Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-10-09 Cooperative journals: 《心理学报》
Abstract： Given the high prevalence and its extensive possible adverse outcomes, a large number of theoretical and longitudinal studies have explored the development of social anxiety, but the research findings are inconsistent or even contradictory in preschool childhood, late childhood, and adolescence. In addition, there is still debate between trait theory and state theory of social anxiety, and there is also a lack of study on the age trend of social anxiety stability.To clarify the above controversies and accurately characterize the age trend of the mean level and the stability of social anxiety, this study conducted a meta-analysis of longitudinal studies involving social anxiety. After pre-registering the study protocol on PROSPERO, we searched literature in six databases (CNKI, Wanfang Data, Web of Science, ProQuest, PubMed, and EBOSCO). In addition, we also backtracked the references cited in previous meta-analyses and reviews. Ultimately, a total of 192 independent samples (N = 170, 192) from 173 longitudinal studies were included in the current meta-analysis. In order to quantify the trajectory of social anxiety more precisely, we divided the sample into 11 age groups according to the mean age of the sample between two adjacent measurement waves, and estimated the mean-level change and stability for each age group. The standardized mean difference (d) between two adjacent waves is used to estimate mean-level change, whereas the correlation coefficient (r) is used to estimate stability. Science most of the included studies reported multiple effect sizes, and these multiple effect sizes were most likely dependent, which violated the basic assumption of independent effect sizes in the conventional meta-analytic methods. We applied the three-level meta-analysis approach to handle such data-independency among effect sizes.Results showed that: (1) The mean level of social anxiety showed a gradual decline from toddlerhood to young adulthood, with only slight increase in mid-adolescence. (2) In terms of rank-order stability, social anxiety rose slowly from toddlerhood to preschool childhood, then swiftly dropped to a low point in elementary childhood, recovered gradually after mid-adolescence, and stabilized at a high level in young adulthood. (3) The mean-level change of social anxiety was not affected by the study characteristics, the sample characteristics, and the variable characteristics. (4) The rank-order stability of social anxiety was moderated by written language, continent, culture, gender, and assessment mode. (5) The stability of social anxiety was a logarithmic function with time lag. Specifically, with the increase of time lag, the stability declined first quickly and then slowly, and almost reached a plateau after 6 years. (6) The results of moderator test for publication status, Egger's test, and Begg's test indicated the absence of publication bias in this meta-analysis.This study makes a valuable contribution in characterizing the age-specific trends and stability of social anxiety from toddler to young adult by using the meta-analytic method. We conclude from this study that, in terms of mean level, the trajectory of social anxiety generally supports the personality maturation hypothesis. For stability, similar to personality traits, social anxiety tend to be a trait rather than a state construct. Overall, this study provides a new perspective for exploring the lifelong development of social anxiety.
Subjects: Psychology >> Developmental Psychology submitted time 2023-04-11
Abstract： Given the high prevalence rate and its extensive possible adverse outcomes, a large number of theoretical and longitudinal studies have explored the development of social anxiety, but the research findings are inconsistent or even contradictory in preschool childhood, late childhood, and adolescence. In addition, there is still debate between trait theory and state theory of social anxiety, and there is also a lack of study on the age trend of social anxiety stability.
To clarify the above controversies and accurately characterize the age trend of the mean level and the stability of social anxiety, this study conducted a meta-analysis of longitudinal studies involving social anxiety. After pre-registering the study protocol on PROSPERO, we searched literature in six databases (CNKI, Wanfang Data, Web of Science, ProQuest, PubMed, andEBOSCO). In addition, we also backtracked the references cited in previous meta-analyses and reviews. Ultimately, a total of 192 independent samples (N = 170,192) from 173 longitudinal studies were included in the current meta-analysis. In order to quantify the trajectory of social anxiety more precisely, we divided the sample into 11 age groups according to the mean age of the sample between two adjacent measurement waves, and estimated the mean-level change and stability for each age group. The standardized mean difference (d) between two adjacent waves is used to estimate mean-level change, whereas the correlation coefficient (r) is used to estimate stability. Science most of the included studies reported multiple effect sizes, and these multiple effect sizes were most likely dependent, which violated the basic assumption of independent effect sizes in the conventional meta-analytic methods. We applied the three-level meta-analysis approach to handle such data-independency among effect sizes.
Results showed that: (1) The mean level of social anxiety showed a gradual decline from toddlerhood to early adulthood, with only slight increase in mid-adolescence. (2) In terms of rank-order stability, social anxiety rose slowly from toddlerhood to preschool childhood, then swiftly dropped to a low point in elementary childhood, recovered gradually after mid-adolescence, and stabilized at a high level in young adulthood. (3) The mean-level change of social anxiety was not affected by the study characteristics, the participant characteristics, and the variable characteristics. (4) The rank-order stability of social anxiety was moderated by written language, continent, culture, gender, and assessment mode. (5) The stability of social anxiety was a logarithmic function with time lag. Specifically, with the increase of time lag, the stability declined first quickly and then slowly, and almost reached a plateau after 6 years. (6) The results of moderator test for publication status, Egger's test, and Begg's test indicated the absence of publication bias in this meta-analysis.
This study makes a valuable contribution in characterizing the age-specific trends and stability of social anxiety from toddler to young adult by using the meta-analytic method. We conclude from this study that, in terms of mean level, the trajectory of social anxiety generally supports the personality maturation hypothesis. For stability, similar to personality traits, social anxiety tend to be a trait rather than a state construct. Overall, this study provides a new perspective for exploring the lifelong development of social anxiety.
Subjects: Biology >> Zoology submitted time 2018-12-25 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮代谢能（ME）水平对产蛋高峰期笼养蛋鸭产蛋性能、蛋品质和血清生化指标的影响。选择250只体重相近且健康的29周龄临武鸭，随机分为5个组，每组5个重复，每个重复10只鸭。采用单因子试验设计，设5个饲粮ME水平：10.09、10.59、11.09、11.59和12.09 MJ/kg，饲粮粗蛋白质水平均为18%。预试期为7 d，正试期为63 d。结果表明：1）随饲粮ME水平升高，平均日采食量呈显著线性降低（P0.05）。3）随饲粮ME水平增加，血清胆固醇和低密度脂蛋白含量呈显著线性提高（P<0.05），而血清尿素氮含量呈显著线性降低（P<0.05）。饲粮ME水平12.09 MJ/kg组血清葡萄糖含量显著高于饲粮ME水平10.09 MJ/kg组（P<0.05）。回归分析显示，以高产蛋率、高日产蛋重和低料蛋比为衡量指标，推荐29~38周龄临武鸭饲粮ME水平为10.73~11.29 MJ/kg。
Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究临武鸭对几种糟渣类原料（白酒糟、啤酒糟、2种酱油渣、灵芝菌糠、柑橘渣和甘蔗糖渣）的养分利用率和代谢能，及添加复合酶制剂（蛋白酶、纤维素酶和木聚糖酶）对几种糟渣类原料养分利用率和代谢能的影响。试验选用48只体重2.0 kg左右的健康成年临武鸭公鸭，随机分为8组，每组6个重复，每重复1只鸭。采用绝食强饲-全收粪法进行代谢试验，将待测原料与无氮饲粮按1:2的重量比混合配成试验原料，每种原料均设对照组和添加复合酶制剂组（试验原料中添加250 mg/kg的复合酶制剂），对照组和添加复合酶制剂组的试验分2个批次进行，测定添加复合酶制剂对临武鸭几种糟渣类原料养分利用率和代谢能。结果表明：临武鸭对几种糟渣类原料的干物质（DM）、粗蛋白质（CP）、粗脂肪（EE）和粗纤维（CF）表观利用率分别为30.73%~51.08%、17.65%~75.62%、10.85%~91.19%和10.84%~67.05%，表观代谢能（AME）和真代谢能（TME）分别为4.58~15.20 MJ/kg和5.57~17.17 MJ/kg。添加复合酶制剂后临武鸭对几种糟渣类原料的DM、CP、EE和CF的有效营养改进值（ENIV）分别为6.46~41.37 g/kg、0.33~13.23 g/kg、0.09~9.73 g/kg和0.70~7.84 g/kg，TME提高了0.13~1.68 MJ/kg。由此可见，添加复合酶制剂能够一定程度地提高临武鸭对糟渣类原料的养分利用率和代谢能。
Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究临武鸭对添加复合酶棕榈粕(PKM)和椰子粕（CM）的养分、氨基酸和能量的利用率。试验选用40只体重（2.0±0.2） kg的健康成年临武鸭公鸭，随机分为5组，每组8个重复，每个重复1只试验鸭。试验鸭进行强饲代谢试验，1、2组试验鸭每只强饲50 g/d棕榈粕，3、4组试验鸭每只强饲50 g/d椰子粕，5组试验鸭强饲50 g/d无氮饲粮。在2、4组原料均添加250 mg/kg复合酶。预试期7 d，正试期4 d。结果表明：1）临武鸭对棕榈粕中干物质（DM）、粗蛋白质（CP）、粗脂肪（EE）、粗纤维（CF）和总能（GE）的真利用率分别为48.81%、54.34%、65.69%、40.36%和39.37%，表观代谢能（AME）和真代谢能（TME）分别为6.18和7.49 MJ/kg，15种氨基酸的真利用率在50.28%~87.97%之间；临武鸭对椰子粕中DM、CP、EE、CF和GE的真利用率分别为52.23%、58.49%、70.28%、34.67%和54.76%，AME和TME分别为7.47和9.64 MJ/kg，15种氨基酸的真利用率在58.53%~90.21%之间。2）添加复合酶后棕榈粕和椰子粕的CP表观利用率和真利用率均显著提高（P＜0.05)，TME分别提高了5.61%和3.63%（P＞0.05)，15种氨基酸的真利用率分别提高了0.27%~7.36%和0.67%~4.99%，棕榈粕中酪氨酸、脯氨酸及椰子粕中天冬氨酸、异亮氨酸、酪氨酸的真利用率均提高显著（P＜0.05)。由此可见，添加含有蛋白酶、纤维素酶和木聚糖酶的复合酶能够提高临武鸭对棕榈粕和椰子粕中养分和能量的利用率。
Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中添加姜黄渣对蛋鸡生产性能、蛋品质及蛋黄中脂肪、胆固醇和丙二醛（MDA）含量的影响。试验选用46周龄健康产蛋期罗曼褐蛋鸡384羽，随机分成4个组，每组6个重复，每个重复16只鸡。对照组饲喂基础饲粮，试验组饲喂在基础饲粮中分别添加0.5%、1.0%和1.5%姜黄渣的试验饲粮。预试期7 d，试验期56 d。结果表明：与对照组相比，饲粮中添加姜黄渣对蛋鸡的平均日采食量、产蛋率、平均蛋重、料蛋比和死淘率均无显著影响（P＞0.05），饲粮中添加1.5%的姜黄渣能够显著提高蛋鸡的合格蛋率（P＜0.05），显著降低软破蛋率和次品蛋率（P＜0.05），饲粮中添加姜黄渣对蛋鸡的蛋品质无显著影响（P＞0.05），饲粮中添加0.5%、1.0%和1.5%的姜黄渣能够显著降低蛋鸡蛋黄中胆固醇和丙二醛含量（P<0.05）。由此可知，饲粮中添加姜黄渣能够提高蛋鸡的合格蛋率，降低次品蛋率和软破蛋率，降低蛋黄中胆固醇和丙二醛含量。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮赖氨酸水平对产蛋高峰期（30~38周龄）临武鸭生产性能、蛋品质、血清生化指标及氮代谢的影响，以确定产蛋高峰期临武鸭赖氨酸需要量。试验选取体重相近、健康状况良好、产蛋率无显著差异（P>0.05）的临武鸭200羽，随机分为5组，每组5个重复，每个重复8只鸭。饲粮中赖氨酸水平分别为0.65%、0.75%、0.85%、0.95%、1.05%，试验期63 d。在饲养试验结束后，每组挑选出10只体重接近各组平均体重的试验鸭进行代谢试验。结果显示：1）0.95%和1.05%赖氨酸组日产蛋重显著高于0.65%和0.75%赖氨酸组（P0.05）。3）0.85%、0.95%和1.05%赖氨酸组血清总蛋白含量显著高于0.65%赖氨酸组（P<0.05）。0.95%赖氨酸组血清中三碘甲腺原氨酸含量显著高于0.65%、0.75%和1.05%赖氨酸组（P<0.05）。4）0.95%赖氨酸组净蛋白质利用率和氮沉积量显著或极显著高于0.65%赖氨酸组（P<0.05或P<0.01）。5）二次曲线分析表明，以总蛋白、净蛋白质利用率和氮沉积为评价指标，产蛋高峰期临武鸭饲粮中赖氨酸需要量分别为0.92%、0.96%和0.95%。由此可见，30~38周龄临武鸭的日产蛋重、料蛋比、总蛋白、净蛋白质利用率和氮沉积对于饲粮中赖氨酸水平的变化较为敏感，而获得较佳的生产性能、血清生化指标和氮平衡的适宜赖氨酸水平为0.92%~0.96%。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究饲粮中硒添加水平对产蛋高峰期临武鸭产蛋性能、蛋品质、血清抗氧化指标和蛋硒含量动态变化的影响。试验选用29周龄体况良好、产蛋率接近的正处于产蛋高峰期的临武鸭200只，随机分为5组，每组5个重复，每个重复8只。对照组饲喂基础饲粮（不额外补充硒源，实测硒含量为0.15 mg/kg）45 d，Ⅰ组、Ⅱ组、Ⅲ组、Ⅳ组分别在基础饲粮中以酵母硒形式添加0.10、0.20、0.40、0.80 mg/kg的硒，饲喂35 d添加硒饲粮后改喂基础饲粮10 d。结果显示：1）饲粮中硒添加水平对蛋鸭产蛋性能和蛋品质各指标均无显著影响（P>0.05）。2）与对照组和Ⅰ组相比，饲粮中添加0.40和0.80 mg/kg的硒可以显著提高蛋鸭血清中硒和谷胱甘肽（GSH）含量以及超氧化物歧化酶（SOD）和谷胱甘肽过氧化物酶（GSH-PX）活性（P0.05），而Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量均呈现先升高后降低的趋势，且均在试验第9天达到峰值。试验第7、9、13、17、21、28和35天，Ⅱ组、Ⅲ组、Ⅳ组蛋硒含量显著高于对照组和Ⅰ组（P0.05）。由此可见，饲粮中添加不同水平的酵母硒形式的硒对产蛋高峰期临武鸭的产蛋性能和蛋品质均无不良影响。饲粮中添加0.40和0.80 mg/kg酵母硒形式的硒可以提高产蛋高峰期临武鸭的蛋硒含量、血清硒含量和抗氧化能力，延长蛋硒的存留时效。综合考虑各因素，产蛋高峰期临武鸭饲粮中硒（以酵母硒形式添加）的适宜添加水平为0.40 mg/kg。
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