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Scientific modeling (SM) is a core practice of science and an important component of scientific literacy. Supporting students in developing the competence to construct, use, evaluate, and revise models is hence of particular relevance. While research has shown that spatial visualization (SV), a core component of spatial ability, is correlated with students' SM performance, it is unclear which role SV plays in students performing the four elements of SM: the construction, the use, the evaluation, and the revision of models. This study analyzes the role of SV in the performance of a series of SM tasks by 279 students in Grades 4 and 7. The findings indicate that SV affects students' performance in SM but that the effect is more significant in Grade 4 than in Grade 7. More specifically, SV is significantly predictive for model revision in Grade 4, but significant for model evaluation in Grade 7. However, there was no gender difference in the effect of SV on SM. The implications are that science teaching and learning must better attend to supporting younger students through visual aids when engaging them in SM. The study also suggests that further studies are needed to understand the different cognitive processes involved in students' SM and their complex interplay.

Introduction: The research on cancer patients returning to work in China is still in its infancy, and there is no research and discussion on the adaptability to returnto-work for cancer patients. It is critical to develop the Adaptability to Return-to-Work Scale (ARTWS) for cancer patients and evaluate its psychometric properties. Methods: The items of the initial scale were compiled based on the theoretical model and literature review results. Through two rounds of Delphi expert consultation (N = 15) and a pilot survey (N = 40), the initial scale was further checked and revised. Conduct a large sample survey (N = 376) and the construct validity and reliability of the ARTWS were assessed by confirmatory factor analysis (CFA) and exploratory factor analysis (EFA). Results: The final ARTWS consisted of 24 items. “Focusing on rehabilitation,” “Rebuilding Self-efficiency,” and “Adjusting plans” as common factors in determining adaptability to return to work for cancer patients, and the cumulative variance contribution rate for these three factors was 66.6%. The S-CVI of the total scale was 0.979. The Cronbach’s α coefficient was 0.937 and the 2-week test–retest reliability was 0.814. Discussion: ARTWS has good correlation validity and can be used as a tool to measure the adaptability of cancer patients’ return to work. The presentation of the manuscript in Research Square [ABSTRACT FROM AUTHOR]

Daphnia galeata is a common and dominant species in warmer waters, and has a strong top-down effect on both phytoplankton and bacteria. The knowledge of its temporal and spatial patterns of genetic diversity is fundamental in understanding its population dynamics and potential ecological function in ecosystems. Its population genetics have been investigated at regional scales but few within regions or at smaller spatial scales. Here, we examined the fine-scale spatial genetic variation of D. galeata within four large, deep reservoirs in wet and dry seasons and the six-year variation of genetic diversity in one of the reservoirs by using cytochrome c oxidase subunit I and microsatellites (simple sequence repeat). Our study shows that fine-scale spatial genetic variation commonly occurred within the reservoirs, indicating strong environmental selection at least in the two of reservoirs with strong longitudinal gradients. Since the environmental gradients established in the dry season was largely reduced in the wet season, the fine-scale spatial genetic variation was much higher in the dry season. The dynamics of local genetic diversity did not follow the theoretical pattern of rapid erosion but peaked in mid or mid-late growth season. The local genetic diversity of D. galeata appears to be shaped and maintained not only by recruitment from resting egg banks but also by gene flow within reservoirs. The temporal and fine-scale genetic variation within a water body suggests that it is necessary to pay attention to sampling periods and locations of a given water body in regional studies. [ABSTRACT FROM AUTHOR]

Several non-native tilapia species, including Oreochromis mossambicus (Peters, 1852), O. niloticus (Linnaeus, 1757) and their hybrids or strains, were introduced into China as major cultured species during the 1950s to 1980s. These are now among the dominant fish species in many tropical and some subtropical reservoirs. Eutrophication is assumed to accelerate their population growth. In the present study, we reported a sharp decline in the catch of stocked bighead carp (Hypophthalmichthys nobilis (Richardson, 1845)) with an extreme increase of tilapia catch in a large reservoir in southern China. In 2006, the catch of tilapia was 150 tons, which exceeded the catch of stocked bighead carp, and reached 500 tons in 2015. Longterm meteorological data over the past two decades did not show any significant change, especially in minimum air and water temperatures, which can be factors limiting tilapia growth. In contrast, water quality conditions, including total nitrogen, total phosphorus (TP), chlorophyll a, chemical oxygen demand, and trophic status, have significantly increased in the reservoir. The phytoplankton community has been mainly composed of small and filamentous species, while the total zooplankton biomass has decreased, with the community now mainly comprised of small rotifers and copepod species. The high ratio of chlorophyll a:TP indicates a weakening topdown effect of zooplankton on phytoplankton. The annual tilapia catch was significantly associated with trophic status of the reservoir, but not with meteorological and hydrological factors. We propose an ecological mechanism for increased population densities of the non-native tilapia under eutrophication, in which an increase in tilapia population size has been accompanied by a reduction in their body size, producing a stronger negative impact on zooplankton and water quality, which contributes to the turnover between bighead carp and tilapia catch. The proposed mechanism provides a useful framework for understanding the process and management of tilapia populations in tropical reservoirs. [ABSTRACT FROM AUTHOR]

Background: Although a high incidence of cardiovascular disease (CVD) is observed among chronic kidney disease (CKD) patients in developed countries, limited information is available about CVD prevalence and risk factors in the Chinese CKD population. The Chinese Cohort of Chronic Kidney Disease (C-STRIDE) was established to investigate the prevalence and risk factors of CVD among Chinese CKD patients.Methods: Participants with stage 1-4 CKD (18-74 years of age) were recruited at 39 clinical centers located in 28 cities from 22 provinces of China. At entry, the socio-demographic status, medical history, anthropometric measurements and lifestyle behaviors were documented, and blood and urine samples were collected. Estimated glomerular filtration rate (eGFR) was calculated by the CKD-EPI creatinine equation. CVD diagnosis was based on patient self-report and review of medical records by trained staff. A multivariable logistic regression model was used to estimate the association between risk factors and CVD.Results: Three thousand four hundred fifty-nine Chinese patients with pre-stage 5 CKD were enrolled, and 3168 finished all required examinations and were included in the study. In total, 40.8% of the cohort was female, with a mean age of 48.21 ± 13.70 years. The prevalence of CVD was 9.8%, and in 69.1% of the CVD cases cerebrovascular disease was observed. Multivariable analysis showed that increasing age, lower eGFR, presence of hypertension, abdominal aorta calcification and diabetes were associated with comorbid CVD among CKD patients. The odds ratios and 95% confidence intervals for these risk factors were 3.78 (2.55-5.59) for age 45-64 years and 6.07 (3.89-9.47) for age ≥65 years compared with age <45 years; 2.07 (1.28-3.34) for CKD stage 3a, 1.66 (1.00-2.62) for stage 3b, and 2.74 (1.72-4.36) for stage 4 compared with stages 1 and 2; 2.57 (1.50-4.41) for hypertension, 1.82 (1.23-2.70) for abdominal aorta calcification, and 1.70 (1.30-2.23) for diabetes, respectively.Conclusions: We reported the CVD prevalence among a CKD patient cohort and found age, hypertension, diabetes, abdominal aorta calcification and lower eGFR were independently associated with higher CVD prevalence. Prospective follow-up and longitudinal evaluations of CVD risk among CKD patients are warranted. [ABSTRACT FROM AUTHOR]

Diaphanosoma excisum is the only Cladoceran in tropical freshwaters and parapatrically occurs with Diaphanosoma dubium in the transition between the tropics and subtropics. Here, we present the complete mitochondrial genome (MG) determined by next-generation sequencing and offer a phylogenetic analysis of D. excisum. The MG of D. excisum is 17,615bp in size, including 13 protein-coding genes (PCGs), 2 ribosomal RNA, 23 tRNA, and 2 putative control regions. The MG has a biased AþT of 65.34% for base composition. Compared to D. dubium, the MG of D. excisum has one more tRNA-Met, one unknown extra putative control region and is different in the arrangement of its tRNAs. The MG sequence and tRNA order provide valuable molecular data for understanding the phylogeny and speciation of Diaphanosoma. [ABSTRACT FROM AUTHOR]

In 1964 and 1965, Shen & Tai described two species of calanoids, which they classified in the South American genus Argyrodiaptomus. We examined new material from the terra typica, South China, and show that both species belong in the Asian genus Sinodiaptomus. A biogeographic anomaly is thus corrected. Moreover, the two appear to be sister species and males are morphologically well separable. No intermediate morphotypes have so far been detected. S. cavernicolax (Shen & Tai, 1965), known only from the type locality, was claimed to be cavernicolous, but shows no stygobitic adaptations, and has eyes. It may have been pushed back into the cave environment by its congener S. ferus (Shen & Tai, 1964) with which it coexists in the same lake system. So far, four species of Sinodiaptomus have been found in China: the two mentioned above, i.e., S. cavernicolax only in Longyan Cave of Zhaoqing City, and S. ferus at about five locations, but its range is limited to a small part of Guangdong Province. All five other species of Sinodiaptomus, among which the other two that occur (also) in China, also occupy small to very small ranges, with the type species (S. chaffanjoni Richard, 1897) only living in North China, and S. indicus Kiefer, 1936 and S. mahanandiensis Reddy & Radhakrishna, 1980 confined to South India (Reddy & Radhakrishna, 1980). S. valkanovi Kiefer, 1938 from Japan is invasive (Ueda & Ohtsuka, 1998; Makino et al., 2010). 5. sarsi Rylov, 1923, distributed in Japan, China, and most of Mongolia, is separated by a wide disjunction from a group of populations in Iran, the Caucasus, and East Anatolia. This western group of populations might be a separate species and deserves more study. [ABSTRACT FROM AUTHOR]

Following a reduction in fish populations in 2004-2005, a new, single annual pulse of pelagic flatworms was observed in early summer during 2006-2009 in Liuxihe, a freshwater reservoir in South China. As soon as these worms appear, Daphnia galeata retreats into dormancy, one month earlier (July) in the presence of flatworms than previously observed (August) with fish, while the population of the related Ceriodaphnia quadrangula tends to increase. We show, through in situ lake sampling, in large enclosures and by laboratory observations, that Ceriodaphnia, although perhaps competitively inferior in its ability to acquire algal food, has a higher tolerance to flatworm toxins. As a result, Ceriodaphnia manages to coexist with and proliferate in the presence of the flatworm. Observations in the laboratory suggest that flatworm population autoregulates by being sensitive to their own toxins and that Ceriodaphnia, even if prey to the worms, likely incurs more benefit than cost from their presence. [ABSTRACT FROM AUTHOR]

The Bumo gold deposit is a low-sulfide quartz vein type deposit, situated in the west of Hainan Island, approximately 25 km southeast of Dongfang City (termed Basuo in alias). Tectonically, the SW-NE-oriented Gezhen Ductile-Shearing Zone was largely attenuated in Bumo. It is hosted by gneisses and schists of Proterozoic age (locally called the Baoban Group), but the radiometric age of ores mainly is Jurassic–Cretaceous, being coeval to the regional metallogenesis along the Eurasian margin. The affinity with the Phanerozoic orogenic gold deposits is indicated by low salinity (2.4 wt% NaCl–10.3 wt% NaCl), intermediate temperature (150–300°C) and appropriate δ18O value (approximately 7–11‰). The gold metal tonnage, proved previously, within an area smaller than 1.0 km2 in the gold belt II amounted to 11.59 t, with the average gold grades for the major Au quartz veins (7 and 8) in this belt of 52.7 and 71.1 g/t, respectively. This shows significant enrichment of gold and an unusual “nugget effect”. A ring structure, mainly represented by ridges, valleys, dikes, big bull quartz veins and lithological borders or pertinent faults, marks the gold field, and its origin was linked to a possible magmatic diapir. It was viewed as macroscopic evidence that the dip angles of strata tend to decline gradually from deeper ones in the center area to nearly horizontal in the outskirts, and certain intrusion-affiliated elements such as Bi, As and W are considerably abundant in soil samples. Two areas, namely the area A (3.06 km2) in the outskirts of the ring structure or in northeastern Bumo and the area B (1.32 km2) in the field center or to the west of the gold belts I and II, were selected for the geochemical survey in a 50 × 50-m sampling grid. The analytical results of the samples from horizon C and in a −80 mesh size showed that the average contents of Bi, As and W amounted to 0.55, 19.3 and 3.67 ppm in the area A (1225 samples) and to 0.79, 68.3 and 4.14 ppm in the area B (529 samples), respectively. This geochemical exploration led to the discovery of several Au quartz veins in both areas A and B, which also manifested an Au nugget effect (the average Au grades between 50 and 100 g/t) in spite of their limited scales (from a couple of centimeters to 50 cm wide and from several meters to 15 m long). A mylonite zone in area A was also found by this study. An intimate spatial correlation between a lithological border (gneiss and schist or pegmatite) or the mylonite zone and Au anomalies indicates an important prospect for further gold exploration. [ABSTRACT FROM AUTHOR]

Objective: Little is known about Child Sexual Abuse (CSA) in Chinese societies. This study examined CSA experiences and associations with demographic factors, self-reported health and risky behaviors among senior high school students in four provinces in central and northern China. Method: Students in four schools in Hubei, Henan, Hebei, and Beijing provinces participated in an anonymous, self-completed questionnaire survey. From a total enrolment of 3,261 students in the target classes in years 11 and 12. 2,300 (70.5%) returned valid questionnaires. Mean age was 17.2 years. The questionnaire was adapted from prior CSA research in Australia and utilized standard scales for depression, self-esteem, and youth risk behavior. Results: Prevalence of any unwanted sexual experience before the age of 16 years was higher among females (16.7%) than males (10.5%). Sexual penetration was rarely reported (1%), while 7% reported at least one type of physical contact abuse (female 8.9%, male 5.0%). Risk of any CSA was not associated with the existence of siblings (one-child vs. two- or more child families), rural/urban residence during childhood, or parental education. Males and females with CSA were more depressed and suicidal, and drank alcohol more often, than unaffected adolescents. Contact CSA was strongly associated with sexual intercourse (ever) for both males and females. Females with CSA were more likely than others to engage in anorexic and bulimic behaviors, while males with CSA were often involved in violence. Conclusion: Social norms for consensual sexual experiences differ between Eastern and Western societies. CSA experiences also differ, with substantially less penetrative and physical contact abuse in China. However, the psychological and behavioral profile of abused, young Chinese people, including the additional burden associated with contact abuse, is similar to that found in other cultures. [ABSTRACT FROM AUTHOR]