In this paper, enlightened by the asymptotic expansion methodology developed by Li [(2013). Maximum-likelihood estimation for diffusion processes via closed-form density expansions. Annals of Statistics 41: 1350–1380] and Li and Chen [(2016). Estimating jump-diffusions using closed-form likelihood expansions. Journal of Econometrics 195(1): 51–70], we propose a Taylor-type approximation for the transition densities of the stochastic differential equations (SDEs) driven by the gamma processes, a special type of Lévy processes. After representing the transition density as a conditional expectation of Dirac delta function acting on the solution of the related SDE, the key technical method for calculating the expectation of multiple stochastic integrals conditional on the gamma process is presented. To numerically test the efficiency of our method, we examine the pure jump Ornstein–Uhlenbeck model and its extensions to two jump-diffusion models. For each model, the maximum relative error between our approximated transition density and the benchmark density obtained by the inverse Fourier transform of the characteristic function is sufficiently small, which shows the efficiency of our approximated method.

Most of the extant literature on the fertility history and social networks of older adults has focused on advanced societies. Nevertheless, a limited number of studies have explored how culturally preferred family structures or living arrangements are related to older adults’ social networks in developing societies. This study examined these issues in the Chinese context and paid particular attention to the filial piety and preference for sons dominating Chinese society. Using nationally representative data of adults aged 60 and over from China Longitudinal Aging Social Survey in 2016, we constructed family and friend network scores following previous studies and developed linear models using multiple imputation for the missing data. The results suggested that childless older adults were the most disadvantaged in receiving support from family networks. Despite China's patrilineal culture, daughters were important sources of support. In terms of friend networks, older men who had no sons were least likely to receive support while co-residing with a partner and a son(s) might benefit them. Further analysis revealed that older rural women, but not older urban women, also had more support from friend networks if living with sons, implying urban–rural differences. Given the impact of social networks on older adults’ health and wellbeing, older Chinese people with no sons might need more support from other sources, such as aged-care programmes from public institutions, to achieve healthy ageing.

Guided by conodont biostratigraphy and unconformities observed in the field, stable carbon isotopic analysis (δ13Ccarb) was performed on 210 samples from Lower–Middle Ordovician (Tremadocian to Darriwilian) sections and wells in the Tarim Basin, NW China. The δ13C trend in the Tarim Basin sections has three distinct characteristics: (1) from the Tremadocian to the Floian, a positive shift from −1.9 ‰ to −0.2 ‰ is observed near the boundary between the Penglaiba Formation and the Yingshan Formation; (2) from the Floian to the Dapingian, a positive shift in δ13C from −3 ‰ to −0.7 ‰ occurred under large-scale sea-level rise and a change in the sedimentary environment from a restricted platform to an open platform. Changes in the conodont type are also observed in the Tabei region; and (3) from the Dapingian to the Darriwilian, δ13C first decreased and then increased, showing a negative shift at the Dapingian–Darriwilian boundary. During the Floian, δ13C decreased in the study area, while it first decreased and then increased in other regions, which may reflect local sea-level movements in response to isostatic crustal movements. Two types of positive shift were identified at the Floian–Dapingian boundary, which likely show the effects of local factors, including a disconformity, dolomitization, and platform restriction, superimposed on the global signal of the carbon isotope. Some conodont zonations and recurrent negative excursions in Tremadocian, Floian and Dapingian stages appear to be truncated by unconformities, which are accompanied by short-term subaerial exposure due to sea-level fall and local tectonic uplift.

The Antarctic subglacial drilling rig (ASDR) is designed to recover 105 mm-diameter ice cores up to 1400 m depth and 41.5 mm-diameter bedrock cores up to 2 m in length. In order to ensure safe and convenient drilling, drilling auxiliaries are designed to support fieldwork and servicing. These auxiliaries are subdivided into several systems for power supply, drill tripping in the borehole, ice core and chip processing, and drill servicing and maintenance. The required equipment also includes two generators, a drilling winch with a cable, logging winch with a cable, control desk, pipe handler with a fixed clamp, chip chamber vibrator, centrifuge, emergency devices and fitting and electrical tools. Additionally, several environmental protective measures such as a new liquid-tight casing with a thermal casing shoe and a bailing device for recovering drilling fluid from the borehole were designed. Most of the auxiliaries were tested during the summer of 2018–2019 near Zhongshan Station, East Antarctica while drilling to the bedrock to a depth of 198 m.

Drilling to the bedrock of ice sheets and glaciers offers unique opportunities for examining the processes occurring in the bed. Basal and subglacial materials contain important paleoclimatic and paleoenvironmental records and provide a unique habitat for life; they offer significant information regarding the sediment deformation beneath glaciers and its effects on the subglacial hydraulic system and geology. The newly developed and tested Antarctic subglacial drilling rig (ASDR) is designed to recover ice and bedrock core samples from depths of up to 1400 m. All of the drilling equipment is installed inside a movable, sledge-mounted, temperature-controlled and wind-protected drilling shelter and workshop. To facilitate helicopter unloading of the research vessel, the shelter and workshop can be disassembled, with individual parts weighing <2–3 tons. The entire ASDR system weighs ~55 tons, including transport packaging. The ASDR is designed to be transported to the chosen site via snow vehicles and would be ready for drilling operations within 2–3 d after arrival. The ASDR was tested during the 2018–2019 summer season near Zhongshan Station, East Antarctica. At the test site, 2-week drilling operations resulted in a borehole that reached bedrock at a depth of 198 m.

Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodisation. We explored the minimum iodine requirements of young adults in China using a balance experiment and the ‘iodine overflow’ hypothesis proposed by our team. Sixty healthy young adults were enrolled to consume a sequential experimental diet containing low, medium and high levels of iodine (about 20, 40 and 60 μg/d, respectively). Each dose was consumed for 4 d, and daily iodine intake, excretion and retention were assessed. All participants were in negative iodine balance throughout the study. Iodine intake, excretion and retention differed among the three iodine levels (P < 0·01 for all groups). The zero-iodine balance derived from a random effect model indicated a mean iodine intake of 102 μg/d, but poor correlation coefficients between observed and predicted iodine excretion (r 0·538 for μg/d data) and retention (r 0·304 for μg/d data). As iodine intake increased from medium to high, all of the increased iodine was excreted (‘overflow’) through urine and faeces by males, and 89·5 % was excreted by females. Although the high iodine level (63·4 μg/d) might be adequate in males, the corresponding level of 61·6 μg/d in females did not meet optimal requirements. Our findings indicate that a daily iodine intake of approximately half the current recommended nutrient intake (120 μg/d) may satisfy the minimum iodine requirements of young male adults in China, while a similar level is insufficient for females based on the ‘iodine overflow’ hypothesis.

A new, modified version of the cable-suspended Ice and Bedrock Electromechanical Drill (IBED) was designed for drilling in firn, ice, debris-rich ice and rock. The upper part of the drill is almost the same for all drill variants and comprises four sections: cable termination, a slip-ring section, an antitorque system and an electronic pressure chamber. The lower part of the IBED comprises an auger core barrel, reamers, a core barrel for ice/debris-ice drilling and a conventional geological single-tube core barrel or custom-made double-tube core barrel. First, the short and full-scale field versions of the IBED were tested at an outdoor testing stand and a testing facility with a 12.5 m-deep ice well. Then, in the 2018–2019 summer season, the IBED was tested in the field at a site ~12 km south of Zhongshan Station, East Antarctica, and a ~6 cm bedrock core was recovered from a 198 m-deep borehole. A total of 18 d was required to penetrate the ice sheet. The retrieved core samples of blue ice, basal ice and bedrock provided valuable information regarding the Earth's paleo-environment.

The perceived velocity gradient tensor (PVGT), constructed from four fluid tracers forming a tetrahedron, provides a natural way to study the structure of velocity fluctuations and its dependence on spatial scales. It generalizes and shares qualitatively many properties with the true velocity gradient tensor. Here, we establish the evolution equation for the PVGT, and, for homogeneous and isotropic incompressible turbulent flows, we analyse the dynamics of the PVGT in particular using its second- and third-order invariants. We show that, for PVGT based on regular tetrads with lateral size $R_{0}$ , the second-order invariants can be expressed solely in terms of the usual second-order velocity structure functions, while the third-order invariants involve the usual third-order longitudinal velocity structure function and a less well known three-point velocity correlation function. For homogeneous and isotropic turbulence, exact relations between the second moments of strain and vorticity, as well as enstrophy production and the third moments of the strain, are derived. These generalized relations are valid for all ranges of $R_{0}$ , and reduce to classical results for the velocity gradient tensor when $R_{0}$ is in the dissipative range. With the help of these relations, we quantify the importance of the various terms, such as vortex stretching, as a function of the scale $R_{0}$ . Our analysis, which is supported by the results of direct numerical simulations of turbulent flows in the Reynolds-number range $100\leqslant R_{\unicode[STIX]{x1D706}}\leqslant 610$ , allows us to demonstrate that strain prevails over vorticity when $R_{0}$ is in the inertial range.

OBJECTIVES/GOALS: To compare the opioid drug requirements amongst those individuals with high levels of catecholamines in blood and acute post-procedural pain, by ICD9/10 codes (experimental) to those with normal levels of catecholamines and acute post-procedural pain (AP-PP) only (controls) METHODS/STUDY POPULATION: In collaboration with both the Informatics and the Biostatistics Departments at CTSI and under the auspices of the IRB at the University of Rochester, we completed the collection of ~8,000 electronic health records(EHRs) of adults 18 years and older with surgical appointments at Strong Memorial Hospital (SMH), who met inclusion criteria, from January 2006 to September 2019 and received Fentanyl therapy for AP-PP management. Subjects were categorized in a two-arm-matched case-control fashion. A ratio of 1(Experimental):1(Control) was utilized. Analytic comparisons were completed using normal distribution statistical methods with p >0.1 for significance. RESULTS/ANTICIPATED RESULTS: After removal of duplicates and exclusion of EHRs, a total of 17 subjects met inclusion criteria for the experimental group. We matched controls (n = 17) with experimental subjects for age, gender and surgical procedure for accurately compare opioid requirements in the postoperative recovery. Mean age of subjects was 69(+/-10.1235) years old. Most of subjects were females (70%). Mean Fentanyl requirement was significantly different in the experimental group 466.17(625.621)mcg compared to 215.58(353.323)mcg in the controls (p value 0.07832) DISCUSSION/SIGNIFICANCE OF IMPACT: It is suggested that healthy individuals with genetic variations in pain pathways including; the COMT and MAOA rendered individuals with higher levels of catecholamines in the body driving abnormal responses to pain sensitivity. We emulated this genetic variation for clinical purposes using ICD10/9 codes of those with conditions related to higher catecholamine levels in the body. Based on our preliminary results, we suggest that COMT and MAOA genetic variations could impact opioid drug use and the current opioid dependency and epidemics in the U.S. This study will address remarkable questions and identify strategies about this topic.

In this paper, the generation of relativistic electron mirrors (REM) and the reflection of an ultra-short laser off the mirrors are discussed, applying two-dimension particle-in-cell simulations. REMs with ultra-high acceleration and expanding velocity can be produced from a solid nanofoil illuminated normally by an ultra-intense femtosecond laser pulse with a sharp rising edge. Chirped attosecond pulse can be produced through the reflection of a counter-propagating probe laser off the accelerating REM. In the electron moving frame, the plasma frequency of the REM keeps decreasing due to its rapid expansion. The laser frequency, on the contrary, keeps increasing due to the acceleration of REM and the relativistic Doppler shift from the lab frame to the electron moving frame. Within an ultra-short time interval, the two frequencies will be equal in the electron moving frame, which leads to the resonance between laser and REM. The reflected radiation near this interval and corresponding spectra will be amplified due to the resonance. Through adjusting the arriving time of the probe laser, a certain part of the reflected field could be selectively amplified or depressed, leading to the selective adjustment of the corresponding spectra.

If a droplet smaller than the capillary length is placed on a substrate with a conical shape, it spreads by itself in the direction of growing fibre radius. We describe this capillary spreading dynamics by developing a lubrication flow approximation on a cone and by using the perturbation method of matched asymptotic expansions. Our results show that the droplet appears to adopt a quasi-static shape and the predictions of the droplet shape and the spreading velocity from the two mathematical models are in excellent agreement. At the contact line regions, a large pressure gradient is generated by the mismatch between the equilibrium contact angle and the apparent contact angle that maintains the viscous flow. It is the conical shape of the substrate that breaks the front/rear droplet symmetry in terms of the apparent contact angle, which is larger at the thicker part of the cone than at its thinner part. Consequently, the droplet is predicted to move from the cone tip to its base, consistent with experimental observations.

As electrode materials, metal-organic frameworks always have low electrical conductivity and poor structural stability, which limits its applications in electrochemical fields. Here, Ni-BPDC/GO composites are synthesized using graphene oxide (GO) as a substrate and 4,4′-biphenyldicarboxylic acid (BPDC) as an organic ligand via a hydrothermal approach. The growth mechanism of the Ni-BPDC and Ni-BPDC/GO composites is proposed. In the composites, highly dispersed Ni-BPDC macro-nanostrips are supported on the GO surface in parallel. The presence of GO does not affect the growth and crystalline structure of Ni-BPDC. Compared with the Ni-BPDC, Ni-BPDC/GO composites exhibit higher specific capacitance, rate capability, and operating current density through lowering intrinsic resistance, charge-transfer resistance, and ion diffusion impedance. Moreover, the assembled Ni-BPDC/GO-3//reduced graphene oxide (rGO) asymmetric supercapacitor has large specific capacitance, good cycling stability, and high energy density (16.5 W h/kg at 250 W/kg). Hence, Ni-BPDC/GO composites are a potential electrode material for supercapacitors.

Achieving control over the morphology of conjugated polymer (CP) blends at nanoscale is crucial for enhancing their performances in diverse organic optoelectronic devices, including thin film transistors, photovoltaics, and light emitting diodes. However, the complex CP chemical structures and intramolecular interactions often make such control difficult to implement. We demonstrate here that cooperative combination of non-covalent interactions, including hydrogen bonding, coordination interactions, and π-π interactions, etc., can be used to effectively define the morphology of CP blend films, in particular being able to achieve accurate spatial arrangement of nanoparticles within CP nanostructures. Through UV-vis absorption spectroscopy and transmission electron microscopy, we show strong attachment of fullerene molecules, CdSe quantum dots, and iron oxide nanoparticles, onto well-defined CP nanofibers. The resulting core/shell hybrid nanofibers exhibit well-defined donor/acceptor interface when employed in photovoltaic devices, which also contributes to enhanced charge separation and transport. These findings provide a facile new methodology of improving CP/nanoparticle interfacial properties and controlling blend morphology. The generality of this methodology demonstrated in current studies points to a new way of designing hybrid materials based on organic polymers and inorganic nanoparticles towards applications in modern electronic devices.

In recent years, investigations of the phase transition behavior of semiconducting nanoparticles under high pressure has attracted increasing attention due to their potential applications in sensors, electronics, and optics. However, current understanding of how the size of nanoparticles influences this pressure-dependent property is somewhat lacking. In particular, phase behaviors of semiconducting CdS nanoparticles under high pressure have not been extensively reported. Therefore, in this work, CdS nanoparticles of different sizes are used as a model system to investigate particle size effects on high-pressure-induced phase transition behaviors. In particular, 7.5, 10.6, and 39.7 nm spherical CdS nanoparticles are synthesized and subjected to controlled high pressures up to 15 GPa in a diamond anvil cell. Analysis of all three nanoparticles using in-situ synchrotron wide-angle X-ray scattering (WAXS) data shows that phase transitions from wurtzite to rocksalt occur at higher pressures than for bulk material. Bulk modulus calculations not only show that the wurtzite CdS nanomaterial is more compressible than rocksalt, but also that the compressibility of CdS nanoparticles depends on their particle size. Furthermore, sintering of spherical nanoparticles into nanorods was observed for the 7.5 nm CdS nanoparticles. Our results provide new insights into the fundamental properties of nanoparticles under high pressure that will inform designs of new nanomaterial structures for emerging applications.