Proteins and Carbohydrates in Xylem Sap from Squash Root

The xylem sap from squash roots was collected from the cut surfaceof stems, and the proteins and carbohydrates in the sap wereanalyzed. The sap contained 18.6 µg ml^–1 proteinand the major polypeptides were as follows: 1) two polypeptides,of 75 and 40 kDa, with high-mannose glycans, the levels of whichincreased for about 24 h after cutting and then decreased; 2)a 32-kDa polypeptide, which appeared soon after cutting, disappearedand then reappeared again 48–64 h after cutting; and 3)a 19-kDa and a 14-kDa polypeptide, which were present constitutively.The carbohydrates contained in the xylem sap were fractionatedinto 80% ethanol-soluble and -insoluble material, and whichwere analyzed by high-performance liquid chromatography, gaschromatography and enzymatic mathods. The former fraction containedconsiderable amounts of myo-inositol and fructose as free sugarsand oligosaccharides composed mainly of galactose, arabinoseand glucose. The latter contained polysaccharides composed mainlyof uronic acids, galactose and arabinose. The possible significanceof these substances, which may mediate the interactions betweenthe root and the aerial organs, is discussed. (Received April 20, 1992; Accepted July 4, 1992)     

Seasonal Changes of the Metabolites in the Leaves, Bark and Xylem Tissues of Olive Tree (Olea europaea. L) II. Carbohydrates

Seasonal changes of starch and soluble carbohydrates in leaves,bark and xylem tissues of olive tree were examined during acomplete annual cycle. Leaf starch and soluble carbohydrateswere detected at high levels during the spring and autumn metabolicallyactive periods. The low level of leaf starch in combinationwith the drastic reduction of soluble carbohydrates and mannitol,defined the summer period of the low metabolic state of thetree. The low leaf starch level in conjunction with the risensoluble carbohydrate levels in leaves in winter were associatedwith cold acclimation processes. The bark and xylem tissueswere performing as starch deposition sites, and differencesin the extent of starch accumulation in these tissues were detectedduring the seasons. The starch fluctuations in bark and xylemwere discussed in relation to the translocation of metabolitesand other physiological processes. Mannitol, the most abundantleaf carbohydrate, was examined in relation to the reducingsugars exported to the bark. The bark mannitol was examinedin conjunction with the sucrose, glucose and starch levels inthe maturing bark tissues and was correlated to the low wintertemperatures. During the winter there was a drastic reductionof mannitol circulation from the bark to xylem. Olive tree, Olea europaea, L, carbohydrates     

Response of African Elephants (Loxodonta africana) to Seasonal Changes in Rainfall

The factors that trigger sudden, seasonal movements of elephants are uncertain. We hypothesized that savannah elephant movements at the end of the dry season may be a response to their detection of distant thunderstorms. Nine elephants carrying Global Positioning System (GPS) receivers were tracked over seven years in the extremely dry and rugged region of northwestern Namibia. The transition date from dry to wet season conditions was determined annually from surface- and satellite-derived rainfall. The distance, location, and timing of rain events relative to the elephants were determined using the Tropical Rainfall Measurement Mission (TRMM) satellite precipitation observations. Behavioral Change Point Analysis (BCPA) was applied to four of these seven years demonstrating a response in movement of these elephants to intra- and inter-seasonal occurrences of rainfall. Statistically significant changes in movement were found prior to or near the time of onset of the wet season and before the occurrence of wet episodes within the dry season, although the characteristics of the movement changes are not consistent between elephants and years. Elephants in overlapping ranges, but following separate tracks, exhibited statistically valid non-random near-simultaneous changes in movements when rainfall was occurring more than 100 km from their location. While the environmental trigger that causes these excursions remains uncertain, rain-system generated infrasound, which can travel such distances and be detected by elephants, is a possible trigger for such changes in movement.     

大绒鼠消化道形态的季节变化

为探讨栖息于横断山地区大绒鼠(Eothenomys miletus)的消化道特征与环境之间的适应关系,对自然环境中大绒鼠消化道各项指标进行了测定.实验分别测定了不同季节大绒鼠胃、小肠、大肠、盲肠的长度,及其含内容物重、去内容物重、干组织重.结果表明,大绒鼠消化道特征存在季节性变化,随着温度降低、食物质量下降,大绒鼠的小肠、盲肠长度增加;各器官重量均在6月份最大;大绒鼠在低温、食物质量下降、繁殖等胁迫因子作用下,通过增加食物摄入、调节消化道形态来满足能量需求的增加,维持正常的生理机能.大绒鼠的消化道在不同季节中表现出的变化模式,与其低纬度高海拔、年平均温度较低的生存环境有关,从一方面反映了该物种在温度胁迫下的生存机制和适应对策.     

Seasonal habitat use by Elephants (Loxodonta africana) in the Mole National Park of Ghana

To avoid unnecessary waste of limited resources and to help prioritize areas for conservation efforts, this study aimed to provide information on habitat use by elephants between the wet and dry seasons in the Mole National Park (MNP) of Ghana. We compiled coordinates of 516 locations of elephants’ encounters, 256 for dry season and 260 for wet season. Using nine predictor variables, we modeled the probability of elephant's distribution in MNP. We threshold the models to “suitable” and “nonsuitable” regions of habitat use using the equal training sensitivity and specificity values of 0.177 and 0.181 for the dry and wet seasons, respectively. Accuracy assessment of our models revealed a sensitivity score of 0.909 and 0.974, and a specificity of 0.579 and 0.753 for the dry and wet seasons, respectively. A TSS of 0.488 was also recorded for the dry season and 0.727 for the wet season indicating a good model agreement. Our model predicts habitat use to be confined to the southern portion of MNP due to elevation difference and a relatively steep slope that separates the northern regions of the park from the south. Regions of habitat use for the wet season were 856 km² and reduced significantly to 547.68 km² in the dry season. We observed significant overlap (327.24 km²) in habitat use regions between the wet and dry seasons (Schoener's D = 0.922 and Hellinger's‐based I = 0.991). DEM, proximity to waterholes, and saltlicks were identified as the key variables that contributed to the prediction. We recommend construction of temporal camps in regions of habitat use that are far from the headquarters area for effective management of elephants. Also, an increase in water point's density around the headquarters areas and selected dry areas of the park will further decrease elephant's range and hence a relatively less resource use in monitoring and patrols.     

白头鹎鸣唱特征的季节差异分析

许多动物的声通讯行为存在显著的季节变化,鸟类的鸣唱也是如此。雄鸟鸣唱具有宣告领域和吸引配偶的功能,在繁殖季节与非繁殖季节之间应存在一定差异,但差异如何？具体表现在哪些方面？这在很多鸟类中尚未可知。本研究以一种在秋季也有显著鸣唱行为的城市常见小型鸣禽——白头鹎（Pycnonotussinensis）为研究对象,比较其在春季（繁殖季）与秋季（非繁殖季）的鸣唱差异,并分析可能的原因。于2020至2021连续两年的春、秋季分别在武汉地区各采集了27只和30只雄性白头鹎的鸣唱录音,共测量分析春季鸣唱372个,秋季鸣唱435个。对测得的各鸣唱参数数据进行季节间比较,结果显示,白头鹎的鸣唱持续时间和鸣唱音节数存在显著季节差异,春季鸣唱的持续时间较秋季更长,鸣唱音节数更多。鸣唱的频率、能量分布等其他声学参数,以及鸣唱型出现率（反映鸣唱曲目大小）均未表现出显著季节差异。白头鹎鸣唱的时程特征相对其他鸣声特征更具季节可塑性。此外,还发现同一采样点的白头鹎春、秋两季使用相同的鸣唱型。本研究结果表明,春季白头鹎的单位时间鸣唱输出量更大,鸣唱行为更活跃,这与繁殖季节鸟类的领域性更强、为繁殖成功投入更多相一致。白头...     

Seasonal Variations in Lemur Edge Proximity in South-Eastern Madagascar

International Journal of Primatology - Edge effects are caused by the penetration of abiotic and biotic conditions from the nonforest matrix into forest interiors. Edge effects are particularly...     

Seasonal Distribution of Carbohydrates in Nodules and Stem Exudate from Field-grown Soya Bean Plants

The concentration of carbohydrates in tap root nodules fromfield-grown soya bean [Glycine max (L.) Merr.] plants was verysimilar to the concentration of compounds previously reportedin greenhouse-grown nodules during vegetative growth of seedlings.The concentration of D-pinitol, sucrose and starch in nodulesdeclined during rapid fruit growth, but the concentration ofother compounds did not decline. The availability of carbohydratein nodules during fruit growth did not seem likely to be thecause of the decline in nitrogen-fixing activity of noduleswhich has been reported by others. All compounds except glucoseand , -trehalose declined to concentrations near zero duringa 10-day period of nodule decay. However, the decline in carbohydratedid not appear to cause nodule senescence because it did notprecede the period of decay and because decayed nodules containedsubstantial quantities of glucose and , -trehalose. Seasonalmean concentrations (72 samples from 24 dates) of compounds,in mg carbohydrate per g f. wt of nodule, were: sucrose, 2.84;D-pinitol, 1.14; D-chiro-inositol, 1.27; glucose, 1.40; , -trehalose,1.34; myo-inositol, 0.65; maltose, 0.31; and fructose, 0.21. Quantities of sugars and cyclitols in stem exudate collectedin the field on 13 dates were small (< 10 percent) relativeto the quantity of nitrogenous compounds transported from rootsto shoots. The seasonal pattern of pinitol transport in thexylem was very similar to the seasonal pinitol concentrationin nodules. A large increase in sugar concentration in stemexudate subsequent to 80 days after planting supports the viewthat lack of carbohydrate was not a cause of nodule senescence. Glycine max (L.) Merr, soya bean, cyclitols, , -trehalose, starch, D-pinitol, carbohydrates, root nodules, senescence     

Seasonal Variations in Socially and Legally Unacceptable Sexual Behaviour

The calendar dates, over the 15-year span 1966-1980, of committed rapes by eight male recidivists and offences of sexually indecent or immoral behaviour by eight other male recidivists were gathered from the files of the Prefecture de Police, Paris, France. Each offender of the first group had committed from two to six rapes, while each offender of the second had committed from two to 16 incidences of indecent behaviour. Although the reported rapes took place during several calendar years, almost all, 18 out of 22 offences, were committed by the eight rape-recidivists during the 4-month span of July-October. Single cosinor analysis of these data revealed a circannual rhythmicity (P<0.03) with ø being 10 August τ 34 days (the 95% CL). The peak time of indecent sexual behaviour, exclusive of rape, against females occurred during September with secondary peaks in February and June; such offences directed against males peaked in October. 'Bootstrap' and 'Jacknife' methods confirmed seasonality within all data sets, except for the offences of indecent behaviour.     

笼养黑颈长尾雉能量摄入的季节变化

2005年10月至2006年9月采用全部收粪法实验和统计分析,对饲养于广西师范大学生物园的黑颈长尾雉(Syrmaticus humiae)进行了不同季节能量摄入的研究。实验测得了4个不同季节(全年12个月和12组温度)的总摄入能、代谢能、排泄能。结果表明,不同季节不同年龄组黑颈长尾雉的总摄入能、代谢能、排泄能与温度之间的相关性均存在显著差异,且随温度的升高而降低;能量消化效率有随温度升高而增大的趋势;相同季节里,4年组黑颈长尾雉的能量消化效率高于1年组黑颈长尾雉。对黑颈长尾雉而言,8月(30℃)的代谢能处于最低,30℃是否是最适温度,有待进一步探讨。     

Crcadian and Seasonal Variations of Lipogenesis in the Gulf Killifish,Fundulus Grandis

Lipogenesis was measured in male Gulf killifish at three seasons under different environmental conditions. Cold temperature is stimulatory for lipogenesis in the fall and spring, but warm temperature is more stimulatory during the summer. The highest rate of lipogenesis occurs during the spring. However, total body fat content is relatively low at that time, which suggests that lipids are being actively mobilized as well. A high rate of lipogenesis also occurs at a cold temperature (20°C) during the fall, and more lipids are stored at that time of year, as evidenced by higher liver and body fat stores. Both lipogenesis and total body fat content are at a minimum during the summer. These results indicate that high levels of lipid synthesis do not necessarily result in higher body fat content, as the latter is the product of both lipid synthesis and lipid mobilization. This study is also in agreement with previous studies which had indicated a changing responsiveness to temperature during the annual cycle of the Gulf killfish.     

Seasonal Variations in the Occurrence of Indole-3-Acetic-Acid in Buds of Pinus silvestris

Studies with a fluorescence spectrophotometer and gas chromatography confirm earlier results that IAA occurs in buds and sprouting shoots of Scots pine. IAA could be found during the whole vegetation period but not during winter dormancy. The largest amount was obtained during shoot growth in spring and early summer. During the most intensive elongation phase, a gradient could be found in the concentration of auxin with the highest amount in the basal part and a decreasing concentration upwards in the shoot.     

见血封喉乳汁中具有细胞毒活性的强心苷

从见血封喉(Antiaris toxicaria (Pers.) Lesch.)乳汁分离得到4个强心苷类化合物,经波谱数据分析,分别鉴定为：毒毛旋花子爪哇糖苷(1)、铃兰毒苷(2)、毒毛旋花子阿洛糖苷(3)和glucostrophanthidin (4)。化合物4为首次从见血封喉中分离得到。细胞毒活性测定结果表明,化合物1~4对慢性髓原白血病细胞(K562)、人胃癌细胞(SGC-7901)和人肝癌细胞(SMMC-7721)的增殖均显示了较强的生长抑制活性。     

Crcadian and Seasonal Variations of Lipogenesis in the Gulf Killifish, Fundulus Grandis

Lipogenesis was measured in male Gulf killifish at three seasons under different environmental conditions. Cold temperature is stimulatory for lipogenesis in the fall and spring, but warm temperature is more stimulatory during the summer. The highest rate of lipogenesis occurs during the spring. However, total body fat content is relatively low at that time, which suggests that lipids are being actively mobilized as well. A high rate of lipogenesis also occurs at a cold temperature (20°C) during the fall, and more lipids are stored at that time of year, as evidenced by higher liver and body fat stores. Both lipogenesis and total body fat content are at a minimum during the summer. These results indicate that high levels of lipid synthesis do not necessarily result in higher body fat content, as the latter is the product of both lipid synthesis and lipid mobilization. This study is also in agreement with previous studies which had indicated a changing responsiveness to temperature during the annual cycle of the Gulf killfish.     

A Stochastic Epidemic Model with Seasonal Variations in Infection Rate

In this paper we consider a modification of Bailey's stochastic model for the spread of an epidemic when there are seasonal variations in infection rate. The resulting nonlinear model is analyzed by employing the diffusion approximation technique. We have shown that for a large population the process, on suitable scaling and normalization, converges to a non-stationary Ornstein-Uhlenbeck process. Consequently the number of infectives has in the steady state a gaussian distribution.     

黑叶猴活动时间季节性变化

为全面了解黑叶猴(Trachypithecus francoisi)的生态习性和活动规律,从中探讨其对喀斯特石山生境的适应策略,从2001年3~12月,在广西扶绥珍贵动物保护区对一群黑叶猴进行了连续的跟踪观察,采用连续记录法收集相关的行为数据。结果表明,黑叶猴的日活动节律表现为上午和下午的觅食高峰,中午进入长时间的休息期。这可能与白天的温度和日照强度的变化有关。它们的活动节律具有明显的季节性变化,主要表现为雨季活动节律中的觅食高峰与旱季相比推迟1h出现;旱季觅食高峰中用于觅食的时间明显增加,且中午出现一个小的觅食高峰。在黑叶猴的活动时间分配中,平均65.4%的时间用于休息,19.6%用于觅食,9.9%用于移动,用于社会活动的时间平均仅占5.1%。它们的活动时间分配表现出明显的季节性变化。在旱季,用于觅食的时间明显多于雨季,而休息时间相应地减少。