Estimation of Regression Model Using a Two Stage Nonparametric Approach

Based on the empirical or theoretical qualitative information about the relationship between response variable and covariates, we propose a new approach to model polynomial regression using a shape restricted regression after estimating the direction by sufficient dimension reduction. The purpose of this paper is to illustrate that in the absence of prior information other than the shape constraints, our approach provides a flexible fit to the data and improves regression predictions. We use central subspace to estimate the directions and fit a final model by shape restricted regression, when the shape is known or is stipulated from empirical inspection. Comparisons with an alternative nonparametric regression are included. Simulated and real data analyses are conducted to illustrate the performance of our approach.

Turkey Creek—A Case Study of Ecohydrology and Integrated Watershed Management in the Low-Gradient Atlantic Coastal Plain, USA

Water yield, water supply and quality, wildlife habitat, and ecosystem productivity and services are important societal concerns for natural resource management in the 21st century. Watershed-scale ecohydrologic studies can provide needed context for addressing complex spatial and temporal dynamics of these functions and services. This study was conducted on the 5240 ha Turkey Creek watershed (WS 78) draining a 3rd order stream on the Santee Experimental Forest within the South Carolina Atlantic Coastal Plain, USA. The study objectives were to present the hydrologic characteristics of this relatively undisturbed, except by a hurricane (Hugo, 1989), forested water-shed and to discuss key elements for watershed management, including water resource assessment (WRM), modeling integrated water resources management, environmental assessment, land use planning, social impact assessment, and information management. Runoff coefficients, flow duration curves, flood and low flow frequency curves, surface and ground water yields were assessed as elements of the WRM. Results from the last 10 years of interdisciplinary studies have also advanced the understanding of coastal ecohydrologic characteristics and processes, water balance, and their modeling including the need of high resolution LiDAR data. For example, surface water dynamics were shown to be regulated primarily by the water table, dependent upon pre- cipitation and evapotranspiration (ET). Analysis of pre- and post-Hugo streamflow data showed somewhat lower but insignificant (α = 0.05) mean annual flow but increased frequency of larger flows for the post-Hugo compared with the pre-Hugo level. However, there was no significant difference in mean annual ET, potentially indicating the resiliency of this coastal forest. Although the information from this study may be useful for comparison of coastal ecohydrologic issues, it is becoming increasingly clear that multi-site studies may be warranted to understand these complex systems in the face of climate change, sea level rise, and increasing development in coastal regions.

Largest dinosaur tracksite in China (Cretaceous, Zhaojue area, Sichuan Province): On the verge of destruction

The Zhaojue(ZJ)tracksites represent multiple steeply-inclined,track-bearing exposures in the clastic Feitianshan Formation of Sichuan Province that have been sequentially,excavated,mapped,expanded and destroyed,by quarrying,erosion or collapse,for almost three decades.The quarried area extends for more almost 1.0 km from north to south and-0.5 km from east to west.Four important track-bearing surfaces have been identified and identified as ZJ-Ⅰ,ZJ-Ⅱ,ZJ-ⅡN and ZJ-Ⅲ,some of which are newly exposed surfaces or expanded surfaces that were previously partially described.Others represent surfaces lost since they were first reported in papers published in 2014-2016.The ZJ-Ⅱ site represents a hugely expanded continuation of a much smaller track-bearing surface described in 2014.It was mapped using drone technology,and now represents the largest tracksite in China,with a minimum count of 933 recognizable tracks,and the longest recorded sauropod and ornithopod trackways from China(-80 m and-52 m respectively),which also reveal a pronounced change in the direction of trackmaker movement.The ZJ-Ⅱ surface represents the best Zhaojue paleo-census sample giving a count of 68 individuals from 61 trackways(37 ornithopod,10 theropod,14 sauropod)and isolated tracks(representing 7 individuals).Thus,ornithopods(both large and small trackmakers)represent-54%of the total number of trackways.The smaller ZJ-Ⅲ surface was mapped using traditional methods,and reveals at least 6 ornithopod-and 4 theropod trackways.Both the ZJ-Ⅱ and ZJ-Ⅲ surfaces reveal parallel ornithopod trackways suggestive of social or gregarious behavior.The combined data from all four Zhaojue surfaces reveal a total of 1928 tracks,and include a few previously reported pterosaurs and theropod swim tracks.The Zhaojue quarry complex provide a good example of multiple track-bearing sites(surfaces)that require long term study and monitoring to extract as much trackway data as possible before in situ physical evidence is lost.

Testing-Related and Geo-Demographic Indicators Strongly Predict COVID-19 Deaths in the United States during March of 2020

The COVID-19 pandemic has wreaked havoc around the globe and caused significant disruptions across multiple domains[1].Moreover,different countries have been differentially impacted by COVID-19—a phenomenon that is due to a multitude of complex and often interacting determinants[2].

Near-infrared polarimetry of the GG Tauri A binary system

A high angular resolution near-infrared image that shows the intensity of polarization for the GG Tau A binary system was obtained with the Subaru Telescope. The image shows a circumbinary disk scattering the light from the central binary. The azimuthal profile of the intensity of polarization for the circumbinary disk is roughly reproduced by a simple disk model with the Henyey-Greenstein phase function and the Rayleigh function, indicating there are small dust grains at the surface of the disk. Combined with a previous observation of the circumbinary disk, our image indicates that the gap structure in the circumbinary disk orbits counterclockwise, but material in the disk orbits clockwise. We propose that there is a shadow caused by material located between the central binary and the circumbinary disk. The separations and position angles of the stellar components of the binary in the past 20 yr are consistent with the binary orbit with a = 33.4 AU and e = 0.34.

Unusual dinosaur trackway preservation as clues to paleo-landscape and behavior from the Lower Cretaceous Luohe Formation,Shaanxi Province,China

Poorly preserved tracks have limited ichnotaxonomic or biotaxon utility,but may reveal useful information about the paleoenvironment,behavior and track taphonomy.Eight mostly parallel to sub parallel trackway segments(T1–T8)were registered on a truncation surface in the Lower Cretaceous Luohe Formation of Shaanxi Province.These attest to the passage of several bipeds,probably all theropods,in a paleo-contour-parallel,south-north direction in an arid setting.Quality of preservation in these trackways is poor,but notably superior in two additional trackways(T9–T10)on a foreset surface.Trackway T9 indicates a didactyl trackmaker,probably a deinonychosaurian,heading north to south.This is the 13th report of deinonychosaurian tracks from the Lower Cretaceous of China.If any or all the eight south-north oriented trackway segments represent continuations of other segments in the same trackways,the total number of individual trackmakers heading in this direction may have been as lowas three.Although the trackway pattern and sedimentological evidence could indicate a physically controlled pathway influencing the direction taken by these trackmakers,the possibility that the trackways also represented small social or gregarious group cannot be ruled out.

A Permutation Test for Unit Root in an Autoregressive Model

A permutation test (based on a finite random sample of permutations) for unit root in an autoregressive process is considered. The test can easily be carried out in practice and the proposed permutation test is neither limited to large sample sizes nor normal white noises. Simulations show that the power of the permutation test is reasonable when sample sizes are small or when the white noises have a heavy tailed distribution. The test is shown to be consistent.

Obsidian: Pattern-Based Unit Test Implementations

There exist many automated unit test-generator tools for Java with the primary task of generating test cases, comprised of inputs and a corresponding oracle, each of which is explicitly paired with a specific supporting test implementation. The authors posit that this explicit pairing, or conflating, of test implementation with test case is unnecessary and counter-productive. The authors address this problem by separating the conflated concerns into two distinct tasks: 1) instantiating test implementations and 2) instantiating test cases. This paper focuses on automating the first task in support of the second with the goal of freeing the test engineer to concentrate on test case instantiation. The authors present a new open-source test-preparation tool Obsidian that produces robust, comprehensive, and maintainable unit test implementations. Obsidian, built on the JUnit framework, uses a set of context patterns and associated algorithms combined with information from the Java Reflection API to generate these unit test implementations from Java byte code. These context patterns guide Obsidian to prepare test implementations that guarantee compilation, support exception handling, enable multiple test cases when required, and provide a suitable location for assertions about the test case outcome(s). Obsidian supports regression testing and test-driven development through its novel audits of the testing process.

A probable tyrannosaurid track from the Upper Cretaceous of southern China

A large number of Upper Cretaceous(Maastrichtian)dinosaur skeletal fossils have been found in the Nanxiong Basin and adjacent Ganzhou area,including those of theropods,sauropods and hadrosaurids.However,known dinosaur ichnoassemblages from the Nanxiong Basin partly indicate a different fauna,with dominating large-and medium-sized ornithopods,theropods,and pterosaurs(1,2)This is one of many known examples where trace and body fossil assemblages from the same formation or geologically discrete region show a different composition.Palecological and paleobiogeographical analyses therefore should consider data from both,before any conclusions can be drawn.Formations can be classified according to the relative degree of similarity or congruity(or difference/incongruity)between trace and body fossils into the 5 categories proposed by Lockley[3].

Analysis of PFAAs in American alligators part 1： Concentrations in alligators harvested for consumption during South Carolina public hunts

Environmental contamination resulting from the production or release of harmful chemicals can lead to negative consequences for wildlife and human health. Perfluorinated alkyl acids（PFAAs） were historically produced as protective coatings for many household items and currently persist in the environment, wildlife, and humans. PFAAs have been linked to immune suppression, endocrine disruption, and developmental toxicity in wildlife and laboratory studies. This study examines the American alligator, Alligator mississippiensis,as an important indicator of ecosystem contamination and a potential pathway for PFAA exposure in humans. Alligator meat harvested in the 2015 South Carolina（SC） public hunt season and prepared for human consumption was collected and analyzed for PFAAs to determine meat concentrations and relationships with animal body size（total length）, sex, and location of harvest. Of the 15 PFAAs analyzed, perfluorooctane sulfonate（PFOS） was found in all alligator meat samples and at the highest concentrations（median 6.73 ng/g）. No relationship was found between PFAA concentrations and total length or sex.Concentrations of one or all compounds varied significantly across sampling locations, with alligators harvested in the Middle Coastal hunt unit having the highest PFOS concentrations（median 16.0 ng/g; p = 0.0001）. Alligators harvested specifically from Berkley County, SC（located in the Middle Coastal hunt unit） had the highest PFOS concentrations and the greatest number of PFAAs detected（p 〈 0.0001）. The site-specific nature of PFAA concentrations in alligator meat observed in this study suggests a source of PFAA contamination in Berkley County, SC.

IDEALIZED SIMULATIONS OF THE INNER CORE BOUNDARY LAYER STRUCTURE IN A LANDFALLING TROPICAL CYCLONE. PART Ⅰ: KINEMATIC STRUCTURE

The effects of coastal topography and coastal location in the distribution of boundary layer winds in the inner core of mature tropical cyclones are examined using a high-resolution multi-level model. In these numerical simulations, the evolution of the tropical cyclone boundary layer(TCBL) is studied in storm-relative coordinates, and in lieu of an actual steering current moving the model vortex, the position of the land-sea interface was shifted through the grid domain at a constant speed with separate surface boundary conditions specified over the land and ocean areas. It is shown that the presence of a coastal boundary produces land-induced asymmetries(along with an internal boundary layer) due to the asymmetric structure of surface drag. This land-induced asymmetry is found in both the azimuthal and radial wind field at landfall. For a moving storm, nonlinear advective interactions between storm-induced asymmetries and land-induced asymmetries can generate a lowlevel vorticity band ahead of the hurricane. When the storm motion vector has a component that is perpendicular to the coastal boundary, the interaction between this band and the mean vortex leads to a temporary weakening and re-intensification cycle. Furthermore, it is shown that the relative magnitude of the land-induced asymmetry depends upon the terrain slope and the terrain height such that the land-induced asymmetry dominates over the motion-induced asymmetry for elevated terrain. These results underscore the specific differences in boundary layer evolution and intensity evolution for hurricanes interacting with complex topographical features.

Analysis of PFAAs in American alligators part 2： Potential dietary exposure of South Carolina hunters from recreationally harvested alligator meat

Exposure to perfluorinated alkyl acids（PFAAs） has been linked to many harmful health effects including reproductive disorders, developmental delays, and altered liver and kidney function. Most human exposure to environmental contaminants, including PFAAs,occurs through consumption of contaminated food or drinking water. This study uses PFAA data from meat samples collected from recreationally harvested American alligators（Alligator mississippiensis） in South Carolina to assess potential dietary exposure of hunters and their families to PFAAs. Consumption patterns were investigated using intercept surveys of 23 hunters at a wild game meat processor. An exposure scenario using the average consumption frequency, portion size, and median perfluorooctane sulfonic acid（PFOS） concentration in alligator meat from all hunt units found the daily dietary exposure to be 2.11 ng/kg body weight per day for an adult human. Dietary PFOS exposure scenarios based on location of harvest suggested the highest daily exposure occurs with alligator meat from the Middle Coastal hunt unit in South Carolina. Although no samples were found to exceed the recommended threshold for no consumption of PFOS found in Minnesota state guidelines, exposure to a mixture of PFAAs found in alligator meat and site-specific exposures based on harvest location should be considered in determining an appropriate guideline for vulnerable populations potentially exposed to PFAAs through consumption of wild alligator meat.

The new ichnotaxon Eubrontes nobitai ichnosp. nov. and other saurischian tracks from the Lower Cretaceous of Sichuan Province and a review of Chinese Eubrontes-type tracks

The Jiaguan Formation and the underlying Feitianshan Formation(Lower Cretaceous) in Sichuan Province yield multiple saurischian(theropod–sauropod) dominated ichnofaunas. To date, a moderate diversity of six theropod ichnogenera has been reported, but none of these have been identified at the ichnospecies level. Thus, many morphotypes have common "generic" labels such as Grallator, Eubrontes, cf. Eubrontes or even "EubrontesMegalosauripus" morphotype. These morphotypes are generally more typical of the Jurassic, whereas other more distinctive theropod tracks(Minisauripus and Velociraptorichnus) are restricted to the Cretaceous. The new ichnospecies Eubrontes nobitai ichnosp nov. is distinguished from Jurassic morphotypes based on a very wellpreserved trackway and represents the first-named Eubrontes ichnospecies from the Cretaceous of Asia.

The Middle-Upper Jurassic dinosaur-pterosaur fauna in Shandong Province,China:Evidence from ichnology

Tracks previously examined between 2002 and 2015 from an incompletely-studied,and now partially lost tracksite site in the Santai Formation of Shandong Province were restudied based on new ex-cavations of additional surfaces.In contrast to the previous reports of tridactyl tracks,including Grallator,the present study discovered an additional assemblage of unequivocal pterosaur tracks(Pteraichnus)and a possible didactyl deinonychosaurian track.The age of the Santai Formation is controversial but it is probably Late Jurassic,which corresponds to the epoch when pterosaur tracks appear worldwide.Age interpretations,based on palynology and isotopic data,tentatively suggests an earlier Middle-Late Jurassic age and might suggest that the pterosaurian tracks are as old or somewhat older than any previously reported.

工作记忆引起的就近效果在汉语作为第二语言加工时的体现（英文）

本实验研究了工作记忆,尤其是工作记忆中的瞬间焦点模块在汉语作为第二语言句子加工时的作用。眼动仪实验中,被试先阅读句子,然后根据句子内容回答句子后的判断题。实验通过控制句子成分的复杂性以及在句中出现的位置来比较被试对离判断题近和离判断题远的信息的理解。实验结果显示,句子成分的复杂性和离判断题的远近对工作记忆容量低的二语被试的影响比对工作记忆容量高的二语被试的影响大,说明第二语言学习者的工作记忆容量是有限的,当句子加工需要的瞬间焦点容量超过二语习得者的瞬间焦点容量时,句子理解就会相应地出现偏差。

非标准分析及其应用

本文简要介绍非标准分析基础及其在其他数学分支中的应用,特别是在组合数论中的应用.所介绍的基础包含数理逻辑常识、非标准模型构造以及非标准分析常用原理和性质.所介绍的应用包含随机微分方程强解的存在性、关于局部群的Hilbert第五问题、精确大数定律及其在经济学中的应用、组合数论中的和集现象、关于密度的Pl¨unnecke类型不等式和Freiman逆问题.

Pricing to Market: Chinese Export Pricing to the USA after the Peg

In July 2005, the Chinese Government unpegged the RMB from the US dollar. As the RMB has followed a remarkably predictable appreciation over time, I examine the price of Chinese exports to the USA after unpegging the exchange rate. Results suggest that the Chinese industries with greater import market share were able to raise their prices after the removal of the pegged exchange rate regime; however, over time there is a significant deflationary trend. Chinese export prices tended to decrease under an unanticipated RMB appreciation; this effect was more pronounced for industries with more pricing flexibility. This suggests that Chinese exporters are consistently ＂pricing to market＂ and thus creating a significant foreign exchange policy implication. Specifically, a more flexible exchange rate regime will likely have little impact on the prices of Chinese exports to the USA but might increase the profit volatility of Chinese firms.

Tailoring spin mixtures by ion-enhanced Maxwell magnetic coupling in colortunable organic electroluminescent devices

In this work,we show that the spin dynamics of excitons can be dramatically altered by Maxwell magnetic field coupling,together with an ion-enhanced,low-internal-splitting-energy organic semiconducting emitter.By employing a unique,alternating current(AC)-driven organic electroluminescent(OEL)device architecture that optimizes this magnetic field coupling,almost complete control over the singlet-to-triplet ratio(from fluorescent to phosphorescent emission in a single device)is realized.We attribute this spin population control to magnetically sensitive polaron–spin pair intersystem crossings(ISCs)that can be directly manipulated through external driving conditions.As an illustration of the utility of this approach to spin-tailoring,we demonstrate a simple hybrid(double-layer)fluorescence–phosphorescence(F–P)device using a polyfluorene-based emitter with a strong external Zeeman effect and ion-induced long carrier diffusion.Remarkable control over de-excitation pathways is achieved by controlling the device-driving frequency,resulting in complete emission blue–red color tunability.Picosecond photoluminescence(PL)spectroscopy directly confirms that this color control derives from the magnetic manipulation of the singlet-totriplet ratios.These results may pave the way to far more exotic organic devices with magnetic-field-coupled organic systems that are poised to usher in an era of dynamic spintronics at room temperature.