Analyzing wearable device data using marked point processes

This paper introduces two sets of measures as exploratory tools to study physical activity patterns: active‐to‐sedentary/sedentary‐to‐active rate function (ASRF/SARF) and active/sedentary rate function (ARF/SRF). These two sets of measures are complementary to each other and can be effectively used together to understand physical activity patterns. The specific features are illustrated by an analysis of wearable device data from National Health and Nutrition Examination Survey (NHANES). A two‐level semiparametric regression model for ARF and the associated activity magnitude is developed under a unified framework using the marked point process formulation. The inactive and active states measured by accelerometers are treated as a 0‐1 point process, and the activity magnitude measured at each active state is defined as a marked variable. The commonly encountered missing data problem due to device nonwear is referred to as “window censoring,” which is handled by a proper estimation approach that adopts techniques from recurrent event data. Large sample properties of the estimator and comparison between two regression models as measurement frequency increases are studied. Simulation and NHANES data analysis results are presented. The statistical inference and analysis results suggest that ASRF/SARF and ARF/SRF provide useful analytical tools to practitioners for future research on wearable device data.     

Immigration history of amphidromous species on a Greater Antillean island

Aim To use molecular data to test for dispersal structuring in the immigration history of an amphidromous community on an island. Location The Caribbean island of Puerto Rico. Methods Mitochondrial DNA sequences were obtained from 11 amphidromous species, including shrimps, fish and a gastropod, sampled from throughout the island. The timing of population expansion (T_E) in each species was calculated using nucleotide variation and molecular clock dating methods. The order of species accumulation was then reconstructed (oldest to most recent estimate for T_E), and groups of species with non‐overlapping estimates for T_E were identified. The temporal span and average immigration rate for each group were calculated and compared with expectations of two previously published models of island immigration [the ‘dispersal‐structured model of island recolonization’ ( Whittaker & Jones, Oikos, 1994 , 69 , 524–529), which predicts short phases of rapid immigration followed by extended phases with relatively slow immigration rates; and the ‘colonization window hypothesis’ ( Carine, Taxon, 2005 , 54 , 895–903), which suggests that opportunities for island colonization are temporally constrained to discrete waves of colonization]. Results The molecular data indicated the immigration history of Puerto Rican amphidromous fauna from the late Pleistocene through the Holocene and identified two groups of species with non‐overlapping estimates for T_E and one group that overlapped with the other two groups. The temporal span, average immigration rate and lack of discreteness between all three groups indicated a continuum of immigration rather than distinct phases of species arrivals. Main conclusions This study did not support the expectations of the immigration models and suggested that amphidromous species from Puerto Rico comprise a single class of marine‐based dispersers. The immigration sequence we report probably reflects a recolonization chronology in this community, in keeping with the notion of species turnover through time. Four areas of future research into the immigration history of amphidromous species on islands are identified, and indicated the possibility that equilibrium processes govern long‐term community change in amphidromous biota on islands.     

Tree line shifts in the Swiss Alps: Climate change or land abandonment?

Questions: Did the forest area in the Swiss Alps increase between 1985 and 1997? Does the forest expansion near the tree line represent an invasion into abandoned grasslands (ingrowth) or a true upward shift of the local tree line? What land cover / land use classes did primarily regenerate to forest, and what forest structural types did primarily regenerate? And, what are possible drivers of forest regeneration in the tree line ecotone, climate and/or land use change? Location: Swiss Alps. Methods: Forest expansion was quantified using data from the repeated Swiss land use statistics GEOSTAT. A moving window algorithm was developed to distinguish between forest ingrowth and upward shift. To test a possible climate change influence, the resulting upward shifts were compared to a potential regional tree line. Results: A significant increase of forest cover was found between 1650 m and 2450 m. Above 1650 m, 10% of the new forest areas were identified as true upward shifts whereas 90% represented ingrowth, and we identified both land use and climate change as likely drivers. Most upward shift activities were found to occur within a band of 300 m below the potential regional tree line, indicating land use as the most likely driver. Only 4% of the upward shifts were identified to rise above the potential regional tree line, thus indicating climate change. Conclusions: Land abandonment was the most dominant driver for the establishment of new forest areas, even at the tree line ecotone. However, a small fraction of upwards shift can be attributed to the recent climate warming, a fraction that is likely to increase further if climate continues to warm, and with a longer time‐span between warming and measurement of forest cover.     

人参总皂苷治疗创伤性脑损伤有效剂量和时间窗的研究

目的:探讨人参总皂苷(GTS)治疗大鼠创伤性脑损伤(TBI)的有效剂量和有效时间窗。方法:采用改良Feeney法制备TBI后,腹腔注射GTS,对伤后大鼠神经功能和伤侧脑组织形态学进行观察。结果:TBI后6 h开始治疗,GTS不同剂量干预,神经行为学与组织学结果显示:伤后2~14 d,(10,20,40,60,80 mg/kg)GTS组与TBI组比较,差异具有统计学意义(P<0.05),其中(20,40,60 mg/kg)GTS的治疗效果更显著,能明显改善神经行为,减少海马部位神经细胞的丢失。在有效时间窗研究中,采用GTS 20 mg/kg,于TBI后3 h、6 h时间点开始治疗,GTS组效果明显,与TBI组比较,差异有统计学意义,TBI后12 h、24 h开始治疗,无明显效果。结论:TBI后给予GTS治疗,可减轻脑组织损伤,促进神经功能恢复,在10~80 mg/kg剂量范围均有一定疗效,最佳剂量范围为20~60 mg/kg;GTS有效时间窗为伤后6 h。     

小骨窗微创手术治疗高血压脑出血患者的疗效

目的:分析小骨窗微创手术在高血压脑出血患者的临床效果。方法:选取我院收治的高血压脑出血患者200例,按照治疗方式的不同分为观察组100例,对照组100例,观察组采用小骨窗微创手术治疗,对照组采用传统开颅手术治疗,对两组疗效及预后进行对比。结果:两组患者的术后残留血肿量较术前明显减少,差异有统计学意义(P0.05),观察组术后残留血肿量(10.3±2.8)m L,对照组术后残留血肿量(11.1±3.0)m L,两组之间术后血肿残留量比较,差异无统计学意义(P0.05)。观察组手术时间(92.8±15.5)分钟,对照组手术时间(125.4±16.1)分钟,观察组手术时间明显短于对照组,差异有统计学意义(P0.05)。观察组住院时间(15.8±5.2)天,对照组住院时间(24.1±5.8)天,观察组住院时间明显短于对照组,差异有统计学意义(P0.05)。再出血率比较:观察组治疗后再出血率3.0%,对照组治疗后再出血率8.0%,观察组出血率明显低于对照组,差异有统计学意义(P0.05)。NDS及ADL比较:两组治疗后NDS及ADL均优于治疗前,差异有统计学意义(P0.05)。观察组NDS及ADL均显著优于对照组,差异有统计学意义(P0.05)。GCS比较:两组评分差异无统计学意义(P0.05)。结论:小骨窗微创手术可以改善患者的预后,可显著提高高血压脑出血治疗效果。     

The energy-environment efficiency of road and railway sectors in China: Evidence from the provincial level

The transportation sector, particularly the road and the railway sectors, is an important source of CO₂ emissions in China. This study combines the non-radial data envelopment analysis (DEA) model with window analysis to measure the energy-environment efficiency of the road and railway sectors of 30 provinces in China, then uses the Tobit regression model to analyze the factors affecting the energy-environment efficiency. The findings suggest that, first of all, although these two sectors are both with high energy-environment efficiency, there is a higher probability for railway sector to improve its energy-environment efficiency than that of road sector, with the average energy-environment efficiency 0.9307 and 0.9815, respectively. Second, the road sector in eastern China with the highest average energy-environment efficiency, lower in the western region, and lowest in the central region. As for the railway sector, the western region has the highest average energy-environment efficiency, followed by the central and the eastern regions. Third, the relationship between energy-environment efficiency and income level in the road and railway sectors follow the U-shaped and inverted U-shaped curves, respectively.     

Confidence Limits on Heritability Under Non-normal Variations

Moment approximation for the non-normal sampling distribution of the ratio of mean squares in the balanced one-way Model II is found close to that of the Snedecor's F-distribution. The confidence limits for heritability of paternal half-sib correlations, derived employing F-distribution, are, in general, remarkably narrow for platykurtic and wide for leptokurtic sire effects than the normal limits. The effect of kurtosis of environmental deviations on these limits is of no consequence whereas the effect of skewness is invisible.