bluuebunny/crossref_metadata_2025 huggingface dataset:
Recent Advances in the Pathogenesis and Treatment of Persistent Pulmonary Hypertension of the Newborn
Authors: Abman Steven H.
Published: June 2007

Persistent pulmonary hypertension of the newborn (PPHN) is a clinical syndrome characterized by failure of the lung circulation to achieve or sustain the normal drop in pulmonary vascular resistance (PVR) at birth. Past laboratory studies identified the important role of nitric oxide (NO)-cGMP signaling in the regulation of the perinatal lung circulation, leading to the development and application of inhaled NO therapy for PPHN. Although inhaled NO therapy has improved the clinical course and outcomes of many infants, pulmonary hypertension can be refractory to inhaled NO, suggesting the need for additional approaches to severe PPHN. To develop novel therapeutic strategies for PPHN, ongoing studies continue to explore basic mechanisms underlying the pathobiology of PPHN in experimental models, including strategies to enhance NO-cGMP signaling. Recent studies have demonstrated that impaired vascular endothelial growth factor (VEGF) signaling may contribute to the pathogenesis of PPHN. Lung VEGF expression is markedly decreased in an experimental model of PPHN in sheep; inhibition of VEGF mimics the structural and functional abnormalities of PPHN, and VEGF treatment improves pulmonary hypertension through upregulation of NO production. Other studies have shown that enhanced NO-cGMP activity through the use of cGMP-specific phosphodiesterase inhibitors (sildenafil), soluble guanylate cyclase activators (BAY 41-2272), superoxide scavengers (superoxide dismutase), and rho-kinase inhibitors (fasudil) can lead to potent and sustained pulmonary vasodilation in experimental PPHN. Overall, these laboratory studies suggest novel pharmacologic strategies for the treatment of refractory PPHN.
Angiogenesis in Lung Development, Injury and Repair: Implications for Chronic Lung Disease of Prematurity
Authors: Thébaud Bernard
Published: June 2007

Since the initial description of bronchopulmonary dysplasia (BPD) 40 years ago, advances in perinatal care have allowed the survival of infants that are more immature. The disease has not disappeared, but it now affects infants with undeveloped distal airspaces, resulting in an arrest of alveolar development. The histological changes that occur during normal lung development are well described, but little is known about the signaling mechanisms that regulate saccular and alveolar development. Understanding how alveoli and the underlying capillary network develop and how these mechanisms are disrupted in preterm infants with BPD is critical to develop efficient and effective therapies for lung diseases characterized by alveolar damage. This brief review focuses on the recently recognized role of angiogenic growth factors during normal alveolar development, injury and repair with a particular emphasis on the vascular endothelial growth factor.
Autoepitopes and Alloepitopes of Type IV Collagen: Role in the Molecular Pathogenesis of Anti-GBM Antibody Glomerulonephritis
Authors: Borza Dorin-Bogdan
Published: June 2007

Anti-glomerular basement membrane (anti-GBM) antibodies elicited by autoimmune or alloimmune mechanisms are associated with aggressive forms of rapid progressive glomerulonephritis. Pathogenic anti-GBM autoantibodies and alloantibodies target the noncollagenous (NC1) domains of the α3α4α5(IV) collagen, a major GBM component. In autoimmune anti-GBM glomerulonephritis, a breakdown of immune self-tolerance leads to the activation of autoreactive B and T cells recognizing epitopes within the α3NC1 subunit. In the GBM, the conformational epitopes targeted by anti-GBM autoantibodies are structurally sequestered within the α3α4α5NC1 hexamer complex formed upon assembly of collagen IV chains into trimeric molecules and networks. Autoantibodies selectively bind to and dissociate a subset of α3α4α5NC1 hexamers composed of monomer subunits, whereas hexamers containing NC1 dimer subunits are resistant to dissociation by autoantibodies. The crypticity of α3NC1 autoepitopes suggests that self-tolerance to α3(IV) collagen is broken by structural alterations of the native α3α4α5NC1 hexamer that unmask normally sequestered epitopes, triggering an autoimmune reaction. Post-transplant anti-GBM nephritis in the renal allograft of transplanted Alport patients is mediated by an alloimmune reaction to the NC1 domains of α3α4α5(IV) collagen, present in the allograft GBM but absent from Alport basement membranes. Alloantibodies from patients with autosomal-recessive Alport syndrome predominantly bind to the α3NC1 domain, whereas alloantibodies from X-linked Alport patients target preferentially, though not exclusively, epitopes within the α5NC1 subunit. The accessibility of the alloantigenic sites within the α3α4α5NC1 hexamers, contrasting with the crypticity of autoantigenic sites, suggest that different molecular forms of α3α4α5(IV) collagen initiate the immunopathogenic responses in the two forms of anti-GBM disease. Advances in elucidating the structure of the GBM antigen and the identification of the pathogenic B and T cell epitopes, along with new insights into the pathogenic mechanisms at cellular and molecular level will facilitate the development of targeted strategies for prevention, detection, and treatment of human anti-GBM antibody glomerulonephritis.
Ontogenetic Development of the Filtration Barrier
Authors: Kriz Wilhelm
Published: June 2007

The development of the filtration barrier is part of a complex sequence of steps proceeding from the early nephron anlage (renal vesicle) via the comma- and S-shaped body to the capillary loop stage and mature glomerulus. The main players are the podocytes (already in the stage of presumptive podocytes), which hold the commander function in this process, and the endothelial and the mesangial cells. A decisive role is also played by the GBM; its change in composition during the developmental process is a precondition for the final maturation of the podocytes, i.e. for the formation of the foot processes and, clearly subsequent, the slit membrane. Failure in the consecutive developmental stages due to genetic mutations or manipulations leads to characteristic hereditary diseases of increasing severity. The last step in this development, the formation of the slit membrane, marks a caesura between diseases with early and late onset; all disorders without a properly developed slit membrane start prenatally or at birth.
Pre-Eclampsia: Clinical Manifestations and Molecular Mechanisms
Authors: Baumwell Suzanne , Karumanchi S. Ananth
Published: June 2007

Preeclampsia affects 3–5% of pregnancies and can have a significant impact on health for both mother and fetus. Risk factors include maternal co-morbidities such as obesity and chronic hypertension, paternal factors, and genetic factors. New hypertension and proteinuria during the second half of pregnancy are key diagnostic criteria, but the clinical features and associated prognostic implications are somewhat heterogeneous and may reflect different mechanisms of disease. Renal dysfunction and proteinuria correspond to the pathologic finding of glomerular endotheliosis, and generally resolve after cure of preeclampsia through fetal and placenta delivery. The molecular mechanisms behind this disease are being discovered and refined. The initial etiologic agents are currently unknown. Pathologic studies show abnormal development of an ischemic placenta with a high-resistance vasculature, which cannot deliver an adequate blood supply to the fetoplacental unit. Endothelial dysfunction plays a central role in the pathogenesis of the maternal syndrome. Dysfunctional endothelial cells produce altered quantities of vasoactive mediators, which lead to a tip in the balance towards vasoconstriction. An imbalance in circulating angiogenic factors is emerging as a prominent mechanism that mediates the endothelial dysfunction and the clinical signs and symptoms of preeclampsia. Soluble fms-like tyrosine kinase 1 (sFlt1), an endogenous anti-angiogenic factor that is a potent vascular endothelial growth factor (VEGF) antagonist, is highly elevated in preeclampsia. VEGF is not only important in angiogenesis, but also in maintaining endothelial health including the formation of endothelial fenestrae (a hallmark of the glomerular vascular endothelium). sFlt1 overexpression in animals induces glomerular endotheliosis with the loss of endothelial fenestrae that resembles the renal histological lesions of preeclampsia. More severe forms of preeclampsia, including the HELLP syndrome, may be explained by a concomitant elevation in both sFlt1 and soluble endoglin, another anti-angiogenic factor. Unraveling of the molecular mechanisms behind preeclampsia may help to expand our armamentarium to treat patients in a more directed fashion, as current management consists of supportive care and expedited delivery. Finally, long-term outcomes of women with preeclampsia include a significantly increased risk for hypertension and cardiovascular disease, including mortality, which may warrant more aggressive screening and treatment in this population.
Congenital Posthemorrhagic Hydrocephalus: A Case of Fetomaternal Alloimmune Thrombocytopenia
Authors: Póvoa Ana M. , Ramalho Carla , Machado Ana P. , Matias Alexandra , Montenegro Nuno
Published: June 2007

Fetal/neonatal alloimmune thrombocytopenia (NAIT) results from fetomaternal mismatch for human platelet alloantigens leading to antibody-mediated destruction of fetal platelets. This is one of the most common causes of severe thrombocytopenia in the newborn with an incidence of 1/800–1,000. In the most severe cases, NAIT may result in intracranial hemorrhage and may lead to death or neurologic sequelae. We report a case of fetal hydrocephalus caused by NAIT and discuss the importance of making an accurate prenatal diagnosis to improve the management of the current pregnancy and the outcome of subsequent pregnancies. Screening of female siblings of affected cases is recommended in order to detect at-risk individuals.
Effect of Maternal Betamethasone Administration on Prenatal Congenital Cystic Adenomatoid Malformation Growth and Fetal Survival
Authors: Peranteau William H. , Wilson R. Douglas , Liechty Kenneth W. , Johnson Mark P. , Bebbington Michael W. , Hedrick Holly L. , Flake Alan W. , Adzick N. Scott
Published: June 2007

Objective: To evaluate the effect of prenatal steroid treatment on the growth of congenital cystic adenomatoid malformations (CCAM) and survival in affected fetuses not amenable to other percutaneous ultrasound-guided prenatal interventions. Methods: A retrospective review of patients with a CCAM or hybrid lesion treated with two maternal prenatal betamethasone injections was performed. Patients receiving cyst aspiration or thoracoamniotic shunting at the time of or after steroid administration were excluded. Growth rates and survival data were compared to historical non-steroid treated controls. Results: Eleven patients were treated with prenatal steroids (10 microcystic and 1 macrocystic). Survival was 100% in fetuses with hydrops (5/5) or a CCAM volume ratio (CVR) >1.6 (7/7) at the time of steroid administration. This compares to a mortality of 100 and 56.2% respectively in historical non-treated controls. Resolution of hydrops was seen in 80% (4/5) of steroid-treated patients. CCAM growth rates were variable after steroid administration. However, when compared to historical data where CVR and CCAM volume have been documented to increase until 28 weeks’ gestation, the CVR and CCAM volume growth rates decreased in 72.73% and 50% of patients respectively from the time of steroid administration to 28 weeks’ gestation. Conclusions: In the fetus with a CCAM, the presence of hydrops fetalis or a CVR >1.6 is indicative of poor fetal outcome without prenatal intervention. The observed effect of antenatal steroid treatment on CCAM growth is variable, but its potential to improve survival in these high-risk groups is encouraging and warrants further controlled evaluations.
Detection of Fetal Sex in the Peripheral Blood of Pregnant Women
Authors: Ren C.C. , Miao X.H. , Cheng H. , Chen L. , Song W.Q.
Published: June 2007

Objective: To choose the best method to examine fetal sex in maternal blood as early as possible and evaluate the quantitative change of fetal-free DNA in maternal plasma. Method: One hundred and fifty pregnant women were studied at 5–9 completed weeks of gestation. Fetal cells were isolated using lymphocyte separation liquid and 3% gelatin. Furthermore, fluorescence in situ hybridization was used to examine the terminal of the Y chromosome. Nested polymerase chain reaction (PCR) and real-time fluorescence quantitative PCR (FQ-PCR) were used to amplify the SRY gene of the plasma DNA extracted from the same 150 samples of maternal blood. Sequential analysis was performed using FQ-PCR during the whole pregnancy on 32 pregnant women carrying male fetuses. Results: Using fluorescence in situ hybridization, we can find male fetal cells in maternal blood as early as the 49th day. We can also find free fetal DNA in maternal plasma as early as the 49th and the 42nd day of pregnancy using nested PCR and FQ-PCR. The amount of fetal DNA was increasing with the gestation week. The standard value of every gestation week was obtained by FQ-PCR. Conclusion: FQ-PCR was the best method to detect fetal sex in early pregnancy. There is a principle of quantitative change of free fetal DNA in maternal plasma.
Discordant Semilobar Holoprosencephaly in Monozygotic Twins with de novo inv dup(15) Marker Chromosome and de novo Mutation on SHH Gene
Authors: Peng Hsiu-Huei , Kuo Pao-Lin , Chao An-Shine , Wang Tzu-Hao , Chang Yao-Lung , Soong Yung-Kuei , Chang Shuenn-Dyh
Published: June 2007

We present a 30-year-old woman with a twin pregnancy, 1 fetus displaying a small head circumference, semilobar holoprosencephaly, and cleft lip as detected by ultrasound at 23 weeks of gestation. Fetal magnetic resonance imaging confirmed the diagnosis of semilobar holoprosencephaly. The other twin, however, had an appropriate fetal growth, devoid of any major structural anomalies. Karyotyping by G-banding of amniocentesis specimens in both fetuses showed 47,XY,+mar. Fluorescence in situ hybridization showed in the marker chromosome positive dicentric signals for the chromosome 15 centromere-specific alpha satellite DNA probe (D15Z1) and negative signals for the SNRPN probe (15q11–13), thus establishing a cytogenetic diagnosis of 47,XX,+mar.ish idic(15)(q11–q13)(D15Z1++,SNRPN–) for both fetuses. The parental karyotypes were normal. The fetuses, therefore, had a de novo inv dup(15) marker chromosome without involvement of the Prader-Willi region. Short tandem repeat markers (total 15 markers) confirmed that the fetuses were monozygotic twins. Short tandem repeat markers at the 15q region (total 6 markers) excluded the possibility of uniparental disomy (15) mat or uniparental disomy (15) pat. Molecular study in both fetuses of TGIF, SHH, SIX3, and ZIC2 genes revealed a heterozygous 1085 C > T (Ser 362 Leu) on the SHH gene, but a homozygous 1085 C > C (Ser 362 Ser) for both parents on the SHH gene. The couple decided to terminate the pregnancy at 26 weeks of gestation. To our knowledge, this is the first report of semilobar holoprosencephaly with inv dup(15) marker chromosome and missense SHH gene mutation 1085 C > T (Ser 362 Leu).
Morphological and Neurochemical Development of the Human Neural Retina
Authors: Nag T.C. , Wadhwa S.
Published: June 2007

The human retina, a derivative of the diencephalon, differentiates into its components in sequential patterns following a spatiotemporal order. The neuronal differentiation in the fovea and central retina begins earlier than that occurring elsewhere, completes by midgestation (19–21 weeks) and continues in the periphery until 30 weeks of gestation. By birth, all retinal layers and neurons are mature over its entire extent, except at the fovea, where photoreceptor differentiation (outer segments) continues up to 5 months postnatally. During differentiation, the neurons express an array of marker molecules, such as amino acid neurotransmitters, neuropeptides, calcium-binding proteins, nitric oxide and proteins of phototransduction pathways. Although their precise involvement in retinal development is unclear, their patterns of expression indicate that many of them may be necessary for neuronal differentiation. In order to gain knowledge on this issue, future studies utilizing embryonic human retinal culture and transplantation of the tissue into suitable hosts and characterization of the role of neurochemicals involved in retinal development appears to be worthwhile. This approach may highlight novel information about the specific neurochemical requirements for the adult retina in normal and pathological states.
Whom to Follow? Central Asia between the EU and China
Authors: Kavalski Emilian
Published: June 2007

This analysis undertakes a preliminary conceptual assessment of the international agency of the European Union (EU) and China in Central Asia. The contention is that the strategies advanced by both Brussels and Beijing in the region reflect not only their desire to introduce a framework of predictability allowing them to make feasible calculations about future intentions, but also the increasing ‘fragmegration’ of international life. The contention is that the external agency of the EU and China attests to the normative power of their foreign policies. However, the values and norms of the international agency of Brussels and Beijing reflect their distinct experiences and suggest their clashing interests. The article concludes with a brief appraisal of the prospective trends in EU-China interactions in Central Asia.
Behavioral Health Practices in the Midst of Black Box Warnings and Mental Health Reform
Authors: Williams Jane , Klinepeter Kurt , Palmes Guy , Pulley Anita , Meschan Foy Jane
Published: June 2007

A standard guide was readministered to 42 primary care pediatricians after community interventions to assess changes in their behavioral health practices. Among the outcome findings: increased screening of young children (6 months to 5 years); attention deficit hyperactivity disorder continued to be the most frequent diagnosis, with a high level of diagnostic comfort and use of stimulants; decreased comfort in the diagnosis and treatment of depression, with a significant decline in use of selective serotonin reuptake inhibitors; nearly all continued to offer nonmedication, behavioral health treatment; and a significant increase in use of social workers for community referrals. Structured interventions had limited influence on the process of change. Black box warnings exerted a powerful effect on prescribing practices. Systemic changes involving financial incentives, increased access to mental health providers, practice guidelines, and technology for continuing education may offer possibilities for changing practice patterns.
Sickle Cell Anemia: Targeting the Role of Fetal Hemoglobin in Therapy
Authors: Coleman Emma , Inusa Baba
Published: June 2007

Sickle cell anemia results from the single amino acid substitution of valine for glutamic acid in the β-chain owing to a nucleotide defect that causes the production of abnormal β-chains in hemoglobin S. Abnormal hemoglobin chains form polymers in the deoxygenated state, leading to the characteristic sickle cells. The polymerization of deoxygenated hemoglobin S accounts for the pathologic changes in sickle cell disease. The main-stay of therapy in sickle cell disease aims to reduce the amount of sickled hemoglobin present through the prevention of polymerization and reversal of this process. One way of discouraging polymerization is to increase the level of fetal hemoglobin, which because of its high oxygen affinity, does not participate in the polymerization process. Fetal hemoglobin production may be induced pharmacologically or by the use of gene therapy and genetic engineering techniques.
Nonfasting Low-Density Lipoprotein Testing: Utility for Cholesterol Screening in Pediatric Primary Care
Authors: de Ferranti Sarah , Shapiro David , Markowitz Robert , Neufeld Ellis , Rifai Nader , Bernstein Henry
Published: June 2007

This prospective study assessed the clinical application of a nonfasting low-density lipoprotein cholesterol measure in a pediatric primary care population. A homogenous direct low-density lipoprotein cholesterol assay was tested in healthy children, aged 4 to 12 years, at risk for hyperlipidemia, as defined by American Academy of Pediatrics, and including patients with incomplete family histories. This nonfasting homogeneous assay was comparable to modified β quantification, the gold standard reference method of measuring low-density lipoprotein cholesterol, and the current recommended screening method, total cholesterol. Results from the study suggest that this nonfasting assay can provide more direct low-density lipoprotein cholesterol measurements for healthy children, with improved clinical utility and greater overall patient convenience in testing for important cholesterol abnormalities.
Misperceptions About Influenza Vaccination Among Parents of Healthy Young Children
Authors: Daley Matthew F. , Crane Lori A. , Chandramouli Vijayalaxmi , Beaty Brenda L. , Barrow Jennifer , Allred Norma , Berman Stephen , Kempe Allison
Published: June 2007

A survey was administered to 828 parents from metropolitan Denver, Colorado, and 57% responded. Of the respondents, 47% thought their child was unlikely to contract influenza, 70% thought influenza vaccine could cause influenza, and 21% considered influenza vaccination unsafe for a 1-year-old child. The influenza immunization rate in children of surveyed parents was 71%. In multivariate analyses, the perception that influenza vaccination was the social norm was positively associated with immunization (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.03-1.69), and anticipating immunization barriers was negatively associated with immunization (OR, 0.68; 95% CI, 0.49-0.95). Parents of young children hold a number of misperceptions about influenza disease and vaccination. Despite this, high immunization rates are achievable in this population.
Optimal Design of Corrugated Cellular Plastic Foam with Semi-elliptical Shaped Upper Surface by Finite Element Frequency Domain Acoustic Analysis
Authors: Tsay Huoy-Shyi , Yeh Fung-Huei
Published: June 2007

A general way to enhance the sound absorption capability of cellular plastic foam is the use of corrugated foam. The corrugated surface can greatly enhance the sound absorption of the foam in the mid and high frequency ranges. In this study, a finite element frequency domain acoustic analysis is used for the analysis. Such a numerical method is more efficient than the methods used in earlier studies as it saves the calculation time on the elements of the incident acoustic field. During the optimal design of the corrugated cellular plastic foam with semi-elliptical shaped upper surface, the cross-sectional width (the length of the minor axis) and the area of one section of the corrugated foam are kept the same throughout the study. The variation of the semi-elliptical shape is performed by changing the length of the semi-major axis. By varying the length of the semi-major axis, the maximum sound absorption capability of the semi-elliptical shaped corrugated foam is found. It is concluded that in the high frequency region (2000—4000 Hz), the foam with the major axis to the cross-sectional width ratio (MWR) of 1.96 has the maximum sound absorption capability and its broadband averaged normal incidence sound absorption coefficient is improved from 0.882 to 0.945.
Foaming of Polystyrene/ Thermoplastic Starch Blends
Authors: Mihai Mihaela , Huneault Michel A. , Favis Basil D.
Published: June 2007

This study investigates the fabrication of extruded foams from polystyrene/thermoplastic starch (PS/TPS) blends. A specially designed twinscrew extrusion process is used for starch gelatinization, PS incorporation, polymer mixing, and blowing agent incorporation. In-line rheometry is used to monitor the viscosity of the TPS/PS blends and to evaluate the plasticizing effect of 1,1,1,2 tetrafluoroethane (HFC-134a) used as blowing agent. Differential scanning calorimetry, scanning electron microscopy, density measurement, and picnometry are used to evaluate the thermal properties, the blend morphology, and the foam cell structure. Glycerol content in the TPS phase and the TPS content in the overall blend have a strong effect on the blend viscosity and, in turn, on the ability to foam the material. The foams blown with the hydrofluorocarbone alone have large open-cell content and their density cannot be reduced below 170 kg/m 3. The addition of a small amount of ethanol however results in three-fold reductions in density and much better foam cell homogeneity.
Longitudinal Compressive Strength of Continuous Fiber Composites
Authors: Dharan C.K.H. , Lin Chun-Liang
Published: June 2007

The in-plane longitudinal compressive strength of continuous fiber-reinforced composites is significantly less than their tensile strength, a phenomenon that is still not well understood. Dow and Rosen attempted in 1965 to explain this phenomenon through a fiber microbuckling model, in which each fiber was modeled as a beam-on-an-elastic-foundation. The model, however, grossly overestimates the compressive strength; researchers have since focused on introducing factors that reduce the predicted compressive strength to fit experimentally observed values. These include initial fiber waviness, fiber and matrix properties, the interfacial strength, and interphase properties. While empirical results have demonstrated the influences of some of these factors, an analytical model that can accurately predict the strength while taking into account the underlying failure mechanism is still lacking. The present study treats the compressive strength prediction of continuous fiber-reinforced composites using a different approach. Here, the matrix surrounding the fiber is not assumed to be homogeneous, but is divided into a discrete interphase region adjacent to the fiber and bulk matrix phase beyond the interphase. The three-phase model is shown to provide a more accurate prediction of the compressive strength of typical high-performance composites, such as glass and carbon fiber-reinforced epoxy. The present model's prediction agrees well with the trends shown in the experimental database available in the literature.
Compressive Behavior of Al2O3—SiC Ceramic Composite Foams Fabricated by Decomposition of Aluminum Sulfate Aqueous Solution
Authors: Altinkok Necat , Demir Adem , Ozsert Ibrahim , Findik Fehim
Published: June 2007

In recent years, a new class of ceramic foams with porosity levels up to 95% has been produced by the chemical method with aeration of a suspension containing foaming agents. The method of foamed suspensions has originated from the chemical reactions of water-soluble salts. In this study, sintered cellular ceramic composites with varying degrees of reticulation are prepared using coarse and fine silicon carbide (SiC) powder. A new process has been developed in order to produce SiC particles containing alumina (Al2 O3) foam by chemical route. An aqueous solution of aluminum sulfate and ammonium sulfate plus SiC particles is fired to prepare ceramic foams up to 1200°C in a ceramic crucible. During heating, the viscous suspension is foamed, sulfate ions are volatilized, and an Al 2O3—SiC composite cake is obtained. The resulting Al2O3 are in networking morphology with flaky struts whereas SiC particles are encapsulated in the flaky alumina. These 3D connections of the struts are responsible for macropores and Al2O3 and SiC grains within the struts are responsible for micropores. Thus, a ceramic composite foam containing bimodal pore distribution is obtained. After sintering at 1550°C, compression tests are applied for the ceramic composite foams. High compressive strength is achieved after post sintering. Both sintering temperature and addition of SiC particles increase the compressive strength of the foam. Both SEM image and XRD analyses are carried out to examine composite microstructures and properties.
We Want the Same Thing: Projection in Judgments of Sexual Intent
Authors: Lenton Alison P. , Bryan Angela , Hastie Reid , Fischer Oliver
Published: June 2007

This article details two studies investigating the proximal role of social projection (i.e., assumed similarity) in judgments of sexual intent. Study 1 demonstrates that men and women who have a greater desire for casual sex are more likely to perceive sexual intent in others. Study 2 replicates this finding in a more realistic context and, further, situates judgments of sexual intent squarely into the cognitive domain, as results show that projection of casual sexual motivation is more likely when the target is similar to the perceiver and when the target's motivation is relatively ambiguous to begin with.
The Perception of Time Heals All Wounds: Temporal Distance Affects Willingness to Forgive Following an Interpersonal Transgression
Authors: Wohl Michael J. A. , McGrath April L.
Published: June 2007

Prior research has assessed the temporal unfolding of forgiveness and found that forgiveness becomes more likely as time distances the victim from the transgression. These findings lend credence to the axiom “time heals all wounds.” This research examines the effect of time perception on forgiveness of others by experimentally manipulating temporal distance. In Experiment 1, respondents reported greater willingness to forgive the transgressor when more time had elapsed since the transgression. Experiments 2 and 3 determined the influence of subjective temporal distance on willingness to forgive. Participants who perceived a hypothetical (Experiment 2) or real (Experimental 3) transgression to be farther away in time were more willing to forgive the target than were participants who perceived the event to be temporally closer. Results suggest that temporal appraisals of an event are central to the forgiveness process.
Reading Dewey: Reflections on the Study of Routine
Authors: Cohen Michael D.
Published: June 2007

Early twentieth-century American pragmatists such as John Dewey placed a strong emphasis on the human faculties of habit and emotion. That contrasts with the emphasis in recent decades on cognitive processes. In contemporary organizational research there has been an increasing interest in recurring action patterns, such as routines and practices. The conceptual difficulties this work has encountered are usefully illuminated by Dewey's view of the primacy of habit and its interplay with emotion and cognition.
Beyond Words: Aesthetic Knowledge and Knowing in Organizations
Authors: Ewenstein Boris , Whyte Jennifer
Published: June 2007

Aesthetic knowledge comes from practitioners understanding the look, feel, smell, taste and sound of things. It is vital to work in many organizational contexts. In this paper, we explore aesthetic knowledge and knowing in organizations through detailed observation of design work in the architectural practice Edward Cullinan Architects. Through our research, we explore aesthetic knowledge in the context of architectural work, we unpack what it is, how it is generated, and how it is applied in design projects, shared between practitioners and developed at the level of the organization. Our analysis suggests that aesthetic knowledge plays an important part in organizational practice, not only as the symbolic context for work, but as an integral part of the work that people do. It suggests that aesthetic reflexivity, which involves an opening up and questioning of what is known, is experienced as part of practice as well as a `time out' from practice.
Social demands, social supports, and psychological distress among low-income women
Authors: Durden Emily D. , Hill Terrence D. , Angel Ronald J.
Published: June 2007

We investigate the association between social demands and psychological distress among low-income women. We argue that perceptions of excessive social demands can be psychologically distressing and examine the extent to which social demands predict psychological distress over 2 years. Our results reveal several important patterns. First, emotional, but not instrumental, demands are positively associated with psychological distress. Second, emotional and instrumental supports are more strongly associated with psychological distress than are emotional demands. Third, emotional support buffers the adverse effects of emotional demands. Finally, other chronic stressors, including economic hardship, neighborhood problems, and household disrepair, are more strongly associated with psychological distress than are social demands.
Perceptions of turmoil within courtship: Associations with intimacy, relational uncertainty, and interference from partners
Authors: Knobloch Leanne K.
Published: June 2007

The goal of this article is to test the relational turbulence model's explanation for people's perceptions of turmoil within courtship. It begins by deducing hypotheses about how intimacy, relational uncertainty, and interference from partners may predict perceptions of turmoil. Then, it reports the results of a cross-sectional, self-report investigation of 268 individuals involved in dating relationships. Consistent with the relational turbulence model, perceptions of turmoil were highest at moderate levels of intimacy (H1). Interference from partners (H4, H5), but not relational uncertainty (H2, H3), partially mediated the convex curvilinear association between intimacy and perceptions of turmoil. These results shed light on how individuals may experience the transition from casual dating to serious involvement within courtship.
Coping as a mediator between interparental conflict and adolescents' romantic attachment
Authors: Rodrigues Leslie N. , Kitzmann Katherine M.
Published: June 2007

This study examined the association between interparental conflict and late adolescents' attachment in romantic relationships through analyses of the mediating and moderating effects of adolescents' coping. Adolescents (n = 96, age 18—19 years, 81% female) reported on dimensions of interparental conflict, romantic attachment, and strategies for coping with parents' conflicts. As expected, higher levels of conflict were associated with significantly higher levels of anxious attachment in romantic relationships. This association was mediated by involuntary disengagement coping, but not by other coping responses (involuntary engagement, voluntary engagement, or voluntary disengagement). Hypotheses regarding moderation were not supported. These results suggest that coping may be influenced by the nature of the parental conflict, which, in turn, shapes the impact of conflict on later romantic relationships.
Local heroes: risk-taking in Iraq
Authors: Loyn David
Published: June 2007

The BBC’s developing world correspondent stresses the responsibilities various news organisations have towards the local journalists working for them in war zones. “For local journalists, and particularly cameramen, the war [in Iraq] represents a unique set of challenges”, he writes. “Anyone working as a journalist in Baghdad is automatically under threat, and many local journalists do not admit their trade to their neighbours, particularly if they work for a foreign news organisation. The threats come not just when the bombs are going off, but in normal daily life. Some days before the anniversary of a grisly massacre of civilians by American soldiers, we asked a stringer in the region to take some general shots of the town and get interviews a year on, if he could. But what would have been a simple routine commission in any other country in the world turned into a life-threatening nightmare: after setting out from his home in Ramadi he was blocked on the road several times and then held up overnight at an American roadblock in a region where anyone out after dark risks their life. He did not get the pictures.”
Crime: everything old is new again
Authors: Willetts Paul
Published: June 2007

Author Willetts claims there is nothing new about either the recent wave of gun-crime and gangsterism in Britain or the reporting of it. Strong echoes of both the phenomenon itself and the media’s treatment of it can be found during the aftermath of the Second World War. Willetts recounts the story of a particularly emotive shooting in North Soho in 1947 and the media frenzy it occasioned. “Had the North Soho shooting occurred today,” he writes, “the police would have had to contend with jostling camera crews from numerous television stations. In the era before most homes had been invaded by television, however, so-called ‘newsreels’ provided a comparable source of coverage... Such was the significance of the…murder that the Pathé company, one of the foremost producers of newsreels in Britain, despatched a cameraman to the scene of the crime. By then, the Metropolitan Police had initiated what would turn into its biggest murder investigation so far that century.”
Shifting Attention Using a Temporal Difference Prediction Error and High-Dimensional Input
Authors: Alexander William H.
Published: June 2007

Research on reinforcement learning has increasingly focused on the role of neuromodulatory systems implicated in associative learning. Formulations of temporal difference (TD) learning have gained a great deal of attention due to the similarity of the TD prediction error and the observed activity of dopamine neurons in the primate midbrain. Recent work has attempted to integrate additional neuromodulatory systems such as noradrenaline and acetylcholine in a TD framework. Additional work has been done to remedy representational issues arising from TD variants that result in incorrect predictions of dopamine activity, as well as to incorporate the TD error signal in models of categorization. In this paper, an actor—critic model incorporating aspects of TD learning and psychological models of attention is described. The development of the model and the behavior of an autonomous agent in a simulated environment are examined and compared with a variant of TD learning lacking an attentional component. The agent learns to behave adaptively due to the shifting of attention to relevant aspects of a high-dimensional input. In contrast, the TD model exhibits perseverative behavior and comparatively slow learning in the same context. It is suggested that real-time models of attention may provide insight into neuromodulatory systems implicated in attention and representational learning.
Making art accessible
Authors: Stenglin Maree
Published: June 2007

This essay analyses an art exhibition installed along the Sydney coastline, explaining how the exhibition immersed people not only in the environment but also in surprising experiences of community.
Video Anekdot: Auteurs and Voyeurs of Russian Flash Animation
Authors: Strukov Vlad
Published: June 2007

In this article, the author addresses the issue of flash animation and humour in computer-mediated communication. He traces Russian national graphic traditions of humour and publicity and provides historical insight into the aesthetics of flash animation. He also suggests a notion of the video anekdot, a form of flash animation that relies on the tradition of oral humorous performances that proliferated in the USSR as an attempt to overcome state censorship. With the abolishing of censorship, the anekdot continues to exist on the internet in the form of short flash animation films. The author analyses new structures of the anekdot and its relation to the previous forms of humorous and satirical art (lubok, the Soviet poster and caricature). Reflecting on the dominating themes and narrative structures of the video anekdot, he concludes with general remarks on transformations in Russian culture in regard to its traditions of oral performance and visual representations.
Lipid rafts are required for Kit survival and proliferation signals
Authors: Jahn Thomas , Leifheit Erica , Gooch Stacie , Sindhu Simran , Weinberg Kenneth
Published: June 2007

In addition to its physiologic role as central regulator of the hematopoietic and reproductive systems, the Kit receptor tyrosine kinase (RTK) is pathologically overexpressed in some forms of leukemia and constitutively activated by oncogenic mutations in mast-cell proliferations and gastrointestinal stromal tumors. To gain insight into the general activation and signaling mechanisms of RTKs, we investigated the activation-dependent dynamic membrane distributions of wild-type and oncogenic forms of Kit in hematopoietic cells. Ligand-induced recruitment of wild-type Kit to lipid rafts after stimulation by Kit ligand (KL) and the constitutive localization of oncogenic Kit in lipid rafts are necessary for Kit-mediated proliferation and survival signals. KL-dependent and oncogenic Kit kinase activity resulted in recruitment of the regulatory phosphatidylinositol 3-kinase (PI3-K) subunit p85 to rafts where the catalytical PI3-K subunit p110 constitutively resides. Cholesterol depletion by methyl-β-cyclodextrin prevented Kit-mediated activation of the PI3-K downstream target Akt and inhibited cellular proliferation by KL-activated or oncogenic Kit, including mutants resistant to the Kit inhibitor imatinib-mesylate. Our data are consistent with the notion that Kit recruitment to lipid rafts is required for efficient activation of the PI3-K/Akt pathway and Kit-mediated proliferation.
An efficient pseudomedian filter for tiling microrrays
Authors: Royce Thomas E , Carriero Nicholas J , Gerstein Mark B
Published: June 2007

Background

Tiling microarrays are becoming an essential technology in the functional genomics toolbox. They have been applied to the tasks of novel transcript identification, elucidation of transcription factor binding sites, detection of methylated DNA and several other applications in several model organisms. These experiments are being conducted at increasingly finer resolutions as the microarray technology enjoys increasingly greater feature densities. The increased densities naturally lead to increased data analysis requirements. Specifically, the most widely employed algorithm for tiling array analysis involves smoothing observed signals by computing pseudomedians within sliding windows, a O(n
2logn) calculation in each window. This poor time complexity is an issue for tiling array analysis and could prove to be a real bottleneck as tiling microarray experiments become grander in scope and finer in resolution.

Results

We therefore implemented Monahan's HLQEST algorithm that reduces the runtime complexity for computing the pseudomedian of n numbers to O(n logn) from O(n
2logn). For a representative tiling microarray dataset, this modification reduced the smoothing procedure's runtime by nearly 90%. We then leveraged the fact that elements within sliding windows remain largely unchanged in overlapping windows (as one slides across genomic space) to further reduce computation by an additional 43%. This was achieved by the application of skip lists to maintaining a sorted list of values from window to window. This sorted list could be maintained with simple O(log n) inserts and deletes. We illustrate the favorable scaling properties of our algorithms with both time complexity analysis and benchmarking on synthetic datasets.

Conclusion

Tiling microarray analyses that rely upon a sliding window pseudomedian calculation can require many hours of computation. We have eased this requirement significantly by implementing efficient algorithms that scale well with genomic feature density. This result not only speeds the current standard analyses, but also makes possible ones where many iterations of the filter may be required, such as might be required in a bootstrap or parameter estimation setting. Source code and executables are available at http://tiling.gersteinlab.org/pseudomedian/.
Preservation of proliferating pancreatic progenitor cells by Delta-Notch signaling in the embryonic chicken pancreas
Authors: Ahnfelt-Rønne Jonas , Hald Jacob , Bødker Anne , Yassin Hani , Serup Palle , Hecksher-Sørensen Jacob
Published: June 2007

Background

Genetic studies have shown that formation of pancreatic endocrine cells in mice is dependent on the cell autonomous action of the bHLH transcription factor Neurogenin3 and that the extent and timing of endocrine differentiation is controlled by Notch signaling. To further understand the mechanism by which Notch exerts this function, we have investigated pancreatic endocrine development in chicken embryos.

Results

In situ hybridization showed that expression of Notch signaling components and pro-endocrine bHLH factors is conserved to a large degree between chicken and mouse. Cell autonomous inhibition of Notch signal reception results in significantly increased endocrine differentiation demonstrating that these early progenitors are prevented from differentiating by ongoing Notch signaling. Conversely, activated Notch1 induces Hes5-1 expression and prevents endocrine development. Notably, activated Notch also prevents Ngn3-mediated induction of a number of downstream targets including NeuroD, Hes6-1, and MyT1 suggesting that Notch may act to inhibit both Ngn3 gene expression and protein function. Activated Notch1 could also block endocrine development and gene expression induced by NeuroD. Nevertheless, Ngn3- and NeuroD-induced delamination of endodermal cells was insensitive to activated Notch under these conditions. Finally, we show that Myt1 can partially overcome the repressive effect of activated Notch on endocrine gene expression.

Conclusion

We conclude that pancreatic endocrine development in the chicken relies on a conserved bHLH cascade under inhibitory control of Notch signaling. This lays the ground for further studies that take advantage of the ease at which chicken embryos can be manipulated.

Our results also demonstrate that Notch can repress Ngn3 and NeuroD protein function and stimulate progenitor proliferation. To determine whether Notch in fact does act in Ngn3-expressing cells in vivo will require further studies relying on conditional mutagenesis.

Lastly, our results demonstrate that expression of differentiation markers can be uncoupled from the process of delamination of differentiating cells from the epithelium.