bluuebunny/crossref_metadata_2025 huggingface dataset:
Seismic imaging using lateral adaptive windows
Authors: Pedersen Ørjan , Brandsberg-Dahl Sverre , Ursin Bjørn
Published: April 2010

One-way wavefield extrapolation methods are used routinely in 3D depth migration algorithms for seismic data. Due to their efficient computer implementations, such one-way methods have become increasingly popular and a wide variety of methods have been introduced. In salt provinces, the migration algorithms must be able to handle large velocity contrasts because the velocities in salt are generally much higher than in the surrounding sediments. This can be a challenge for one-way wavefield extrapolation methods. We present a depth migration method using one-way propagators within lateral windows for handling the large velocity contrasts associated with salt-sediment interfaces. Using adaptive windowing, we can handle large perturbations locally in a similar manner as the beamlet propagator, thus limiting the impact of the errors on the global wavefield. We demonstrate the performance of our method by applying it to synthetic data from the 2D SEG/EAGE [Formula: see text] salt model and an offshore real data example.
Progesterone Is Essential for Maintenance and Growth of Uterine Leiomyoma
Authors: Ishikawa Hiroshi , Ishi Kazutomo , Serna Vanida Ann , Kakazu Rafael , Bulun Serdar E. , Kurita Takeshi
Published: April 2010

Uterine leiomyomata (ULs) represent the most common tumor in women and can cause abnormal uterine bleeding, large pelvic masses, and recurrent pregnancy loss. Although the dependency of UL growth on ovarian steroids is well established, the relative contributions of 17β-estradiol and progesterone are yet to be clarified. Conventionally, estradiol has been considered the primary stimulus for UL growth, and studies with cell culture and animal models support this concept. In contrast, no research model has clearly demonstrated a requirement of progesterone in UL growth despite accumulating clinical evidence for the essential role of progesterone in this tumor. To elucidate the functions of ovarian steroids in UL, we established a xenograft model reflecting characteristics of these tumors by grafting human UL tissue beneath the renal capsule of immunodeficient mice. Leiomyoma xenografts increased in size in response to estradiol plus progesterone through cell proliferation and volume increase in cellular and extracellular components. The xenograft growth induced by estradiol plus progesterone was blocked by the antiprogestin RU486. Furthermore, the volume of established UL xenografts decreased significantly after progesterone withdrawal. Surprisingly, treatment with estradiol alone neither increased nor maintained the tumor size. Although not mitogenic by itself, estradiol induced expression of progesterone receptor and supported progesterone action on leiomyoma xenografts. Taken together, our findings define that volume maintenance and growth of human UL are progesterone dependent.
Improved Molecular Diagnostics of Idiopathic Short Stature and Allied Disorders: Quantitative Polymerase Chain Reaction-Based Copy Number Profiling of SHOX and Pseudoautosomal Region 1
Authors: D'haene Barbara , Hellemans Jan , Craen Margarita , De Schepper Jean , Devriendt Koen , Fryns Jean-Pierre , Keymolen Kathelijn , Debals Eveline , de Klein Annelies , de Jong Elisabeth M. , Segers Karin , De Paepe Anne , Mortier Geert , Vandesompele Jo , De Baere Elfride
Published: April 2010

Context: Short stature has an incidence of three in 100 in children. Reliable molecular genetic testing may be crucial in the context of beneficial disease management. Deletions spanning or surrounding the SHOX gene account for a significant proportion of patients with idiopathic short stature (ISS) and allied disorders, such as Leri-Weill dyschondrosteosis.

Objective: Several shortcomings of current strategies for copy number profiling of the SHOX region prompted us to develop an improved test for molecular diagnostics of the SHOX region.

Design and Results: We introduced a quantitative PCR (qPCR)-based copy number profiling test, consisting of 11 amplicons targeting clinically relevant regions, i.e. the SHOX gene and regulatory regions. To ensure an optimal sensitivity and specificity, this test was validated in 32 controls and 18 probands with previously identified copy number changes. In addition, 152 probands with SHOX-associated phenotypes were screened, revealing 10 novel copy number changes.

Conclusion: This highly validated qPCR test supersedes other approaches for copy number screening of the SHOX region in terms of reliability, accuracy, and cost efficiency. In addition, another strong point is the fact that it can be easily implemented in any standard equipped molecular laboratory. Our qPCR-based test is highly recommended for molecular diagnostics of idiopathic short stature and allied disorders.
Effect of Rhythmic Gymnastics on Volumetric Bone Mineral Density and Bone Geometry in Premenarcheal Female Athletes and Controls
Authors: Tournis S. , Michopoulou E. , Fatouros I. G. , Paspati I. , Michalopoulou M. , Raptou P. , Leontsini D. , Avloniti A. , Krekoukia M. , Zouvelou V. , Galanos A. , Aggelousis N. , Kambas A. , Douroudos I. , Lyritis G. P. , Taxildaris K. , Pappaioannou N.
Published: April 2010

Context and Objective: Weight-bearing exercise during growth exerts positive effects on the skeleton. Our objective was to test the hypothesis that long-term elite rhythmic gymnastics exerts positive effects on volumetric bone mineral density and geometry and to determine whether exercise-induced bone adaptation is associated with increased periosteal bone formation or medullary contraction using tibial peripheral quantitative computed tomography and bone turnover markers.

Design and Setting: We conducted a cross-sectional study at a tertiary center.

Subjects: We studied 26 elite premenarcheal female rhythmic gymnasts (RG) and 23 female controls, aged 9–13 yr.

Main Outcome Measures: We measured bone age, volumetric bone mineral density, bone mineral content (BMC), cortical thickness, cortical and trabecular area, and polar stress strength index (SSIp) by peripheral quantitative computed tomography of the left tibia proximal to the distal metaphysis (trabecular) at 14, 38 (cortical), and 66% (muscle mass) from the distal end and bone turnover markers.

Results: The two groups were comparable according to height and chronological and bone age. After weight adjustment, cortical BMC, area, and thickness at 38% were significantly higher in RG (P < 0.005–0.001). Periosteal circumference, SSIp, and muscle area were higher in RG (P < 0.01–0.001). Muscle area was significantly associated with cortical BMC, area, and SSIp, whereas years of training showed positive association with cortical BMC, area, and thickness independent of chronological age.

Conclusions: RG in premenarcheal girls may induce positive adaptations on the skeleton, especially in cortical bone. Increased duration of exercise is associated with a positive response of bone geometry.
Peptide YY Levels across Pubertal Stages and Associations with Growth Hormone
Authors: Lloyd Benjamin , Ravi Praful , Mendes Nara , Klibanski Anne , Misra Madhusmita
Published: April 2010

Context: Changes in appetite-regulating peptides may impact food intake during puberty and facilitate the pubertal growth spurt. Peptide YY (PYY) is an anorexigenic hormone that is high in anorexia nervosa and low in obesity, inhibits GnRH secretion, and is suppressed by GH administration. The relationship between PYY and GH has not been examined across puberty.

Objectives: We hypothesized that PYY would be inversely associated with GH in adolescents and would be lowest when GH is highest.

Design and Setting: We conducted a cross-sectional study at a Clinical Research Center.

Subjects: We studied 87 children, 46 boys and 41 girls ages 9–17 yr at Tanner stages 1–5 of puberty (10th–90th percentiles for body mass index).

Outcome Measures: We measured fasting PYY and nadir GH levels after administration of an oral glucose load. Leptin levels were also measured.

Results: Fasting PYY was lowest and nadir GH highest in boys in Tanner stages 3–4 (P = 0.02) and in girls in Tanner stages 2–3 (P = 0.02). Leptin levels were highest in early pubertal boys and late pubertal girls. For the group as a whole and within genders, even after controlling for body mass index, log nadir GH correlated inversely with log PYY (P = 0.003, 0.07, and 0.02). PYY levels did not correlate with leptin levels.

Conclusions: During mid-puberty, at a time when GH levels are the highest, PYY is at a nadir, and these low PYY levels may facilitate pubertal progression and growth.
Associations of Circulating Adiponectin with Measures of Vascular Function and Morphology
Authors: Gustafsson Stefan , Lind Lars , Söderberg Stefan , Ingelsson Erik
Published: April 2010

Context: Some previous studies have reported an association between circulating adiponectin and selected measures of vascular function and morphology, but most of these studies have been performed in small samples of patients with preexisting disease.

Objective: We aimed to evaluate associations between circulating adiponectin and comprehensive measures of vascular function and morphology in a large sample of individuals from the community.

Design, Settings, and Participants: We conducted a cross-sectional investigation of 981 70-yr-old participants (50% women) of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS).

Main Outcome Measures: Measures of outcome included vascular function [common carotid artery (CCA) distensibility, flow-mediated dilation, endothelium-dependent and endothelium-independent vasodilation using invasive methods] and vascular morphology [intima-media (IM) thickness, plaque presence, gray scale median (GSM) in the IM and plaques].

Results: In age- and sex-adjusted models, adiponectin was positively associated with IM-GSM, plaque GSM, CCA distensibility, endothelium-dependent and endothelium-independent vasodilation. In multivariable models (with additional adjustment for body mass index; systolic blood pressure; antihypertensive, antidiabetic, and lipid-lowering medication; fasting blood glucose; total cholesterol; high-density lipoprotein cholesterol; creatinine; and smoking), adiponectin remained positively associated with IM-GSM [β = 2.06; 95% confidence interval (CI), 0.54, 3.58], plaque GSM (β = 3.11; 95% CI, 0.36, 5.86), and CCA distensibility (β = 0.04; 95% CI, 0.00, 0.07).

Conclusions: Serum levels of adiponectin were positively associated with IM-GSM and plaque GSM (indicating lower fat content in the IM and plaques) and CCA distensibility (indicating higher wall elasticity), independent of potential confounders. Our results imply that adiponectin is associated with less arterial pathology.
Expression Profiling of Nuclear Receptors in the NCI60 Cancer Cell Panel Reveals Receptor-Drug and Receptor-Gene Interactions
Authors: Holbeck Susan , Chang Jianjun , Best Anne M. , Bookout Angie L. , Mangelsdorf David J. , Martinez Elisabeth D.
Published: April 2010

We profiled the expression of the 48 human nuclear receptors (NRs) by quantitative RT-PCR in 51 human cancer cell lines of the NCI60 collection derived from nine different tissues. NR mRNA expression accurately classified melanoma, colon, and renal cancers, whereas lung, breast, prostate, central nervous system, and leukemia cell lines exhibited heterogeneous receptor expression. Importantly, receptor mRNA levels faithfully predicted the growth-inhibitory qualities of receptor ligands in nonendocrine tumors. Correlation analysis using NR expression profiles and drug response information across the cell line panel uncovered a number of new potential receptor-drug interactions, suggesting that in these cases, individual receptor levels may predict response to chemotherapeutic interventions. Similarly, by cross-comparing receptor levels within our expression dataset and relating these profiles to existing microarray gene expression data, we defined interactions among receptors and between receptors and other genes that can now be mechanistically queried. This work supports the strategy of using NR expression profiling to classify various types of cancer, define NR-drug interactions and receptor-gene networks, predict cancer-drug sensitivity, and identify druggable targets that may be pharmacologically manipulated for potential therapeutic intervention.
Fission yeast Rad26ATRIP delays spindle-pole-body separation following interphase microtubule damage
Authors: Herring Matthew , Davenport Nick , Stephan Kendra , Campbell Shawna , White Rebecca , Kark Jonathan , Wolkow Tom D.
Published: April 2010

The conserved fission yeast protein Rad26ATRIP preserves genomic stability by occupying central positions within DNA-structure checkpoint pathways. It is also required for proper cellular morphology, chromosome stability and following treatment with microtubule poisons. Here, we report that mutation of a putative nuclear export sequence in Rad26ATRIP disrupted its cytoplasmic localization in untreated cells and conferred abnormal cellular morphology, minichromosome instability and sensitivity to microtubule poisons without affecting DNA-structure checkpoint signaling. This mutation also disrupted a delay to spindle-pole-body separation that occurred following microtubule damage in G2. Together, these results demonstrate that Rad26ATRIP participates in two genetically defined checkpoint pathways – one that responds to genomic damage and the other to microtubule damage. This response to microtubule damage delays spindle-pole-body separation and, in doing so, might preserve both cellular morphology and chromosome stability.
Rab7b controls trafficking from endosomes to the TGN
Authors: Progida Cinzia , Cogli Laura , Piro Francesco , De Luca Azzurra , Bakke Oddmund , Bucci Cecilia
Published: April 2010

Rab7b is a recently identified member of the Rab GTPase protein family and has high similarity to Rab7. It has been reported that Rab7b is lysosome associated, that it is involved in monocytic differentiation and that it promotes lysosomal degradation of TLR4 and TLR9. Here we investigated further the localization and function of this GTPase. We found that wild-type Rab7b is lysosome associated whereas an activated, GTP-bound form of Rab7b localizes to the Golgi apparatus. In contrast to Rab7, Rab7b is not involved in EGF and EGFR degradation. Depletion of Rab7b or expression of Rab7b T22N, a Rab7b dominant-negative mutant, impairs cathepsin-D maturation and causes increased secretion of hexosaminidase. Moreover, expression of Rab7b T22N or depletion of Rab7b alters TGN46 distribution, cation-independent mannose-6-phosphate receptor (CI-MPR) trafficking, and causes an increase in the levels of the late endosomal markers CI-MPR and cathepsin D. Vesicular stomatitis virus G protein (VSV-G) trafficking, by contrast, is normal in Rab7b-depleted or Rab7b-T22N-expressing cells. In addition, depletion of Rab7b prevents cholera toxin B-subunit from reaching the Golgi. Altogether, these data indicate that Rab7b is required for normal lysosome function, and, in particular, that it is an essential factor for retrograde transport from endosomes to the trans-Golgi network (TGN).
Asna1/TRC40-mediated membrane insertion of tail-anchored proteins
Authors: Favaloro Vincenzo , Vilardi Fabio , Schlecht Rainer , Mayer Matthias P. , Dobberstein Bernhard
Published: April 2010

Tail-anchored (TA) proteins insert post-translationally into the membrane of the endoplasmic reticulum (ER) and span the membrane by their C-terminal transmembrane domain. We have reconstituted membrane insertion of TA proteins from recombinant Asna1/TA protein complexes and ER-derived membranes. Our data show that Asna1 can mediate membrane insertion of RAMP4 and Sec61β without the participation of other cytosolic proteins by a mechanism that depends on the presence of ATP or ADP and a protease-sensitive receptor in the ER membrane. By contrast, membrane insertion of cytochrome b5 can proceed independently of Asna1 and nucleotides.
The N-terminal domain of the type 1 Ins(1,4,5)P3 receptor stably expressed in MDCK cells interacts with myosin IIA and alters epithelial cell morphology
Authors: Hours Michel C. , Mery Laurence
Published: April 2010

Cytosolic Ca2+ controls a wide range of cellular events. The versatility of this second messenger depends on its ability to form diverse spatial and temporal patterns, including waves and oscillations. Ca2+-signaling patterns are thought to be determined in part by the subcellular distribution of inositol (1,4,5)-trisphosphate receptors [Ins(1,4,5)P3Rs] but little is currently known about how the localization of the Ins(1,4,5)P3R itself is regulated. Here, we report that the recruitment of GFP-tagged Ins(1,4,5)P3Rs in the vicinity of tight junctions in Madin-Darby canine kidney (MDCK) cells requires the N-terminal domain. Stable expression of this domain in polarized MDCK cells induced a flattened morphology, affected cytokinesis, accelerated cell migration in response to monolayer wounding and interfered with the cortical targeting of myosin IIA. In addition, downregulation of myosin IIA in polarized MDCK cells was found to mimic the effects of stable expression of the N-terminal part of Ins(1,4,5)P3R on cell shape and to alter localization of endogenous Ins(1,4,5)P3Rs. Taken together, these results support a model in which the recruitment of Ins(1,4,5)P3Rs at the apex of the lateral membrane in polarized MDCK cells, involves myosin IIA and might be important for the regulation of cortical actin dynamics.
Distinct plasma-membrane PtdIns(4)P and PtdIns(4,5)P2 dynamics in secretagogue-stimulated β-cells
Authors: Wuttke Anne , Sågetorp Jenny , Tengholm Anders
Published: April 2010

Phosphoinositides regulate numerous processes in various subcellular compartments. Whereas many stimuli trigger changes in the plasma-membrane PtdIns(4,5)P2 concentration, little is known about its precursor, PtdIns(4)P, in particular whether there are stimulus-induced alterations independent of those of PtdIns(4,5)P2. We investigated plasma-membrane PtdIns(4)P and PtdIns(4,5)P2 dynamics in insulin-secreting MIN6 cells using fluorescent translocation biosensors and total internal reflection microscopy. Loss of PtdIns(4,5)P2 induced by phospholipase C (PLC)-activating receptor agonists or stimulatory glucose concentrations was paralleled by increased PtdIns(4)P levels. In addition, glucose-stimulated cells regularly showed anti-synchronous oscillations of the two lipids. Whereas glucose-induced PtdIns(4)P elevation required voltage-gated Ca2+ entry and was mimicked by membrane-depolarizing stimuli, the receptor-induced response was Ca2+ independent, but sensitive to protein kinase C (PKC) inhibition and mimicked by phorbol ester stimulation. We conclude that glucose and PLC-activating receptor stimuli trigger Ca2+- and PKC-dependent changes in the plasma-membrane PtdIns(4)P concentration that are independent of the effects on PtdIns(4,5)P2. These findings indicate that enhanced formation of PtdIns(4)P, apart from ensuring efficient replenishment of the PtdIns(4,5)P2 pool, might serve an independent signalling function by regulating the association of PtdIns(4)P-binding proteins with the plasma membrane.
Pericellular fibronectin is required for RhoA-dependent responses to cyclic strain in fibroblasts
Authors: Lutz Roman , Sakai Takao , Chiquet Matthias
Published: April 2010

To test the hypothesis that the pericellular fibronectin matrix is involved in mechanotransduction, we compared the response of normal and fibronectin-deficient mouse fibroblasts to cyclic substrate strain. Normal fibroblasts seeded on vitronectin in fibronectin-depleted medium deposited their own fibronectin matrix. In cultures exposed to cyclic strain, RhoA was activated, actin-stress fibers became more prominent, MAL/MKL1 shuttled to the nucleus, and mRNA encoding tenascin-C was induced. By contrast, these RhoA-dependent responses to cyclic strain were suppressed in fibronectin knockdown or knockout fibroblasts grown under identical conditions. On vitronectin substrate, fibronectin-deficient cells lacked fibrillar adhesions containing α5 integrin. However, when fibronectin-deficient fibroblasts were plated on exogenous fibronectin, their defects in adhesions and mechanotransduction were restored. Studies with fragments indicated that both the RGD-synergy site and the adjacent heparin-binding region of fibronectin were required for full activity in mechanotransduction, but not its ability to self-assemble. In contrast to RhoA-mediated responses, activation of Erk1/2 and PKB/Akt by cyclic strain was not affected in fibronectin-deficient cells. Our results indicate that pericellular fibronectin secreted by normal fibroblasts is a necessary component of the strain-sensing machinery. Supporting this hypothesis, induction of cellular tenascin-C by cyclic strain was suppressed by addition of exogenous tenascin-C, which interferes with fibronectin-mediated cell spreading.
Nano-topography sensing by osteoclasts
Authors: Geblinger Dafna , Addadi Lia , Geiger Benjamin
Published: April 2010

Bone resorption by osteoclasts depends on the assembly of a specialized, actin-rich adhesive ‘sealing zone’ that delimits the area designed for degradation. In this study, we show that the level of roughness of the underlying adhesive surface has a profound effect on the formation and stability of the sealing zone and the associated F-actin. As our primary model substrate, we use ‘smooth’ and ‘rough’ calcite crystals with average topography values of 12 nm and 530 nm, respectively. We show that the smooth surfaces induce the formation of small and unstable actin rings with a typical lifespan of ~8 minutes, whereas the sealing zones formed on the rough calcite surfaces are considerably larger, and remain stable for more than 6 hours. It was further observed that steps or sub-micrometer cracks on the smooth surface stimulate local ring formation, raising the possibility that similar imperfections on bone surfaces may stimulate local osteoclast resorptive activity. The mechanisms whereby the physical properties of the substrate influence osteoclast behavior and their involvement in osteoclast function are discussed.
Arabidopsis root K+-efflux conductance activated by hydroxyl radicals: single-channel properties, genetic basis and involvement in stress-induced cell death
Authors: Demidchik Vadim , Cuin Tracey A. , Svistunenko Dimitri , Smith Susan J. , Miller Anthony J. , Shabala Sergey , Sokolik Anatoliy , Yurin Vladimir
Published: April 2010

Reactive oxygen species (ROS) are central to plant stress response, signalling, development and a multitude of other processes. In this study, the plasma-membrane hydroxyl radical (HR)-activated K+ channel responsible for K+ efflux from root cells during stress accompanied by ROS generation is characterised. The channel showed 16-pS unitary conductance and was sensitive to Ca2+, tetraethylammonium, Ba2+, Cs+ and free-radical scavengers. The channel was not found in the gork1-1 mutant, which lacks a major plasma-membrane outwardly rectifying K+ channel. In intact Arabidopsis roots, both HRs and stress induced a dramatic K+ efflux that was much smaller in gork1-1 plants. Tests with electron paramagnetic resonance spectroscopy showed that NaCl can stimulate HR generation in roots and this might lead to K+-channel activation. In animals, activation of K+-efflux channels by HRs can trigger programmed cell death (PCD). PCD symptoms in Arabidopsis roots developed much more slowly in gork1-1 and wild-type plants treated with K+-channel blockers or HR scavengers. Therefore, similar to animal counterparts, plant HR-activated K+ channels are also involved in PCD. Overall, this study provides new insight into the regulation of plant cation transport by ROS and demonstrates possible physiological properties of plant HR-activated K+ channels.
Sperm equatorial segment protein 1, SPESP1, is required for fully fertile sperm in mouse
Authors: Fujihara Yoshitaka , Murakami Masao , Inoue Naokazu , Satouh Yuhkoh , Kaseda Kazuhiro , Ikawa Masahito , Okabe Masaru
Published: April 2010

Mammalian fertilization is a multistep process that culminates in the fusion of the sperm and egg plasma membrane. It is widely accepted that the equatorial segment of the acrosome-reacted sperm is important in initiating fusion with the egg plasma membrane during fertilization. There are various proteins known to be distributed only in the equatorial segment of sperm. The role of these proteins must be clarified to understand the membrane fusion process. We produced a mouse line that lacked SPESP1 (sperm equatorial segment protein 1) and analyzed the fertilizing ability of the sperm. The average number of pups that were fathered by Spesp1+/− and Spesp1−/− males was significantly lower than that of wild-type fathers. In these mouse lines, fewer sperm were found to migrate into oviducts and fewer eggs were fertilized. The Spesp1+/− and Spesp1−/− sperm showed a lower fusing ability compared with the wild-type sperm. The disruption of Spesp1 was shown to cause an aberrant distribution of various sperm proteins. Moreover, scanning electron microscopy revealed that the membrane in the equatorial segment area, which usually forms an acrosomal sheath, disappears after acrosome reaction in Spesp1-deficient mice. It was demonstrated that SPESP1 is necessary to produce the fully ‘fusion competent’ sperm.
Malaria Eradication in the Americas: A Retrospective Analysis of Childhood Exposure
Authors: Bleakley Hoyt
Published: April 2010

This study uses the malaria-eradication campaigns in the United States (circa 1920) and in Brazil, Colombia, and Mexico (circa 1955) to measure how much childhood exposure to malaria depresses labor productivity. The campaigns began because of advances in health technology, which mitigates concerns about reverse causality. Malarious areas saw large drops in the disease thereafter. Relative to non-malarious areas, cohorts born after eradication had higher income as adults than the preceding generation. These cross-cohort changes coincided with childhood exposure to the campaigns rather than to pre-existing trends. Estimates suggest a substantial, though not predominant, role for malaria in explaining cross-region differences in income. (JEL I12, I18, J13, O15)
Modern Medicine and the Twentieth Century Decline in Mortality: Evidence on the Impact of Sulfa Drugs
Authors: Jayachandran Seema , Lleras-Muney Adriana , Smith Kimberly V
Published: April 2010

This paper studies the contribution of sulfa drugs, a groundbreaking medical innovation in the 1930s, to declines in US mortality. For several infectious diseases, sulfa drugs represented the first effective treatment. Using time-series and difference-in-differences methods, we find that sulfa drugs led to a 24 to 36 percent decline in maternal mortality, 17 to 32 percent decline in pneumonia mortality, and 52 to 65 percent decline in scarlet fever mortality between 1937 and 1943. Altogether, sulfa drugs reduced mortality by 2 to 3 percent and increased life expectancy by 0.4 to 0.7 years. We also find that sulfa drugs benefited whites more than blacks. (JEL I12, L65, N32, N72)
Information, Preferences, and Public Benefit Participation: Experimental Evidence from the Advance EITC and 401(k) Savings
Authors: Jones Damon
Published: April 2010

Within a field experiment, I present a treatment group with reductions in information, administrative, stigma, and procrastination costs associated with the Advance EITC. The treatment increases Advance participation from 0.3 to 1.2 percent. Another treatment simultaneously encourages 401(k) savings, increasing 401(k) participation from 46 to 50 percent. However, there is no additional increase in Advance participation when coupled with the 401(k) treatment, casting doubt on a long-term forced savings motive. The results indicate that EITC recipients actively forgo the Advance. Further work is needed to identify what underlies these preferences. Possible explanations include uncertainty and/or short-term forced savings motives. (JEL D14, D82, H23, H24, H31)
Promoting Healthy Choices: Information versus Convenience
Authors: Wisdom Jessica , Downs Julie S , Loewenstein George
Published: April 2010

Success in slowing obesity trends would benefit from policies aimed at reducing calorie consumption. In a field experiment at a fast-food sandwich chain, we address the effects of providing calorie information, mimicking recent legislation, and test an alternative approach that makes ordering healthier slightly more convenient. We find that calorie information reduces calorie intake. Providing a daily calorie target does as well, but only for non-overweight individuals. Making healthy choices convenient reduces intake when the intervention is strong. However, a milder implementation reduces sandwich calories, but does not reduce total calories due to compensatory effects on side orders and drinks. (JEL I12, I18, L81)
Disclosure by Politicians
Authors: Djankov Simeon , La Porta Rafael , Lopez-de-Silanes Florencio , Shleifer Andrei
Published: April 2010

We collect data on the rules and practices of financial and conflict disclosure by members of Parliament in 175 countries. Although two-thirds of the countries have some disclosure laws, less than one-third make disclosures available to the public, and less than one-sixth of potentially useful information is publicly available in practice, on average. Countries that are richer, more democratic, and have free press have more disclosure. Public disclosure, but not internal disclosure to parliament, is positively related to government quality, including lower corruption. (JEL J13, I21, I12)
An Empirical Analysis of the Gender Gap in Mathematics
Authors: Fryer Roland G , Levitt Steven D
Published: April 2010

We document and analyze the emergence of a substantial gender gap in mathematics in the early years of schooling using a large, recent, and nationally representative panel of US children. There are no mean differences between boys and girls upon entry to school, but girls lose more than two-tenths of a standard deviation relative to boys over the first six years of school. The ground lost by girls relative to boys is roughly half as large as the black-white test score gap that appears over these same ages. We document the presence of this gender math gap across every strata of society. We explore a wide range of possible explanations in the data, including less investment by girls in math, low parental expectations, and biased tests, but find little support for these theories. Moving to cross-country comparisons, we find earlier results linking the gender gap in math to measures of gender equality are sensitive to the inclusion of Muslim countries, where, in spite of women's low status, there is little or no gender gap in math. (JEL I23, J26)
Identification of Social Interactions through Partially Overlapping Peer Groups
Authors: De Giorgi Giacomo , Pellizzari Michele , Redaelli Silvia
Published: April 2010

In this paper, we demonstrate that, in a context where peer groups do not overlap fully, it is possible to identify all the relevant parameters of the standard linear-in-means model of social interactions. We apply this novel identification structure to study peer effects in the choice of college major. Results show that one is more likely to choose a major when many of her peers make the same choice. We also show that peers can divert students from majors in which they have a relative ability advantage, with adverse consequences on academic performance, entry wages, and job satisfaction. (JEL I23, J24, J31, Z13)
Malaria Eradication and Educational Attainment: Evidence from Paraguay and Sri Lanka
Authors: Lucas Adrienne M
Published: April 2010

Mid-twentieth century malaria eradication campaigns largely eliminated malaria from Paraguay and Sri Lanka. Using these interventions as quasi-experiments, I estimate malaria's effect on lifetime female educational attainment through the combination of pre-existing geographic variation in malarial intensity and cohort exposure based on the timing of the national anti-malaria campaigns. The estimates from Sri Lanka and Paraguay are similar and indicate that malaria eradication increased years of educational attainment and literacy. The similarity of the estimates across the countries reinforces our confidence in the validity of the identification strategy. (JEL I12, I18, I21, J16, O15, O18)
Early-life Malaria Exposure and Adult Outcomes: Evidence from Malaria Eradication in India
Authors: Cutler David , Fung Winnie , Kremer Michael , Singhal Monica , Vogl Tom
Published: April 2010

We examine the effects of exposure to malaria in early childhood on educational attainment and economic status in adulthood by exploiting geographic variation in malaria prevalence in India prior to a nationwide eradication program in the 1950s. We find that the program led to modest increases in household per capita consumption for prime age men, and the effects for men are larger than those for women in most specifications. We find no evidence of increased educational attainment for men and mixed evidence for women. (JEL I12, I18, I21, 015, 018)
Labor Markets and Monetary Policy: A New Keynesian Model with Unemployment
Authors: Blanchard Olivier , Galí Jordi
Published: April 2010

We construct a utility-based model of fluctuations with nominal rigidities and unemployment. We first show that under a standard utility specification, productivity shocks have no effect on unemployment in the constrained efficient allocation. That property is also shown to hold, despite labor market frictions, in the decentralized equilibrium under flexible prices and wages. Inefficient unemployment fluctuations arise when we introduce real-wage rigidities. As a result, in the presence of staggered price setting by firms, the central bank faces a trade-off between inflation and unemployment stabilization, which depends on labor market characteristics. We draw the implications for optimal monetary policy. (JEL E12, E24, E52)
Globalization and Innovation in Emerging Markets
Authors: Gorodnichenko Yuriy , Svejnar Jan , Terrell Katherine
Published: April 2010

Globalization brings opportunities and pressures for domestic firms in emerging markets to innovate and improve their competitive position. Using data from 27 emerging market economies, we estimate the effects of foreign competition and linkages with foreign firms on innovation by domestic firms. We provide robust evidence of a positive relationship between foreign competition and innovation, broadly defined. The supply chain of multinational enterprises and trade are also important channels. There is no evidence for an inverted U relationship between innovation and foreign competition. Moreover, the relationship between globalization and innovation does not differ across the manufacturing and service sectors. (JEL F02, F23, M16, O33)
How Much Does Immigration Boost Innovation?
Authors: Hunt Jennifer , Gauthier-Loiselle Marjolaine
Published: April 2010

We measure the extent to which skilled immigrants increase innovation in the United States. The 2003 National Survey of College Graduates shows that immigrants patent at double the native rate, due to their disproportionately holding science and engineering degrees. Using a 1940–2000 state panel, we show that a 1 percentage point increase in immigrant college graduates' population share increases patents per capita by 9–18 percent. Our instrument for the change in the skilled immigrant share is based on the 1940 distribution across states of immigrants from various source regions and the subsequent national increase in skilled immigration from these regions. (JEL J24, J61, O31, O33)
High-risk sexual behaviours and genital chlamydial infections in high school students in Southern Taiwan
Authors: Hsieh Y-H , Shih T-Y , Lin H-W , Hsieh T-C , Kuo M-J , Lin C-W , Gaydos C A
Published: April 2010

Summary

The objective of this study was to determine the prevalence of high-risk sexual behaviours and sexually transmitted infections (STIs) and associated risk factors in Taiwanese high school students. Students in grades 10 and 11 (mean age: 15.9 ± 0.9; range: 13–20 years) at two schools were recruited. An anonymous online real-time computer-assisted self-interviewing questionnaire was designed to assess demographic factors and sexual behaviours. Urine specimens were tested for genital chlamydial and gonococcal infections. The same survey and screening was conducted one year later on the same group of students. Overall, 670 individual students (993 visits) were enrolled with 323 students in both surveys. Twenty-seven percent had had sexual intercourse, and more than three quarters (79%) of them had engaged in high-risk sexual behaviours. Having friends using drugs increased the odds of practicing high-risk sexual behaviours (odds ratio [OR] 1.99, 95% CI: 1.13 to 3.50). Among 182 sexually active students, 8.8% had chlamydial (female: 12.5%; male: 5.3%) and 1.1% had gonococcal infections. Having sex with someone met on the Internet was the most significant risk factor for acquiring chlamydia (OR 8.14, 95% CI: 2.82 to 23.51). In conclusion, this adolescent population reported high prevalence of high-risk sexual behaviours and had a high prevalence of chlamydia supportive of a potential epidemic of STIs and HIV.
Syphilis and HIV co-infection in an Israeli HIV clinic: incidence and outcome
Authors: Agmon-Levin N , Elbirt D , Asher I , Gradestein S , Werner B , Sthoeger Z
Published: April 2010

Summary

The re-emergence of syphilis among HIV-infected patients has been reported in recent years. We evaluated co-infection among heterosexual immigrants in an Israeli AIDS center. The records of 1060 HIV-infected patients were evaluated for positive syphilis serology between the years 2000 and 2005, and all seropositive patients were further evaluated. We found 150 HIV/syphilis co-infected patients (57% men, 93% of African origin), of who 135 were found to have late latent syphilis. Lumbar puncture (LP) was performed in 51 patients, 16 (31 %) had abnormal cerebrospinal fluid (CSF) compatible with neurosyphilis. Abnormal CSF correlated with the absence of previous anti-syphilis treatment, but not with CD4 count, viral load or Venereal Disease Research Laboratory titres. Penicillin was recommended to all patients according to their disease stages and 81 patients completed 12 months post-treatment follow-up. Twenty-one of 81 (26%) treatments were successful, 33 (41 %) showed ‘serofast reaction’ and 27 (33%) failed therapy. In conclusion, a high incidence of syphilis with CSF reactivity suggestive of neurosyphilis was observed in heterosexual Ethiopian HIV-infected patients. Thus, repeated serological screening and CSF evaluation seems to be indicated in these patients. Penicillin therapy resulted in ‘serofast reaction’ or treatment failure for most patients. More, intensive treatment might be needed for HIV/syphilis in co-infected patients, especially those with severe immune-deficiency and prolonged syphilis infection.
Field collection of rectal samples for sexually transmitted infection diagnostics among men who have sex with men
Authors: Dodge B , Van Der Pol B , Rosenberger J G , Reece M , Roth A M , Herbenick D , Fortenberry J D
Published: April 2010

Summary

Rectal sexually transmitted infections (STIs) are common in men at risk for urethral infections with these pathogens, particularly men who have sex with men (MSM). However, for those individuals not regularly seen by a clinician, screening for rectal STI is not currently a widespread option. Qualitative data and samples (i.e. self-obtained rectal specimens) were collected from 75 MSM in a variety of venues. Upon completion of the rectal self-sampling, each participant completed a brief interview regarding their overall experience with the process. Participants reported an overall high level of acceptability and comfort-level involved with self-sampling for rectal STI. Of the majority of men who agreed to provide a rectal self-sample, all reported that they would provide a sample again in the future. However, many men also appreciated the interaction with a health-care provider that a clinical setting offered. In conclusion, self-sampling is a feasible and acceptable option when offered to MSM in a range of community-based venues. Further research is needed to determine which combinations of STI testing and treatment methods (including self-sampling) are most appropriate for diverse groups of men.
Lymphogranuloma venereum serovar L2b in Portugal
Authors: Castro R , Baptista T , Vale A , Nunes H , Prieto E , Araújo C , Mansinho K , Pereira F Da Luz Martins
Published: April 2010

Summary

Chlamydia trachomatis, serovar L2, is the causative agent of lymphogranuloma venereum (LGV), which during recent years has been responsible for various outbreaks reported among men who have sex with men (MSM) in Western Europe, America, Canada and Australia. Samples from nine patients with chronic proctitis, seen at a local hospital were sent to us for identification of C. trachomatis serovar L2. The presence of C. trachomatis serovar L DNA was identified by realtime polymerase chain reaction (PCR) in two patients. They both had high positive C. trachomatis antibody titres (≥ 10,000) and were found to be infected with serovar L2b by sequencing after amplification of the omp 1 gene by a nested PCR technique. These two individuals met the diagnostic criteria for LGV serovar L2b infection and, to our knowledge, these are the first cases described in Portugal.
Something for the weekend! Saturday services – what do patients want and what do they need?
Authors: Challenor R , Warwick Z
Published: April 2010

Summary

We investigated our patients’ preferences for weekend services at the same time as commencing a new Saturday clinic. Patients were asked for their views on weekend services: 374 questionnaires were returned; 210 (56%) from women and 164 (44%) from men. Saturday services were rated as more important than Sunday services. One hundred and eleven patients (29.7%) said they would be likely/very likely to use a Saturday service, whereas only 67 (17.9%) rated Sunday services as important/very important. We also undertook an evaluation of our new Saturday service. A total of 214 patients (187 new/rebooks and 27 follow-ups) attended during the first 12 weeks; average 18 patients per clinic; 107 (50%) men. Introducing text appointment reminders reduced did not attend (DNA) rates from 19% to 14% (background clinic DNA rate 10%). There were more men (P = 0.01), more patients with symptoms (P < 0.0001) and more with sexually transmitted infections (STIs) (P = 0.02) attending on Saturdays. We have increased access for those patients who have difficulty attending on weekdays (56%), reduced anxiety (44%) and accessed a population with a high prevalence of STIs (44%). We conclude our Saturday service is affordable, sustainable and in patients’ interests. Other clinics may wish to look at the needs of their local population and design services appropriate to their own area.
Previous history of gonococcal infection as a risk factor in patients presenting with gonorrhoea
Authors: Fowler T , Caley M , Johal R , Brown R , Ross J D C
Published: April 2010

Summary

Recidivism is common in patients infected with gonorrhoea. Identifying the factors most closely associated with recurrent gonococcal infection can help to target health promotion and disease prevention interventions. A case-control study design was used to quantify the importance of past infection as a risk marker for gonorrhoea while controlling for other demographic and behavioural factors. Data were available for 134 cases of gonorrhoea and 150 controls. A history of gonorrhoea (odds ratio [OR] 4.36 [95% CI 1.78–10.71]) was the strongest predictor of current infection. The number of partners in the last month (OR 2.19 [95% CI 1.20–4.02]) was also significantly associated with a diagnosis of gonorrhoea. Patients presenting with gonorrhoea are a specific high-risk group who require additional interventions and should be prioritized for evidence-based, enhanced and interactive counselling.
Pilot study of the utility and acceptability of tampon sampling for the diagnosis of Neisseria gonorrhoeae and Chlamydia trachomatis infections by duplex realtime polymerase chain reaction in United Kingdom sex workers
Authors: Phd P T Kimmitt , Phd S N Tabrizi , Crosatti M , Frcpa S M Garland , Frcp P C Schober , Frcpa K Rajakumar , Mrcp C A Chapman
Published: April 2010

Summary

We aimed to evaluate the acceptability of self-collected tampon samples for the screening of female sex workers for sexually transmitted infections. We recruited 65 sex workers, and 63 agreed to provide tampon samples. The tampon samples were processed by realtime polymerase chain reaction (PCR) targeting Neisseria gonorrhoeae and Chlamydia trachomatis. Urethral and endocervical swabs were also obtained from 61 of 63 participants and tested using culture (N. gonorrhoeae) and the BD ProbeTec™ strand displacement amplification (SDA) (C. trachomatis) assay. Tampon sampling was preferred by 95% of the women and all favoured being tested away from genitourinary medicine clinics; the most common reasons cited were avoidance of embarrassment (40%) and convenience (30%). Besides near-universal acceptability of tampon sampling, the tampon sampling–PCR approach described in this study appeared to have enhanced sensitivity compared with conventional testing, suggesting the possibility of a residual hidden burden of N. gonorrhoeae and/or C. trachomatis genital infections in UK female sex workers.
Sampling for Chlamydia trachomatis infection – a comparison of vaginal, first-catch urine, combined vaginal and first-catch urine and endocervical sampling
Authors: Falk L , Coble B-I , Mjörnberg P-A , Fredlund H
Published: April 2010

Summary

The aim of the study was to evaluate the sensitivity of patients’ self-sampled vaginal specimens, first-catch urine (FCU), combined vaginal/FCU specimens and endocervical specimens for detecting chlamydial infection in women. Women attending sexually transmitted disease clinics, youth clinics and a women's health clinic were enrolled. They self-collected a vaginal specimen with two swabs, which were placed into a sterile tube and into a tube containing a buffer medium, respectively. An FCU sample was collected and aliquoted into both an empty tube and the tube containing the vaginal swab. A clinician collected an endocervical swab. The samples were sent to laboratories for analysis using polymerase chain reaction testing and strand displacement amplification testing, respectively. The sensitivities calculated in all 171 Chlamydia trachomatis-infected women were equal for endocervical specimens (97.1 %), vaginal specimens (96.5%) and combined vaginal/FCU specimens (95.3%), whereas the sensitivity for FCU was significantly lower (87.7%). The sensitivity of vaginal specimens for the detection of C. trachomatis is as high as that of combined vaginal/FCU specimens.
Gonococcal NAATs: what is the current state of play in England and Wales?
Authors: Benzie A , Alexander S , Gill N , Greene L , Thomas S , Ison C
Published: April 2010

The aim of this study was to determine how widespread the use is of dual nucleic acid amplification tests (NAATs) for the diagnosis of both Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) in England and Wales. A structured telephone questionnaire was used to collect information on the method of dual testing used by laboratories, the patient groups tested, the types of specimens obtained and the use of GC culture. Of the 108 laboratories participating, 29% performed dual CT and GC NAAT assays. The platforms used included: (i) BD Probetec™ (19/31), (ii) Aptima® Combo 2 (9/31) and (iii) COBAS® AMPLICOR (2/31). GC-positive specimens were either repeated using the same test (21) or an alternative target (9). Most laboratories confirmed positive GC NAATs by performing culture (26/31). Laboratories performed dual NAAT testing on specimens sourced from both community and genitourinary medicine clinic settings, and on a wide variety of different specimen types. This survey highlights a lack of consistency in the current use of dual NAAT platforms in the UK and the need for national guidelines.