Artificial light at night decreases the pupillary light response of dark-adapted toads to bright light

Artificial light at night (ALAN) is expanding worldwide. Many physiological effects have been reported in animals, but we still know little about the consequences for the visual system. The pupil contributes to control incoming light onto the retina. Sudden increases in light intensity evokes the pupil light reflex (PLR). Intrinsically photosensitive retinal ganglion cells (ipRGC) affect PLR and melatonin expression, which largely regulate circadian rhythms and PLR itself. IpRCG receive inputs from various photoreptors with different peak sensitivities implying that PLR could be altered by a broad range of light sources. We predicted ALAN to enhance PLR. Contrary to our prediction, dark-adapted cane toads Rhinella marina, exposed to ALAN (5 lx) for 12 days, exhibited a lower PLR than controls and individuals exposed to 0.04 lx, even after 1 h in bright light. We cannot conclude whether ALAN induced a larger pupil size in dark-adapted toads or a slower initial contraction. Nevertheless, the response was triggered by a light source with an emission peak (590 nm) well above the sensitivity peak of melanopsin, the main photoreceptor involved in PLR. Therefore, ALAN alters the capacity of toads to regulate the incoming light in the eye at night, which may reduce the performance of visually guided behaviors, and increase mortality by predators or road kills at night. This first study emphasizes the need to focus on the effect of ALAN on the vision of nocturnal organisms to better understand how this sensory system is altered and anticipate the consequences for organisms.     

带幅设计对玉米/苜蓿间作群体光环境特征及光能利用效率的影响北大核心CSCD

探究间作带幅设计对玉米/苜蓿间作群体光环境特征、产量及光能利用效率(LUE)的影响,提出黄土高原旱作条件下玉米/苜蓿间作群体最佳带幅比例。研究设置了玉米单作(SM)、紫花苜蓿单作(SA)以及玉米/紫花苜蓿1∶2(I_(12))、2∶2(I_(22))和2∶4(I_(24))间作5种种植模式,并采用田间试验和数学模拟相结合的方法,分别测定了玉米和苜蓿的干物质产量及作物冠层光合有效辐射(PAR)等指标;建立了考虑光线入射角度和群体冠层结构几何关系的玉米/苜蓿间作群体辐射传输模型,并用实测值对其进行了验证。试验结果表明,在2018年,单作处理的苜蓿干物质产量显著高于间作处理(P<0.05),而在2019年各间作处理苜蓿的干物质分别比单作高197.8、180.3和197.0 g·m^(-2);处理I_(12)、I_(22)和I_(24)两年总的玉米生物量比SM处理高12.1%、0.9%和23.9%。所有间作处理的土地当量比在2019年均大于1.0,表现出间作优势。辐射传输模型可准确模拟玉米/苜蓿间作群体冠层底部的光合有效辐射,间作群体光合有效辐射模拟值与实测值的平均绝对误差和均方根误差分别为59.0和66.6μmol·m^(-2)·s^(-1)。除玉米和苜蓿生育前期及玉米收获后,不同间作处理苜蓿群体冠层上方的PAR均低于单作苜蓿。2018和2019年I_(12)、I_(22)和I_(24)间作处理玉米的光能利用效率分别比单作处理高52.5%、9.3%、51.7%和28.5%、9.6%、21.0%,而间作苜蓿的LUE仅在2019年显著高于单作19.2%、32.4%和20.9%(P<0.05)。因此,合理的玉米/苜蓿间作带幅搭配可改善苜蓿的光照环境,提高其光能利用效率,尤其是玉米/紫花苜蓿2∶4间作群体光能利用效率和产量优势显著,建议在具有类似气候的地区推广种植。     

不同光强下4种鸭跖草科植物的生物量分配、水分生理及光响应特征

以紫鸭跖草、‘花叶’水竹草、吊竹梅和‘绿叶’水竹草为试验材料,利用遮光网人工模拟5个光强梯度,研究不同光强对4种鸭跖草科植物生物量分配、水分生理以及光响应曲线特征的影响。结果表明：随光强的降低,4种植物的地上生物量均呈先升后降的趋势,并在遮光度25%至75%期间显著升高（P<0.05）,除紫鸭跖草的总生物量无显著变化外,其他3种植物的总生物量也呈先升后降趋势;不同光强对4种植物的物质分配规律及冠根比的影响不同,但4种植物的茎贡献率均呈上升趋势;正午水势随光强的降低而增加,且与失水速率的变化趋势具有较高的一致性,其中紫鸭跖草和吊竹梅的失水速率较低;在不同光强处理下,4种植物的光响应曲线均呈现出随着光合有效辐射（PAR）的增加而先增加后趋于平缓的趋势;随着光强的降低,4种植物的最大净光合速率、表观量子效率和光饱和点均呈现出先升后降的趋势;紫鸭跖草和吊竹梅具有较高的最大净光合速率、表观量子效率、光饱和点以及较低的暗呼吸速率,且水分利用效率在不同处理间无显著差异,均表现出较高的水平。综上所述,4种植物在适当的弱光环境中（遮光度25%~75%）,可以通过调整形态、物质分配规律及光响应特征的方式去更有效的利用弱光资源,但不同种植物的应对能力呈现出一定的差异性,其中紫鸭跖草和吊竹梅的光适应性较强。     

植物形态生物质材料的制备与力学性能

发展绿色环保新材料是当今生物质研究的一项重大任务。本研究分析了一年生黑麦草（Lolium multiflorum）、高羊茅（Festuca arundinacea）和白三叶（Trifolium repens）经自然反复倒置生长，根茎交联成型后用高分子溶液浸泡制备生物质材料的过程以及种子添加量与力学性能之间的关系，初步探索了生物质经不同浓度的高分子溶液处理后，材料的力学性能。其中用浓度为10%的聚乙烯醇处理的生物质力学性能最佳。3种草坪芽苗中，一年生黑麦草制备的生物质材料优于其余两种草坪品种，经浓度为10%聚乙烯醇处理后的生物质力学性能各参数值分别为最大力191.959 N、最大变形23.581 mm、拉伸强度0.512 MPa、伸长率58.95%、弹性模量0.87 MPa，这能为生物材料的开发提供了新的思路。     

光照对932、7532蚕品种化性的调控试验

本试验通过对中系品种932和日系品种7532在大蚕期高温饲养环境中进行24h长光照感光处理试验,了解长光照对化性的调控作用。结果表明：日系品种7532的化性较稳定,对长光照处理不敏感。但长光照对中系品种932的化性影响很大,易趋于多化而诱发生种,以隔代长光照处理的影响最大,生种率最高达97．64％;同时,932品种受长光照作用所产的不滞育卵,在自然光照下正常饲养,化性得到恢复和稳定,生种率降至正常水平,可利用这一特性筛选出适合作为转基因受体的新品系。大蚕期连续多代长光照选育对932的化性有稳定的趋向,选择黑种继代,生种率显著下降,有利于筛选出适合蚕业生产所需的产滞育卵稳定的新品系。     

不同光照强度对水培草莓果实品质的影响

由于重庆为寡日照地区,秋冬季节光照条件差,影响水培草莓生长、果实品质及产量。本试验主要研究达赛莱克特和甜查理在人工增光条件下的果实品质变化。试验结果表明：不同光照强度对水培草莓的单果重、产量、可溶性固形物、可溶性糖、可溶性还原糖、维生素C均有显著影响,对水培草莓的果形指数、有机酸含量无显著影响;不同品种草莓对光强的反应稍有不同,达赛莱克特受光强影响较大。     

Morphology of the leather defect light flecks and spots.

The skin histology and the scanning electron microscope morphology of the hide defect light flecks and spots after tanning were studied in 11 steers infested with biting lice (Damalinia bovis). Nine steers from herds free of lice were used as controls. Skin biopsies from 6 of the animals in the lice infested group showed mild to moderate hyperkeratosis and moderate perivascular to diffuse dermatitis with infiltration of mainly mononuclear cells and some eosinophilic granulocytes. The steers were slaughtered at an age of 18 to 23 months. Light flecks and spots occurred on all examined hides from the infested group after tanning. No examined hides from the control group demonstrated similar damage. Both light microscopic examination of sections of tanned hide with light flecks and spots and scanning electron microscopy of the same defects showed superficial grain loss and craters with a irregular fibre base encircled by smooth and intact grain. The association between louse infestation at an early age and damage of hides following slaughter 6 to 15 months later, suggested that louse infestations lead to a prolonged or lifelong weakening in the dermis. This weakening may cause superficial grain loss during the tanning process.     

Onset of luteal activity in foaling and seasonally anoestrous mares treated with artificial light.

Sixty-four mares (27 foaling, 37 barren or maiden), mainly Finnhorses, were subjected to treatment with 14.5 h of light and 9.5 h of darkness, starting at the beginning of December. The onset of cycling in non-foaling mares was estimated by weekly serum progesterone determinations. All of the non-foaling mares cycled in the middle of March. They started to cycle on average in the middle of February, 11.1 weeks after the beginning of the trial. There were statistically significant differences in relation to breed (Finnhorses started to cycle 2 weeks later than warm blooded, p less than 0.02) and in relation to age (brood mares with mean age 10 years, started to cycle 10 days later than those 3 years old, p less than 0.03). However, there was no statistical significant relation to previous lactation, although lactating mares lactating up to the previous autumn started to cycle 7 days later than dry mares (p less than 0.15). Artificial insemination of 14 mares in the 2nd oestrus of the year, in March, resulted in 12 foalings in the subsequent year (86%). The following winter, all pregnant mares (N = 27) were exposed to the same kind of light treatment, starting on 1st December. The 1st mare foaled at the end of January. The time from foaling to 1st post partum ovulation was significantly longer (17.0 days) in foalings taking place within 10 weeks from the beginning of the light treatment period, than in foalings occurring after more than 10 weeks of lighting (12.1 days) (p less than 0.01).     

Effects of stocking density,light and perches on broiler growth

The aim of this study was to determine the effect of stocking density, light intensity and light color on broiler growth. The experiment consisted of four 35‐day phases during each of which 320 chickens were surveyed. The research was performed at stocking densities of four and six birds/m². Illuminances of 15 and 30 lx were obtained through commercial lamps with 4000 K and 6000 K color temperatures. Lighting was used 17 h a day, between 06.00 and 23.00 hours (17 L:7 D). The results showed a decrease in body, carcass, breast and thighs weight (P < 0.05) with the increase in stocking density. Body weight decreased by 10.5% and carcass weight decreased by 9.4% at six birds/m² stocking density. Contrastingly, no differences were found for the tested light colors. Increasing illuminance from 15 to 30 lx caused a 1.9% decrease in body weight. The analysis of the effect of perches revealed that using perches significantly increased body (2.5%) and breast weight (11.8%). The interactions between light intensity or color and stocking density and between light intensity and light color were analyzed.     

放牧和光照对林下栽培草地生产力的影响

研究了不同放牧强度G0(0只/hm2)、G1(22.2 只/hm2)、G2(44.4只/hm2)和不同光照条件(100%光强、68.83%光强和54.29%光强)对香樟(Cinnamomum camphora)林下混播草地生产力的影响.结果显示,在整个生长季,草地现存量、再生量和净初级生产力在同一放牧强度下均呈现随光照...     

4个苜蓿品种愈伤组织诱导对光照的响应及再生体系建立

为实现苜蓿(Medicago sativa)的遗传改良,建立稳定、高效的离体培养再生体系,以甘农1号、巨人、WL324和三得利4个苜蓿品种为试验材料,以下胚轴为外植体,MS、UM、改良HS、改良UM为基本培养基,分别添加2,4-D、KT和水解酪蛋白诱导愈伤组织,通过体细胞胚发生途径建立再生体系,研究光照对苜蓿愈伤组织诱导及愈伤组织形态对体细胞胚发生的影响。结果表明,光照对愈伤组织诱导率差异不显著,均为100%;光暗交替条件下诱导的愈伤组织褐化率高、生长更快、更旺盛,颜色稍显绿或黄绿相间。在不同光照条件下4个苜蓿品种诱导的愈伤组织,以甘农1号的体细胞胚发生率最高,为20.83%~56.25%,而且光暗交替条件下诱导的愈伤组织更易形成体细胞胚;不同培养基中,UM+0.1 mg/L NAA+0.5 mg/L KT下体细胞胚发生率最高,为56.25%。     

Quantitative assessment of pupillary light reflex in normal and anesthetized dogs: a preliminary study

The purpose of this study was to quantitatively assess the pupillary light reflex (PLR) in normal and anesthetized dogs using a pupillometer. Eleven dogs (20 eyes) of various breeds were included. PLRs were measured with a handheld pupillometer in dim light before and during anesthesia. Anesthesia was conducted with atropine, xylazine and ketamine. Parameters of pupillometry included neurological pupil index (NPi), pupil size, percent of change (%CH), latency (LAT), constriction velocity (CV), maximum constriction velocity (MCV) and dilation velocity (DV). NPi,%CH, CV and MCV were significantly decreased during anesthesia compared with the pre-anesthesia data. The results suggest that atropine-xylazine-ketamine combination anesthesia depresses the PLR. Additionally, this study demonstrates the feasibility of the use of a pupillometer in dogs.     

LED红光对乙烯褪绿脆蜜金柑果实贮藏特性的影响

探索红光对乙烯褪绿脆蜜金柑果实着色及贮藏品质的影响，以期为提高脆蜜金柑果实的外观品质和商业价值提供理论依据。以7年生脆蜜金柑为试材，采用660nm红光照射乙烯褪绿脆蜜金柑果实，在贮藏期定期测定果皮色差、单果重、硬度、呼吸强度、可溶性固形物含量、可滴定酸含量、果皮叶绿素和类胡萝卜素含量等色泽和品质指标。结果表明：红光处理通过促进脆蜜金柑果皮中叶绿素（a，b）的降解和总类胡萝卜素的合成，改善果实的外观色泽，乙烯利处理的效果不如红光，两者单独使用均存在转色不均匀的问题。经红光和低剂量乙烯共同处理后，脆蜜金柑果实5d即可均匀转色，660nm红光协同300ppm乙烯利处理可有效促进采后脆蜜金柑果皮转色。     

Characterization of the bovine immunoglobulin lambda light chain constant IGLC genes

To characterize the bovine immunoglobulin lambda light chain constant region (IGLC) genes, we have isolated a bacterial artificial chromosome (BAC) clone by a PCR based approach from a bovine genomic DNA library, constructed using a genital ridge cell line derived from a male Holstein fetus. The positive BAC clone, containing the bovine IGLC genes, was fully sequenced and had a 138 kb insert. Sequence analysis revealed that the bovine immunoglobulin lambda light chain locus consisted of four joining-constant gene recombination units spanning approximately 20 kb DNA in length. A detailed examination of the recombination signal sequences, RNA splicing sites and coding sequences of the four joining-constant gene recombination units suggested that only two IGLC genes (IGLC2 and IGLC3) were functional while the IGLC1 and IGLC4 appeared to be pseudogenes. This conclusion was further confirmed by a series of RT-PCR amplifications, which also showed that among these four genes the IGLC3 was preferentially expressed in cattle. Phylogenetic analysis indicated that the bovine IGLC genes were more closely related to their equivalents in sheep and goats than that to other mammals.     

不同光照强度对叉花草叶片结构和叶绿素含量的影响

为探讨叉花草的耐荫特性,研究了不同光照强度对其株高、叶面积、叶绿素含量及叶片结构的影响。结果表明,与全光照相比,株高、叶面积和叶绿素含量随遮光度的增加而增加,遮光70%以上使植株变得柔软;叉花草的栅栏组织为1层,海绵组织相对较为发达,在不同遮荫条件下,叶片厚度、栅栏组织和海绵组织均变薄,栅栏组织/海绵组织比值减小;叶片中叶绿素 a/b 随遮光度的增加而减小,表明叉花草适宜在遮光度60%~70%的环境下生长。     

不同光照强度对几种狗牙根形态与草坪品质的影响

采集野生狗牙根(Cynodon dactylon)种源4份，用Tifway 419作对照，在不同光照强度下，对地上部形态变化与草坪品质的影响进行研究，为开发使用野生狗牙根种质资源提供依据。结果表明，在光照强度减弱至68％和38.5％的情况下，直立茎的高度、茎节间长度和叶长沿纵向延长生长相对较快，并且叶面积扩大，与光照强度呈负相关关系；茎直径、叶宽则横向收缩变小生长，与光照强度呈正相关关系。由于茎、叶形态变化的影响，草坪品质下降，两者间呈明显正相关关系。狗牙根1号、4号茎叶形态变化小，草坪品质高，是耐阴性较强的乡土草种，几乎可与对照种Tifway 419媲美；狗牙根3号变化最大，草坪品质最差。     

4种轻型屋顶绿化植物抗旱能力的综合评价

为了综合评定锦绣苋(Alternanthera bettzickiana)、玉吊钟(Kalanchoe fedtschenkoi‘Rosy Dawn’)、藓状景天(Sedum polytrichoides)、洋竹草(Callisiasp.)4种轻型屋顶绿化植物的抗旱能力,采用盆栽控水法测定其在干旱胁迫下的永久萎蔫率、叶片失水率、叶片相对含水量、叶绿素荧光参数(Fv/Fm、Fv’/Fm’、ETR、ΦPSⅡ、NPQ)等生理指标,并结合胁迫时与复水后的表观形态变化,采用隶属函数法,综合评价4种植物的抗旱能力强弱。结果表明,1)植物的永久萎蔫率和叶片失水率以洋竹草和玉吊钟相对较低,表现出较强的抗旱性。2)4种植物的叶片相对含水量指标随着干旱时间的延长而降低;F_v/F_m、F_v’/F_m’、ETR、ΦPSⅡ参数呈不同程度的降低趋势;而NPQ呈不同程度的升高趋势。3)4种植物的抗旱性排序依次为洋竹草玉吊钟藓状景天锦绣苋,与实际形态观测结果一致,其中洋竹草、玉吊钟、藓状景天能忍受华南地区夏季高温条件下12d左右的持续干旱而保证正常生长,适合应用于轻型屋顶绿化。     

滴灌模式下旱后复水对甜菜叶丛期光合光响应特性的影响

为探索甜菜叶丛期叶片光合生理特性及光响应特征参数对旱后复水的响应机制,以旱敏感型品种‘XJT9907’和耐旱型品种‘XJT9916’为材料,在甜菜叶丛期控水为45%~50%田间持水量持续7 d时,复水达70%~75%田间持水量(对照,CK)48 h后,测定其叶片光合生理指标,采用非直角双曲线模型进行叶片净光合速率(P_n)与光强非线性拟合,并计算其光响应特征参数。结果表明,甜菜叶丛期干旱胁迫显著降低甜菜叶片的叶绿素相对含量(SPAD)、净光合速率(P_n)、气孔导度(G_s)、胞间CO₂浓度(C_i)和蒸腾速率(T_r)。复水后,两种品种的叶片SPAD值、P_n、G_s、C_i和T_r虽均有所提高,但XJT9916品种光合生理参数值明显高于XJT9907,且均未超过正常供水水平,表现出一定的补偿效应。旱后复水处理下,XJT9907和XJT9916品种叶片光响应特征参数最大净光合速率(P_nmax)分别比CK低17.1%和6.2%,表观量子效率(AQY)分别比CK低12.2%和6.5%,暗呼吸速率(Rd)分别比CK低14.9%和19.1%,光饱和点(LSP)分别比CK低14.1%和19.6%,而光补偿点(LCP)显著高于CK,分别高17.6%和15.4%,其光能利用区间较窄,光能利用效率降低。综合来看,当甜菜叶丛期土壤含水量为田间持水量的45%~50%时对其叶片光合潜能的发挥不利,其叶片光合能力减弱,复水后光合能力仍无法恢复到正常水平。耐旱型甜菜XJT9916品种光合作用旱后复水恢复能力更强。     

光强和刈割处理对柠条幼苗补偿生长的影响

在3个光强,100%自然全光照(natural sunlight,NS)、37%NS和16%NS的遮阴条件下,研究了5个刈割强度处理(留茬高度为30、20、10、3cm和不刈割)对柠条(Caragana korshinskii)幼苗补偿生长的影响。结果表明,1)强光照和刈割均促进幼苗刈割后的补偿生长,刈割处理后幼苗的萌条数和萌条基径都在强光下最大,但随着刈割强度的增大呈减小趋势。2)幼苗株高、基径、主根长和侧根数在所有刈割处理均表现为100%NS37%NS16%NS;刈割处理幼苗的株高和基径均小于不刈割对照,且随刈割强度的增大而减小;尽管轻度刈割促进幼苗主根生长和侧根数增加,但二者都随刈割强度的增大而受到抑制。3)强光照有利于幼苗刈割后的生物量积累,但幼苗总生物量在不同光照条件下都随刈割程度的增大逐渐减小,即表现为欠补偿生长;幼苗生物量补偿指数随着光照强度的减弱而增大,在16%NS下不同强度刈割处理间变化不大,表明幼苗刈割后的生物量积累在强光下主要依赖于光合作用新合成的光合产物,而在弱光下主要依赖于根系和残留树桩贮藏的营养物质。研究表明,柠条幼苗刈割后的补偿生长能力随着刈割强度的增大而减小,且表现为欠补偿;强光照对柠条幼苗刈割后的补偿生长具有促进作用。本研究可为柠条的幼苗培育、饲草生产和草地生态系统管理提供参考。