The Baby Boom, Baby Busts, and Grandmothers

Studies in family economics and anthropology suggest that grandmothers are a highly valuable source of childcare assistance. As such, availability of grandmothers affects the cost of having children, and hence fertility decisions of young parents. In this paper, we develop a simple model to assess the fertility implications of the fluctuations in both output (as argued by demographers) and grandmother-availability induced child-care costs over the period 1920-1970. Model does a good job of mimicking the bust-boom-bust pattern during this period. When the child-care cost channel is shut down, the model’s performance weakens significantly; in particular, it fails to capture the bust in the 1960’s altogether.fertility, baby boom, baby bust, female labor-force participation, grandmother availability

Religion, Income Inequality, and the Size of the Government

Recent empirical research has demonstrated that countries with higher levels of religiosity are characterized by greater income inequality. We argue that this is due to the lower level of government services demanded in more religious countries. Religion requires that individuals make financial sacrifices and this leads the religious to prefer making their contributions voluntarily rather than through mandatory means. To the extent that citizen preferences are reflected in policy outcomes, religiosity results in lower taxes, which in turn implies lower levels of spending on both public goods and redistribution. Since measures of income typically do not fully take into account the part of income coming from donations received, this increases measured income inequality. We formalize these ideas in a general equilibrium political economy model and also show that the implications of our model are supported by cross-country data.religion, voluntary donations, taxation, redistribution, income inequality

Effect of Pumice Aggregate and Air Entrainment on the Freeze-Thaw Durabilities of HSC

The objective of this work is to calculate the compressive strength and relative dynamicmodulus of elasticity (RDME) induced into concrete during freezing and thawing. Freeze thaw durability of concrete is of great importance to hydraulic structures in cold areas. In thispaper, freezing of pore solution in concrete exposed to a freeze-thaw cycle is studied byfollowing the change of concrete some mechanical and physical properties with freezing temperatures. The effects of pumice aggregate (PA) ratios on the high strength concrete(HSC) properties were studied at 28 days. PA replacements of fine aggregate (0-2 mm) wereused: 10%, 20%, and 30%. The properties examined included compressive strength and RDME properties of HSC. Results showed that compressive strength and RDME of samples were decreased with increase in PA ratios. Test results revealed that HSC was still durable after 100, 200 and 300 cycles of freezing and thawing in accordance with ASTM C666, Bprocedure. After 300 cycles, HSC showed a reduction in compressive strength between 6 to 21 percent, and reduction in RDME up to 16 percent

Centralized and Decentralized ML-Enabled Integrated Terrestrial and Non-Terrestrial Networks

Non-terrestrial networks (NTNs) are a critical enabler of the persistent connectivity vision of sixth-generation networks, as they can service areas where terrestrial infrastructure falls short. However, the integration of these networks with the terrestrial network is laden with obstacles. The dynamic nature of NTN communication scenarios and numerous variables render conventional model-based solutions computationally costly and impracticable for resource allocation, parameter optimization, and other problems. Machine learning (ML)-based solutions, thus, can perform a pivotal role due to their inherent ability to uncover the hidden patterns in time-varying, multi-dimensional data with superior performance and less complexity. Centralized ML (CML) and decentralized ML (DML), named so based on the distribution of the data and computational load, are two classes of ML that are being studied as solutions for the various complications of terrestrial and non-terrestrial networks (TNTN) integration. Both have their benefits and drawbacks under different circumstances, and it is integral to choose the appropriate ML approach for each TNTN integration issue. To this end, this paper goes over the TNTN integration architectures as given in the 3rd generation partnership project standard releases, proposing possible scenarios. Then, the capabilities and challenges of CML and DML are explored from the vantage point of these scenarios.Comment: This work was supported in part by the Scientific and Technological Research Council of Turkey (TUBITAK) under Grant No. 5200030 with the cooperation of Vestel and Istanbul Medipol Universit

Systematic cavitation tunnel tests of a propeller in uniform and inclined flow conditions as part of a round robin test campaign

The effect of shaft inclination can induce important unsteady hydrodynamic phenomenon usually associated with small and high-speed craft. This paper presents systematic cavitation tunnel tests with a 214 mm diameter model propeller of a catamaran research vessel. The propeller is subjected to uniform and inclined flow conditions, to investigate its efficiency, cavitation and underwater radiated noise characteristics. The experiments were conducted in the Emerson Cavitation Tunnel of Newcastle Uni- versity based on the starboard 5-bladed right-hand propeller of the University's research vessel, The Princess Royal. In the paper the details of the tests and significant findings for the effect of the shaft inclination on the propeller efficiency, cavitation and underwater radiated noise characteristics are presented. A better understanding is sought in relation to the noise signatures of different types of cavitation. The systematic tests presented in the paper also have a long-term objective, being the first of an organised round robin test campaign that is being currently undertaken by the members of the Underwater Noise Community of Practice (CoP) of Hydro-Testing Forum (HTF). This long-term objective is to repeat similar tests in the different facilities of all CoP members to reveal the relative merits of their testing facilities for underwater noise investigations

Numerical optimization and experimental validation for a tidal turbine blade with leading-edge tubercles

Recently the leading-edge tubercles on the pectoral fins of humpback whales have attracted the attention of researchers who wish to exploit this feature in the design of turbine blades to improve the blade performance. The main objective of this paper is therefore to make a further investigation into this biomimetic design inspiration through a fundamental research study involving a hydrofoil section, which represents a straightened tidal turbine blade, with and without the leading-edge tubercles, using computational and experimental methods. Firstly a computational study was conducted to optimise the design of the leading-edge tubercles by using commercial CFD code, ANSYS-CFX. Based on this study the optimum tubercle configuration for a tidal turbine blade with S814 foil cross-section was obtained and investigated further. A 3D hydrofoil model, which represented a "straightened" tidal turbine blade, was manufactured and tested in the Emerson Cavitation Tunnel of Newcastle University to investigate the effect of various tubercle options on the lift and drag characteristics of the hydrofoil. The experiments involved taking force measurements using a 3-component balance device and flow visualisation using a Particle Image Velocimetry (PIV) system. These tests revealed that the leading-edge tubercles may have significant benefits on the hydrodynamic performance of the hydrofoil in terms of an improved lift-to-drag ratio performance as well as reducing the tip vortex which is main cause of the undesirable end-effect of 3D foils. The study explores further potential benefits of the application of leading-edge tubercles on tidal turbine blades

An 11-Year-Old Child with Autosomal Dominant Polycystic Kidney Disease Who Presented with Nephrolithiasis

Patients with autosomal dominant polycystic kidney disease become symptomatic and are diagnosed usually at adulthood. The rate of nephrolithiasis in these patients is 5–10 times the rate in the general population, and both anatomic and metabolic abnormalities play role in the formation of renal stones. However, nephrolithiasis is rare in childhood age group. In this paper, an 11-year-old child with autosomal dominant polycystic kidney disease presenting with nephrolithiasis is discussed

The clinical value of urinary N-acetyl-beta-D-glucosaminidase levels in childhood age group.

N-acetyl-beta-D-glucosaminidase is a high molecular-weight lysosomal enzyme found in many tissues of the body. It cannot pass into glomerular ultrafiltrate due to its high molecular weight. However, this enzyme shows high activity in renal proximal tubular cells, and leaks into the tubular fluid as the ultrafiltrate passes through proximal tubules. When proximal tubular cells are injured due to to any disease process including glomerular proteinuria, nephrolithiasis, hyperglycemia, interstitial nephritis, transplant rejection or nephrotoxic agents such as antibiotics, antiepileptics, or radiocontrast agents, its urine level increases and thus is used as a reflection of proximal tubular cell necrosis. However, the clinical use of urinary N-acetyl-beta-D-glucosaminidase determination is limited in childhood because of certain technical problems. In addition, the urinary level of this enzyme changes with the maturational level of proximal tubular cells. Thus, difficulties are involved in assessing normal urine levels of this enzyme for age. On the other hand, successive measurements of urinary N-acetyl-beta-D-glucosaminidase during the longitudinal follow-up of the patients may enhance its clinical use as an indicator of ongoing tubular injury.</p

The Baby Boom, Baby Busts, and Grandmothers

Studies in family economics and anthropology suggest that grandmothers are a highly valuable source of childcare assistance. As such, availability of grandmothers affects the cost of having children, and hence fertility decisions of young parents. In this paper, we develop a simple model to assess the fertility implications of the fluctuations in both output (as argued by demographers) and grandmother-availability induced child-care costs over the period 1920-1970. Model does a good job of mimicking the bust-boom-bust pattern during this period. When the child-care cost channel is shut down, the model’s performance weakens significantly; in particular, it fails to capture the bust in the 1960’s altogether