热分析方法及裂解气相色谱在树木分类上的试探性研究

热分析是在程序控制温度下自动连续跟踪物质的物理性质与温度关系的一类技术。尤其是差热分析和热重法与其他手段联合,可用于化合物稳定性、分解机理和相转变等方面的研究。由于种子是一个复杂化合物的有机体,我们期望发现各不同种子化合物之间在成份上和组成方式上的共性和差异性,从热化学的角度对木本植物进行热化学分类。我们选用针叶类两个科(松科、杉木科)的种子进行了DTA、TG、550℃裂解气相色谱分析;300℃逸出成份分析,发现松科种子DTA图上在240±5℃有一个共同的吸热峰,而杉木则出现在320±5 ℃。TG曲线同科的不同种之间非常相似,逸出成份分析和裂解气相色谱分析同科的不同种之间也具共同特征,且又显示出一定的差异性。这种分类方法是可靠的,且可为树木(或植物)分类学提供更有价值的信息。     

钙—钙调素与小麦苗中热激蛋白的诱导

在３４℃热激条件下,种子经钙预处理的小麦苗中的钙调素含量随着热激时间的延长而增加,热激９０ｍｉｎ时达最大值,面种子用钙离子螯合剂ＥＧＴＡ预处理的小麦苗中钙调素含量无明显增加。种子用ＥＧＴＡ及钙调素拮抗剂ＣＰＺ和ＴＦＰ预处理的小麦幼苗在３４℃热激时,热激蛋白的合成量减少。４ｄ的小麦幼苗在３４℃或３７℃热激条件下,能诱导耐热性的获得,分别用ＥＧＴＡ、钙离子通道阻断剂易博定、钙调素拮抗剂ＴＦＰ或ＣＰＺ预     

农田生态条件下玉米秸秆腐解过程腐解物的热解变化特征

用热分析法研究了农田生态条件下玉米秸杆腐解过程腐解物的热解变化特征,并探讨了腐解物中不同组分对腐解物热解特征的影响。结果表明,腐解物ＤＴＡ曲线的２８０℃、３３０℃、４５０℃放热峰,ＤＴＧ曲线的第二失重峰和ｈ３３０℃／ｈ４５０℃值可作为表征腐解进程的特征峰和特征值。由腐解特ＤＴＡ、ＤＴＧ所得能量各参数（△Ｈ,Ｅ）与文献「３」所述腐解物能态（Ｑｖ）呈现波动起伏,趋于稳定２个阶段相符,二者相互印证,显示     

五种提取马尾松基因组DNA方法的比较

对于含有大量多糖如酚、酯、萜等其它二次代谢产物的松科和杉科等针叶植物,要从其组织中提取高质量的基因组ＤＮＡ一般都比较困难。本文以马尾松（ｐｉｎｕｓ ｍａｓｓｏｎｉａｎａ）针叶为材料,分别采取了简易提取法、高盐沉淀法、ＣＴＡＢ沉淀法、Ｚｉｅｇｅｎｈａｇｅｎ法和ＱＬＡＧＥＮ公司ＤＮｅａｓｙ Ｐｌａｎｔ Ｍｉｎｉ Ｋｉｔｓ５种方法提取基因组ＤＮＡ;并通过琼脂糖凝胶电泳、限制性内切酶自理和ＲＡＰＤ３种方法对     

苦荞麦营养器官的解剖学研究

苦荞麦营养器官的解剖学研究慕勤国（长庆油田第二中学,甘肃省庆阳地区马岭７４５１１３）关键词苦荞麦,营养器官,解剖ＡＮＡＴＯＭＩＣＡＬＳＴＵＤＩＥＳＯＮＴＨＥＶＥＧＥＴＡＴＩＶＥＯＲＧＡＮＳＯＦＦＡＧＯＰＹＲＵＭＴＡＴＡＲＩＣＵＭ￥ＭｕＱｉｎｇｕｏ（Ｔ...     

钙提高玉米种子活力的作用研究

本文以玉米种子为材料,研究了钙对种子活力的影响．在０—４０ｍｍｏｌ／ＬＣａ（２＋）的浓度范围,低浓度的Ｃａ（２＋）提高种子的发芽率和活力,最适浓度为１０ｍｍｏｌ／Ｌ,超过此浓度Ｃａ（２＋）的促进作用减弱．Ｃａ（２＋）提高种子发芽率和活力的原因可能是Ｃａ（２＋）促进胚和胚乳中α－和β－淀粉酶的活性,加速胚乳中贮藏物质如淀粉和可溶性蛋白的动员．在种子萌发过程中,ＥＧＴＡ和ＥＤＴＡ能降低种子活力,２．５和１０ｍｍｏｌ／ＬＣａ（２＋）能部分解除ＥＧＴＡ和ＥＤＴＡ的抑制作用．     

不同品种花生种子蛋白质的电泳分析

对中国花生（ＡｒａｃｈｉｓｈｙｐｏｇａｅａＬ．）５种不同类型的４６个栽培品种的种子蛋白质进行电泳分析。ＳＤＳＰＡＧＥ和ＩＥＦＳＤＳＰＡＧＥ（双向电泳）的结果显示,不同品种的花生种子蛋白多肽组成存在４种类型。与初步纯化的花生球蛋白及伴花生球蛋白的ＳＤＳＰＡＧＥ结果比较,花生种子蛋白组成的主要差异在于花生球蛋白亚基组成的不同,其中类型Ⅰ花生球蛋白主要含有４１ｋＤ、３８５ｋＤ和２个１８ｋＤ亚基,类型Ⅱ主要含４１ｋＤ、３８５ｋＤ、３７５ｋＤ和３个１８ｋＤ亚基,类型Ⅲ主要含４１ｋＤ、３８．５ｋＤ、３６．５ｋＤ和３个１８ｋＤ亚基,类型Ⅳ主要含４１ｋＤ、３８．５ｋＤ、３７５ｋＤ、３６．５ｋＤ和３个１８ｋＤ亚基。不同品种的伴花生球蛋白多肽组成基本一致。对不同类型８个品种种子蛋白的氨基酸组成进行测定,发现类型Ⅰ的含硫氨基酸含量较高。     

种子引发提高小麦抗渗透胁迫能力的效应

种子经渗透势－０．８ＭＰａ或－１．２ＭＰａＰＥＧ－６０００处理后,抗旱性不同小麦（ＴｒｉｔｉｃｕｍａｅｓｔｉｖｕｍＬ．）“晋麦３３”和“８４Ｇ６”种子萌发率均有提高,种子电解质外渗率明显降低,种子萌发适应渗透胁迫能力提高,种子可溶蛋白质含量、ＰＡＬ和ＰＯＤ活性显著增加,“晋麦３３”种子ＣＡＴ活性增加,两品种幼苗ＰＡＬ、ＰＯＤ和ＣＡＴ活性也均有提高,但“８４Ｇ６”种子ＣＡＴ活性下降。     

MALDI-TOF-MS对寡核苷酸的序列分析

通过对几种基质测定含不同碱基的寡核苷酸的灵敏度及精确度的比较,发现用混合基质α－氰基４－羟基肉桂酸（α－Ｃｙａｎｏ）／３－羟基吡啶羧酸（３ＨＰＡ）用于基质辅助激光解吸附电离飞行时间质谱中测定脱氧寡核苷酸,不仅能得到较好的分子离子峰,而且一些金属离子的加合物峰能得到有效的抑制,提高了测定的灵敏度。用３′－和５′－外切酶对脱氧寡核苷酸１２－ｍｅｒ（５′－ＡＴＧＣＡＴＡＴＧＣＡＴ－３′）进行部分降解,再进行ＭＡＬＤＩ－ＴＯＦ－ＭＳ分析,得到了完整的寡核苷酸的序列。     

粘虫核型多角体病毒一个新基因的序列和结构研究

本文报道ＴｓＮＰＶＤＮＡＥｃｏＲＶ／ＸｈｏＩ的５．５ｋｂ片段的克隆及其物理图谱。测定了其中一个８１９ｂＰ片段的全序列。在长３４６ｂｐ的完整ＯＲＦ的５’端除有ＴＡＴＡｂｏｘ和ＣＡＡＴｂｏｘ以外,还发现有典型的早期基因启动子元件ＡＣＧＴ和ＧＣ单元以及晚期基因的转录起始保守序列ＴＴＡＡＧ。预测的ＯＲＦ产物为１１４个氨基酸、分子量为１３ｋＤ的蛋白质,故命名为ｐ１３蛋白。在ｐ１３基因的Ｃ端和Ｎ端分别有一个亮氨酸拉链和两个类亮氨酸拉链结构（我们称为亮氨酸转型结构和ＬＶＴ重复结构〕．从终止密码起有一个双发卡环结构,ｐ１３基因的５’端调控单元及其排列与ＢｍＮＰＶ和ＡｃＮＰＶ的细胞序死抑制基因（ｐ３５）十分相似,但ｐ１３基因与已经发现的杆状病毒基因序列和氨基酸序列没有同源性．因此,这是一个新的早晚期基因,其调控元件可能具有重要功能。     

Artificial ice crystal formation in excised short shoots of Pinus silvestris L.

Controlled freezing methods adopted for Thermal Analysis (TA) and Differential Thermal Analysis (DTA), were used to investigate the capacity for subcooling short shoots of Pinus silvestris L. of various ages. Both methods showed that there were no differences in subcooling temperature along the length of the short shoots. Differences in age and water content have a significant effect on the freezing profiles. Short shoots of the current years growth were able to subcool to about −13°C. One-year-old short shoots subcooled to about −9°C. There were no apparent variations in subcooling temperatures from June to September. Rainfall or dry periods had no effect on subcooling temperatures. The freezing profiles of living material was characteristic and was not repeated during subsequent freezing cycles. Detection of ice crystal formation during refreezing experiments indicated whether short shoots were alive or dead.     

Object-based classification of land cover and tree species by integrating airborne LiDAR and high spatial resolution imagery data

We evaluated the effectiveness of integrating discrete return light detection and ranging (LiDAR) data with high spatial resolution near-infrared digital imagery for object-based classification of land cover types and dominant tree species. In particular we adopted LiDAR ratio features based on pulse attributes that have not been used in past studies. Object-based classifications were performed first on land cover types, and subsequently on dominant tree species within the area classified as trees. In each classification stage, two different data combinations were examined: LiDAR data integrated with digital imagery or digital imagery only. We created basic image objects and calculated a number of spectral, textural, and LiDAR-based features for each image object. Decision tree analysis was performed and important features were investigated in each classification. In the land cover classification, the overall accuracy was improved to 0.975 when using the object-based method and integrating LiDAR data. The mean height value derived from the LiDAR data was effective in separating “trees” and “lawn” objects having different height. As for the tree species classification, the overall accuracy was also improved by object-based classification with LiDAR data although it remained up to 0.484 because spectral and textural signatures were similar among tree species. We revealed that the LiDAR ratio features associated with laser penetration proportion were important in the object-based classification as they can distinguish tree species having different canopy density. We concluded that integrating LiDAR data was effective in the object-based classifications of land cover and dominant tree species.     

Generalist grasshoppers from thermally variable sites do not have higher thermal tolerance than grasshoppers from thermally stable sites - A study of five populations

Thermal tolerance allows many organisms, including insects, to withstand stressful temperatures. Thermal generalists are expected to have higher thermal tolerance than specialists, but the environmental conditions leading to the evolution of a thermal generalist life history are not fully understood. Thermal variability has been put forth as an evolutionary driver of high thermal tolerance, but rarely has this been empirically tested. We used a generalist agricultural pest grasshopper, Melanoplus differentialis, to test upper and lower thermal limits of populations that experienced different levels of thermal variability.We quantified thermal heterogeneity at five sites in a longitudinal transect in the Midwestern U.S. by examining, over a 101-year period, 1) variance in daily thermal maxima and minima; and 2) daily range. Also, as a measure of a biologically relevant thermal extreme, we depicted days per month at each site that reached a stressfully high temperature for M. differentialis. We collected individuals from these sites and tested their upper and lower thermal limits. We found that most of our metrics of thermal heterogeneity differed among sites, while all sites experienced an average of at least two stressfully high temperature events per month. We found that heavier males from these sites were able to withstand both warmer and colder temperatures than smaller males, while heavier females had no thermal advantage over lighter females. However, site of origin had no effect on thermal tolerance.Our findings indicate three things: 1) there is no clear correlation between thermal variability and thermal tolerance in the populations we studied; 2) weight affects thermal tolerance range among sites for M. differentialis males, and 3) thermal extremes may be more important than thermal variability in determining CTMax in this species.     

Thermo-Mechanical Analysis of Restored Molar Tooth using Finite Element Analysis

The aim of the study is to find most optimum combination of crown material and adhesive to avoid loosening and thereby failure of restored tooth. This study describes the Thermo-Mechanical analysis of restored molar tooth crown for determination of the stress levels due to thermal and mechanical loads on restored molar tooth. The potential use of the 3-D model was demonstrated and analyzed using different materials for crown. Thermal strain, stress and deformation were measured at hot and cold conditions in ANSYS and correlated with analytical calculation and existing experimental data for model validation and optimization. It is concluded that amongst various material porcelain crown with composite resin adhesive cement closely simulates the behavior of natural crown and should ideally result into long lasting restoration.     

Study of banana and coconut fibers Botanical composition, thermal degradation and textural observations

Four fibers from banana-trees (leaf, trunk) and coconut-tree (husk, fabric) were examined before their incorporation in cementitious matrices, in order to prepare insulating material for construction. Their botanical compositions have been determined following a method described previously. Thermal degradation of these fibers were studied between 200 and 700 degrees C under nitrogen gas flow. Temperature of pyrolysis was the experimental parameter investigated. The solid residues obtained were analyzed by classical elemental analysis, Fourier Transform Infra Red (FTIR) spectroscopy and were observed by Scanning Electron Microscopy (SEM). This study has shown (1) the relation between botanical, chemical composition with both localization of fibers in the tree and type of tree; (2) the rapid and preferential decomposition of banana fibers with increasing temperature of pyrolysis and (3) the rough samples are made of hollow fibers.     

Standardized ethograms and a device for assessing amphibian thermal responses in a warming world

Most predictions of how populations and species of ectotherms will respond to global warming are based on estimates of the temperature at which organisms lose motor control (i.e., CT_max - the Critical Thermal Maximum). Here, we describe a non-lethal protocol and ethograms to estimate the relative tolerance of amphibians to increasing temperatures. These methods—suitable for field or laboratory conditions—are replicable, inexpensive and applicable to both post-metamorphic stages and organisms with direct development. We illustrate the use of this standardized protocol for four amphibians from a tropical cloud forest in Veracruz, Mexico with contrasting life histories: a lungless salamander (Aquiloeurycea cafetalera: Plethodontidae), a leaf-litter frog (Craugastor rhodopis: Craugastoridae), a semiaquatic frog (Lithobates berlandieri: Ranidae), and a tree frog (Rheohyla miotympanum: Hylidae). We identified four behavioral responses preceding CT_max for all amphibians included in this study: 1) Optimal Activity Range, 2) Supra-optimal Activity Range, 3) Heat Stress Range, and 4) Involuntary Movements Range. Additionally, we identified a fifth parameter associated with resilience to heat shock: 5) Recovery Stage after reaching CT_max. We conclude that the behavioral responses preceding the Critical Thermal Maximum are as informative as CT_max. Using behavioral responses to estimate thermal tolerance has the additional advantage of reducing the risk of injury or death of amphibians during physiological experiments.     

Temperature acclimation affects thermal preference and tolerance in three Eremias lizards

We acclimated adult males of three Eremias lizards from different latitudes to 28℃,33℃ or 38℃ to examine whether temperature acclimation affects their thermal preference and tolerance and whether thermal preference and tolerance of these lizards correspond with their latitudinal distributions.Overall,selected body temperature（Tsel）and viable temperature range（VTR）were both highest in E.brenchleyi and lowest in E.multiocellata,with E.argus in between;critical thermal minimum（CTMin）was highest in E.multiocellata and lowest in E.brenchleyi,with E.argus in between;critical thermal maximum（CTMax）was lower in E.multiocellata than in other two species.Lizards acclimated to 28℃ and 38℃ overall selected lower body temperatures than those acclimated to 33℃;lizards acclimated to high temperatures were less tolerant of low temperatures,and vice versa;lizards acclimated to 28℃ were less tolerant of high temperatures but had a wider VTR range than those acclimated to 33℃ and 38℃.Lizards of three species acclimated to the three temperatures always differed from each other in CTMin,but not in Tsel,CTMax and VTR.Our results show that：temperature acclimation plays an important role in influencing thermal preference and tolerance in the three Eremias lizards,although the degrees to which acclimation temperature affects thermal preference and tolerance differ among species;thermal preference rather than tolerance of the three Eremias lizards corresponds with their latitudinal distributions.     

Behavioral classification of low‐frequency acceleration and temperature data from a free‐ranging small mammal

The miniaturization and affordability of new technology is driving a biologging revolution in wildlife ecology with use of animal‐borne data logging devices. Among many new biologging technologies, accelerometers are emerging as key tools for continuously recording animal behavior. Yet a critical, but under‐acknowledged consideration in biologging is the trade‐off between sampling rate and sampling duration, created by battery‐ (or memory‐) related sampling constraints. This is especially acute among small animals, causing most researchers to sample at high rates for very limited durations. Here, we show that high accuracy in behavioral classification is achievable when pairing low‐frequency acceleration recordings with temperature. We conducted 84 hr of direct behavioral observations on 67 free‐ranging red squirrels (200–300 g) that were fitted with accelerometers (2 g) recording tri‐axial acceleration and temperature at 1 Hz. We then used a random forest algorithm and a manually created decision tree, with variable sampling window lengths, to associate observed behavior with logger recorded acceleration and temperature. Finally, we assessed the accuracy of these different classifications using an additional 60 hr of behavioral observations, not used in the initial classification. The accuracy of the manually created decision tree classification using observational data varied from 70.6% to 91.6% depending on the complexity of the tree, with increasing accuracy as complexity decreased. Short duration behavior like running had lower accuracy than long‐duration behavior like feeding. The random forest algorithm offered similarly high overall accuracy, but the manual decision tree afforded the flexibility to create a hierarchical tree, and to adjust sampling window length for behavioral states with varying durations. Low frequency biologging of acceleration and temperature allows accurate behavioral classification of small animals over multi‐month sampling durations. Nevertheless, low sampling rates impose several important limitations, especially related to assessing the classification accuracy of short duration behavior.     

Inter-population variation in thermal sensitivity of the tropical toad Duttaphrynus melanostictus,across a small spatial scale in Sri Lanka

Inter-population disparities in a species have been shown to occur as an adaptation to different thermal regimes in the environment. We investigated the thermal sensitivities of the tropical toad Duttaphrynus melanostictus (Asia Common Toad) from two populations at different altitudes: Nuwara-Eliya – 1870 m, and Polonnaruwa – 25 m, above mean sea level. The two locations were separated by what may be considered a short direct distance – 110 km. Thermal sensitivity trials were conducted at six temperatures between 12 and 39 °C. Assessments were made using the performance indicators jump distance, jump force, contact time on the test plate following stimulus to jump, and righting time after being overturned. Optimum performance is taken to be the greatest jump distance and jump force, the least contact time on the test plate, and the least righting time. The populations at the two altitudes had markedly different thermal sensitivities – toads in the cool area (Nuwara-Eliya) performed at an optimal level under low temperatures, whereas the toads in the warm area (Polonnaruwa) performed optimally under high temperatures. The finding that the thermal optima (i.e., the temperatures at which the optimal performance for the four performance indicators was recorded) of the toads in Polonnaruwa were below the mean maximum ambient temperature at this location suggests that these toads would be more susceptible to global warming than those in Nuwara-Eliya whose thermal optima were above the mean maximum ambient temperature in that location. This was consistent with the narrower thermal safety margin (i.e., difference between the mean optimum temperature and mean ambient temperature) of toads in Polonnaruwa, compared to those in Nuwara-Eliya. Importantly, these findings demonstrate that, although thermal sensitivity is considered a conservative trait, differentiation does occur even over a small spatial scale presumably because it offers an adaptive advantage to the population concerned.