A Formal Treatment of Generalized Preferential Attachment and its Empirical Validation

Generalized preferential attachment is defined as the tendency of a vertex to acquire new links in the future with respect to a particular vertex property. Understanding which properties influence link acquisition tendency (LAT) gives us a predictive power to estimate the future growth of network and insight about the actual dynamics governing the complex networks. In this study, we explore the effect of age and degree on LAT by analyzing data collected from a new complex-network growth dataset. We found that LAT and degree of a vertex are linearly correlated in accordance with previous studies. Interestingly, the relation between LAT and age of a vertex is found to be in conflict with the known models of network growth. We identified three different periods in the network's lifetime where the relation between age and LAT is strongly positive, almost stationary and negative correspondingly

The Effects of a Novel Sport-Based Intervention on Lower Body Muscle Function in Older Adults

Objective: This study aimed to examine the effects of a novel, small-court racquet sport, Pickleball, on lower body muscle power and functional performance of older adults, aged 60-75. Background: Physical inactivity in the older adult population is associated with increased risks of falls, chronic illness, and decreased quality of life. Sports participation may have multiple benefits for improving these risks and have the added benefit of increased adherence among older adults. Pickleball, a popular new sport, is a small-court racquet sport that is moderate intensity, widely accessible, cost effective, and enjoyed by many older adults across the nation. Methods: Five participants performed three isokinetic maximum voluntary contractions at 240°·s-1 for the knee extensor’s muscle group and three vertical jumps for measuring knee extensor power and lower body function, respectively, at baseline and after participating in 6 weeks of Pickleball play. Pickleball sessions were 1hour and occurred twice per week. Variables included mean knee extensor power and countermovement vertical jump height. Results: The intervention resulted in moderate gains in knee extensor power (18.7% increases) and small gains in vertical jump height (7.5% increases). The effect sizes were 0.63 and 0.17 for the knee extensor power and jump height variables, respectively. Conclusions: These findings offer some support showing that 6 weeks of Pickleball participation may elicit some modest gains, in a relatively short duration, for lower body function which could help older adults meet physical activity recommendations and help reduce the burdens of dysfunction on a long-term basis with a sport-based model that may offer advantages of sustainable physical activity. However, more work is needed to corroborate these findings with larger sample sizes and longer duration interventions

Big Dreams and Pyramid Schemes: The FTC’s Path to Improving Multi-Level Marketing Consumer Protections in Light of AMG Capital Management and the 2016 Herbalife Settlement

Multi-level marketing, also known as “MLM,” is a type of sales business that relies on both sales to consumers and recruitment of sellers into the company’s tiered commission structure. MLMs are wildly and enduringly popular, especially because they claim to be a flexible and easy source of income for people who need it most. However, almost everyone who joins an MLM will lose money, and many MLMs are illegal pyramid schemes. Millions of Americans are harmed by MLMs every year. Despite this, the government does very little to punish MLMs who lie to prospective participants about their odds of success. How are MLMs allowed to operate relatively unchecked? MLMs have a powerful political lobby which has ensured that state and federal regulations remain favorable to their operations. Furthermore, the Supreme Court’s 2021 decision in AMG Capital Management, LLC v. Federal Trade Commission abrogated the FTC’s power to pursue financial restitution for consumers harmed by MLMs. To overcome this setback, this Note argues that the FTC must frequently and aggressively use its Sections 5 and 19 powers to reimburse harmed MLM customers and deter further MLM misconduct, without falling into the pitfalls exemplified by its 2016 settlement with Herbalife, a nutrition MLM. The FTC must also require full disclosure of the odds of success in an MLM, obtain proportionate financial punishments against offenders, and more widely publicize the harmful nature of MLMs

Methods for Evaluating Respondent Attrition in Web-Based Surveys

Background: Electronic surveys are convenient, cost effective, and increasingly popular tools for collecting information. While the online platform allows researchers to recruit and enroll more participants, there is an increased risk of participant dropout in Web-based research. Often, these dropout trends are simply reported, adjusted for, or ignored altogether. Objective: To propose a conceptual framework that analyzes respondent attrition and demonstrates the utility of these methods with existing survey data. Methods: First, we suggest visualization of attrition trends using bar charts and survival curves. Next, we propose a generalized linear mixed model (GLMM) to detect or confirm significant attrition points. Finally, we suggest applications of existing statistical methods to investigate the effect of internal survey characteristics and patient characteristics on dropout. In order to apply this framework, we conducted a case study; a seventeen-item Informed Decision-Making (IDM) module addressing how and why patients make decisions about cancer screening. Results: Using the framework, we were able to find significant attrition points at Questions 4, 6, 7, and 9, and were also able to identify participant responses and characteristics associated with dropout at these points and overall. Conclusions: When these methods were applied to survey data, significant attrition trends were revealed, both visually and empirically, that can inspire researchers to investigate the factors associated with survey dropout, address whether survey completion is associated with health outcomes, and compare attrition patterns between groups. The framework can be used to extract information beyond simple responses, can be useful during survey development, and can help determine the external validity of survey results

Identifying Attrition Phases in Survey Data: Applicability and Assessment Study

Background: Although Web-based questionnaires are an efficient, increasingly popular mode of data collection, their utility is often challenged by high participant dropout. Researchers can gain insight into potential causes of high participant dropout by analyzing the dropout patterns. Objective: This study proposed the application of and assessed the use of user-specified and existing hypothesis testing methods in a novel setting—survey dropout data—to identify phases of higher or lower survey dropout. Methods: First, we proposed the application of user-specified thresholds to identify abrupt differences in the dropout rate. Second, we proposed the application of 2 existing hypothesis testing methods to detect significant differences in participant dropout. We assessed these methods through a simulation study and through application to a case study, featuring a questionnaire addressing decision-making surrounding cancer screening. Results: The user-specified method set to a low threshold performed best at accurately detecting phases of high attrition in both the simulation study and test case application, although all proposed methods were too sensitive. Conclusions: The user-specified method set to a low threshold correctly identified the attrition phases. Hypothesis testing methods, although sensitive at times, were unable to accurately identify the attrition phases. These results strengthen the case for further development of and research surrounding the science of attrition

Large second harmonic generation enhancement in SiN waveguides by all-optically induced quasi phase matching

Integrated waveguides exhibiting efficient second-order nonlinearities are crucial to obtain compact and low power optical signal processing devices. Silicon nitride (SiN) has shown second harmonic generation (SHG) capabilities in resonant structures and single-pass devices leveraging intermodal phase matching, which is defined by waveguide design. Lithium niobate allows compensating for the phase mismatch using periodically poled waveguides, however the latter are not reconfigurable and remain difficult to integrate with SiN or silicon (Si) circuits. Here we show the all-optical enhancement of SHG in SiN waveguides by more than 30 dB. We demonstrate that a Watt-level laser causes a periodic modification of the waveguide second-order susceptibility. The resulting second order nonlinear grating has a periodicity allowing for quasi phase matching (QPM) between the pump and SH mode. Moreover, changing the pump wavelength or polarization updates the period, relaxing phase matching constraints imposed by the waveguide geometry. We show that the grating is long term inscribed in the waveguides, and we estimate a second order nonlinearity of the order of 0.3 pm/V, while a maximum conversion efficiency (CE) of 1.8x10-6 W-1 cm-2 is reached

An Unfinished Canvas: Allocating Funding and Instructional Time for Elementary Arts Education

An Unfinished Canvas found that California's elementary schools face unique challenges inproviding all students with sequential, standards-based arts education. In particular, elementary principals identified inadequate funding and insufficient instructional time as significant barriers to the provision of arts education. For this study, we sought to further understand the impact of funding and time on elementary arts education. To do so, we examined the allocation of funding and instructional time in 10 schools across five states (Kentucky, Massachusetts, Minnesota, New Jersey, and California)

Teachers as Readers: An Extension of the \u27Impact of Reading\u27 Survey

Do teachers have a responsibility to help students to develop positive attitudes about reading? The idea that teachers can and should play a major role in the development of students\u27 reading habits and interests has never been seriously questioned. In fact, most reading methods texts and many journal articles repeatedly stress this aspect of teachers\u27 responsibilities. Interests do not grow in a vacuum ... the teacher\u27s task, then, is not only to feed the interests the child already possesses but to open up new avenues of interest and opportunity (Strickland, 1957). Developing permanent interests in reading must be the goal of every teacher regardless of the particular subject she (sic) may be teaching (Barbe, 1963)

Are the Oxygen Isotope Values of the Late Cretaceous Western Interior Seaway Different from the Open Ocean?

The Western Interior Seaway (WIS) was a North American epicontinental sea that was connected to the open ocean through the passage of the northern Boreal Sea and the southern Tethys Sea from the early Albian (~113 million years ago) to the early Paleogene (~65 million years ago). The WIS began to recced and lost its connection to the southern Tethys Sea in the late Campanian (~72 million years ago). In the early Paleogene, the WIS dried up completely. The oxygen isotopic composition (δ18O) of benthic bivalves was measured from the upper Campanian and lower Maastrichtian (75 million years ago to 69 million years ago) to decipher if the WIS had different δ18O values than the δ18O values of the open ocean. This study would begin to answer the question if the δ18O values of the WIS changed over time since the WIS began to retreat from the open ocean in the late Campanian. We measured δ18O of a variety of well-preserved epifaunal (Anisomyon, Endocostea, Inoceramus, Ostrea, and Pteria) and infaunal (Cucullaea, Cymbophora, Geltena, Lucina, Nucula, and Tenuiptera) bivalves. Then, we compared the δ18O values of the WIS benthic bivalves to a literature search conducted on the δ18O values of WIS bivalves and ammonites and δ18O values of the open ocean foraminifera, bivalves, and ammonites. Most WIS δ18O values range from -6‰ to 0‰ and these δ18O values overlap with the open ocean studies, which range from -5‰ to +2‰. The δ18O values of the WIS are not significantly different than the δ18O values of the open ocean even though the WIS began to lose its connection to the open ocean. However, the WIS does has lower δ18O values than the open ocean and this could possibly be due to freshwater input to the WIS or increased evaporation in the WIS. This systematically collected dataset of bivalve δ18O values may contribute to Late Cretaceous climate models and paleoecological and paleoenvironmental studies

piRNAs and Aubergine cooperate with Wispy poly(A) polymerase to stabilize mRNAs in the germ plasm

Piwi-interacting RNAs (piRNAs) and PIWI proteins play a crucial role in germ cells by repressing transposable elements and regulating gene expression. In Drosophila, maternal piRNAs are loaded into the embryo mostly bound to the PIWI protein Aubergine (Aub). Aub targets maternal mRNAs through incomplete base-pairing with piRNAs and can induce their destabilization in the somatic part of the embryo. Paradoxically, these Aub-dependent unstable mRNAs encode germ cell determinants that are selectively stabilized in the germ plasm. Here we show that piRNAs and Aub actively protect germ cell mRNAs in the germ plasm. Aub directly interacts with the germline-specific poly(A) polymerase Wispy, thus leading to mRNA polyadenylation and stabilization in the germ plasm. These results reveal a role for piRNAs in mRNA stabilization and identify Aub as an interactor of Wispy for mRNA polyadenylation. They further highlight the role of Aub and piRNAs in embryonic patterning through two opposite functions