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Grounding our research in social exchange theory and the conservation of resources perspective, we hypothesized a model that examines the effects of servant leadership (SL) on employees' workplace thriving via agentic work behaviors. To clarify the effects, employee core self-evaluations (CSEs) were investigated to determine boundary conditions on the relationship between SL and thriving. Data were collected at three points in time from 260 professionals across diverse functional backgrounds and industries. The analysis results confirmed an indirect effect from SL to workplace thriving via agentic work behaviors. Importantly, the moderation results demonstrated that the relationship between SL and workplace thriving is stronger when individuals have high CSEs. Implications for theory and practice are discussed.
Previous studies documented a “gender citation gap” in political science whereby women are less likely to be cited in published research and course syllabi, especially by male scholars. However, no previous study examined citation patterns among students in political science courses to determine if similar patterns are evident in their research. This article analyzes an original database of individual as well as group research assignments from an undergraduate research methods course. Our analysis indicates that male students are significantly less likely than female students to cite research published by women—whether as first authors, any of the authors, or the average percentage of authors per team. However, in a subsequent group research assignment, gender diversity had no discernible effect on group citation patterns. We discuss the implications of these findings for current pedagogical practices and the future state of the discipline.
The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines recommend Royal Free Hospital-Nutritional Prioritizing Tool (RFH-NPT) to identify malnutrition risk in patients with liver disease. However, little is known about the application of RFH-NPT to screen for the risk of malnutrition in China, where patients primarily suffer from hepatitis virus-related cirrhosis. A total of 155 cirrhosis patients without liver cancer or uncontrolled comorbid illness were enrolled in this prospective study. We administered the Nutritional Risk Screening 2002 (NRS-2002), RFH-NPT, Malnutrition Universal Screening Tool(MUST), and Liver Disease Undernutrition Screening Tool (LDUST) to the patients within 24 h after admission and performed follow-up observations for 1.5 years. The RFH-NPT and NRS-2002 had higher sensitivities (64.8% and 52.4%) and specificities (60% and 70%) than the other tools with regard to screening for the malnutrition risk in cirrhotic patients. The prevalence of nutritional risk was higher under the use of RFH-NPT against the NRS-2002(63% vs. 51%). RFH-NPT tended more easily to detect the malnutrition risk in patients with advanced Child-Pugh classes (B and C) and lower MELD scores (<15) compared with NRS-2002. The RFH-NPT score was an independent predictive factor for mortality. Patients identified as being at high malnutrition risk with the RFH-NPT had a higher mortality rate than those at a low risk; the same result was not obtained with the NRS-2002. Therefore, we suggest that using RFH-NPT improves the ability of clinicians to predict malnutrition risk in patients with cirrhosis primarily caused by hepatitis virus infection at an earlier stage.
Excessive gestational weight gain (GWG) increases the risk of maternal anemia during pregnancy, but whether it is associated with offspring anemia has not been investigated. We aimed to prospectively investigate the association of GWG rate in the second/third trimester with infant hemoglobin concentration and anemia risk. This study comprised 13 765 infants born during 2006–2009 to mothers who participated in a trial on prenatal micronutrient supplementation. The GWG was calculated by subtracting the maternal weight at enrollment from the end-pregnancy. The GWG rate was calculated as dividing the GWG by number of weeks between the two measurements, and classified into quintiles within each category of maternal body mass index. Infant hemoglobin concentrations were measured at 6 and 12 months of age, and anemia was defined as a hemoglobin concentration<11.0 g/dL. Of the 13 765 infants, 949 (6.9%) were anemic at 6 months and 728 (5.3%) at 12 months. The GWG rate was inversely and linearly associated with the infant hemoglobin concentrations at both 6 and 12 months (P<0.001 for linearity). Compared with the middle quintile of GWG rate, the highest quintile was associated with an increased risk of anemia at 6 months (adjusted odds ratio [OR] 1.30, 95% confidence interval [CI] 1.07, 1.59) and 12 months (adjusted OR 1.74, 95% CI 1.40, 2.17). The associations were consistently mediated by maternal anemia during pregnancy (P<0.001). In conclusion, excessive GWG rate appears to be associated with an increased risk of infant anemia, partly independent of maternal anemia during pregnancy that mediates the association.
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.
Guanidinoacetic acid (GAA) can improve the growth performance of bulls. This study investigated the influences of GAA addition on growth, nutrient digestion, ruminal fermentation and serum metabolites in bulls. Forty-eight Angus bulls were randomly allocated to experimental treatments, that is, control, low-GAA (LGAA), medium-GAA (MGAA) and high-GAA (HGAA), with GAA supplementation at 0, 0.3, 0.6 and 0.9 g/kg DM, respectively. Bulls were fed a basal diet containing 500 g/kg DM concentrate and 500 g/kg DM roughage. The experimental period was 104 days, with 14 days for adaptation and 90 days for data collection. Bulls in the MGAA and HGAA groups had higher DM intake and average daily gain than bulls in the LGAA and control groups. The feed conversion ratio was lowest in MGAA and highest in the control. Bulls receiving 0.9 g/kg DM GAA addition had higher digestibility of DM, organic matter, NDF and ADF than bulls in other groups. The digestibility of CP was higher for HGAA than for LGAA and control. The ruminal pH was lower for MGAA, and the total volatile fatty acid concentration was greater for MGAA and HGAA than for the control. The acetate proportion and acetate-to-propionate ratio were lower for MGAA than for LGAA and control. The propionate proportion was higher for MGAA than for control. Bulls receiving GAA addition showed decreased ruminal ammonia N. Bulls in MGAA and HGAA had higher cellobiase, pectinase and protease activities and Butyrivibrio fibrisolvens, Prevotella ruminicola and Ruminobacter amylophilus populations than bulls in LGAA and control. However, the total protozoan population was lower for MGAA and HGAA than for LGAA and control. The total bacterial and Ruminococcus flavefaciens populations increased with GAA addition. The blood level of creatine was higher for HGAA, and the activity of l-arginine glycine amidine transferase was lower for MGAA and HGAA, than for control. The blood activity of guanidine acetate N-methyltransferase and the level of folate decreased in the GAA addition groups. The results indicated that dietary addition of 0.6 or 0.9 g/kg DM GAA improved growth performance, nutrient digestion and ruminal fermentation in bulls.
Data on average iodine requirements for the Chinese population are limited following implementation of long-term universal salt iodization. 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 days, 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 feces 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 RNI (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.
The common view time transfer and two-way time and frequency transfer methods are currently the main means for achieving time synchronisation at nanosecond level. However, these methods have some limitations in real time and cost, which limit their wide applications in many fields, such as time synchronisation among base stations of the upcoming 5G network. In order to meet the requirements of nanosecond time synchronisation, a low-cost differential timing method is proposed in this paper by changing the manner of generation of traceability model parameters in GNSS navigation messages. The time deviation between GNSS system time and the timing laboratory that maintains Coordinated Universal Time (UTC) kept by timing laboratory named k (UTC(k)) is monitored by receiving the GNSS signal in space with monitoring receivers. The new traceability model parameters are generated with the monitored time deviations and then broadcast to users through the GNSS navigation message. The precision of the one-way timing method can be improved from tens of nanoseconds to the order of several nanoseconds with the proposed method. In addition, there are obvious advantages to carry out this method on the geostationary satellites in the BeiDou navigation satellite (BDS) constellation. The proposed method is verified on an experimental platform based on the UTC(NTSC) time frequency signal and the geostationary satellites in the BDS-3 constellation.
An autonomous motion planning framework is proposed, consisting of path planning and trajectory generation. Primarily, a spacious preferred probabilistic roadmap algorithm is utilized to search a safe and short path, considering kinematics and threats from obstacles. Subsequently, a minimum-snap and position-clearance polynomial trajectory problem is transformed into an unconstrained quadratic programming and solved in a two-step optimization. Finally, comparisons with other methods based on statistical simulations are implemented. The results show that the proposed method achieves computational efficiency and a safe trajectory.
In the present study, the effect of Al addition on microstructure evolution, mechanical properties, and wear performances of a newly developed Ni–Si-containing complex brass was studied. The results showed that with increasing Al content from 0 to 3 wt%, the corresponding strengthening phase evolves from δ-Ni2Si to [Ni(Al)]2Si phases. Simultaneously, it is of great interest that the increasing Al addition also brings about a remarkable change in morphology of the secondary strengthening phase from dendrite and thin rod to regular block. Additionally, the hardness, yield strength and tensile strength of complex brass effectively increase with increasing Al content, and the fracture mechanism transforms from cleavage failure and microvoids accumulation fracture to cleavage failure. It was also found that the brass with adding 3 wt% Al exhibits the solidification microstructure with the uniform distribution of the block-shaped strengthening phase and has the best wear resistance. This present study provides a potential strategy for further improving the comprehensive performance of existing complex brass.
As for the efficient dye-sensitized solar cells (DSSCs), one of the important goals is to increase the light harvesting efficiency to further improve the photoelectric conversion efficiency (PCE). The excellent photoanode materials should possess a uniform porous structure, a large surface area, high crystallinity, and good stability. Herein, the porous TiO2 electrode (named as S-1.5) with the above merits had been prepared by the simple template-assisted method with camphene as the pore-forming reagent. The surface area of the porous TiO2 electrode can be tailored by introducing the amount of camphene. The porous TiO2 layer with the optimal surface area directly adhered on the top of the ultra-thin P25 dense layer had been constructed and this unique electrode with a “double layers structure”, which named as S-1.5/P25. When DSSCs assembled with this photoanode, a desirable PCE of 8.31% had been achieved, which was obviously higher than that of the commercial P25 (7.62%) in parallel. The improved PCE can be attributed to the improved utilization of sunlight, the facilitated photo-generated electron transfer, and the reduced interface resistance. Meanwhile, the related characterization including electrochemical impedance spectroscopy, intensity-modulated photovoltage spectroscopy, and intensity-modulated photocurrent spectroscopy was characterized to explore the possible mechanism.
The Wulian complex is located on the northern margin of the Sulu orogenic belt, and was formed by collision between the North China Craton (NCC) to the north and South China Craton (SCC) to the south. It consists of the metasedimentary Wulian Group, gneissic granite and meta-diorite. The U–Pb analyses for the detrital zircons from the Wulian Group exhibit one predominant age population of 2600–2400 Ma with a peak at c. 2.5 Ga and several secondary age populations of > 3000, 3000–2800, 2800–2600, 2200–2000, 1900–1800, 1500–1300 and 1250–950 Ma; some metamorphic zircons have metamorphic ages of c. 2.7, 2.55–2.45, 2.1–2.0 and 1.95–1.80 Ga, which are consistent with magmatic-metamorphic events in the SCC. Additionally, the Wulian Group was intruded by the gneissic granite and meta-diorite at c. 0.76 Ga, attributed to Neoproterozoic syn-rifting bimodal magmatic activity in the SCC and derived from partial melting of Archaean continental crust and depleted mantle, respectively. The Wulian Group therefore has tectonic affinity to the SCC and was mainly sourced from the SCC. The detrital zircons have positive and negative ϵHf(t) values, indicating that their source rocks were derived from reworking of both ancient and juvenile crustal rocks. The major early Precambrian crustal growth took place during c. 3.4–2.5 Ga with a dominant peak at 2.96 Ga and several secondary peaks at 3.27, 2.74 and 2.52 Ga. The two oldest zircons with ages of 3307 and 3347 Ma record the recycling of ancient continental crust (> 3.35 Ga) and crustal growth prior to c. 3.95 Ga in the SCC.
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.