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1.
切断位置对赤子爱胜蚓再生速度的影响   总被引:4,自引:0,他引:4  
将赤子爱胜蚓从脑、生殖环部位和总体节的 1/ 2和 3/ 4的位置切断 ,得到有头无尾、无头无尾、无头有尾 3种类型 16个处理体段 ,在 (2 0± 1)℃人工气候箱中培养 ,测定其再生速度 .结果表明 ,赤子爱胜蚓切断的位置不同 ,其再生速度不同 .其中 ,脑部的存在与否 ,对再生速度没有显著的影响 .但是生殖环存在的处理比切除生殖环的处理再生速度快 ,且存活率高 .无头无尾体段再生前部和再生后部的比较表明 ,再生前部比再生后部慢 .体节的损失越少 ,再生的速度越快 .图 6表 3参 11  相似文献   

2.
用不同浓度柠檬醛处理不同部位剪切的蚯蚓,和处理剪切后不同时间段的蚯蚓体段,探讨了柠檬醛对赤子爱胜蚓再生作用的体段、作用浓度和敏感时间段.结果表明,柠檬醛对蚯蚓再生有明显影响,但这种作用依不同体段而异,以体段P7和P25作用最显著,而A25,A90和P60的受柠檬醛影响较小; 柠檬醛影响蚯蚓头部再生,而不影响尾部再生;对再生有影响的柠檬醛浓度为1mmolkg-1, 0. 1mmolkg-1和0. 01mmolkg-1 (土壤),对蚯蚓再生作用的时间为切后0. 5~1d.试验显示,柠檬醛干扰蚯蚓再生头部形成而且还影响再生头尾体轴形成;内源视黄酸在蚯蚓头尾轴再生图式形成中有重要作用. 图4表4参18  相似文献   

3.
铜暴露下赤子爱胜蚓(Eisenia foetida)活体基因的损伤研究   总被引:6,自引:0,他引:6  
通过碱性单细胞凝胶电泳法研究了Cu2+暴露剂量对赤子爱胜蚓(Eiseniafoetida)活体基因损伤的动态影响.结果显示:不添加Cu2+的对照组和添加Cu2+的处理组蚯蚓体腔细胞尾部DNA含量和尾长均呈非正态分布(p<0.05);在暴露72h时,125mg·L-1Cu2+处理组尾部DNA含量值最大,为41.44%,100mg·L-1Cu2+处理组尾长值最大,为33.79μm;随着Cu2+暴露剂量的增加,尾部DNA含量和尾长损伤频率增加;对照组和处理组的尾部DNA含量和尾长之间均存在显著性差异(p<0.05),Spearman非参数相关分析表明,尾部DNA百分含量和尾长之间呈显著相关(p<0.01,n=21),Cu2+暴露浓度与尾部DNA百分含量、尾长具有良好的剂量-构效关系(p<0.01).在125mg·L-1Cu2+浓度下暴露72h时蚯蚓的基因损伤程度达到最大,损伤程度为3级.可见,蚯蚓DNA生物标志物是重金属污染基因毒理诊断的重要指标,碱性SCGE试验是检测Cu2+暴露对赤子爱胜蚓活体基因损伤的有效手段.  相似文献   

4.
渔游蛇精子的超微结构   总被引:1,自引:0,他引:1  
扫描电镜观察表明,渔游蛇(Natrix Piscater)精子总长度约110μm,分为头和尾两部分;头部呈前稍尖的细长圆柱形,略变曲,约长8.5μm,直径以经约0.6μm。尾部又分4段:颈段、中段、主段和末段;其与从不同之处是中段较长,约73μm,占精子总长度的2/3多;线料体型鞘由近500圈超过5000个线粒体构成;透射电镜揭示了头部顶体体覆疬于核前约1/2;尾部颈段的结构较复杂,包括连接片的踝  相似文献   

5.
不同培肥措施对土壤团聚体中微生物特性的影响   总被引:3,自引:0,他引:3  
土壤微生物生物量是土壤肥力的指示性指标。探讨不同培肥措施对土壤团聚体中微生物特性的影响,对合理培肥和改善土壤性状具有重要的实际意义。通过野外与室内实验,研究了不同培肥措施[施蚯蚓(Eisenia fetida)粪wormcast(WC)、套养蚯蚓earthworm breeding(EB)、施牛粪cattle manure(CM)、施化肥chemical fertilizer(FL)和对照(CK)]对华南地区果园土壤团聚体中微生物特性的影响,旨在为果园土壤生态培肥提供依据。结果表明,与CK相比,各有机培肥措施均可显著提高各级团聚体的微生物生物量碳、氮、磷含量,且以施蚯蚓粪处理效果(分别为133.4、22.6、66.5 mg·kg~(-1))最佳。各处理0.25 mm粒径土壤团聚体的微生物生物量碳(87.0 mg·kg~(-1))、氮含量(15.2 mg·kg~(-1))均低于其他粒径团聚体。与CK相比,AWCD值的变化速度和最高值均有不同程度的提高,其大小顺序为:WCCMEBFLCK。由此可见,不同培肥措施均提高了团聚体中的微生物活性,且以施蚯蚓粪处理的效果最好。多样性指数分析表明:与CK相比,各培肥措施(施化肥除外)均可显著提高团聚体中的微生物群落丰富度,但各培肥措施对土壤常见微生物种类影响不大,且使微生物群落均匀度有所降低。综上可见,施蚯蚓粪对华南地区退化果园的土壤微生物特性改善明显,是提升其肥力的有效措施。  相似文献   

6.
采用人工土壤培养法,通过14 d急性暴露试验,研究了全氟辛烷磺酸(PFOS)对赤子爱胜蚓(Eisenia fetida)的死亡率、谷胱甘肽硫转移酶(GST)和过氧化氢酶(CAT)活性以及DNA损伤的影响。研究结果表明:PFOS对蚯蚓14 d-LC50为478.0 mg·kg-1,显示为低毒;急性暴露期间,PFOS显著抑制蚯蚓生长,生长抑制率随着PFOS浓度增加而增大,且有良好的剂量效应关系(r=0.951,P<0.01);PFOS对蚯蚓GST和CAT活性均没有显著性影响,没有观察到剂量效应关系;PFOS可致蚯蚓体腔细胞DNA损伤,不同浓度的PFOS对蚯蚓体腔细胞尾长、尾部DNA含量和尾矩的影响具有一定的剂量效应关系(P<0.01),与对照组之间存在显著性差异(P<0.05)。上述结果表明,PFOS对蚯蚓的存活影响显示为低毒,但是对生长有一定影响,可致蚯蚓体腔细胞DNA损伤。  相似文献   

7.
用蒙脱石、稻草、鸡粪作为改良剂,研究不同改良剂对铜矿尾矿砂与菜园土混合土壤PH、有效态重金属含量、脲酶和磷酸酶活性以及混合土壤上种植的黑麦草生长的影响。结果表明:添加蒙脱石对不同生长期黑麦草的生长量没有显著影响;使用稻草和鸡粪处理尽管在开始阶段不利于黑麦草(第1茬和第2茬)的生长,但随时间延长,黑麦草的生物量(第3茬和第4茬)明显增加,表现出很好的后效。黑麦草的根重与鸡粪的添加量关系显著,施用稻草的纯尾矿砂处理组(处理22)根重最大,而且蚯蚓只能在使用适量稻草的处理条件下才能在混合土壤中生长。土壤酶的分析发现,磷酸酶的活性除了在蚯蚓能够生长的处理组表现出较高外,其它处理之间无明显差异,但脲酶的活性则随着稻草和鸡粪施用量的增加而显著提高。各处理之间土壤的PH值变化不大。添加稻草减少了土壤中有效态重金属的含量,而使用鸡粪处理明显增加了土壤中包括铜、铅和锌等有效态重金属的含量,说明在施用含有重金属的畜禽粪便时务必小心谨慎,以防二次污染。  相似文献   

8.
蚯蚓是潜在的富硒蛋白饲料.在大棚环境条件下采用不同配比的3种农业废弃物(牛粪、菌渣和残余菜叶)和低浓度硒(Na_2SeO_3,0/20/40 mg/kg)对赤子爱胜蚓(Eisenia fetida)进行培养,研究不同培养基质和硒添加量对蚯蚓生长繁殖和富硒能力的影响.结果发现,培养45 d后,与相同浓度硒处理的其他3组基质[纯牛粪、牛粪+菌渣+菜叶(干重比为6/2/2和3/6/1)]相比,牛粪+菌渣组(干重比为1/1)蚯蚓总生物量、蚓茧数、蚓体硒富集量和富集系数均达到最大,其中总生物量比培养前最大增加了18.21%,每100条蚯蚓产蚓茧数量达68.35-72.45个,蚓体硒富集量最高达到151.56mg/kg,蚓体硒富集系数最大为4.91.当硒添加浓度为20 mg/kg和40 mg/kg时,以牛粪+菌渣+菜叶为基质的两组(干重比为6/2/2,3/6/1)在培养初期对蚯蚓活性和培养后的总生物量增加均有一定的抑制作用,蚯蚓总生物量最大降低了8.48%.在不同基质培养条件下,外源添加硒对蚓体硒富集量和硒富集系数增加有促进作用,蚓体硒富集量与基质硒添加量均呈现出剂量-效应关系.上述结果表明,赤子爱胜蚓对硒具有极强的富集能力且培养基质种类对蚯蚓的生长繁殖具有很大的影响,牛粪和菌渣组合(干重比为1/1)是最佳的富硒蚯蚓培养基质且基质硒添加浓度≤40 mg/kg不影响蚯蚓生长繁殖.(图3表4参25)  相似文献   

9.
采用模拟培养法,对农业有机废弃物的蚯蚓堆制条件进行因素优化,并以优化后条件组合作为培养条件,进一步研究了蚯蚓堆制物性状的变化.结果表明,随蚯蚓处理时间增加,堆制物pH和C/N比值均显著降低,电导率却显著增加;速效N、P含量均在处理45天时达到最高,速效K含量在处理30天时达到最高;在堆制前期,蔗糖酶、脲酶及过氧化氢酶活性均增强,而磷酸酶活性则呈下降趋势.在蚯蚓堆制60天时,与猪粪+稻草混合堆制物[m(猪粪):m(稻草)=7:3,温度15℃,湿度75%,接种密度10尾·盆-1]的特性相比,猪粪+木屑混合堆制物[m(猪粪):m(木屑)=7:3,温度20℃,湿度75%,接种密度15尾·盆-1]的pH、电导率及速效K含量相对较低,而蔗糖酶、磷酸酶活性均相对较高.相对而言,利用蚯蚓对猪粪和木屑进行混合堆制可同时达到安全和资源化利用的目的.  相似文献   

10.
利用土壤五氯酚(PCP)污染模拟实验,研究两种不同生态型蚯蚓(赤子爱胜蚓Eisenia foetida和壮尾环毛蚓Amynthas robustus E.Perrie)和堆肥固定化添加模式对漆酶降解土壤PCP的影响。在42 d培养期内,测试了不同处理下PCP质量分数、漆酶活性,以及土壤呼吸和微生物碳氮等微生物指标。结果表明:堆肥固定化漆酶降解土壤PCP的效果优于壳聚糖固定化漆酶和自由漆酶,主要原因是堆肥固定化漆酶能够有效地提高漆酶稳定性,减缓其活性下降速度。此外,堆肥还能提高土壤微生物的数量与活性,显著提升土壤漆酶的活性。添加两种生态型蚯蚓对漆酶活性影响不显著,但均可以显著提高土壤微生物的数量与活性,加速土壤中PCP的降解。壮尾环毛蚓对土壤微生物数量与活性的提升效果优于赤子爱胜蚓。  相似文献   

11.
Conservation science is a crisis discipline in which the results of scientific enquiry must be made available quickly to those implementing management. We assessed the extent to which scientific research published since the year 2000 in 20 conservation science journals is publicly available. Of the 19,207 papers published, 1,667 (8.68%) are freely downloadable from an official repository. Moreover, only 938 papers (4.88%) meet the standard definition of open access in which material can be freely reused providing attribution to the authors is given. This compares poorly with a comparable set of 20 evolutionary biology journals, where 31.93% of papers are freely downloadable and 7.49% are open access. Seventeen of the 20 conservation journals offer an open access option, but fewer than 5% of the papers are available through open access. The cost of accessing the full body of conservation science runs into tens of thousands of dollars per year for institutional subscribers, and many conservation practitioners cannot access pay‐per‐view science through their workplace. However, important initiatives such as Research4Life are making science available to organizations in developing countries. We urge authors of conservation science to pay for open access on a per‐article basis or to choose publication in open access journals, taking care to ensure the license allows reuse for any purpose providing attribution is given. Currently, it would cost $51 million to make all conservation science published since 2000 freely available by paying the open access fees currently levied to authors. Publishers of conservation journals might consider more cost effective models for open access and conservation‐oriented organizations running journals could consider a broader range of options for open access to nonmembers such as sponsorship of open access via membership fees. Obtención de Acceso Abierto a la Ciencia de la Conservación  相似文献   

12.
Protected areas (PAs) are often implemented without consideration of already existing PAs, which is likely to cause an overrepresentation of certain biophysical conditions. We assessed the representativeness of the current PA network with regard to the world's biophysical conditions to highlight which conditions are underprotected and where these conditions are located. We overlaid terrestrial and marine PAs with information on biophysical conditions (e.g., temperature, precipitation, and elevation) and then quantified the percentage of area covered by the PA network. For 1 variable at a time in the terrestrial realm, high temperature, low precipitation, and medium and very high elevation were underrepresented. For the marine realm, low and medium sea surface temperature (SST), medium and high sea surface salinity (SSS), and the deep sea were underrepresented. Overall, protection was evenly distributed for elevation across the terrestrial realm and SST across the marine realm. For 2 variables at a time, cold and very dry terrestrial environments had mostly low protection, which was also the case for low SST and low and medium SSS across most depths for marine environments. Low protection occurred mostly in the Sahara and the Arabian Peninsula for the terrestrial realm and along the Tropic of Capricorn and toward the poles for the marine realm. Although biodiversity measures are of prime importance for the design of PA networks, highlighting biophysical gaps in current PAs adds a frequently overlooked perspective. These gaps may weaken the potential of PAs to conserve biodiversity. Thus, our results may provide useful insights for researchers, practitioners, and policy makers to establish a more comprehensive global PA network.  相似文献   

13.
Summary The adaptation of defensive secretions to their target organisms was examined for the abdominal gland secretions ofBledius furcatus, B. spectabilis andB. arenarius. Therefore the target organisms of the secretion of theseBledius species (i.e. their predators) had to be identified. At the collection sites examined these were the earwigLabidura riparia, the antCataglyphis bicolor, the flyLispe candicans, different carabids of the generaPogonus, Dichirotrichus, Dyschirius, Bembidion andCalathus and the wading birdsHaematopus ostralegus andCalidris alba. The secretion of the abdominal glands contains the toxin ptoluquinone dissolved in either-dodecalactone and 1-undecene (B. furcatus andB. spectabilis) or in octanoic acid and octyloctanoate (B. arenarius). The ratio of these solvents is species-specific. Application experiments using some of the natural insect predators (L. riparia, C. bicolor, Pogonus, Di. gustavii, Dyschirius) revealed that these solvent ratios provided a more effective deterrent than other possible ratios. Thus by combining the solvents in certain ratios, the capability of cuticular penetration and therefore the effectiveness of the defensive secretions are adapted to their natural targets.  相似文献   

14.
The politics of development includes subtexts of choice, as underpinned by community consensus (or lack of it), against the larger backdrop of a liberal democracy, with its intricate power structures that influence the choice of concepts and often lead to complicity rather than consent. A dilemma exists between the understanding of field-level practitioners and that of academics, whose understandings of progress differ. Progress can (and often does) imply long-term change across generations whereas development is often more a matter of crisis management and delivering tangible results to end-users. This makes it a bone of contention across political systems, irrespective of local or global dynamics. Development can emerge as a tool to be wielded for power and further political mileage at the expense of progress. Progress cannot be studied as a counterpoint to development as the sense of history is often missing in development interventions. Development tends to be piecemeal as its very logic often stems from the rationale of power. This is not to suggest, however, that development is only about politics; it is definitely more than the politics of everyday life and involves all of civil society that requires its critical and immediate attention. In this sense, it has become a priority for politicians with an underlying agenda designed to out-manouevre dissent and all statements of protest.  相似文献   

15.
As landscapes continue to fall under human influence through habitat loss and fragmentation, fencing is increasingly being used to mitigate anthropogenic threats and enhance the commercial value of wildlife. Subsequent intensification of management potentially erodes wildness by disembodying populations from landscape-level processes, thereby disconnecting species from natural selection. Tools are needed to measure the degree to which populations of large vertebrate species in formally protected and privately owned wildlife areas are self-sustaining and free to adapt. We devised a framework to measure such wildness based on 6 attributes relating to the evolutionary and ecological dynamics of vertebrates (space, disease and parasite resistance, exposure to predation, exposure to limitations and fluctuations of food and water supply, and reproduction). For each attribute, we set empirical, species-specific thresholds between 5 wildness states based on quantifiable management interventions. We analysed data from 205 private wildlife properties with management objectives spanning ecotourism to consumptive utilization to test the framework on 6 herbivore species representing a range of conservation statuses and commercial values. Wildness scores among species differed significantly, and the proportion of populations identified as wild ranged from 12% to 84%, which indicates the tool detected site-scale differences both among populations of different species and populations of the same species under different management regimes. By quantifying wildness, this framework provides practitioners with standardized measurement units that link biodiversity with the sustainable use of wildlife. Applications include informing species management plans at local scales; standardizing the inclusion of managed populations in red-list assessments; and providing a platform for certification and regulation of wildlife-based economies. Applying this framework may help embed wildness as a normative value in policy and mitigate the shifting baseline of what it means to truly conserve a species.  相似文献   

16.
Summary Interactions were studied among alkaloid-containing legumes (Erythrina corallodendrum andSpartium junceum) and non-toxic plants (Citrus sinensis, Cucurbita moschata andEuphorbia tirucalli), several polyphagous homopterans,Aphis craccivora (Aphididae),Icerya purchasi, I. aegyptiaca (Margarodidae),Lepidosaphes ulmi (Diaspididae) andPlanococcus citri (Pseudococcidae), and some major natural enemies of these homopterans. Significant reductions in survival due to negative effects of alkaloid containing as compared with non-alkaloidal plants were recorded for the predatorsRodolia cardinalis andChilocorus bipustulatus, but not forCryptolaemus montrouzieri (Coleoptera: Coccinellidae),Chrysoperla carnea (Neuroptera: Chrysopidae) andSympherobius sanctus (Neuroptera: Sympherobiidae). The development time of the larvae or pupae ofR. cardinalis, C. carnea andS. sanctus was longer on the toxic plants than on the non-toxic ones. The percentage of parasitism ofA. craccivora collected from the non-alkaloidal plantsVicia palaestina andMelilotus albus was much higher than that onS. junceum. The parasitoid complexes ofA. craccivora differed between both plant groups. The nutritive value of honeydew ofI. purchasi andA. craccivora, as expressed by the life span ofEncyrtus infelix (Hymenoptera: Encyrtidae) adults, was also investigated. Life spans were significantly longer when the wasps fed on honeydew produced on non-alkaloidal plants (C. sinensis andPittosporum tobira) than on alkaloid containing plants whenI. purchasi — but notA. craccivora — was the producer. It is suggested that the chemical defense ofE. corallodendrum andS. junceum is exploited by polyphagous phytophages to reduce predation. In nature, population growth and density of four of the investigated homopterans are conspicuously high when they developed on the alkaloid containing plant species, and very low on non-alkaloid plants. The efficiency of their natural enemies may be reduced by sequestration of alkaloids (or other toxic plant compounds) or their transfer into excreted honeydew. Therefore it is assumed that a generalist phytophagous homopteran may be protected from its natural enemies, although at different rates of efficiency, if it can safely sequester the host allelochemical when it develops on toxic species within its host range.  相似文献   

17.
Abstract: In the United States, as elsewhere, a growing debate pits national energy policy and homeland security against biological conservation. In rural communities the extraction of fossil fuels is often encouraged because of the employment opportunities it offers, although the concomitant itinerant workforce is often associated with increased wildlife poaching. We explored possible positive and negative factors associated with energy extraction in the Greater Yellowstone Ecosystem (GYE), an area known for its national parks, intact biological diversity, and some of the New World's longest terrestrial migrations. Specifically, we asked whether counties with different economies—recreation (ski), agrarian (ranching or farming), and energy extractive (petroleum)—differed in healthcare (gauged by the abundance of hospital beds) and in the frequency of sexual predators. The absolute and relative frequency of registered sex offenders grew approximately two to three times faster in areas reliant on energy extraction. Healthcare among counties did not differ. The strong conflation of community dishevel, as reflected by in‐migrant sexual predators, and ecological decay in Greater Yellowstone is consistent with patterns seen in similar systems from Ecuador to northern Canada, where social and environmental disarray exist around energy boomtowns. In our case, that groups (albeit with different aims) mobilized campaigns to help maintain the quality of rural livelihoods by protecting open space is a positive sign that conservation can matter, especially in the face of rampant and poorly executed energy extraction projects. Our findings further suggest that the public and industry need stronger regulatory action to instill greater vigilance when and where social factors and land conversion impact biological systems.  相似文献   

18.
Summary Acanthoscelides obtectus (Say) is one of the most damaging pests of kidney beans,Phaseolus vulgaris L. worldwide. However, aromatic plants from the families Lamiaceae, Lauraceae, Myrtaceae and Poaceae can protect kidney beans by direct or delayed insecticidal effect, through increased adult mortality and inhibition of beetle reproduction (both oviposition and adult emergence). The efficiency of hydrodistillated and intact plants fromThymus vulgaris andT. serpyllum, Mentha piperata, Rosmarinus officinalis, Satureia hortensis, Eucalyptus globulus, Laurus nobilis, Origanum vulgare, andCymbopogon nardus was compared. For both extracts,Origanum vulgare had the best effect. The insecticidal effect was induced by more than the essential oils because no significant difference was noticed between distilled and intact plants extract. Inhibition of reproduction was particularly important. These results suggest that lipidic as well as non lipidic, allelochemicals, such as phenolics, or non-protein amino-acids, or flavonoids may be involved in the toxicity of aromatic plants to this beetle.  相似文献   

19.
A bioblitz inexpensively and quickly generates biodiversity data, but bioblitzes are often conducted with haphazard, unreplicated sampling. Results tend to be taxonomically, geographically, or temporally biased, lack metadata, and consist of lists of observed taxa that do not enable further analyses or correction for imperfect detection. A rapid, recurring, structured survey (RRSS) uses a structured sampling design and temporal and spatial replication to survey randomly selected sites on a conservation property. We participated in a loosely structured bioblitz and a subsequent RRSS at Big Canoe Creek Nature Preserve in Springville (St. Clair County), Alabama (USA) to compare observed richness derived from the 2 survey approaches. The RRSS data structure enabled us to fit models that accounted for imperfect detection to estimate abundances, occupancy probabilities, and habitat associations. The loosely structured bioblitz data could not be used in such models. We present a new integrated multispecies abundance model that we applied to avian RRSS data. Our model extension enables estimation for the community, employs data augmentation to estimate the number of undetected species, and incorporates covariates. The RRSS generated a more comprehensive and less biased list of observed taxonomic richness than the loosely structured bioblitz (e.g., 73 vs. 45 bird species and 104 vs. 63 insect families from the RRSS vs. loosely structured bioblitz, respectively). Models fit to the RRSS data identified seasonal patterns in avian community composition and allowed for estimation of habitat–occupancy relationships for insect taxa. The RRSS protocol has potential for broad transferability as a standardized, quick, and inexpensive way to inventory biodiversity and estimate ecological parameters while providing an outreach opportunity.  相似文献   

20.
Land-use change via human development is a major driver of biodiversity loss. To reduce these impacts, billions of dollars are spent on biodiversity offsets. However, studies evaluating offset project effectiveness that examine components such as the overall compliance and function of projects remain rare. We reviewed 577 offsetting projects in freshwater ecosystems that included the metrics project size, type of aquatic system (e.g., wetland and creek), offsetting measure (e.g., enhancement, restoration, and creation), and an assessment of the projects’ compliance and functional success. Project information was obtained from scientific and government databases and gray literature. Despite considerable investment in offsetting projects, crucial problems persisted. Although compliance and function were related to each other, a high level of compliance did not guarantee a high degree of function. However, large projects relative to area had better function than small projects. Function improved when projects targeted productivity or specific ecosystem features and when multiple complementary management targets were in place. Restorative measures were more likely to achieve targets than creating entirely new ecosystems. Altogether the relationships we found highlight specific ecological processes that may help improve offsetting outcomes.  相似文献   

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