Miracle-dz/UniFAR-FTUs huggingface dataset:
Impact of Prepaid Incentives in Face-to-Face Surveys: A Large-Scale Experiment with Postage Stamps

Nonresponse is a general problem in survey research. Although response rates and the nonresponse trends differ between countries, the general trend is that response rates have been declining over the years (De Leeuw & De Heer, 2002). A high nonresponse rate is a problem as it reduces the number of respondents and consequently the precision of estimates. In addition, nonresponse can be selective. This occurs when nonrespondents differ systematically from respondents as to the survey objectives. As a result, the survey estimates of the key indicators may be biased. Nonresponse is not only a statistical problem, but it is also a financial problem as declining response rates cause increasing survey costs. In the nineties, a response rate of 55 percent in face-to-face surveys conducted by Statistics Netherlands was not unusual (De Heer, 1999). Due to a substantial reorganization of the fieldwork department and the raise of the minimum number of contact efforts from three to six, the response in Statistics Netherlands’ face-to-face surveys gradually increased to 65 percent in 2005 (De Bie & Luiten, 2005). In order to realize a further increase in the response rate, we decided to focus on the refusals. As Statistics Netherlands does not use a refusal conversion policy—which is a common practice in many other fieldwork organizations, including National Statistical Institutes—we had to consider other measures. One option was the use of incentives. Prepaid cash incentives are known to be most effective, but sending cash by mail is not allowed in the Netherlands. Therefore, postage stamps are chosen as a prepaid incentive, which are expected to be an opportunity to bridge the gap between cash and material incentives. In this article, the effect of stamps as a prepaid incentive in face-to-face surveys on response is tested in a large-scale field experiment embedded in the Dutch Labor Force Survey.
Support for Individualizing Teacher Induction

Abstract An alarmingly high attrition rate of newly qualified teachers has spawned investigation of the problems faced by beginning teachers. The resulting induction programs prescribed assistance that aided new teachers in solving these common problems. Recently, these programs have utilized mentors who guide new teachers in actual teaching situations, which has reduced the number of new teachers leaving the profession. Trained mentors, however, are not always successful because they fail to recognize the wide variety of developmental needs of beginning teachers. Through a state-wide survey, 286 first-year teachers were asked to report the types and amounts of assistance they found most supportive during their transition into teaching. They reported as helpful a vareity of assistance with classroom procedures, lesson plans, teaching methods, and discipline. As teaching situations became more challenging, more teachers in this study desired more assistance. The data support varying the quantity and type o.
Exploring the Tourism-Poverty Nexus

Current discourse surrounding ‘pro-poor tourism’, a term emerging out of the writing of UK researchers in the late 1990s, suggests that tourism can effectively work as a tool to alleviate poverty. This proposition is alluring given that tourism is a significant or growing economic sector in most countries with high levels of poverty. Consequently the idea of utilising tourism to eliminate poverty has been embraced by donors, governments, non-governmental organisations, conservation organisations and tourism bodies, including the World Tourism Organisation. Academic views on the relationship between poverty and tourism have however varied widely over the past half century. While in the 1950s tourism was identified as a modernisation strategy that could help newly-independent Third World countries to earn foreign exchange, in the 1970s and 1980s many social scientists argued that poor people and non-Western countries are typically excluded from or disadvantaged by what tourism can offer. It is thus fascinating to see how there has been a concerted push towards a reversal of this thinking in the 1990s, coinciding with the development industry's global focus on poverty alleviation. This paper will detail this evolution of thinking and in doing so, explore theoretical debates on the tourism-poverty nexus.
Sliding fourier transform with generalized triangular windows

In this paper, we propose an algorithm to compute time-dependent Fourier transform (TDFT) with generalized triangular window. The algorithm recursively computes the TDFT at arbitrary frequency with integrated triangular windowing. A common way to compute TDFT with window is to firstly multiply the input data by the window function and then carry out the TDFT on the windowed data. In this paper, we show that the TDFT with triangular window at a given frequency satisfies a complex-coefficient second-order difference equation. To compute the TDFT, only seven complex multiplications and six additions are needed. The window can be a family of triangular functions, including the Bartlett window and the Welch window of the first order. Our result is useful for estimating single, few, or unevenly distributed frequencies.
Patent foramen ovale is not associated with hypoxemia in severe chronic obstructive pulmonary disease and does not impair exercise performance.

RATIONALE Patent foramen ovale (PFO) may be disadvantageous in chronic obstructive pulmonary disease (COPD). It is unknown whether right-to-left shunting through PFO increases during exercise impairing exercise performance. OBJECTIVES To determine whether (1) PFO prevalence is greater in hypoxemic versus less hypoxemic patients with COPD, (2) PFO is associated with clinically relevant impairment, and (3) right-to-left shunting increases during exercise and impairs exercise performance. METHODS Patients with COPD and age-matched control subjects underwent contrast transthoracic echocardiography and transcranial Doppler to identify PFO. Patients with COPD with no shunt and patients with large PFO underwent cardiopulmonary exercise tests with contrast transcranial Doppler, esophageal, and gastric balloon catheters. MEASUREMENTS AND MAIN RESULTS PFO prevalence was similar in 50 patients with COPD and 50 healthy control subjects (46% vs. 30%; P = 0.15). Large shunts were more common in patients with COPD (26% vs. 6%; P = 0.01). In an expanded COPD cohort, PFO prevalence was similar in 31 hypoxemic (Pao2 ≤ 7.3 kPa) and 63 less hypoxemic (Pao2 > 8.0 kPa) patients with COPD (39% vs. 52%; P = 0.27). Patients with intrapulmonary shunting had lower Pao2 than both patients with PFO and those with no right-to-left shunt (7.7 vs. 8.6 vs. 9.3 kPa, respectively; P = 0.002). Shunting significantly increased during exercise in patients with COPD with PFO. Endurance time at 60% Vo2max was 574 (178) seconds for patients with PFO and 534 (279) seconds for those without (P = ns). CONCLUSIONS Hypoxemic patients with COPD do not have a higher prevalence of PFO. Patients with COPD with PFO do not perform less well either on a 6-minute walk or submaximal exercise testing despite increased right-to-left shunting during exercise.
The Case of the Occasionally Cheap Computer: Low-cost Devices and Classrooms in the Developing Regions

The quest for the low-cost computer has been one of the most significant pursuits of ICTD since the 1990s. This article examines the experiences of low-cost computing projects in developing regions and looks at some of the common entrepreneurial and technical problems faced by past and current initiatives. Focusing specifically on the domain of education, we look at the quest for low-cost devices and consider their economic and socio-cultural appropriateness to the typical classroom in the developing world. Using field studies and interviews conducted in rural Indian classrooms, we show that shared rather than single-user devices constitute a more realistic and sustainable approach for low-cost computing projects targeting children’s education.
Translation And Scale Invariant Landmark Recognition Using Receptive Field Neural Networks

In this paper we present a neural net- work based approach to landmark recognition. Landmarks are used by mobile robots for navi- gation and self referencing information. Due to the motion of the robot, the location and size of the landmark in the sensor is always changing. The network architecture presented here is capable of overcoming changes in scale as well as position of the landmark. The neu- ral network is directly fed with intensity im- ages. This is a significant reduction in compu- tation overhead since no high-level image pro- cessing is needed. Since robot motion in un- structured environments requires dynamic path planning, the detection algorithm must also be able to output guidance results. The network described here is able to output results in real time for the input patterns. We have trained the network to recognize common landmarks such as road signs (stop sign, yield sign, pedestrian-crossing sign, etc.). The algorithm has been successfully integrated into a mobile robot testbed developed at the Robotics and In- telligent Systems Laboratory at North Carolina State University.
How important are spatial spillovers in conditional cash transfer programs

Randomized evaluations have become the gold standard due to their ability to provide unbiased causal eects. However, they are not without drawbacks. This paper addresses one criticism, the assumption that outcomes are not aected by the treatment status of others, commonly referred to as SUTVA or no interference. We focus on settings where randomization is carried out at group-level, but where there may be spatial spillovers among groups. When the analysis is performed at the individual-level, most studies control for group-level correlation by clustering their standard errors. Here, we question whether this correction is appropriate. To arrive at an answer, we begin by estimating spatial outcome correlation across Progresa villages. Then, we attempt to generalize our results by conducting Monte Carlo simulations to study how spatial spillovers aect treatment eect estimates. The ndings suggest that spatial spillovers are more relevant than the literature suggests, mostly aect precision of the estimate, and in some cases bias the estimate itself. We advocate the use of spatial methods to enhance the program evaluation toolkit since they allow testing assumptions, controlling for spatial externalities, and identifying mechanisms that drive outcomes.
A Balanced Look at Self-Employment Transitions Later in Life

One partial solution to the strains of an aging society is continued work later in life, and self-employment is one way that some older Americans have chosen to remain in the labor force. The individual and societal benefits of continued work are straightforward: each additional year that retirement is delayed is one additional year of earnings and possible savings and one fewer year that assets are spent down. Further, continued work later in life has been shown to maintain or improve the physical and mental health of older workers. Looking ahead to the increasing effects of societal aging and a challenged labor market, and with the perception of intergenerational job competition, is self-employment a partial solution to both societal aging and a stagnant economy? In this brief article, we document some of the policy issues surrounding transitions into self-employment later in life.
What Causes Spatial Variations in Economic Development in the United States?

This article examines the causes of spatial disparities in economic development in the United States. A theoretical model is developed to analyze the location decisions of firms and households. An empirical model is estimated to quantify the contribution of alternative factors to spatial variations in wage, employment density, housing price, and land development density. Results suggest that remoteness is a primary cause of spatial disparities in economic development, while natural amenities are a major determinant of housing prices. Despite the dominant role of geography, public investments in infrastructure and human capital development could contribute to economic development in remote areas. Copyright 2008, Oxford University Press.
T Follicular Helper, but Not Th1, Cell Differentiation in the Absence of Conventional Dendritic Cells

Development of long-lived humoral immunity is dependent on CXCR5-expressing T follicular helper (Tfh) cells, which develop concomitantly to effector Th cells that support cellular immunity. Conventional dendritic cells (cDCs) are critical APCs for initial priming of naive CD4+ T cells but, importantly, also provide accessory signals that govern effector Th cell commitment. To define the accessory role of cDCs during the concurrent development of Tfh and effector Th1 cells, we performed high-dose Ag immunization in conjunction with the Th1-biased adjuvant polyinosinic:polycytidylic acid (pI:C). In the absence of cDCs, pI:C failed to induce Th1 cell commitment and IgG2c production. However, cDC depletion did not impair Tfh cell differentiation or germinal center formation, and long-lived IgG1 responses of unaltered affinity developed in mice lacking cDCs at the time point for immunization. Thus, cDCs are required for the pI:C-driven Th1 cell fate commitment but have no crucial accessory function in relation to Tfh cell differentiation.
10.5 A three-level single-inductor triple-output converter with an adjustable flying-capacitor technique for low output ripple and fast transient response

Advanced CMOS devices below 28nm allow supply voltages lower than 1V. For applications with higher input voltage in such devices, stacked MOSFET structures with a three-level technology are commonly employed. The stacked structure can also reduce the output voltage ripple substantially. Figure 10.5. 1 shows a three-level single-inductor triple-output (SITO) converter and also compares the transient response with the SITO converter without the three-level technique. The three-level topology applies three different voltages, Vin, 1/2Vin, and VSS, to the node VX. The operation mode is determined by the duty cycle, i.e., the node Vx swings between 1/2Vin and VSS when duty cycle (D < 0.5), and between 1/2Vin and Vin, otherwise (D>0.5). In state-of-the-art [1–3], the key issue of the three-level topology is how to balance the cross voltage of flying capacitor CFLY at the point of 1/2Vin. In general, the restrained output voltage ripple and the flatter inductor current (IL) slope seriously result in worse transient response and severe cross-regulation (CR) problems, respectively. Results in Figure 10.5. 1 show that the three-level SITO converter achieves a smaller output voltage ripple in steady state, but it causes the problems of slower transient response time, longer recovery time, larger overshoot/undershoot, and severe CR. Thus, it is desired to develop a technique that can adjust the cross voltage of CFLY such that the three-level topology achieves higher efficiency, lower output voltage ripple, and fast transient response simultaneously.
The Distributional Effects of Direct College Costs

This paper examines the distributional impacts of direct college costs - that is, whether the response of educational decisions to college costs varies by student characteristics. The primary obstacle in estimating these effects is the endogeneity of schooling costs. To overcome this issue, I use two measures of direct costs that are plausibly exogenous: living within commuting distance to a university and the elimination of the Social Security Student Benefit Program in the United States. Both sources of variation indicate that lower ability students are the most responsive to changes in college costs. In contrast, I find that the effect of both cost measures on college attendance and graduation does not substantially vary by family income, parent education, race or gender.
Cross-Layer Scheduling and Adaptive Modulation for QoS Support on Wireless Multimedia Networks

In this paper we present a cross-layer scheduling algorithm based on a priority function that combines information from the channel quality (SINR), the quality of service (QoS) and the modulation scheme allowed, intended for usage in the process of packet scheduling transmission between a base station and mobile terminals. The objective is to jointly exploit the temporal variation in users channel conditions and select users which can use the channel in a more efficient way, while also ensuring that resource allocation fairness and QoS constraints are satisfied. The algorithm is evaluated and compared against the best SIR (signal to interference ratio) and FIFO (first in first out) algorithms, for the case where the environment is the downlink of a MC-CDMA/TDD wireless communications system. Two classes of service are considered: real-time and non-real-time. The results show significant improvements in terms of user satisfaction can be achieved by considering adaptive modulation jointly with channel and QoS aware scheduling
AN ECONOMIC PRODUCTION QUANTITY MODEL WITH LEARNING AND FORGETTING CONSIDERATIONS

The focus of this work is on the effects of learning on economic production quantity in batch production systems. We assumed that both unit variable manufacturing time and setup time follow a learning curve. We modified the classical Economic Production Quantity model to incorporate these two types of learning phenomena. We also incorporated the forgetting effect in our model so that a fraction of the learning is lost between consecutive lots. We developed a dynamic program to obtain the optimal solution to the problem. We investigated the nonincreasing lot size property and used it to improve the efficiency of our dynamic program. We consider a special case of the model in which all lot sizes are assumed equal. After theoretical treatment, we carried out a computational study of the effect of assuming equal lot sizes on the optimal solutions. The results of our examples strongly indicate that the assumption of equal lot sizes not only simplifies the determination of the optimal solutions, but also provides close approximations to the optimal solutions.
Computed tomography with energy-resolved detection: a feasibility study

The feasibility of computed tomography (CT) with energy-resolved x-ray detection has been investigated. A breast CT design with multi slit multi slice (MSMS) data acquisition was used for this study. The MSMS CT includes linear arrays of photon counting detectors separated by gaps. This CT configuration allows for efficient scatter rejection and 3D data acquisition. The energy-resolved CT images were simulated using a digital breast phantom and the design parameters of the proposed MSMS CT. The phantom had 14 cm diameter and 50/50 adipose/glandular composition, and included carcinoma, adipose, blood, iodine and CaCO3 as contrast elements. The x-ray technique was 90 kVp tube voltage with 660 mR skin exposure. Photon counting, charge (energy) integrating and photon energy weighting CT images were generated. The contrast-to-noise (CNR) improvement with photon energy weighting was quantified. The dual energy subtracted images of CaCO3 and iodine were generated using a single CT scan at a fixed x-ray tube voltage. The x-ray spectrum was electronically split into low- and high-energy parts by a photon counting detector. The CNR of the energy weighting CT images of carcinoma, blood, adipose, iodine, and CaCO3 was higher by a factor of 1.16, 1.20, 1.21, 1.36 and 1.35, respectively, as compared to CT with a conventional charge (energy) integrating detector. Photon energy weighting was applied to CT projections prior to dual energy subtraction and reconstruction. Photon energy weighting improved the CNR in dual energy subtracted CT images of CaCO3 and iodine by a factor of 1.35 and 1.33, respectively. The combination of CNR improvements due to scatter rejection and energy weighting was in the range of 1.71–2 depending on the type of the contrast element. The tilted angle CZT detector was considered as the detector of choice. Experiments were performed to test the effect of the tilting angle on the energy spectrum. Using the CZT detector with 20° tilting angle decreased the tailing of the measured x-ray spectrum as compared to a conventional CZT detector. It was concluded that the energy-resolved MSMS CT with tilted angle CZT detector is potentially feasible and could provide a unique combination of photon counting, energy weighting, scatter rejection and single kVp dual energy subtraction CT imaging.
Touchdowns and test scores: exploring the relationship between athletics and academics

This article examines the relationship between college football success and SAT scores using an updated data series on football winning percentages. The finding here of a positive and significant relationship supports the idea that collegiate athletics, namely football, serves the institution's admissions process. Selective institutions are able to enhance the quality of their student populations. 1 Some studies (e.g. Tucker, 1992; Tucker and Amato, 1993; Bremmer and Kesselring, 1995; Shulman and Bowen, 2001) and surveys (e.g. Art & Science Group of Baltimore, 1991; American Council on Education, 1991) indicate that there is little, or no, relationship between athletic success and the university's educational mission (see Marklein, 2001). The spinoff benefit of winning teams is such a well-known phenomenon among university administrators that they even have a name for it – ‘the Flutie factor,’ for the 33 percent increase in applications that Doug Flutie helped bring Boston College when he was a football star there in the early 1980s. (Allen, 1999: 2)
Primary role for adherent leukocytes in sickle cell vascular occlusion: A new paradigm

Vascular occlusion is the major cause of morbidity and mortality in sickle cell disease but its mechanisms are poorly understood. We demonstrate by using intravital microscopy in mice expressing human sickle hemoglobin (SS) that SS red blood cells (RBCs) bind to adherent leukocytes in inflamed venules, producing vasoocclusion of cremasteric venules. SS mice deficient in P- and E-selectins, which display defective leukocyte recruitment to the vessel wall, are protected from vasoocclusion. These data uncover a previously unsuspected paradigm for the pathogenesis of sickle cell vasoocclusion in which adherent leukocytes play a direct role and suggest that drugs targeting SS RBC–leukocyte or leukocyte–endothelial interactions may prevent or treat the vascular complications of this debilitating disease.
Diagnostic value of contrast-enhanced ultrasound of thyroid nodules coexisting with Hashimoto's thyroiditis.

OBJECTIVE To evaluate the value of contrast-enhanced ultrasound (CEUS) in diagnosing thyroid nodules coexisting with Hashimoto's thyroiditis (HT). METHODS Totally 62 thyroid nodules in 48 HT patients were retrospectively analyzed. The CEUS characteristics were reviewed, and diagnostic value of enhancement pattern and peak intensity were calculated. RESULTS Peak intensity (P=0.002) and enhancement pattern (P<0.001) differed significantly between malignant and benign thyroid nodules. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of heterogeneous enhancement were 97.6%, 85.7%, 93.0%, 94.7%, and 93.5%, respectively. Sensitivity, specificity, PPV, NPV and accuracy of low intensity at peak time were 85.4%, 52.4%, 77.8%, 64.7%, and 74.2%, respectively. CONCLUSIONS Heterogeneous enhancement is effective in the diagnosis of malignant thyroid nodules coexisting with HT. CEUS can improve the diagnostic accuracy in distinguishing thyroid nodules with unknown malignancy under the conventional ultrasound.