5,093 research outputs found

    Women and Power: Unwilling, Ineffective, or Held Back?

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    We develop a model that nests previous explanations for women under-representation in positions of power. Focusing on democratic electoral dynamics, our framework delineates the three types of mechanisms that may be at play: consumer demand, candidate supply, and internal party dynamics beyond electoral markets. We use Spain's Equality Law, requiring a 40 percent female quota in electoral lists, to test the alternative theories. The law was enacted by the social-democratic party after the surprise parliamentary electoral results following the Madrid terrorist bombings, and was therefore completely unexpected by regional political machines. The law only applied to towns with populations above 5000, so we can use a treatment-control, before-and-after discontinuity design to learn about the impact of female politicians in local elections. Our evidence is most consistent with the existence of entrenched male-dominated political machines capturing influential power positions within the parties.female political representation

    Owning versus leasing: do courts matter?

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    The authors develop a legal contract enforcement theory of the own versus lease decision. The allocation of ownership rights will minimize enforcement costs when the legal system is inefficient. In particular, when legal enforcement of contracts is costly, there will be a shift from arrangements that rely on such enforcement (such as a rental agreement) toward other forms that do not (such as direct ownership). The authors then test this prediction and show that costly enforcement of rental contracts hampers the development of the rental housing market in a cross-section of countries. They argue that this association is not the result of reverse causation from a developed rental market to more investor-protective enforcement and is not driven by alternative institutional channels. The results provide supportive evidence on the importance of legal contract enforcement for market development and the optimal allocation of property rights.

    Women and power: Unwilling, ineffective, or held back?

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    We develop a model that nests previous explanations for women under-representation in positions of power. Focusing on democratic electoral dynamics, our framework delineates the three types of mechanisms that may be at play: consumer demand, candidate supply, and internal party dynamics beyond electoral markets. We use Spain's Equality Law, requiring a 40 percent female quota in electoral lists, to test the alternative theories. The law was enacted by the social-democratic party after the surprise parliamentary electoral results following the Madrid terrorist bombings, and was therefore completely unexpected by regional political machines. The law only applied to towns with populations above 5000, so we can use a treatment-control, before-and-after discontinuity design to learn about the impact of female politicians in local elections. Our evidence is most consistent with the existence of entrenched male-dominated political machines capturing influential power positions within the parties

    Owning Versus Leasing: Do Courts Matter?

    Get PDF
    We develop a legal contract enforcement theory of the own versus lease decision. The allocation of ownership rights will minimize enforcement costs when the legal system is inefficient. In particular, when legal enforcement of contracts is costly, there will be a shift from arrangements that rely on such enforcement (such as a rental agreement) toward other forms that do not (such as direct ownership). We then test this prediction and show that costly enforcement of rental contracts hampers the development of the rental housing market in a cross-section of countries. We argue that this association is not the result of reverse causation from a developed rental market to more investor-protective enforcement and is not driven by alternative institutional channels. The results provide supportive evidence on the importance of legal contract enforcement for market development and the optimal allocation of property rights

    Low-Variance Surface-Enhanced Raman Spectroscopy Using Confined Gold Nanoparticles over Silicon Nanocones

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    Surface-enhanced Raman spectroscopy (SERS) substrates are of utmost interest in the analyte detection of biological and chemical diagnostics. This is primarily due to the ability of SERS to sensitively measure analytes present in localized hot spots of the SERS nanostructures. In this work, we present the formation of 67 ± 6 nm diameter gold nanoparticles supported by vertically aligned shell-insulated silicon nanocones for ultralow variance SERS. The nanoparticles are obtained through discrete rotation glancing angle deposition of gold in an e-beam evaporating system. The morphology is assessed through focused ion beam tomography, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The optical properties are discussed and evaluated through reflectance measurements and finite-difference time-domain simulations. Lastly, the SERS activity is measured by benzenethiol functionalization and subsequent Raman spectroscopy in the surface scanning mode. We report a homogeneous analytical enhancement factor of 2.2 ± 0.1 × 107 (99% confidence interval for N = 400 grid spots) and made a comparison to other lithographically derived assemblies used in SERS. The strikingly low variance (4%) of our substrates facilitates its use for many potential SERS applications.All authors acknowledge the financial support by the Netherlands Center for Multiscale Catalytic Energy Conversion (MCEC), an NWO Gravitation programme. This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No. 801359.Peer reviewe

    Cardiopulmonary Rehabilitation Improves Respiratory Muscle Function and Functional Capacity in Children with Congenital Heart Disease : A Prospective Cohort Study

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    Critical surgical and medical advances have shifted the focus of congenital heart disease (CHD) patients from survival to achievement of a greater health-related quality of life (HRQoL). HRQoL is influenced, amongst other factors, by aerobic capacity and respiratory muscle strength, both of which are reduced in CHD patients. This study evaluates the influence of a cardiopulmonary rehabilitation program (CPRP) on respiratory muscle strength and functional capacity. Fifteen CHD patients, ages 12 to 16, with reduced aerobic capacity in cardiopulmonary exercise testing (CPET) were enrolled in a CPRP involving strength and aerobic training for three months. Measurements for comparison were obtained at the start, end, and six months after the CPRP. A significant improvement of inspiratory muscle strength was evidenced (maximum inspiratory pressure 21 cm H2O, 23%, p < 0.01). The six-minute walking test showed a statistically and clinically significant rise in walked distance (48 m, p < 0.01) and a reduction in muscle fatigue (1.7 out of 10 points, p = 0.017). These results suggest CPRP could potentially improve respiratory muscle function and functional capacity, with lasting results, in children with congenital heart disease, but additional clinical trials must be conducted to confirm this finding

    Alternative nano-lithographic tools for shell-isolated nanoparticle enhanced Raman spectroscopy substrates

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    Chemically synthesized metal nanoparticles (MNPs) have been widely used as surface-enhanced Raman spectroscopy (SERS) substrates for monitoring catalytic reactions. In some applications, however, the SERS MNPs, besides being plasmonically active, can also be catalytically active and result in Raman signals from undesired side products. The MNPs are typically insulated with a thin (∼3 nm), in principle pin-hole-free shell to prevent this. This approach, which is known as shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS), offers many advantages, such as better thermal and chemical stability of the plasmonic nanoparticle. However, having both a high enhancement factor and ensuring that the shell is pin-hole-free is challenging because there is a trade-off between the two when considering the shell thickness. So far in the literature, shell insulation has been successfully applied only to chemically synthesized MNPs. In this work, we alternatively study different combinations of chemical synthesis (bottom-up) and lithographic (top-down) routes to obtain shell-isolated plasmonic nanostructures that offer chemical sensing capabilities. The three approaches we study in this work include (1) chemically synthesized MNPs + chemical shell, (2) lithographic substrate + chemical shell, and (3) lithographic substrate + atomic layer deposition (ALD) shell. We find that ALD allows us to fabricate controllable and reproducible pin-hole-free shells. We showcase the ability to fabricate lithographic SHINER substrates which report an enhancement factor of 7.5 × 103 ± 17% for our gold nanodot substrates coated with a 2.8 nm aluminium oxide shell. Lastly, by introducing a gold etchant solution to our fabricated SHINER substrate, we verified that the shells fabricated with ALD are truly pin-hole-free.</p

    HMGA1 overexpression in adipose tissue impairs adipogenesis and prevents diet-induced obesity and insulin resistance

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    High-Mobility-Group-A1 (HMGA1) proteins are non-histone proteins that regulate chromatin structure and gene expression during embryogenesis, tumourigenesis and immune responses. In vitro studies suggest that HMGA1 proteins may be required to regulate adipogenesis. To examine the role of HMGA1 in vivo, we generated transgenic mice overexpressing HMGA1 in adipose tissues. HMGA1 transgenic mice showed a marked reduction in white and brown adipose tissue mass that was associated with downregulation of genes involved in adipogenesis and concomitant upregulation of preadipocyte markers. Reduced adipogenesis and decreased fat mass were not associated with altered glucose homeostasis since HMGA1 transgenic mice fed a regular-chow diet exhibited normal glucose tolerance and insulin sensitivity. However, when fed a high-fat diet, overexpression of HMGA1 resulted in decreased body-weight gain, reduced fat mass, but improved insulin sensitivity and glucose tolerance. Although HMGA1 transgenic mice exhibited impaired glucose uptake in adipose tissue due to impaired adipogenesis, the increased glucose uptake observed in skeletal muscle may account for the improved glucose homeostasis. Our results indicate that HMGA1 plays an important function in the regulation of white and brown adipogenesis in vivo and suggests that impaired adipocyte differentiation and decreased fat mass is not always associated with impaired whole-body glucose homeostasis

    R Coronae Borealis stars in the Galactic Bulge discovered by EROS-2

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    Rare types of variable star may give unique insight into short-lived stages of stellar evolution. The systematic monitoring of millions of stars and advanced light curve analysis techniques of microlensing surveys make them ideal for discovering also such rare variable stars. One example is the R Coronae Borealis (RCB) stars, a rare type of evolved carbon-rich supergiant. We have conducted a systematic search of the EROS-2 database for the Galactic catalogue Bulge and spiral arms to find Galactic RCB stars. The light curves of \sim100 million stars, monitored for 6.7 years (from July 1996 to February 2003), have been analysed to search for the main signature of RCB stars, large and rapid drops in luminosity. Follow-up spectroscopy has been used to confirm the photometric candidates. We have discovered 14 new RCB stars, all in the direction of the Galactic Bulge, bringing the total number of confirmed Galactic RCB stars to about 51. After reddening correction, the colours and absolute magnitudes of at least 9 of the stars are similar to those of Magellanic RCB stars. This suggests that these stars are in fact located in the Galactic Bulge, making them the first RCB stars discovered in the Bulge. The localisation of the 5 remaining RCBs is more uncertain: 4 are either located behind the Bulge at an estimated maximum distance of 14 kpc or have an unusual thick circumstellar shell; the other is a DY Per RCB which may be located in the Bulge, even if it is fainter than the known Magellanic DY Per. From the small scale height found using the 9 new Bulge RCBs, 61<hBulgeRCB<24661<h^{RCB}_{Bulge}<246 pc (95% C.L.), we conclude that the RCB stars follow a disk-like distribution inside the Bulge.Comment: 20 pages, 26 figures, Accepted in A&

    Low-Variance Surface-Enhanced Raman Spectroscopy Using Confined Gold Nanoparticles over Silicon Nanocones

    Get PDF
    Surface-enhanced Raman spectroscopy (SERS) substrates are of utmost interest in the analyte detection of biological and chemical diagnostics. This is primarily due to the ability of SERS to sensitively measure analytes present in localized hot spots of the SERS nanostructures. In this work, we present the formation of 67 ± 6 nm diameter gold nanoparticles supported by vertically aligned shell-insulated silicon nanocones for ultralow variance SERS. The nanoparticles are obtained through discrete rotation glancing angle deposition of gold in an e-beam evaporating system. The morphology is assessed through focused ion beam tomography, energy-dispersive X-ray spectroscopy, and scanning electron microscopy. The optical properties are discussed and evaluated through reflectance measurements and finite-difference time-domain simulations. Lastly, the SERS activity is measured by benzenethiol functionalization and subsequent Raman spectroscopy in the surface scanning mode. We report a homogeneous analytical enhancement factor of 2.2 ± 0.1 × 107 (99% confidence interval for N = 400 grid spots) and made a comparison to other lithographically derived assemblies used in SERS. The strikingly low variance (4%) of our substrates facilitates its use for many potential SERS applications
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