Essays of Educational Attainment

One of the very interesting demographic features in the US over the last several decades is the persistent racial educational gap between blacks and whites and the reverse gender education gap as a result of the rapid rise in women's educational attainment. This dissertation is to investigate the reasons behind it. I first investigated the educational gap between blacks and whites. I propose a new model to identify if and how much the educational attainment gap between blacks and whites is due to the difference in their neighborhoods. In this model, individuals belong to two unobserved types: the endogenous type who may move in response to the neighborhood effect on their education; or the exogenous type who may move for reasons unrelated to education. The Heckman sample selection model becomes a special case of the current model in which the probability of one type of individuals is zero. Although I cannot find any significant neighborhood effect in the usual Heckman sample selection model, I do find heterogeneous effects in our type-consistent model. In particular, there is a substantial neighborhood effect for the movers who belong to the endogenous type. No significant effects exist for other groups. On average, I find that the neighborhood variable, the percentage of high school graduates in the neighborhood, accounts for about 37.7% of the education gap between blacks and whites. This dissertation sheds some insight about women?s educational attainment by studying the motivations of education for women: to pursue higher wages and to find highly educated spouses. The identification strategy is that the college education is exogenous to the partner choice if education is driven by pursuing higher job market return (the type of marry-for-romance), and is endogenous if the education decision is driven by marriage market return (the type of marry-for-money). I find that the marry-for-romance type has higher education than the other type and given everything else the same, with the same education level, the women who marry for money have a higher probability of finding a highly educated husband than those marrying for romance. Therefore, the reversal educational gap could be the result of more marry-for-romance women

The Influence of Fandom Culture on the Formation of Primary School Students’ Values

The chief object of this study is to survey the influence of fandom culture on the formation of primary school students’ values and guidance strategies. Past studies have examined the impact of worshiping stars on the values of teenagers, but there are no specific research or guidance strategies on the effects of fandom culture on the value formation of primary students who are still in the early stages of value formation. The method used in our study is known as the literature analysis method, participatory observation method, questionnaire method, and Data analysis method. The research has recorded valuable data about the influence of fandom culture on the formation of primary school students’ values and has proved that the formation of values of primary school students is hardly influenced by fandom culture. This research finally put forward useful strategies to guide primary school students to form correct values from various perspectives

Model based wind turbine gearbox fault detection on SCADA data

Developing effective wind turbine fault detection algorithm is not only meaningful for improving wind turbine reliability but also crucial for future intelligent wind farm operation and management. Typical wind turbine gearbox condition monitoring is based on vibration signals, which is effective to detect failures with high frequency signal range. But it may not be effective on low speed components which have low frequency signal characteristic of different failure modes. SCADA system collecting multiple low frequency signals provides a cost-effective way to monitor wind turbines health and performance, while its capability on fault detection is still an open issue. To systematic understand wind turbine systems, this paper presents research results of model based wind turbine gearbox fault detection. Through a detail analysis of thermodynamic process of gearbox lubrication system, a wind turbine drive train model which considers heat transferring mechanism in gearbox lubrication system is built to derive robust relationships between transmission efficiency, temperature, and rotational speed signals of wind turbine gearbox and suggest useful information for lubrication system design and optimization. The result obtained in this work is useful for wind turbine gearbox design and effective algorithm development of fault detection

Impaired sensitivity to thyroid hormones is associated with hyperuricemia in a Chinese euthyroid population

ObjectiveImpaired sensitivity to thyroid hormones has been reported as a common metabolic disorder, and it remains poorly understood whether it interplays with uric acid (UA) metabolism as an established risk factor for cardiovascular diseases (CVDs). We aimed to investigate the relationship between thyroid hormone sensitivity and elevated UA in a Chinese euthyroid population.MethodsA total of 15,955 euthyroid subjects were included in this study. Thyroid hormone sensitivity indices were calculated, including the thyroid feedback quantile-based index (TFQI), the Chinese-referenced parametric TFQI (PTFQI), the TSH index (TSHI), and the thyrotropin thyroxine resistance index (TT4RI), and the FT3/FT4 ratio. Linear and logistic regression analyses were performed to detect the association between thyroid hormone sensitivity and elevated UA.ResultsSubjects with reduced sensitivity to thyroid hormones had increased UA levels in both genders (p for trend < 0.001). Logistic and linear regression analyses showed that higher TFQI, PTFQI, TSHI, and TT4RI were positively associated with elevated UA levels, but negatively associated with the FT3/FT4 ratio. The odds ratio (OR) of the highest versus the first quartile of TFQI was 1.20 (1.05, 1.38) in men and 1.80 (1.46, 2.23) in women (p < 0.001). PTHQI, TSHI, and TT4RI obtained similar results in both genders. Conversely, the highest quartile of the FT3/FT4 ratio was negatively correlated with elevated UA levels [men: OR 0.78 (0.68,0.89), women: OR 0.66 (0.53,0.81)].ConclusionImpaired sensitivity to thyroid hormones was associated with elevated UA levels in euthyroid subjects. Our findings shed light on the role of thyroid hormone sensitivity in UA metabolism

Temporally and Longitudinally Tailored Dynamic Space-Time Wave Packets

In general, space-time wave packets with correlations between transverse spatial fields and temporal frequency spectra can lead to unique spatiotemporal dynamics, thus enabling control of the instantaneous light properties. However, spatiotemporal dynamics generated in previous approaches manifest themselves at a given propagation distance yet not arbitrarily tailored longitudinally. Here, we propose and demonstrate a new versatile class of judiciously synthesized wave packets whose spatiotemporal evolution can be arbitrarily engineered to take place at various predesigned distances along the longitudinal propagation path. Spatiotemporal synthesis is achieved by introducing a 2-dimensional spectrum comprising both temporal and longitudinal wavenumbers associated with specific transverse Bessel-Gaussian fields. The resulting spectra are then employed to produce wave packets evolving in both time and axial distance - in full accord with the theoretical analysis. In this respect, various light degrees of freedom can be independently manipulated, such as intensity, polarization, and transverse spatial distribution (e.g., orbital angular momentum). Through a temporal-longitudinal frequency comb spectrum, we simulate the synthesis of the aforementioned wave packet properties, indicating a decrease in relative error compared to the desired phenomena as more spectral components are incorporated. Additionally, we experimentally demonstrate tailorable spatiotemporal fields carrying time- and longitudinal-varying orbital angular momentum, such that the local topological charge evolves every ~1 ps in the time domain and 10 cm axially. We believe that our space-time wave packets can significantly expand the exploration of spatiotemporal dynamics in the longitudinal dimension, and potentially enable novel applications in ultrafast microscopy, light-matter interactions, and nonlinear optics

Morphine paradoxically prolongs neuropathic pain in rats by amplifying spinal NLRP3 inflammasome activation

Pain after disease/damage of the nervous system is predominantly treated with opioids, but without exploration of the long-term consequences. We demonstrate that a short course of morphine after nerve injury doubles the duration of neuropathic pain. Using genetic and pharmacological interventions, and innovative Designer Receptor Exclusively Activated by Designer Drugs disruption of microglia reactivity, we demonstrate that opioid-prolonged neuropathic pain arises from spinal microglia and NOD-like receptor protein 3 inflammasome formation/activation. Inhibiting these processes permanently resets amplified pain to basal levels, an effect not previously reported. These data support the “two-hit hypothesis” of amplification of microglial activation—nerve injury being the first “hit,” morphine the second. The implications of such potent microglial “priming” has fundamental clinical implications for pain and may extend to many chronic neurological disorders