditions. Scanning electron microscopy (SEM) was utilized to study the worn surfaces of PMMA composites. Experimental results showed that the addition of HDPE decreased the friction coefficient of SiO2/PMMA composites slightly and reduced the wear volume loss of the PMMA composites obviously. SEM studies indicated that the addition of HDPE could reduce the abrasive wear of SiO2/PMMA composites. The dispersion of SiO2 in PMMA composites was also improved.
The Neurodevelopmental Basis of Math Anxiety
Authors: Young Christina B. , Wu Sarah S. , Menon Vinod
Published: March 2012

Math anxiety is a negative emotional reaction to situations involving mathematical problem solving. Math anxiety has a detrimental impact on an individual’s long-term professional success, but its neurodevelopmental origins are unknown. In a functional MRI study on 7- to 9-year-old children, we showed that math anxiety was associated with hyperactivity in right amygdala regions that are important for processing negative emotions. In addition, we found that math anxiety was associated with reduced activity in posterior parietal and dorsolateral prefrontal cortex regions involved in mathematical reasoning. Multivariate classification analysis revealed distinct multivoxel activity patterns, which were independent of overall activation levels in the right amygdala. Furthermore, effective connectivity between the amygdala and ventromedial prefrontal cortex regions that regulate negative emotions was elevated in children with math anxiety. These effects were specific to math anxiety and unrelated to general anxiety, intelligence, working memory, or reading ability. Our study identified the neural correlates of math anxiety for the first time, and our findings have significant implications for its early identification and treatment.
Control and resistance in the psychology of lying
Authors: Derksen Maarten
Published: March 2012

Psychology’s obsession with control, with manipulating the experimental situation and the behavior of participants, has often been criticized. Mainstream, experimental psychology, it is said, abuses its power in the laboratory to artificially create docile participants who fit its experimental regime. I argue that this criticism accords too much control to the experimenter. Using the psychology of lying and lie detection as an example, I show that the psychologist does not exert full control in the laboratory, but meets resistance. In the psychological laboratory, lying and lie detection are constructed on a technological model in which both the psychologist and the liar are operators of devices, locked in battle. The critical focus, I conclude, should be on the technologies and counter-technologies at work on the laboratory, and on the limitations of this model.
The fragility of a robust therapeutic technique: The case of Bion’s experience group
Authors: Vikkelsø Signe
Published: March 2012

How can therapeutic techniques simultaneously be tools for emancipation and act as subtle forms of control? The article investigates this seeming paradox by examining a technique for group analysis developed by Wilfred Bion aimed at surfacing the inclination of a group to prompt inexpedient leadership. Over time, the technique developed a reputation as a very effective, but also a very challenging, and even disturbing method, and was subsequently translated into less intense versions. By analyzing its key principles and operational risks, the article discusses Bion’s experience group as illustrative of the “scaling problems” associated with the operation of therapeutic techniques. The handling of such problems is central to the effects and survivability of a particular method, and in this case the original purpose was gradually eroded. The article concludes that a focus on the “sociomechanics” of such techniques offers an opportunity to resuscitate their instituted purposes combined with a more precise understanding of the risks associated with their attainment.
Successful treatment of chronic inflammatory demyelinating polyneuropathy (CIDP) in systemic lupus erythematosus (SLE) with oral cyclophosphamide
Authors: Jasmin R , Sockalingam S , Shahrizaila N , Cheah T-E , Zain AA , Goh K-J
Published: March 2012

Peripheral neuropathy is a known manifestation of systemic lupus erythematosus. However, the association of primary autoimmune inflammatory neuropathies such as chronic inflammatory demyelinating polyneuropathy (CIDP) with SLE is uncommon. We report a 26-year-old man who simultaneously presented with severe CIDP and photosensitive rash, but was unresponsive to intravenous immunoglobulin infusion and continued to progress. He was found to have underlying SLE and improved with combined corticosteroid and immunosuppressive therapy with oral cyclophosphamide. CIDP with underlying SLE may be more resistant to conventional therapy with IVIG, requiring the addition of other immunosuppressive agents.
The Brain’s Learning and Control Architecture
Authors: Chein Jason M. , Schneider Walter
Published: March 2012

Many brain-imaging studies are designed with the goal of isolating brain regions responsible for a specific mental function. The results, which reveal islands of activity scattered about the brain, can give the impression that the brain is just a disorganized collection of specialized processing centers. However, examination of how brain activity changes as a new skill is learned reveals a structured learning architecture composed of three hierarchically organized systems, each with a distinct role in learning and each characterized by a distinct pattern of learning-dependent plasticity. These systems are a representation system, which supports associative learning; a cognitive control network, which allocates attention during the execution of newly learned behaviors; and a metacognitive system, which guides the establishment of new behavioral routines, monitors the quality of ongoing behaviors, and oversees the transitions from one behavior to another. The combined involvement of these systems allows humans to learn rapidly and to flexibly transfer existing knowledge to novel contexts.
What Is It Like to Have a Body?
Authors: Longo Matthew R. , Haggard Patrick
Published: March 2012

Few issues in psychology are as fundamental or as elusive as the sense of one’s own body. Despite widespread recognition of the link between body and self, psychology has only recently developed methods for the scientific study of bodily awareness. Experimental manipulations of embodiment in healthy volunteers have allowed for important advances in knowledge. Synchronous multisensory inputs from different modalities play a fundamental role in producing body ownership: the feeling that my body is “mine.” Indeed, appropriate multisensory stimulation can induce a sense of ownership over external objects, virtual avatars, and even other people’s bodies. We argue that bodily experience is not monolithic, but rather has measurable internal structure and components that can be identified psychometrically and psychophysically, which suggests that the apparent phenomenal unity of self-consciousness may be illusory. We further review evidence that the sense of one’s own body is highly plastic, with representations of body structure and size particularly sensitive to multisensory influences.
Pupil Dilation Reflects the Creation and Retrieval of Memories
Authors: Goldinger Stephen D. , Papesh Megan H.
Published: March 2012

It has long been known that pupils—the apertures that allow light into the eyes—dilate and constrict not only in response to changes in ambient light but also in response to emotional changes and arousing stimuli (e.g., Fontana, 1765). Charles Darwin (1872) related changes in pupil diameter to fear and other “emotions” in animals. For decades, pupillometry has been used to study cognitive processing across many domains, including perception, language, visual search, and short-term memory. Historically, such studies have examined the pupillary reflex as a correlate of attentional demands imposed by different tasks or stimuli—pupils typically dilate as cognitive demand increases. Because the neural mechanisms responsible for such task-evoked pupillary reflexes (TEPRs) implicate a role for memory processes, recent studies have examined pupillometry as a tool for investigating the cognitive processes underlying the creation of new episodic memories and their later retrieval. Here, we review the historical antecedents of current pupillometric research and discuss several recent studies linking pupillary dilation to the on-line consumption of cognitive resources in long-term-memory tasks. We conclude by discussing the future role of pupillometry in memory research and several methodological considerations that are important when designing pupillometric studies.
Group Affect
Authors: Barsade Sigal G. , Gibson Donald E.
Published: March 2012

We review and synthesize the research literature examining group affect and its consequences, focusing on groups who interact together to accomplish a task. We use a definition of group affect that incorporates the mutual influence of a group’s affective context and affective composition (the amalgamation of group members’ state and trait affect). Our focus is on the influence of group affect on individual members’ behaviors and attitudes and on group-level outcomes. We call for more research in this area, including the study of more specific discrete group emotions and a broadening of the types of groups studied in this research area.
Is Political Apology a Sorry Affair?
Authors: Thompson Janna
Published: March 2012

Making apologies is one of the ways that governments have attempted to deal with past injustices. However, political apologies are often criticised for being meaningless or morally suspect. I will argue that an apology signals the commitment of those who make it, sponsor it and support it to a national undertaking, and whether we can regard an apology as meaningful depends on our reasons for thinking that this undertaking has been initiated and will continue. To defend political apologies from moral criticisms it is necessary to address questions about responsibility: whether citizens can and should take responsibility for past injustices, including injustices of the historical past. The answer to these questions, I will argue, requires an account of the responsibilities entailed in being a citizen of an intergenerational polity.
Characterization of actuation properties of magnetorheological elastomers with embedded hard magnetic particles
Authors: Koo Jeong-Hoi , Dawson Alexander , Jung Hyung-Jo
Published: March 2012

This study investigates a new generation of magnetorheological elastomers based on hard magnetic particles. Unlike traditional magnetorheological elastomers that use iron particles, a dispersion of hard magnetic materials aligned in an electromagnetic field will produce a magnetorheological elastomer with magnetic poles. When a magnetic field is applied, perpendicularly to these poles, the filler particles generate torque and cause rotational motion of the magnetorheological elastomer blend. The primary goal of this study is to fabricate and characterize the actuation properties of magnetorheological elastomers filled with various hard magnetic particles. To this end, samples of magnetorheological elastomers consisting of hard magnetic materials were fabricated using four different particle types, and a test setup (electromagnet) was constructed. After mounting the magnetically anisotropic samples in a fixed-free configuration, uniform magnetic fields are applied to the samples (perpendicular to the poled direction), which causes the sample to bend, similar to a cantilevered beam. The blocked force and tip displacement of the samples were measured to characterize actuation properties of the samples. The results show that the responses of the deflection and the blocked force at the tip show linear trends over a reasonable range, suggesting that magnetorheological elastomers consisting of hard magnetic materials can be used as bending-type actuators in small mechanical systems and devices.
Colorectal Stents Orient Specimens and Induce Artifacts That Mimic Crohn Disease
Authors: Amini Nima , Haydel Dana , Reisian Niloufar , Sempa Geoffrey , Chu Julia , Wang Qun , Zhao Guohua , Stamos Michael J. , Wu Mark Li-cheng
Published: March 2012

Colorectal malignancies may be stented to alleviate obstruction. The stent is a polarized and braided network of metallic wires. Pathology associated with colorectal stents is yet to be described. The authors reviewed 7 cases involving stented colorectal segments from patients lacking clinical suspicion of Crohn disease. In 4 cases, orientation of the specimens and stents matched the corresponding anatomic landmarks. In 3 cases, the specimens lacked helpful anatomic landmarks, and orientation was possible only after correlating with the intrinsic polarity of the stents. Stented areas showed artifacts resembling Crohn disease, including rounded cobblestones, pseudopolyps, and simple fissures, as well as unique artifacts including rhomboid cobblestones, complex fissures, oblique fissures with remarkably straight edges, and conical fragments of tissue that appeared to float. Crohn disease was misdiagnosed in 1 case in which the stent was removed intraoperatively and was never received. Colorectal stents help orient ambiguous specimens and induce patterned injury that can be confused with Crohn disease.
The Psychological Profiles of Internet, Contact, and Mixed Internet/Contact Sex Offenders
Authors: Elliott Ian A. , Beech Anthony R. , Mandeville-Norden Rebecca
Published: March 2012

A sample of 526 contact offenders, 459 internet offenders, and 143 mixed contact/internet offenders was compared on a range of self-report psychological measures assessing offense-supportive beliefs, socioaffective functioning, emotional management, and socially desirable responding. A multivariate general linear model found a mixed offender profile that was similar to internet offenders rather than contact offenders. The contact group demonstrated lower victim empathy, a greater level of pro-offending attitudes, an externalized locus of control, more assertiveness, a diminished ability to relate to fictional characters, and greater impulsivity than the internet and mixed offender groups. The mixed offender group demonstrated a higher level of empathic concern than the other two groups. The mixed offender group could also be distinguished from the internet group by increased personal distress and perspective-taking ability. A discriminant function analysis highlighted the key linear factor distinguishing between the groups to be one relating to offense-supportive attitudes and identification with fictional characters. A second factor was related to higher levels of empathic concern and poor self-management. These findings are discussed in the context of the potential pathways between internet and contact sexual offenses.
Using video feedback to improve early father–infant interaction: A pilot study
Authors: Lawrence Peter J. , Davies Beverley , Ramchandani Paul G.
Published: March 2012

Preventive interventions with parents of infants have tended to focus on mothers. Recent research focused on fathers suggests that their involvement in interventions might enhance effectiveness. One effective approach with mothers is the brief, home-based Video-feedback Intervention to promote Positive Parenting (VIPP). This paper is a report of a pilot study of VIPP with fathers to assess its feasibility.

Five fathers were recruited from an existing longitudinal study of parents. The primary outcome was acceptability, assessed using a semi-structured questionnaire after completion of the intervention.

All fathers completed all sessions of the intervention. Fathers rated the intervention as having had a significant impact on their understanding of their child’s thoughts and feelings, and as having improved their communication and relationship with their baby. Fathers’ feedback was generally positive. The flexibility to conduct sessions at home (or at fathers’ places of work) and the flexible timing of sessions were identified as fundamental to successful delivery.

The results of this pilot study are encouraging, as VIPP with fathers was feasible. In light of the modest sample size, and the use of a non-clinical sample, the intervention must be evaluated with larger, clinical samples to evaluate its efficacy with fathers.
Media consumption across platforms: Identifying user-defined repertoires
Authors: Taneja Harsh , Webster James G. , Malthouse Edward C. , Ksiazek Thomas B.
Published: March 2012

New media have made available a wide range of platforms and content choices. However, audiences cope with abundant choices by using more narrowly defined repertoires. Unfortunately, we know little of how users create repertoires across media platforms. This study uses factor analysis to identify user-defined repertoires from data obtained by following 495 users throughout an entire day. Results indicate the presence of four repertoires that are powerfully tied to the rhythms of people’s daily lives. These were in turn explained by a combination of factors such as audience availability and individual demographics.
Urban, Suburban, and Rural Variations in Separation/Divorce Rape/Sexual Assault
Authors: Rennison Callie Marie , DeKeseredy Walter S. , Dragiewicz Molly
Published: March 2012

To date, no large study has looked at whether separation/divorce sexual assault varies across urban, suburban, and rural areas. The authors use 1992-2009 NCVS (National Crime Victimization Survey) data to estimate the percentage of separation/divorce sexual assault against women in urban, suburban, and rural communities. In addition, the authors identify and compare the relative risk of sexual assault victimization for women across areas. Findings indicate that a higher percentage of rural divorced/separated women were victims of rape/sexual assault than were urban divorced/separated women. In addition, rural separated women are victims of intimate rape/sexual assault at significantly higher rates than their suburban and urban counterparts.
Clinical management of SIADH
Authors: Gross Peter
Published: March 2012

Hyponatremia is the most frequent electrolyte disorder and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) accounts for approximately one-third of all cases. In the diagnosis of SIADH it is important to ascertain the euvolemic state of extracellular fluid volume, both clinically and by laboratory measurements. SIADH should be treated to cure symptoms. While this is undisputed in the presence of grave or advanced symptoms, the clinical role and the indications for treatment in the presence of mild to moderate symptoms are currently unclear. Therapeutic modalities include nonspecific measures and means (fluid restriction, hypertonic saline, urea, demeclocycline), with fluid restriction and hypertonic saline commonly used. Recently vasopressin receptor antagonists, called vaptans, have been introduced as specific and direct therapy of SIADH. Although clinical experience with vaptans is limited at this time, they appear advantageous to patients because there is no need for fluid restriction and the correction of hyponatremia can be achieved comfortably and within a short time. Vaptans also appear to be beneficial for physicians and staff because of their efficiency and reliability. The side effects are thirst, polydipsia and frequency of urination. In any therapy of chronic SIADH it is important to limit the daily increase of serum sodium to less than 8–10 mmol/liter because higher correction rates have been associated with osmotic demyelination. In the case of vaptan treatment, the first 24 h are critical for prevention of an overly rapid correction of hyponatremia and the serum sodium should be measured after 0, 6, 24 and 48 h of treatment. Discontinuation of any vaptan therapy for longer than 5 or 6 days should be monitored to prevent hyponatremic relapse. It may be necessary to taper the vaptan dose or restrict fluid intake or both.
X marks the spot: Marxist intercourse and Kantian anarchism in Kojin Karatani
Authors: Goonewardena Kanishka , Orzeck Reecia
Published: March 2012

In this commentary Kanishka Goonewardena and Reecia Orzeck analyze the theoretical, political, and practical implications of Kojin Karatani’s valorization of the mode of exchange relative to the mode of production.
Cotargeting signaling pathways driving survival and cell cycle circumvents resistance to Kit inhibitors in leukemia
Authors: Buet Dorothée , Gallais Isabelle , Lauret Evelyne , Denis Nicole , Lombard Bérangère , Guillonneau François , Kosmider Olivier , Loew Damarys , Dusanter-Fourt Isabelle , Guillouf Christel , Mayeux Patrick , Moreau-Gachelin Françoise
Published: March 2012

Oncogenic mutations leading to persistent kinase activities are associated with malignancies. Therefore, deciphering the signaling networks downstream of these oncogenic stimuli remains a challenge to gather insights into targeted therapy. To elucidate the biochemical networks connecting the Kit mutant to leukemogenesis, in the present study, we performed a global profiling of tyrosine-phosphorylated proteins from mutant Kit-driven murine leukemia proerythroblasts and identified Shp2 and Stat5 as proximal effectors of Kit. Shp2 or Stat5 gene depletion by sh-RNA, combined with pharmacologic inhibition of PI3kinase or Mek/Erk activities, revealed 2 distinct and independent signaling pathways contributing to malignancy. We demonstrate that cell survival is driven by the Kit/Shp2/Ras/Mek/Erk1/2 pathway, whereas the G1/S transition during the cell cycle is accelerated by both the Kit/Stat5 and Kit/PI3K/Akt pathways. The combined use of the clinically relevant drugs NVP-BEZ235, which targets the cell cycle, and Obatoclax, which targets survival, demonstrated synergistic effects to inhibit leukemia cell growth. This synergy was confirmed with a human mast leukemia cell line (HMC-1.2) that expresses mutant Kit. The results of the present study using liquid chromatography/tandem mass spectrometry analysis have elucidated signaling networks downstream of an oncogenic kinase, providing a molecular rationale for pathway-targeted therapy to treat cancer cells refractory to tyrosine kinase inhibitors.
The Ets-1 transcription factor is required for Stat1-mediated T-bet expression and IgG2a class switching in mouse B cells
Authors: Nguyen Hai Vu , Mouly Enguerran , Chemin Karine , Luinaud Romain , Despres Raymonde , Fermand Jean-Paul , Arnulf Bertrand , Bories Jean-Christophe
Published: March 2012

In response to antigens and cytokines, mouse B cells undergo class-switch recombination (CSR) and differentiate into Ig-secreting cells. T-bet, a T-box transcription factor that is up-regulated in lymphocytes by IFN-γ or IL-27, was shown to regulate CSR to IgG2a after T cell–independent B-cell stimulations. However, the molecular mechanisms controlling this process remain unclear. In the present study, we show that inactivation of the Ets-1 transcription factor results in a severe decrease in IgG2a secretion in vivo and in vitro. No T-bet expression was observed in Ets-1–deficient (Ets-1−/−) B cells stimulated with IFN-γ and lipopolysaccharide, and forced expression of T-bet in these cells rescued IgG2a secretion. Furthermore, we identified a transcriptional enhancer in the T-bet locus with an activity in B cells that relies on ETS-binding sites. After IFN-γ stimulation of Ets-1−/− B cells, activated Stat1, which forms a complex with Ets-1 in wild-type cells, no longer binds to the T-bet enhancer or promotes histone modifications at this site. These results demonstrate that Ets-1 is critical for IgG2a CSR and acts as an essential cofactor for Stat1 in the regulation of T-bet expression in B cells.
Quality of experience evaluation of voice communication: an affect-based approach
Authors: Bhattacharya Abhishek , Wu Wanmin , Yang Zhenyu
Published: March 2012

Voice communication systems such as Voice-over IP (VoIP), Public Switched Telephone Networks, and Mobile Telephone Networks, are an integral means of human tele-interaction. These systems pose distinctive challenges due to their unique characteristics such as low volume, burstiness and stringent delay/loss requirements across heterogeneous underlying network technologies. Effective quality evaluation methodologies are important for system development and refinement, particularly by adopting user feedback based measurement. Presently, most of the evaluation models are system-centric (Quality of Service or QoS-based), which questioned us to explore a user-centric (Quality of Experience or QoE-based) approach as a step towards the human-centric paradigm of system design. We research an affect-based QoE evaluation framework which attempts to capture users' perception while they are engaged in voice communication. Our modular approach consists of feature extraction from multiple information sources including various affective cues and different classification procedures such as Support Vector Machines (SVM) and k-Nearest Neighbor (kNN). The experimental study is illustrated in depth with detailed analysis of results. The evidences collected provide the potential feasibility of our approach for QoE evaluation and suggest the consideration of human affective attributes in modeling user experience.
The RNA-binding landscapes of two SR proteins reveal unique functions and binding to diverse RNA classes
Authors: Änkö Minna-Liisa , Müller-McNicoll Michaela , Brandl Holger , Curk Tomaz , Gorup Crtomir , Henry Ian , Ule Jernej , Neugebauer Karla M
Published: March 2012

Background

The SR proteins comprise a family of essential, structurally related RNA binding proteins. The complexity of their RNA targets and specificity of RNA recognition in vivo is not well understood. Here we use iCLIP to globally analyze and compare the RNA binding properties of two SR proteins, SRSF3 and SRSF4, in murine cells.

Results

SRSF3 and SRSF4 binding sites mapped to largely non-overlapping target genes, and in vivo consensus binding motifs were distinct. Interactions with intronless and intron-containing mRNAs as well as non-coding RNAs were detected. Surprisingly, both SR proteins bound to the 3' ends of the majority of intronless histone transcripts, implicating SRSF3 and SRSF4 in histone mRNA metabolism. In contrast, SRSF3 but not SRSF4 specifically bound transcripts encoding numerous RNA binding proteins. Remarkably, SRSF3 was shown to modulate alternative splicing of its own as well as three other transcripts encoding SR proteins. These SRSF3-mediated splicing events led to downregulation of heterologous SR proteins via nonsense-mediated decay.

Conclusions

SRSF3 and SRSF4 display unique RNA binding properties underlying diverse cellular regulatory mechanisms, with shared as well as unique coding and non-coding targets. Importantly, CLIP analysis led to the discovery that SRSF3 cross-regulates the expression of other SR protein family members.
Wired to run: exercise-induced endocannabinoid signaling in humans and cursorial mammals with implications for the ‘runner’s high’
Authors: Raichlen David A. , Foster Adam D. , Gerdeman Gregory L. , Seillier Alexandre , Giuffrida Andrea
Published: March 2012

Humans report a wide range of neurobiological rewards following moderate and intense aerobic activity, popularly referred to as the ‘runner’s high’, which may function to encourage habitual aerobic exercise. Endocannabinoids (eCBs) are endogenous neurotransmitters that appear to play a major role in generating these rewards by activating cannabinoid receptors in brain reward regions during and after exercise. Other species also regularly engage in endurance exercise (cursorial mammals), and as humans share many morphological traits with these taxa, it is possible that exercise-induced eCB signaling motivates habitual high-intensity locomotor behaviors in cursorial mammals. If true, then neurobiological rewards may explain variation in habitual locomotor activity and performance across mammals. We measured circulating eCBs in humans, dogs (a cursorial mammal) and ferrets (a non-cursorial mammal) before and after treadmill exercise to test the hypothesis that neurobiological rewards are linked to high-intensity exercise in cursorial mammals. We show that humans and dogs share significantly increased exercise-induced eCB signaling following high-intensity endurance running. eCB signaling does not significantly increase following low-intensity walking in these taxa, and eCB signaling does not significantly increase in the non-cursorial ferrets following exercise at any intensity. This study provides the first evidence that inter-specific variation in neurotransmitter signaling may explain differences in locomotor behavior among mammals. Thus, a neurobiological reward for endurance exercise may explain why humans and other cursorial mammals habitually engage in aerobic exercise despite the higher associated energy costs and injury risks, and why non-cursorial mammals avoid such locomotor behaviors.
Differentiation between benign and malignant breast tumors using kinetic features of real-time harmonic contrast-enhanced ultrasound
Authors: Saracco Ariel , Szabó Botond K , Aspelin Peter , Leifland Karin , Wilczek Brigitte , Celebioglu Fuat , Axelsson Rimma
Published: March 2012

Background

Contrast-enhanced ultrasound (CEUS) has gained interest because of its ability to gather vascular information in diverse organs. There is still a subject of debate concerning its value in breast lesions, especially as a differential diagnostic tool.

Purpose

To investigate whether kinetic parameters of CEUS can differentiate between malignant and benign breast lesions.

Material and Methods

We evaluated 75 malignant and 21 benign lesions in the breast or axilla. Contrast harmonic imaging (CHI) US was performed after the injection of a bolus dose of 2.4 mL of Sono Vue® (Bracco, Milano, Italy). The following parameters were calculated for kinetic analysis: initial slope, time to peak enhancement, wash-out ratios W21 and W50 (relative decrease in signal intensity from the peak enhancement to 21 s and 50 s, respectively).

Results

A significant difference was found between the benign and malignant lesions in time-to-peak ( P value <0.05) and wash-out ratios W21 ( P value <0.001) and W50 ( P value <0.001). The mean time-to-peak was 9.3 s for malignant and 14.6 s for benign lesions. The mean signal drop from peak to signal intensity measured at 50 s was 85% for malignant and 66% for benign lesions. There was no difference in absolute values of peak signal intensity and initial slope. The most significant difference between standardized benign and malignant wash-out curves was found at 21 s but statistical significance was reached in the range of 14–50 s.

Conclusion

Real-time CEUS can evolve into a new non-invasive option for differentiate malignant from benign breast lesions.
The evolution of the cerebral blood volume abnormality in patients with ischemic stroke: a CT perfusion study
Authors: d'Esterre Christopher D , Aviv Richard I , Lee Ting Yim
Published: March 2012

Background

Accurate identification of the acute infarct core abnormality is important for guiding acute stroke treatment. Abnormality volumes from diffusion-weighted MRI (DWI) and CT perfusion (CTP)-cerebral blood volume (CBV) are highly correlated. DWI lesions have been shown to be reversible at 24 h.

Purpose

To examine the temporal profile of the CT perfusion (CTP)-derived CBV abnormality out to 7 days post ischemic stroke.

Material and Methods

Twenty-six patients were included. Group A ( n = 13) underwent a non-contrast CT (NCCT), CTP/CT angiography (CTA) within 6 h of stroke onset, CTP/CTA at 24 h, and CTP/NCCT at 5–7 days post stroke. Group B ( n = 13) underwent a NCCT, CTP/CTA within 6 h of stroke onset, and NCCT at 5–7 days. Recanalization status was established in all patients. For both groups, infarct volumes were traced on 5–7 day NCCT images and superimposed onto all CTP-CBV functional maps to determine CBV. Group B ( n = 13) admission images were used to define CBV infarct thresholds for gray and white matter. CBV-lesion over-estimation was determined for Group A using the thresholds from Group B.

Results

CBV (mL·100g− 1; mean ± stdev) for gray/white matter, within confirmed infarcted regions (CBVI) at admission, 24 h, and 5–7 days were 1.82 ± 0.56, 1.56 ± 0.42, 1.75 ± 0.31, and 1.38 ± 0.65, 1.13 ± 0.31, 1.32 ± 0.44, respectively, when averaged over all patients ( P > 0.05). Four patients had tissue time-density curves from ischemic lesions (TDCi) with an incomplete contrast medium wash-out phase (truncation) at admission and/or 24 h. Compared to admission, gray matter CBVI was higher at 5–7 days for patients with TDCi truncation ( P < 0.05). There were no significant CBVI increases for the eight patients without truncation ( P > 0.05). Over-estimation of acute CBV lesion was present in 3/4 (75%) and 1/9 (11%) of patients with/without TDCi truncation, respectively.

Conclusion

CTP-derived CBV lesion reversal is associated with TDCi truncation during the acute stroke phase.
Mammographic density and urbanization: a population-based screening study
Authors: Viel Jean-François , Rymzhanova Raouchan
Published: March 2012

Objectives

The high incidence of female breast cancer that has been consistently reported in urban areas could be mediated by breast density, which is considered to reflect the cumulative exposure of breast tissues to hormones. The aim of this study was to assess how mammographic density varies by the degree of urbanization.

Setting

The population consisted of 55,597 cancer-free women, aged 50–59 years, who participated in a French breast cancer screening programme (Franche-Comté region) between 2005 and 2009.

Methods

Ordered logistic regression was run with mammographic density as the outcome, and degree of urbanization as the independent variable, while adjusting for some known confounding factors. Multiple imputation was used to deal with missing data.

Results

A significant positive linear trend with urbanization was found in a univariate approach ( P trend <10−3), and after adjusting for risk factors ( P trend = 10−3). A negative and highly significant association with mammographic density was highlighted both for age at the time of mammography (odds ratio (OR) 0.41, 95% confidence interval (CI) 0.39–0.43, per 10 years), and for low socioeconomic status (OR 0.71, 95% CI 0.67–0.75). The OR for hormone replacement therapy use was 1.51 (95% CI 1.43–1.58).

Conclusions

Knowledge of this urbanization gradient in density (whatever its mechanism) may help to identify women who may require full-field digital mammography for the early detection of breast cancer, and could assist primary care providers in recommending the best screening strategy in a risk factor-based approach.
Asymptotic Irrelevance of Initial Conditions for Skorohod Reflection Mapping on the Nonnegative Orthant
Authors: Kella Offer , Ramasubramanian S.
Published: March 2012

A reflection map, induced by the deterministic Skorohod problem on the nonnegative orthant, is applied to a vector-valued function X on the nonnegative real line and then to a + X, where a is a nonnegative constant vector. A question that was posed over 15 years ago is, under what conditions does the difference between the two resulting regulated functions converge to zero for any choice of a as time diverges. This, in turn, implies that if one imposes enough stochastic structure that ensures that the reflection map applied to a multidimensional process X converges in distribution, then it will also converge in distribution when it is applied to η + X, where η is any almost surely finite-valued random vector that may even depend on the process X. In this paper we obtain a useful equivalent characterization of this property. As a result, we are able to identify a natural sufficient condition in terms of the given data X and the constant routing matrix. A similar necessary condition is also indicated. A particular implication of our analysis is that under additional stochastic assumptions, asymptotic irrelevance of the initial condition does not require the existence of a stationary distribution. As immediate corollaries of our (and earlier) results we conclude that under the natural stability conditions, a reflected Lévy process as well as a Markov additive process has a unique stationary distribution and converges in distribution to this stationary distribution for every initial condition. Extensions of the sufficient condition are then developed for reflection maps with drift and routing coefficients that may be time- and state-dependent; some implications to multidimensional insurance models are briefly discussed.
Lower Bounds and Heuristics for Supply Chain Stock Allocation
Authors: Marklund Johan , Rosling Kaj
Published: March 2012

Assume that m periods with stochastic demand remain until the next replenishment arrives at a central warehouse. How should the available inventory be allocated among N retailers?

This paper presents a new policy and a new lower bound for the expected cost of this problem. The lower bound becomes tight as N → ∞ . The infinite horizon problem then decomposes into N independent m-period problems with optimal retailer ship-up-to levels that decrease over the m periods, and the warehouse is optimally replenished by an order-up-to level that renders zero (local) warehouse safety stock at the end of each replenishment cycle.

Based on the lower bound solution, we suggest a heuristic for finite N. In a numerical study it outperforms the heuristic by Jackson [Jackson, P. L. 1988. Stock allocation in a two-echelon distribution system or what to do until your ship comes in. Management Sci. 34(7) 880–895], and the new lower bound improves on Clark and Scarf's [Clark, A. J., H. Scarf. 1960. Optimal policies for a multi-echelon inventory problem. Management Sci. 6(4) 475–490] bound when N is not too small. Moreover, the warehouse zero-safety-stock heuristic is comparable to Clark and Scarf's warehouse policy for lead times that are not too long.

The suggested approach is quite general and may be applied to other logistical problems. In the present application it retains some of the risk-pooling benefits of holding central warehouse stock.
From the Editor—Operations Research: The Next Three Years
Authors: Zenios Stefanos
Published: March 2012

Stefanos Zenios, editor in chief of Operations Research, provides his vision and goals for the journal's next three years.
Dapagliflozin for the Treatment of Type 2 Diabetes
Authors: Anderson Sarah L , Marrs Joel C
Published: March 2012

Objective:

To review the literature and describe the pharmacologic, pharmacokinetic, and pharmacodynamic properties; clinical safety; and efficacy of dapagliflozin, a new drug currently under review by the Food and Drug Administration (FDA) for the treatment of type 2 diabetes.

Data Sources:

A MEDLINE (1995-November 2011) and ClinicalTrials.gov search was conducted using the terms dapagliflozin, sodium-glucose cotransporter 2 inhibitor, and SGLT2 inhibitor. Reference citations from publications identified were also reviewed.

Study Selection and Data Extraction:

All English-language studies, including abstracts, evaluating dapagliflozin use in humans were included in this review.

Data Synthesis:

Dapagliflozin is the first-in-class oral sodium-glucose cotransporter 2 (SGLT2) inhibitor that represents a new potential therapeutic option for the treatment of type 2 diabetes mellitus. Its mechanism of action is insulin- and insulin-sensitivity independent. Preliminary data suggest that dapagliflozin decreases hemoglobin A1c, fasting plasma glucose, and postprandial plasma glucose, while also promoting weight loss. In Phase 1, 2, and 3 clinical trials, dapagliflozin has exhibited a safety and tolerability profile similar to that of placebo.

Conclusions:

Dapagliflozin is a novel oral antihyperglycemic agent that has demonstrated promise as monotherapy and as synergistic combination therapy with currently available agents in Phase 3 clinical trials. On January 19, 2012, the FDA issued a complete response letter to AstraZeneca and Bristol-Myers Squibb regarding the new drug application for dapagliflozin. The FDA is requesting additional clinical data—from ongoing studies and potentially new clinical trials—to better describe the risk-benefit profile of the drug. Both manufacturers remain committed to the development of dapagliflozin, and there are currently 8 Phase 3 trials ongoing. Dapagliflozin has the potential to be the next new oral agent in the diabetes drug armamentarium.
Corruption: A View from the Persian Gulf
Authors: Askari Hossein , Rehman Scheherazade S. , Arfaa Noora
Published: March 2012

Corruption has been and continues to be evident in all societies, with differences only in manifestation and degrees. We focus on the manifestation and impact of corruption in the Persian Gulf oil-exporting countries and benchmark these countries against a set of non-oil-exporting Islamic countries and major non-Islamic oil-exporting countries. We first measure the degree of corruption in these countries using five of the most widely accepted direct and indirect indices of corruption. We then examine the relationship between corruption and various indicators of economic, social, and human development. Finally, we examine the association between corruption and oil endowment and the Islamic label, two common characteristics of the countries in the Persian Gulf. As such, the key focus of the paper is on the manifestation and impact of corruption in the Persian Gulf oil-exporting countries from a political-economy stand point and measurement of the impact of corruption on economic, social, and human development in the region. It should be mentioned that this paper was written before the blossoming of the “2011 Arab Spring.” The major reasons, to varying degrees, for the protests in the Mideast and North Africa have been because of decades of economic deprivation, autocratic rule, political injustice, institutional corruption, and human rights violations.
The Inheritance Procedure: Multiple Testing of Tree-structured Hypotheses
Authors: Goeman Jelle J. , Finos Livio
Published: March 2012

Hypotheses tests in bioinformatics can often be set in a tree structure in a very natural way, e.g. when tests are performed at probe, gene, and chromosome level. Exploiting this graph structure in a multiple testing procedure may result in a gain in power or increased interpretability of the results.We present the inheritance procedure, a method of familywise error control for hypotheses structured in a tree. The method starts testing at the top of the tree, following up on those branches in which it finds significant results, and following up on leaf nodes in the neighborhood of those leaves. The method is a uniform improvement over a recently proposed method by Meinshausen. The inheritance procedure has been implemented in the globaltest package which is available on www.bioconductor.org.
Note on the Budget of the European Union and an Internet Communication Tax
Authors: Leen Auke R.
Published: March 2012

The European Union (EU) wants to finance part of the EU budget with a European tax which citizens would pay directly to the Union. One option is a communication tax. After a brief view of the finances of the EU and the history of the idea of taxing communication, the note states the criteria used in selecting a EU tax. After an assessment according to the criteria, the article concludes that at this moment a European Internet communication tax is not a viable option. For the citizen, it is a visible and equitable tax that does not distort economic decision‐making. However, it makes hardly any sense from the point of view of the other budgetary, efficiency, and political criteria. To reform this situation, an EU policy on information and communication technologies is planned, including the dedication of resources to an EU‐wide infrastructure and digital networks, which could make taxation of communications at the EU level a more feasible option. However, the technical aspects of taxing the Internet and other media — which are, at present, hardly discussed — may still prove to be significant barriers to such a policy.
Internet Diffusion and Implications for Taxation: Evidence from U.S. Cigarette Sales
Authors: Goel Rajeev K. , Nelson Michael A.
Published: March 2012

Using state level U.S. data from 1994‐2009, this research examines the impact of the Internet on cigarette demand and discusses resulting implications for tax policy. Results show that the Internet increases the demand price elasticity of cigarettes, which limits the ability of governments to generate additional tax revenues through cigarette tax increases. Further, the smuggling of cigarettes, both across domestic and international borders, remains significant, and tobacco producers and Indian casinos undermine efforts to lower cigarette sales.
The Spread of Obesity in Developing and Transitional Countries: A Focus on the Mekong Region, Southeast Asia
Authors: Pawloski Lisa R. , Thurman Shaneka , Curtin Kevin M. , Ruchiwit Manyat
Published: March 2012

Introduction: Obesity policies in transitional countries are limited as most have needed to focus resources on reducing hunger, poverty, and infectious diseases. The Mekong Region is one such area that is still facing issues of undernutrition and infectious disease, yet has a growing population at risk of obesity related diseases. Such a dual burden creates a dilemma regarding which issue to address first, given limited resources. This review addresses this problem from a policy perspective. Materials and Methodology: Comparative analyses of literature reviews, existing policy, and previous research were synthesized among countries within the Mekong Region. Results: Traditional diets, quickly emerging fast food markets, and urbanization add levels of complexity to managing and creating obesity policy. Existing policies have not been successful and there are few measurable outcomes. Conclusion and Policy Implications: Obesity‐related policies have been initiated in the Mekong Region, but with few resources and conflicting priorities, several countries are at risk of being left behind. Suggested policies in the region include utilizing mass media education campaigns, modeling other successful public health programs, and promoting culturally and regionally appropriate interventions.
An elementary proof of the vanishing of the second cohomology of the Witt and Virasoro algebra with values in the adjoint module
Authors: Schlichenmaier Martin
Published: March 2012

By elementary and direct calculations the
vanishing of the (algebraic) second
Lie algebra cohomology of the Witt and the Virasoro algebra with
values in the adjoint module is shown. This yields infinitesimal and formal rigidity or these
algebras. The first (and up to now only) proof of this
important result was given 1989 by Fialowski in an unpublished note. It is based on cumbersome calculations. Compared to the original proof
the presented one is quite elegant and considerably simpler.