Wave-separation in complex systems. Application to brain-signals

A departure from single-system dynamics, that may arise in characterizing self-organized dynamics of complex systems, is dealt with by using the Karhunen-Loève expansion of the trajectory matrix to decompose an experimental signal in a sum of spectral features. For an electroencephalographic -signal, a separation of waves and extraction of additive sub-signals are achieved, each sub-signal covering a well-bounded and physiologically meaningful frequency range. From the subsignals, an attractor that vanishes on phase-randomizing the data is characterized, under conditions where none was found for the recorded signal.     

The interaction of the vanadyl(IV) cation with phytic acid

The interactions of VO²⁺ with phytate to form both soluble and insoluble complexes, have been studied by electronic absorption spectroscopy. A soluble 1∶1 VO²⁺: phytate complex is formed at pH <1. At higher pH-values insoluble complexes are produced. Two different solid complexes, obtained respectively at pH=2 and 4, were isolated and characterized. The maximal bonding ratio of VO²⁺: phytate was found to be 4, on the basis of a pH binding profile.     

新生儿接种小剂量乙肝疫苗后3-5年随访观察

本文对９３８例初生婴儿接种小剂量（１０ｕｇ×３）乙肝疫苗后３－５年的预防效果进行了随访观察,并以２５３例初生儿未接种疫苗者作为对照,结果表明,接种组３－５年后抗－ＨＢｓ阳性率显著高于对照组,ＨＢｓＡｇ阳性率则较对照组显著为低。感染保护率８６．７％。结果还表明,接种乙肝疫苗３年后加强１次,比不加强者Ｐ／Ｎ均值显著增高。文章认为初生儿接种小剂量乙肝疫苗有长期免疫效果;接种后３年加强接种１次,可保持较高免疫力。     

The Value of a hoard: not just energy

We present a stochastic dynamic programming model of the contributionof stored food to winter survival. Using the acorn woodpecker(Melanerpes formtcivorus) as a model organism, we demonstratethat a hoard of small energetic value can impart considerableimprovement in the probability of surviving the winter and soimprove fitness. With this model we hope to resolve Koenig andMumme's paradox, that acorn woodpeckers expend much time andeffort to create and maintain hoards of acorns which provideno more that 16% of their energetic needs over the period inwhich they are used. We further demonstrate that the contributionof hoarded acorns to survival depends on the variability inforaging outcome, independently of the energetic value of thehoard in absolute terms. We point out that the results applyin principle to all hoarding animals and suggest a number offurther elaborations of the model.     

Effects of fire on landscape heterogeneity in Yellowstone National Park,Wyoming

Abstract. A map of burn severity resulting from the 1988 fires that occurred in Yellowstone National Park (YNP) was derived from Landsat Thematic Mapper (TM) imagery and used to assess the isolation of burned areas, the heterogeneity that resulted from fires burning under moderate and severe burning conditions, and the relationship between heterogeneity and fire size. The majority of severely burned areas were within close proximity (50 to 200 m) to unburned or lightly burned areas, suggesting that few burned sites are very far from potential sources of propagules for plant reestablishment. Fires that occurred under moderate burning conditions early during the 1988 fire season resulted in a lower proportion of crown fire than fires that occurred under severe burning conditions later in the season. Increased dominance and contagion of burn severity classes and a decrease in the edge: area ratio for later fires indicated a slightly more aggregated burn pattern compared to early fires. The proportion of burned area in different burn severity classes varied as a function of daily fire size. When daily area burned was relatively low, the proportion of burned area in each burn severity class varied widely. When daily burned area exceeded 1250 ha, the burned area contained about 50 % crown fire, 30 % severe surface burn, and 20 % light surface burn. Understanding the effect of fire on landscape heterogeneity is important because the kinds, amounts, and spatial distribution of burned and unburned areas may influence the reestablishment of plant species on burned sites.     

Distribution and conservation status of coastal sage scrub in southwestern California

Abstract. A landscape-based characterization of vegetation has been developed for southwestern California using satellite imagery, air photos, existing vegetation maps, and field data. Distribution maps of nine dominant coastal scrub species and 13 species assemblages that were identified by divisive information analysis have been analyzed to quantify spatial patterns of species co-occurrence. Three general distribution patterns are identified that suggest the Diegan, Ventaran and Riversidian Associations identified by other workers. Vegetation data have also been related to land ownership and management to assess the conservation status of upland plant communities. A large proportion of the mapped distribution of species and vegetation types is on private land, and several taxa show less than 4 % of mapped distribution in nature reserves. The analysis highlights the need to extend current conservation planning efforts into the northern part of the region to encompass areas where Salvia leucophylla is a frequent community dominant.     

Storage-protein variation in wild emmer (Triticum turgidum ssp.dicoccoides) from Jordan and Turkey.

Genetic diversity in the seed storage-proteins encoded at theGlu-A1,Glu-B1 andGli-B1/Glu-B3 loci was studied electrophoretically in 315 individuals belonging to nine populations ofT. dicoccoides from Jordan and three from Turkey. The inter- and intra-population distribution of seed storage-protein alleles at the considered loci and its link with geographical factors were investigated. Population differentiation in seed storage-proteins was in some cases very high with very weak correlations with geographic distance. Greater gene differentiation was found within and between populations which were geographically very close in Jordan than between those from Jordan and Turkey. However the distribution of alleles appeared to be non random. Samples collected from populations at locations over 900 m above sea level were less polymorphic than those collected at lower altitudes (500–700 m), whereas the relative genetic differentiation between populations was greater between those collected at higher altitudes. Seed storage-protein differentiation was significantly correlated with the altitude of the collecting sites. Although it is difficult to point out the selective pressure of altitude per se, altitude can reflect an integration of several environmental parameters. The possible adaptive value of seed storage-proteins is discussed.     

慈竹无性系种群能值特点及其影响能值计测因素的研究

 本文引用Harper(1977)的构件结构理论,从构件结构单位、无性系分株和无性系三个层次,对四川南充市郊慈竹无性系种群的能值特点及其影响能值的计测因素进行了定量研究。研究结果表明：慈竹无性系种群中,各构件单位的去灰分热值(AFCV)分别为：根15349.42J／g、根茎16372.92J／g、秆17106.06J／g、枝18111.99J／g和叶19451.90J／g;慈竹无性系分株的AFCV(J／g)随龄级增大而递增;慈竹无性系水平上的AFCV为：Ⅰ龄占16.47%、Ⅱ龄占25.76%、Ⅲ龄占36.32%、Ⅳ龄为13.08%及Ⅴ龄为8.37%。用恒容燃烧法测定热值时,其能值变化与氧分压密切相关。用经验公式计算的能值较作图法高;用AFCV表示能值较总干重热值(GCV)准确。     

金沙江下游典型库区消落带植被恢复模式

消落带植被分布、生活型、多样性的调查研究显著促进了消落带植被恢复技术的进步,然而相邻两梯级库区消落带植被分布的差异以及植被群落特征的年际变化并不明确。此外,金沙江下游部分区域表现出一定的干热特征,其影响下的消落带植被群落特征有待深入了解。基于2019年和2021年向家坝和溪洛渡库区消落带植被调查结果,分析表明：(1)金沙江下游消落带按照下垫面特性主要分为硬岩型、软岩型、松软堆积型3种类型,坡度平缓的松软堆积型消落带是植被恢复的主要类型;(2)整体上,消落带优势植被类型是一年生和多年生草本,单优势种、少优势种群落较为普遍,两个库区消落带优势种重要值差异显著,植被生活型较少;(3)向家坝、溪洛渡库区消落带在分别经历6次和8次周期性水淹后,消落带植被分布与群落物种多样性特征变化不显著,表明消落带植被群落结构相对稳定。综上说明向家坝、溪洛渡两个相邻的梯级库区消落带植被恢复需要以灌草为主,且具有不同的潜在恢复模式,因此需要对应采取不同的恢复策略。研究对于科学指导金沙江下游梯级水电站库区消落带植被恢复具有重要意义。     

海南潜在世界自然遗产地的突出普遍价值初探

世界自然遗产地是全球最具有保护价值的自然保护地,强调全球突出普遍价值的完整性和在全球的唯一性。世界自然遗产有助于更好地保护生态系统的完整性和原真性,促进人类与自然的可持续发展。该研究在大量文献资料的基础上,以海南潜在世界自然遗产地(海南热带雨林国家公园)原生动植物及植被群落(亚洲北缘热带雨林)为研究对象,从植被类型、物种多样性、区系组成、特有种等生物生态过程方面,评估海南潜在世界自然遗产地的全球突出普遍价值。结果表明:(1)海南潜在世界自然遗产地分布有3 653种野生维管植物,资源植物种类丰富。陆栖脊椎动物有540种,各类野生动物占全国的比例高达10%～30%,生物多样性极高。(2)植物区系独特,海南岛的热带雨林植被区划属于印度-马来雨林群系,属马来区的部分呈现出热带性和与中国华南大陆的共源性显示出明显的热带边缘性质,为中国华南植物区系与亚洲热带雨林的过渡类型。(3)植物区系中的植物物种特有性较低,特有属仅有7个,特有种仅约占岛内植物的1/10,较低的特有性表明了其大陆起源特征,是生物多样性不可替代的元素,具有鲜明的环境指示特色。该研究明确了海南潜在世界自然遗产地在全球背景下的突出普遍价值,为海南未来申遗提供科学依据和技术支撑。