bluuebunny/crossref_metadata_2025 huggingface dataset:
Economic Incentives and Foster Care Placement
Authors: Duncan Brian , Argys Laura
Published: July 2021

Using micro‐level data on children entering foster care in 1998, we estimate how the financial compensation paid to foster caregivers affects the placement of foster children. Controlling for observable child and county characteristics as well as for unobservable state effects, our estimates indicate that a $100 increase in the basic monthly foster care payment reduces the number of children placed in group homes by 28.7%, with more children instead going to nonrelative foster homes. Further estimates indicate that the children moved out of group homes are equally likely to be placed in two‐parent and single‐parent homes, but they are disproportionately placed with caregivers who do not share the child's race or ethnicity. Finally, a $100 increase in foster care payment will decrease the number of times the average child is moved from one foster placement to another by 20%.
Economic Freedom and Unemployment around the World
Authors: Feldmann Horst
Published: July 2021

Using data from 87 countries and the years 1980‐2003, this paper empirically analyzes whether and to what extent economic freedom affects unemployment. According to the regression results, economic freedom is likely to substantially reduce unemployment, especially among women and young people. A small government sector and a legal system characterized by an independent judiciary, impartial courts, and an effective protection of property rights most clearly seem to have beneficial effects. In addition, there are indications that freedom to trade across national boundaries and a light regulatory burden may also lower unemployment, though apparently in the long term only.
Losing Ground: Latin American Growth from 1955 to 1999
Authors: Grier Robin
Published: July 2021

I evaluate Latin America's relative economic performance by combining the Solow growth coefficients from 22 rich countries and the actual factor accumulation in the region. I find that actual income growth was consistently below simulated growth for all of the countries in the sample, indicating that low productivity is likely behind slow gross domestic product growth in the region. The low productivity growth is partially explained by government consumption spending, ethnic diversity, autocracy, export composition, and educational quality.
The Political, Economic, and Social Aspects of Katrina
Authors: Boettke Peter , Chamlee‐Wright Emily , Gordon Peter , Ikeda Sanford , Leeson Peter T. , Sobel Russell
Published: July 2021

In this paper, we examine the resiliency of community recovery after a natural disaster. We argue that a resilient recovery requires robust economic/financial institutions, political/legal institutions, and social/cultural institutions. We explore how politically and privately created disaster preconditions and responses have contributed to or undermined institutional robustness in the context of the Gulf Coast's recovery after Hurricane Katrina. We find that where postdisaster resiliency has been observed, private‐sector responses contributing to the health of these institutional arenas are largely responsible. Where postdisaster fragility and slowness has been observed, public‐sector responses contributing to the frailty of these institutional arenas are largely the cause. In other words, we engage in a comparative institutional analysis of civil society, entrepreneurial commercial society, and government agencies and political actors in the wake of a natural disaster.
Is More Information Always Better? An Experimental Study of Charitable Giving and Hurricane Katrina
Authors: Eckel Catherine , Grossman Philip J. , Milano Angela
Published: July 2021

We report results of an experiment designed to assess the impact of Hurricane Katrina on the pattern and level of charitable contributions of donors. The study includes an experimental measure of charitable giving and targets three charities: the American Red Cross, the Salvation Army, and Oxfam International. In the experiment subjects make allocation decisions from three endowments ($10, $20, and $50) and with four different matching subsidies (0%, 25%, 50%, and 100%), with the matching amount provided by the experimenter. Two locations (Texas and Minnesota) and two information conditions are used. Survey measures of sympathy, risk perceptions, and perceptions of Katrina victims are also collected. The probability and amount of giving are responsive to the experimental design parameters—the endowment and match. We find evidence of “Katrina overload” as those closest to the disaster respond negatively to Katrina‐related priming information. Perceptions of the psychological attitudes of the victims of the disaster have a significant effect on the amount given.
Negative Expected Value Suits in a Signaling Model
Authors: Farmer Amy , Pecorino Paul
Published: July 2021

We extend the 1986 signaling model of Reinganum and Wilde by allowing for the possibility of negative expected value (NEV) suits. If filing costs are zero, the equilibrium consistent with the D1 refinement implies that settlement offers face a rejection rate of 100%. If filing costs are positive, an equilibrium with settlement can be restored. In this equilibrium plaintiffs with NEV suits choose not to file, but settlement rates fall below the level in the model without NEV suits. This fall in settlement rates may be substantial. In addition, by making the filing decision endogenous, we are able to derive new insights into the effects of fee shifting in the signaling model.
Hunting the Whale: More Evidence on State Government Leviathans
Authors: Campbell Noel D. , Finney R. Zachary , Mitchell David T.
Published: July 2021

Caplan holds that governments are Leviathans, seeking to extend their power by increasing government expenditures beyond the level preferred by voters. We extend Caplan's model by examining the real (percentage) growth rates of government. We also examine whether government size increases at an increasing rate as the minority party weakens. We find evidence that supports and fails to support the original Leviathan hypothesis. We also fail to support our extensions of Caplan's hypothesis. Furthermore, our significant and contrary results have intuitively appealing interpretations. From these results, we conclude that the impact of political party power on government spending is ambiguous.
Where Do the Sick Go? Health Insurance and Employment in Small and Large Firms
Authors: Kapur Kanika , Escarce José J. , Marquis M. Susan , Simon Kosali I.
Published: July 2021

Small firms that offer health insurance to their employees may face variable premiums if the firm hires an employee with high‐expected health costs. To avoid expensive premium variability, a small firm may attempt to maintain a workforce with low‐expected health costs. In addition, workers with high‐expected health costs may prefer employment in larger firms with health insurance rather than in smaller firms. This results in employment distortions. We examine the magnitude of these employment distortions in hiring, employment, and separations using the Medical Expenditure Panel Survey from 1996 to 2001. We find that workers with high‐expected health costs are less likely to be new hires in insured small firms and are less likely to be employed in insured small firms. We find no evidence that state small group health insurance reforms designed to restrict insurers' ability to deny coverage and restrict premium variability have reduced the extent of these distortions.
Aid, Policies, and Growth in Developing Countries: A New Look at the Empirics
Authors: Alvi Eskander , Mukherjee Debasri , Shukralla Elias Kedir
Published: July 2021

The relationship between foreign aid and economic growth has been the subject of much controversy. A recent theme suggesting that aid promotes growth, but only in a good policy environment has ratcheted up that debate. In this paper, we assess the importance of policy and aid in generating growth when the aid, policy, and growth relationship is nonlinear. This allows us to examine the varying effects of aid and policy in different data segments, which we do without imposing any particular structure on the underlying relationship. We find that policy is an important determinant of growth. We also find partial corroboration of the view that aid is growth enhancing in a good policy environment, and some evidence of diminishing returns to aid. These findings suggest that nonlinearities if not appropriately addressed fail to capture the detailed underlying dynamics and thereby mask some key features of the aid‐policy‐growth relationship.
Social Position and Distributive Justice: Experimental Evidence
Authors: Swope Kurtis , Cadigan John , Schmitt Pamela , Shupp Robert
Published: July 2021

Using a simple, double‐blind dictator experiment, we examine the extent to which subjects' choices of distributive shares are influenced by unearned social position. We measure social position by the initial distributive shares (resources) and the subjects' ability to determine the final distributive shares (power). We find that subjects' decisions are consistent with Rawls' (1971) hypothesis that individuals expect a greater share when in a position with more power and initial resources. Finally, we test if subjects' choices under a laboratory veil of ignorance are consistent with Rawls' concept of distributive justice. “Veiled” individuals exhibit preferences that are less risk‐averse and have greater variance than Rawls hypothesized.
A Guide to Graduate Study in Economics: Ranking Economics Departments by Fields of Expertise
Authors: Grijalva Therese C. , Nowell Clifford
Published: July 2021

Ph.D. programs in economics are ranked overall and by subject field. The results provide insight to students researching graduate programs in economics in specific subject fields. Results indicate that (i) differences in overall research productivity measures diminish as a university's rank declines; (ii) a university ranked highly in a particular subject field may be the result of a single, extremely productive faculty member; and (iii) many programs outside the traditional top 20 programs are ranked high in specific subject fields.
Temporary Help Service Firms' Use of Employer Tax Credits: Implications for Disadvantaged Workers' Labor Market Outcomes
Authors: Hamersma Sarah , Heinrich Carolyn
Published: July 2021

Temporary help services (THS) firms are increasing their hiring of disadvantaged individuals while also increasing their use of employment subsidies for doing so. Do these subsidies—the Work Opportunity Tax Credit (WOTC) and Welfare‐to‐Work Tax Credit (WtW)—create incentives that improve employment outcomes for THS workers? We examine the distinct effects of THS employment and WOTC/WtW subsidies on earnings and job duration using new survey and administrative data. We find that, even controlling for a broad range of worker and firm characteristics, some important differences persist between THS workers, WOTC/WtW‐certified workers, and those who are both THS and WOTC/WtW certified. THS workers who are WOTC certified have similar job duration to eligible unsubsidized workers but much higher quarterly earnings. Among WOTC‐certified workers, those in THS firms have similar quarterly earnings to those in other industries but much shorter average job duration. Panel estimates suggest that these effects do not persist over time.
Uncertainty and monetary policy in good and bad times: A replication of the vector autoregressive investigation by Bloom (2009)
Authors: Caggiano Giovanni , Castelnuovo Efrem , Nodari Gabriela
Published: July 2021

This paper revisits the well‐known vector autoregressive (VAR) evidence on the real effects of uncertainty shocks by Bloom (2009, https://doi.org/10.3982/ECTA6248). We replicate the results in a narrow sense using EViews. In a wide sense, we extend his study by working with a smooth transition VAR framework that allows for business cycle‐dependent macroeconomic responses to an uncertainty shock. We find a significantly stronger response of real activity in recessions. Counterfactual simulations point to a greater effectiveness of systematic monetary policy in stabilizing real activity in expansions.
Promoting an integrating recovery style: A mentalization‐informed approach
Authors: Ridenour Jeremy M. , Knauss Daniel , Neal David W.
Published: July 2021

How a person recovers after a psychotic episode is known to be a key predictor of treatment response, impacting a person's sense of self and interpersonal relationships. An integrating recovery style, characterized by more curiosity about the psychotic episode and its potential meaning, has been shown to produce better outcomes. A novel therapeutic treatment, mentalization‐based therapy for psychosis, targets the potential mechanisms (i.e., curiosity about mental states, affect modulation, and interpersonal awareness) that might foster an integrating recovery style, enabling a person to make meaning of their episode and use others to facilitate exploration. In this case study, we present the treatment of an emerging adult who sought residential treatment following her first psychotic episode and who initially presented with a guarded, dismissive approach to her symptoms and gradually formed a more integrating recovery style.
Knowledge and perceptions of the genetic counseling profession among a national cross‐sectional sample of U.S. adults
Authors: Pasca Christina , Carroll Riley , Cragun Ryan T. , Cragun Deborah L.
Published: July 2021

Awareness of the genetic counseling (GC) profession may influence access to genetic services, yet awareness among the U.S. population is unknown. A survey of U.S. adults was conducted using age‐ and sex‐based quotas. Participants were asked if they had heard of the GC profession and to describe what genetic counselors (GCs) do. After reading a brief description of what GCs do, participants were asked the likelihood they would request to see a genetic counselor if they were concerned about a genetic condition. We used descriptive statistics to characterize the population, logistic regression to determine factors related to awareness of the GC profession, and ordinary least squares regression to identify which factors correlated with likelihood of seeking GC services. Thematic analysis was used to code open‐ended responses. Among the final sample of 543, the majority were White individuals (79.7%) with an average age of 46.5 and median income between $60,000 and $69,999. Although 20% indicated they had heard of the GC profession, further analysis of the qualitative follow‐up question suggested only 13.4% understood the role of GCs (CI 10.6%–16.3%). Factors positively and significantly correlated with knowledge of the GC profession included identifying as White or female and having higher educational attainment or higher science knowledge after controlling for income, age, and political views. Approximately 45% of respondents indicated they would likely or very likely seek GC if concerned about a genetic condition. Biological sex, age, religious affiliation, science knowledge, and awareness of the GC profession were significantly correlated with likelihood of seeking GC services while controlling for race, income, educational attainment, and political views. Curiosity/interest, the perception of benefits, and trust in GCs were all major themes that emerged to explain reasons for seeking an appointment with GCs. Lack of awareness, lack of perceived benefit, and lack of trust in GCs or greater trust in other healthcare providers were reasons for not wanting a GC appointment. Despite the 50‐year existence of the GC profession, awareness remains low and negative attitudes exist.
Global exposure of population and land‐use to meteorological droughts under different warming levels and SSPs: A CORDEX‐based study
Authors: Spinoni Jonathan , Barbosa Paulo , Bucchignani Edoardo , Cassano John , Cavazos Tereza , Cescatti Alessandro , Christensen Jens H. , Christensen Ole B. , Coppola Erika , Evans Jason P. , Forzieri Giovanni , Geyer Beate , Giorgi Filippo , Jacob Daniela , Katzfey Jack , Koenigk Torben , Laprise René , Lennard Christopher J. , Kurnaz M. Levent , Li Delei , Llopart Marta , McCormick Niall , Naumann Gustavo , Nikulin Grigory , Ozturk Tugba , Panitz Hans‐Jürgen , da Rocha Rosmeri Porfirio , Solman Silvina A. , Syktus Jozef , Tangang Fredolin , Teichmann Claas , Vautard Robert , Vogt Jürgen V. , Winger Katja , Zittis George , Dosio Alessandro
Published: July 2021

Global warming is likely to cause a progressive drought increase in some regions, but how population and natural resources will be affected is still underexplored. This study focuses on global population, forests, croplands and pastures exposure to meteorological drought hazard in the 21st century, expressed as frequency and severity of drought events. As input, we use a large ensemble of climate simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX), population projections from the NASA‐SEDAC dataset and land‐use projections from the Land‐Use Harmonization 2 project for 1981–2100. The exposure to drought hazard is presented for five Shared Socioeconomic Pathways (SSP1‐SSP5) at four Global Warming Levels (GWLs: 1.5°C to 4°C). Results show that considering only Standardized Precipitation Index (SPI; based on precipitation), the SSP3 at GWL4 projects the largest fraction of the global population (14%) to experience an increase in drought frequency and severity (versus 1981–2010), with this value increasing to 60% if temperature is considered (indirectly included in the Standardized Precipitation‐Evapotranspiration Index, SPEI). With SPEI, considering the highest GWL for each SSP, 8 (for SSP2, SSP4, SSP5) and 11 (SSP3) billion people, that is, more than 90%, will be affected by at least one unprecedented drought. For SSP5 at GWL4, approximately 2 × 106 km2 of forests and croplands (respectively, 6% and 11%) and 1.5 × 106 km2 of pastures (19%) will be exposed to increased drought frequency and severity according to SPI, but for SPEI this extent will rise to 17 × 106 km2 of forests (49%), 6 × 106 km2 of pastures (78%) and 12 × 106 km2 of croplands (67%), being mid‐latitudes the most affected. The projected likely increase of drought frequency and severity significantly increases population and land‐use exposure to drought, even at low GWLs, thus extensive mitigation and adaptation efforts are needed to avoid the most severe impacts of climate change.
Spatially Explicit Assessment of Sandhill Crane Exposure to Potential Transmission Line Collision Risk
Authors: Hays Quentin R. , Tredennick Andrew T. , Carlisle Jason D. , Collins Daniel P. , Carleton Scott A.
Published: July 2021

Infrastructure development can affect avian populations through direct collision mortality. Estimating the exposure of local bird populations to the risk of direct mortality from infrastructure development requires site‐ and species‐specific data, which managers may find difficult to obtain at the scale over which management decisions are made. We quantify the potential exposure of sandhill cranes (Antigone canadensis) to collision with horizontal structures (e.g., transmission lines) within vital wintering grounds of the Middle Rio Grande Valley (MRGV), New Mexico, USA, 2014–2020. Limited maneuverability and visual acuity make sandhill cranes vulnerable to collisions with infrastructure bisecting their flight paths. We used data from 81 global positioning system (GPS)‐tagged cranes to estimate the spatially explicit flight height distribution along the MRGV, the passage rate across hypothetical transmission lines, and the resulting exposure rate (exposed passes/crane/day). The exposure rate ranged from 0–0.28 exposed passes/crane/day (median = 0.015) assuming an exposure zone of 7–60 m above ground level, and identified hotspots of potential exposure within the MRGV. Mapped exposure rates can assist in the siting of proposed high‐voltage transmission lines, or other infrastructure, to limit effects on sandhill cranes and other avian species at risk of collision. Our approach can be replicated and applied in similar situations where birds are exposed to possible collision with power lines. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.
Expansion of the mutational spectrum of BMPER leading to diaphanospondylodysostosis and description of the associated disease process
Authors: Braun Frederik , Gangfuß Andrea , Stöbe Petra , Haack Tobias B. , Schweiger Bernd , Roos Andreas , Schara Ulrike
Published: July 2021

Background

Diaphanospondylodysostosis (DSD) is a rare congenital, lethal skeletal disorder caused by recessively inherited mutations in the BMPER gene, which encodes the bone morphogenetic protein‐binding endothelial cell precursor‐derived regulator. The most prominent features of DSD are missing ossification of the axial skeleton, rib abnormalities and thoracic hypoplasia/insufficiency, as well as intralobar nephrogenic rests within the kidneys.

Methods

We report on the case of a 22‐month‐old patient with DSD where trio‐exome sequencing was performed.

Results

Genetic testing revealed a homozygous nonsense variant c.1577G>A (p.Trp526*) in the BMPER gene, leading to a premature stop in protein translation. Both parents are asymptomatic carriers for the BMPER variant, which has not been described in the literature before.

Conclusions

Our findings expand the genotypic and phenotypic spectrum of BMPER variants leading to DSD.
Technical Note: Scanner dependence of adaptive statistical iterative reconstruction with 3D noise power spectrum central frequency and noise magnitude ratios
Authors: Hasegawa Akira , Ishihara Toshihiro , Allan Thomas Matthew , Pan Tinsu
Published: July 2021

Purpose

In this study, the noise reduction properties of the adaptive statistical iterative reconstruction (IR) on two different CT scanners of 64 and 256‐slice were compared and their differences were assessed.

Methods and materials

The homogeneous module of the ACR CT phantom was scanned on the 64 and 256 slices CT scanners from the same vendor in the range of 15–40 mA. On each scanner, the data were reconstructed using filtered back projection (FBP) and at all strengths of IR with the STANDARD kernel. For each reconstruction, a 3D noise power spectrum (NPS) was calculated and the central frequency ratio in the xy plane (CFRxy), CFR in the z‐direction (CFRz), and noise magnitude ratio (NMR) were derived. CFR is the central frequency ratio of NPS between the denoised image and the FBP image, and NMR is the ratio of the areas under the NPS curves. Ideally, both CFRxy and CFRz should be near 1, indicating minimal texture changes in both xy and z directions, while NMR should be as close to 0 as possible, indicating more noise reduction.

Results

When comparing strengths with equivalent impact on noise texture, IR on the 64‐slice reduced the noise magnitude in the xy plane more than that on the 256‐slice. In the z‐direction, the IR on the 256‐slice produced a central frequency shift on the 256‐slice but not on the 64‐slice. In addition, the noise reduction effects of the IR on the 256‐slice were affected when radiation exposure was below 2.0 mGy, but there was no observable dose‐dependence on the 64‐slice.

Conclusions

Our noise property analysis revealed that iterative reconstructions on different scanner platforms from the same vendor can be distinct, with unique effects on the noise texture and magnitude in CT images. The IR on a 64‐slice scanner provides slightly enhanced noise reduction and maintains a noise reduction rate independent of dose, unlike the one on a 256‐slice scanner. Notably, the IR on the 64‐slice scanner was a 2D noise reduction technique (NRT), while the one on the 256‐slice was a 3D NRT. These observations showcase the impact of different NRTs on clinical CT images, even when comparing the same NRT on different scanners.
Nurses' experiences of psychosocial care needs of children with thalassaemia and their families in Jordan: A phenomenological study
Authors: Abu Shosha Ghada Mohammad , Al‐Kalaldeh Mahmoud , Shoqirat Noordeen
Published: July 2021

Aim

To explore the experiences of Jordanian nurses regarding the psychosocial care needs of children with thalassaemia and their families.

Design

A descriptive phenomenological approach was employed.

Methods

A purposive sampling strategy was used to select 10 nurses who had experience in caring for children with thalassaemia. Unstructured, face‐to‐face interviews were conducted. Coliazzi's data analysis process was applied.

Results

The analysis revealed three major themes: (1) valuing psychosocial support; (2) caring for paediatric patients needs certain competencies in nurses and (3) barriers to providing psychosocial care. Nurses expressed the importance of providing psychosocial care. A lack of specialists in psychosocial care as well as a lack of screening tools, and entertainment facilities for children was identified to be impeding effective psychosocial care. Implementing training programmes for nurses concerning providing psychosocial care and making the appropriate changes in nursing curricula at the educational level are recommended.
Error estimate of a finite element method for an optimal control problem with corner singularity using the stress intensity factor
Authors: Kim Seokchan , Lee Hyung‐Chun
Published: July 2021

We consider an optimal control problem for the Poisson equation on a non‐convex polygonal domain with the corner singularity. Previously, we proposed a novel algorithm for the accurate numerical solution for the Poisson equation on a polygonal domain with the domain singularity. Then, we investigated the error estimate and its efficient procedure for the numerical algorithm. In this article, we propose an efficient algorithm and perform an error estimate for a distributed optimal control problem of the Poisson equation. The solutions of the optimality system with such singularity have singular decompositions: regular part plus singular part for each state variable and adjoint variable. The coefficient of the singular function is usually called stress intensity factor and can be computed by the extraction formula. We introduced a modified optimality system which has “zero” stress intensity factors using this stress intensity factor, from whose solutions we can compute very accurate solution of the original optimality system simply by adding a singular part. We give a precise error analysis and provide numerical results which justify the results therein.
First-In-Human, First-In-Class, Phase I Trial of the Fucosylation Inhibitor SGN-2FF in Patients with Advanced Solid Tumors
Authors: Do Khanh T. , Chow Laura Quan Man , Reckamp Karen , Sanborn Rachel E. , Burris Howard , Robert Francisco , Camidge D. Ross , Steuer Conor E. , Strickler John H. , Weise Amy , Specht Jennifer M. , Gutierrez Martin , Haughney Peter , Hengel Shawna , Derleth Christina Louise , Yap Timothy A.
Published: July 2021

Lessons Learned

Background

We conducted a first-in-human, first-in-class, phase I study of SGN-2FF, a potent small-molecule inhibitor of glycoprotein fucosylation, in patients with advanced solid tumors.

Methods

The study consisted of four parts: SGN-2FF monotherapy dose-escalation (part A) and expansion (part B), and SGN-2FF + pembrolizumab dose-escalation (part C) and expansion (part D). The objectives were to evaluate safety and tolerability, maximum tolerated dose (MTD), pharmacokinetics (PK), pharmacodynamics (PD), and antitumor activity of SGN-2FF monotherapy and SGN-2FF + pembrolizumab.

Results

Forty-six patients were enrolled (part A, n = 33; part B, n = 6; part C, n = 7; part D did not enroll any patients). During part A (n = 32) exploring 1–15 g once daily (QD) and 2–5 g twice daily (b.i.d.), grade 3 dose-limiting toxicities were diarrhea (2 g and 15 g QD) and increased lipase (2 g QD). The MTD was 10 g daily. In part A, common toxicities were grades 1–2 diarrhea, fatigue, and nausea (each 47%); thromboembolic events (grades 2–5) occurred in 5 of 32 patients (16%). Safety measures included concurrent prophylactic anticoagulation with low-molecular weight heparin (LMWH). In part C, despite the safety measures implemented, a thromboembolic event occurred in one of seven patients (14%) during the SGN-2FF lead-in period. Of 28 evaluable patients in part A, 1 patient with advanced head and neck squamous cell carcinoma achieved Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 complete response (CR) and 10 (36%) had RECIST v1.1 stable disease, including 1 patient with advanced triple-negative breast cancer with 51% tumor burden reduction. SGN-2FF administration led to dose-proportional increases in exposure and PD reduction in protein fucosylation.

Conclusion

SGN-2FF demonstrated proof-of-mechanism and preliminary antitumor activity but was associated with thromboembolic events leading to study termination.
The relationship between knee radiographs and the timing of physical therapy in individuals with patellofemoral pain
Authors: Young Jodi L. , Snodgrass Suzanne J. , Cleland Joshua A. , Rhon Daniel I.
Published: July 2021

Background

Routine knee radiographs are discouraged for individuals with nontraumatic knee pain, but they are often still ordered despite limited evidence of their value in guiding treatment choices. Radiograph utilization may delay the use of physical therapy, which has been associated with improved outcomes and lower long‐term costs.

Objective

To examine the relationship between obtaining knee radiographs for patients with patellofemoral pain (PFP) and the timing of physical therapy, and the association between ordering radiographs for patients who use physical therapy and the likelihood of knee pain recurrence.

Study Design

Retrospective cohort.

Setting

United States Military Health System civilian and military clinics.

Patients

A total of 23,332 individuals ages 18 to 50 years who were diagnosed with PFP between 2010 and 2011 in the United States Military Health System and who received physical therapy.

Interventions

Physical therapy provided to individuals with or without an initial radiograph.

Main Outcome Measures

Timing of physical therapy and recurrence of knee pain were compared between groups (with and without initial radiographs).

Results

If radiographs were obtained, the odds of initiating physical therapy (adjusted odds ratio [aOR] 0.78, 95% confidence interval [CI] 0.64–0.94) within 30 days of the initial diagnosis were significantly lower. The mean days from diagnosis to initiating physical therapy was 12.1 (95% CI 9.1–16.1) if patients had radiographs versus 6.9 (95% CI 5.2–9.1) without. The odds of knee pain recurrence were no greater if radiographs were used (aOR 1.01, 95% CI 0.83–1.22).

Conclusions

Acquisition of knee radiographs as part of initial care for PFP was associated with delayed initiation of physical therapy, but there was no association between early knee radiographs and recurrence of knee pain. Routine use of radiographs for PFP is not warranted, and can potentially delay appropriate treatment.
Changing trends in the prevalence of childhood asthma over 40 years in Greece
Authors: Ntzounas Alexandros , Giannakopoulos Ioannis , Lampropoulos Panagiotis , Vervenioti Aggeliki , Koliofoti Eleana‐Georgia , Malliori Styliani , Priftis Kostas N. , Dimitriou Gabriel , Anthracopoulos Michael B. , Fouzas Sotirios
Published: July 2021

Background

A series of repeated questionnaire surveys among 8‐ to 9‐year‐old school children in the city of Patras, Greece, demonstrated a continuous rise in the prevalence of wheeze/asthma from 1978 to 2003, with a plateau between 2003 and 2008. We further investigated wheeze/asthma trends within the same environment over the last decade.

Methods

Two follow‐up surveys were conducted in 2013 (N = 2554) and 2018 (N = 2648). Physician‐diagnosed wheeze and asthma were analyzed in relation to their occurrence (recent‐onset: within the last 2 years; noncurrent: before 2 years; persistent: both prior and within the last 2 years). In 2018, spirometry was also performed in participants reporting symptoms and in a sample of healthy controls.

Results

The prevalence of current wheeze/asthma declined from 6.9% in 2008% to 5.2% in 2013% and 4.3% in 2018. The persistent and noncurrent wheeze/asthma groups followed this overall trend (P‐for‐trend <0.001), while the prevalence of recent‐onset wheeze/asthma remained unchanged (P‐for‐trend >0.05). Persistent and noncurrent wheezers were also more frequently diagnosed with asthma, in contrast to those with recent‐onset wheeze. The FEV1 z‐score was less than –1 in 32.1% of children with recent‐onset and in 22.4% of those with persistent wheeze/asthma; both rates were higher than those of the Noncurrent wheeze/asthma group (7.1%; p < .05) and of healthy controls (3.5%; p < .001).

Conclusions

The prevalence of childhood wheeze/asthma has declined significantly during the last decade in Greece. The reversing trend may in part be attributed to changing asthma perceptions among physicians and/or parents, especially in the case of younger children with troublesome respiratory symptoms.
Trap‐Assisted Transition Energy Levels of SrF2:Pr3+−Yb3+ Nanophosphor in TiO2 Photoanode for Luminescence Tuning in Dye‐Sensitized Photovoltaic Cells
Authors: Kaliamurthy Ashok Kumar , Kang Hyeong Cheol , Asiam Francis Kwaku , Yoo Kicheon , Lee Jae-Joon
Published: July 2021

Luminescent nanophosphors as spectral converters offer immense potential for dye‐sensitized photovoltaics (DSPV) to harvest a wide range of the solar spectrum. Herein, a novel structural design of DSPV using a downconversion (dc) nanophosphor layer in the TiO2 photoanode for both indoor (ambient) and outdoor applications is demonstrated. Cubic SrF2:Pr3+−Yb3+ nanoparticles are synthesized by a template‐free hydrothermal technique. The dc nanophosphor absorbs photons of the blue region, leading to emission of a broad luminescence band (green and red), which is well matched with N719‐dye absorption. The mixed‐valence state of Pr ions (Pr3+ and Pr4+) leads to trap‐assisted transition levels, which result in a broad visible emission. For the first time, a unique Pr3+−Yb3+ codoped dc system yielding tuned and intensified luminescence by effective crossrelaxation (CR) with a back energy transfer (BET) mechanism is designed and efficient working of the dc nanophosphor‐layered DSPVs under both outdoor 1 sun (AM 1.5 G) and indoor light (Warm‐3200 K; Day‐5000 K) conditions is demonstrated. Improved efficiency of 9.07% is attained in dc‐dye‐sensitized solar cells (DSSC) compared with a control‐DSSC (8.39%) at 1 sun intensity. Under indoor low‐light conditions (1000 lux), the dc‐DSPV achieves high power conversion efficiencies (PCEs) of 14.85 and 15.9%, respectively. This approach results in a 63.44% increment in output power density for dc‐DSPV compared with the control‐DSPV under LED 3200 K irradiation. These findings suggest that this configuration of dc‐layered DSPV can provide a new strategy for future indoor electronic operations under ambient light conditions.
Carbohydrate Nanomaterials Addition to Starch‐Based Packaging: A Review about Fundamentals and Application
Authors: Maniglia Bianca Chieregato , La Fuente Carla Ivonne Arias , Siqueira Larissa do Val , Tadini Carmen Cecilia
Published: July 2021

Starch‐based packaging has been explored as an alternative to conventional plastics. However, the former material shows a poorer performance when compared with the latter. Carbohydrate nanomaterials addition has proved to be promising to solve this issue, improving mechanical and barrier properties. The use of carbohydrates nanomaterials has many advantages since the raw material is highly available in nature, obtained from renewable, low‐cost, and non‐toxic sources. This review shows the different methods of producing nanomaterials from the main carbohydrate sources, cellulose, chitosan, and starch. The study begins the approach with the most conventional method, acid hydrolysis, proceeding with the methods explored on a smaller scale such as enzymatic hydrolysis, oxidation, ultrasound, and electrospinning. Besides, the study shows works involving the production of starch‐based nanocomposites and discussions about the improvement of its properties promoted by the addition of these nanomaterials. Works in the literature have shown starch‐based nanocomposites with higher crystallinity, transparency, thermal stability, reinforcement, oxygen barrier, lower water absorption, and even anti‐microbial activity, making them suitable for packaging. Finally, the future perspectives of this research field are shown and discussed .
Synergistic Effect of Metagenome‐Derived Starch‐Degrading Enzymes on Quality of Functional Bread with Antioxidant Activity
Authors: Sadeghian Motahar Seyedeh Fatemeh , Salami Maryam , Ariaeenejad Shohreh , Emam‐Djomeh Zahra , Sheykh Abdollahzadeh Mamaghani Atefeh , Kavousi Kaveh , Moghadam Maryam , Hosseini Salekdeh Ghasem
Published: July 2021

Starch‐degrading enzymes have gained particular importance in recent decades due to their crucial role in numerous industrial applications especially, in the bakery industry. In this study, a novel thermostable pullulanase (PersiPul1) is screened from the metagenomic data for improving the quality of functional bread. The novel PersiPul1 is active over a wide range of temperature (30–80 °C) and pH (4–9) and exhibits high thermal stability, retaining 58.70% of activity at 80 °C. A cocktail of thermostable pullulanase and α‐amylase (PersiPul1and PersiAmy2) is developed to be used in bread fortified with quinoa protein (Chenopodium quinoa Willd). The bread fortified with 7% quinoa protein isolate possess the highest reducing power and ABTS (73.64%) and DPPH (72.27%) radical scavenging activities. The addition of the enzyme mixture decreases the hardness and chewiness of the bread. The porosity, specific volume, and browning index of bread with pullulanase and α‐amylase are higher than control. Also, sensory analysis of the functional bread reveals higher scores in the presence of enzymes. Based on the results, the novel starch‐degrading enzyme cocktail is a promising alternative for improving the physical and sensory characteristics of the antioxidant bread enriched with quinoa protein isolate to be used in the bakery industry as a potential bio‐additive.
Advances in metal phosphides for sodium‐ion batteries
Authors: Li Qifei , Yang Dan , Chen Haoliang , Lv Xiang , Jiang Yu , Feng Yuezhan , Rui Xianhong , Yu Yan
Published: July 2021

Sodium‐ion batteries (SIBs) have been extensively studied as the potential alternative to lithium‐ion batteries (LIBs) due to the abundant natural reserves and low price of sodium resources. Nevertheless, Na+ ions possess a larger radius than Li+, resulting in slow diffusion dynamics in electrode materials, and thus seeking appropriate anode materials to meet high performance standards has become a trend in the field of SIBs. In this context, owing to the advantages of high theoretical capacity and proper redox potential, metal phosphides (MPs) are considered to be the promising materials to make up for the gap of SIBs anode materials. In this review, the recent development of MPs anode materials for SIBs is reviewed and analyzed comprehensively and deeply, including the synthesis method, advanced modification strategy, electrochemical performance, and Na storage mechanism. In addition, to promote the wide application of the emerging MPs anodes for SIBs, several research emphases in the future are pointed out to overcome challenges toward the commercial application.
Investigation of the usage potential of calcium alginate beads functionalized with sodium dodecyl sulfate for wastewater treatment contaminated with waste motor oil
Authors: Bilici Zeynep , Ozay Yasin , Ozbey Unal Bahar , Dizge Nadir
Published: July 2021

In this study, calcium alginate (Ca‐Alg) beads, an inexpensive, easily available, biodegradable material, were activated with anionic surfactant and used for the treatment of wastewater contaminated with waste motor oil. First, polyethyleneimine (PEI) was used to bind sodium dodecyl sulfate (SDS) onto the Ca‐Alg beads' surface. Three different SDS concentrations (25, 50, & 100 mg/L) were prepared and treated with Ca‐Alg beads for 1, 2, 4, 6, and 24 h. SDS binding yield reached equilibrium at the end of the 24 h, and the binding efficiencies of 25, 50, and 100 mg SDS/L were determined 84%, 72%, and 48%, respectively. The effect of pH between 2 and 10 was also investigated on oil adsorption. Maximum adsorption efficiency (77%) was obtained in the range of pH 6–8. After determining the optimum pH value for oil adsorption, the effect of beads amount (2.5–30 g/L) was also investigated on oil removal efficiency. When the amount of beads increased from 2.5 to 30 g/L, the oil adsorption efficiency increased from 77% to 95%. It was also observed that the oil adsorption efficiency increased when the size of the beads decreased from 4 to 1 mm. For the kinetic calculation, three different concentrations (250, 500, &1000 mg/L) of oily solution were prepared, and oil adsorption was investigated versus time. The kinetic studies for the adsorption of the oily solution using SDS functionalized Ca‐Alg beads showed the second‐order kinetics. When the initial oil concentration increased from 250 to 1000 mg/L, the amount of adsorbed oil molecules increased from 8.34 to 22.12 mg/g. Langmuir and Freundlich isotherm models were used to explain the relationship between adsorbent and adsorbate, and Langmuir isotherm was the most suitable model because of its high regression coefficient (r2) value. Column studies were also carried out, and it was concluded that the proposed adsorbent can be used effectively in the treatment of oily wastewater.

Practitioner points

Although there are numerous adsorption studies and studies on the use of alginate beads in various fields in the literature, its use in oil treatment has not been found to our knowledge.

The study aims to produce a selective adsorbent for the removal of oil from water by functionalizing the surface of the alginate beads with active agents.

In conventional adsorption studies, pollutants are transported from liquid phase to solid phase. With the proposed new adsorbent material, oils will be specifically removed from wastewater and used as fuel. Thus, obtaining an organic origin adsorbent with high calorific value constitutes the original value of the study. In addition, no secondary pollutants will emerge after the adsorption process.
A High-Resolution Model of the Human Entorhinal Cortex in the ‘BigBrain’ – Use Case for Machine Learning and 3D Analyses
Authors: Behuet Sabrina , Bludau Sebastian , Kedo Olga , Schiffer Christian , Dickscheid Timo , Brandstetter Andrea , Massicotte Philippe , Omidyeganeh Mona , Evans Alan , Amunts Katrin
Published: July 2021

The ‘BigBrain’ is a high-resolution data set of the human brain that enables three-dimensional (3D) analyses with a 20 µm spatial resolution at nearly cellular level. We use this data set to explore pre-α (cell) islands of layer 2 in the entorhinal cortex (EC), which are early affected in Alzheimer’s disease and have therefore been the focus of research for many years. They appear mostly in a round and elongated shape as shown in microscopic studies. Some studies suggested that islands may be interconnected based on analyses of their shape and size in two-dimensional (2D) space. Here, we characterized morphological features (shape, size, and distribution) of pre-α islands in the ‘BigBrain’, based on 3D-reconstructions of gapless series of cell-body-stained sections. The EC was annotated manually, and a machine-learning tool was trained to identify and segment islands with subsequent visualization using high-performance computing (HPC). Islands were visualized as 3D surfaces and their geometry was analyzed. Their morphology was complex: they appeared to be composed of interconnected islands of different types found in 2D histological sections of EC, with various shapes in 3D. Differences in the rostral-to-caudal part of EC were identified by specific distribution and size of islands, with implications for connectivity and function of the EC. 3D compactness analysis found more round and complex islands than elongated ones. The present study represents a use case for studying large microscopic data sets. It provides reference data for studies, e.g. investigating neurodegenerative diseases, where specific alterations in layer 2 were previously reported.
The Statistical Physics of Learning Revisited: Typical Learning Curves in Model Scenarios
Authors: Biehl Michael
Published: July 2021

The exchange of ideas between computer science and statistical physics has advanced the understanding of machine learning and inference significantly. This interdisciplinary approach is currently regaining momentum due to the revived interest in neural networks and deep learning. Methods borrowed from statistical mechanics complement other approaches to the theory of computational and statistical learning. In this brief review, we outline and illustrate some of the basic concepts. We exemplify the role of the statistical physics approach in terms of a particularly important contribution: the computation of typical learning curves in student teacher scenarios of supervised learning. Two, by now classical examples from the literature illustrate the approach: the learning of a linearly separable rule by a perceptron with continuous and with discrete weights, respectively. We address these prototypical problems in terms of the simplifying limit of stochastic training at high formal temperature and obtain the corresponding learning curves.
Computational Modelling of Cerebellar Magnetic Stimulation: The Effect of Washout
Authors: Antonietti Alberto , Casellato Claudia , D’Angelo Egidio , Pedrocchi Alessandra
Published: July 2021

Nowadays, clinicians have multiple tools that they can use to stimulate the brain, by means of electric or magnetic fields that can interfere with the bio-electrical behaviour of neurons. However, it is still unclear which are the neural mechanisms that are involved and how the external stimulation changes the neural responses at network-level. In this paper, we have exploited the simulations carried out using a spiking neural network model, which reconstructed the cerebellar system, to shed light on the underlying mechanisms of cerebellar Transcranial Magnetic Stimulation affecting specific task behaviour. Namely, two computational studies have been merged and compared. The two studies employed a very similar experimental protocol: a first session of Pavlovian associative conditioning, the administration of the TMS (effective or sham), a washout period, and a second session of Pavlovian associative conditioning. In one study, the washout period between the two sessions was long (1 week), while the other study foresaw a very short washout (15 min). Computational models suggested a mechanistic explanation for the TMS effect on the cerebellum. In this work, we have found that the duration of the washout strongly changes the modification of plasticity mechanisms in the cerebellar network, then reflected in the learning behaviour.