A study of direct moxibustion using mathematical methods

Direct moxibustion is an important and widely used treatment method in traditional medical science. The use of a mathematical method to analyse direct moxibustion treatment is necessary and helpful in exploring the new direct moxibustion instruments and their standardisation. Thus, this paper aims to use a mathematical method to study direct moxibustion in skin to demonstrate a direct relationship between direct moxibustion and skin stimuli. In this paper, the transient thermal response of skin layers is analysed to study direct moxibustion using the data got from standardised method to measure the temperature of a burning moxa cone. Numerical simulations based on an appropriate finite element model are developed to predict the heat transfer, thermal damage and thermal stress distribution of barley moxa cones and jujube moxa cones in the skin tissue. The results are verified by the ancient literatures of traditional Chinese medicine and clinical application, and showed that mathematical method can be a good interface between moxa cone and skin tissue providing the numerical value basis for moxibustion.     

艾燃烧生成物对SAM小鼠学习记忆行为的影响

目的：艾灸不仅可以延年益寿而且可以未病先防。然而仅有少量研究证实,艾灸的燃烧生成物具有抗氧化作用从而延缓衰老。本试验从行为学方面研究艾燃烧生成物对快速老化模型小鼠SAM—W8学习记忆行为的影响。方法：选用6月龄雄性快速老化模型（SAM）小鼠50只,其中SAM—R／1系10只作为空白组,SAM—W8系40只随机分为模型组、单纯艾烟熏吸组、无烟艾灸组和常规艾灸组,每组10只。选取关元穴为治疗穴位,令常规艾灸关元组小鼠在艾灸关元穴的同时处在一定浓度艾烟的环境中;单纯艾烟熏吸组小鼠处在与常规艾灸关元组相同浓度的艾烟环境但不艾灸其穴位;而无烟艾灸关元组则是在艾灸小鼠关元穴的同时立即将艾烟抽除;其余空白组和模型组小鼠进行相同的空白抓取。治疗前后分别进行学习记忆行为的被动逃避试验,并对实验结果进行分析。结果：与空白组比较,治疗前模型组及治疗各组小鼠进行被动逃避试验的潜伏期均明显变短,有显著性差异（P〈0．05,P〈0．05,P〈0．01,P〈0．01）,治疗后模型组及常规艾灸关元组小鼠治疗后潜伏期均明显缩短,有显著性差异（P〈0．01,P〈0．05）;与模型组比较,各治疗组小鼠治疗后潜伏期均明显延长,有显著差异（P〈0．01,P〈0．01,P〈0．05）。与治疗前比较,各治疗组治疗后潜伏期均较前明显延长,有显著性差异（P〈0．01,P〈0．05,P〈0．05）。结论：艾燃烧生成物可延长快速老化模型小鼠被动逃避试验的潜伏期。提示其在一定程度上改善老化模型小鼠的学习记忆功能,为今后艾灸抗衰老在临床上的应用开辟了新思路。     

艾灸治疗压疮的研究现状

艾灸能够发挥温经散寒、行气活血通经活络散瘀通滞的作用,治疗压疮的临床疗效显著,但其分子机制仍不清楚。新血管的生成在压疮修复、愈合的过程中发挥重要的作用,可为新生组织提供着氧气和营养成分。虽然现代医学对褥疮组织的血管新生分子机制研究不断深入,但仍缺乏有效的治疗手段。艾条的种类、施灸操作种类及艾灸的作用机理等方面均可影响艾灸治疗压疮的疗效。如何将艾灸治疗褥疮的中医原创特色与现代医学对于新生血管深入的分子机制研究有机结合是值得思考的问题。     

A mathematical model for photoreceptor interactions

The interactions between rods and cones in the retina have been the focus of innumerable experimental and theoretical biological studies in previous decades yet the understanding of these interactions is still incomplete primarily due to the lack of a unified concept of cone photoreceptor organization and its role in retinal diseases. The low abundance of cones in many of the non-primate mammalian models that have been studied make conclusions about the human retina difficult. A more complete knowledge of the human retina is crucial for counteracting the events that lead to certain degenerative diseases, in particular those associated with photoreceptor cell death (e.g., retinitis pigmentosa). In an attempt to gain important insight into the role and interactions of the rods and the cones we develop and analyze a set of mathematical equations that model a system of photoreceptors and incorporate a direct rod-cone interaction. Our results show that the system can exhibit stable oscillations, which correspond to the rhythmic renewal and shedding of the photoreceptors. In addition, our results show the mathematical necessity of this rod-cone direct interaction for survival of both and gives insight into this mechanism.     

Visual modelling suggests a weak relationship between the evolution of ultraviolet vision and plumage coloration in birds

Birds have sophisticated colour vision mediated by four cone types that cover a wide visual spectrum including ultraviolet (UV) wavelengths. Many birds have modest UV sensitivity provided by violet‐sensitive (VS) cones with sensitivity maxima between 400 and 425 nm. However, some birds have evolved higher UV sensitivity and a larger visual spectrum given by UV‐sensitive (UVS) cones maximally sensitive at 360–370 nm. The reasons for VS–UVS transitions and their relationship to visual ecology remain unclear. It has been hypothesized that the evolution of UVS‐cone vision is linked to plumage colours so that visual sensitivity and feather coloration are ‘matched’. This leads to the specific prediction that UVS‐cone vision enhances the discrimination of plumage colours of UVS birds while such an advantage is absent or less pronounced for VS‐bird coloration. We test this hypothesis using knowledge of the complex distribution of UVS cones among birds combined with mathematical modelling of colour discrimination during different viewing conditions. We find no support for the hypothesis, which, combined with previous studies, suggests only a weak relationship between UVS‐cone vision and plumage colour evolution. Instead, we suggest that UVS‐cone vision generally favours colour discrimination, which creates a nonspecific selection pressure for the evolution of UVS cones.     

Avian Cone Photoreceptors Tile the Retina as Five Independent,Self-Organizing Mosaics

The avian retina possesses one of the most sophisticated cone photoreceptor systems among vertebrates. Birds have five types of cones including four single cones, which support tetrachromatic color vision and a double cone, which is thought to mediate achromatic motion perception. Despite this richness, very little is known about the spatial organization of avian cones and its adaptive significance. Here we show that the five cone types of the chicken independently tile the retina as highly ordered mosaics with a characteristic spacing between cones of the same type. Measures of topological order indicate that double cones are more highly ordered than single cones, possibly reflecting their posited role in motion detection. Although cones show spacing interactions that are cell type-specific, all cone types use the same density-dependent yardstick to measure intercone distance. We propose a simple developmental model that can account for these observations. We also show that a single parameter, the global regularity index, defines the regularity of all five cone mosaics. Lastly, we demonstrate similar cone distributions in three additional avian species, suggesting that these patterning principles are universal among birds. Since regular photoreceptor spacing is critical for uniform sampling of visual space, the cone mosaics of the avian retina represent an elegant example of the emergence of adaptive global patterning secondary to simple local interactions between individual photoreceptors. Our results indicate that the evolutionary pressures that gave rise to the avian retina''s various adaptations for enhanced color discrimination also acted to fine-tune its spatial sampling of color and luminance.     

Modelling of the vertebrate visual system 3. topological analysis of the cone mosaic

Spatial organization of the cone mosaic of the generalized vertebrate retina consists of rows of red and green cones alternating with rows of blue and blank cones. Cone inputs to retinal elements are defined spatially by red and green unit hexagons. Topological analysis entails determining for each cone in the mosaic the number of each cone type present in the unit hexagon which the activated cone can influence via electrical coupling between cones and/or stray light. Only weighted inputs in one-half of a sextant of the unit hexagon need be designated, since all other weighted inputs can be determined by rules giving systematic transformations of all cone types from one sextant to another: these rules arise from symmetries of the cone mosaic. Four retinal types are possible depending on replacement of blank cones by specific cone types; three cone-dominant retinas, where all blank cones are replaced by a specific cone type, and two forms of a trichromatic retina, where blank cones are replaced by equal numbers of red and green cones. The weighted input is the sum of individual cone type contributions and depends on the number of each cone type in the unit hexagon which can influence the cone in question. Weighted inputs for cone-dominant retinas are readily found by replacing blank cones with the proper cone type, while weighted inputs for trichromatic retinas require use of a specified cone mosaic to determine extra red and green cones. Receptive field size of post-cone elements as well as overlap of the center and surround fields of annular organized receptive fields of retinal elements increased with increasing values for attenuation factors.     

Growth cone collapse through coincident loss of actin bundles and leading edge actin without actin depolymerization

Repulsive guidance cues can either collapse the whole growth cone to arrest neurite outgrowth or cause asymmetric collapse leading to growth cone turning. How signals from repulsive cues are translated by growth cones into this morphological change through rearranging the cytoskeleton is unclear. We examined three factors that are able to induce the collapse of extending Helisoma growth cones in conditioned medium, including serotonin, myosin light chain kinase inhibitor, and phorbol ester. To study the cytoskeletal events contributing to collapse, we cultured Helisoma growth cones on polylysine in which lamellipodial collapse was prevented by substrate adhesion. We found that all three factors that induced collapse of extending growth cones also caused actin bundle loss in polylysine-attached growth cones without loss of actin meshwork. In addition, actin bundle loss correlated with specific filamentous actin redistribution away from the leading edge that is characteristic of repulsive factors. Finally, we provide direct evidence using time-lapse studies of extending growth cones that actin bundle loss paralleled collapse. Taken together, these results suggest that actin bundles could be a common cytoskeletal target of various collapsing factors, which may use different signaling pathways that converge to induce growth cone collapse.     

Computational determination of refractive index distribution in the crystalline cones of the compound eye of Antarctic krill (Euphausia superba)

In order to understand how a compound eye channels light to the retina and forms an image, one needs to know the refractive index distribution in the crystalline cones. Direct measurements of the refractive indices require sections of fresh, unfixed tissue and the use of an interference microscope, but frequently neither is available. Using the eye of the Antarctic krill Euphausia superba (the main food of baleen whales) we developed a computational method to predict a likely refractive index distribution non-invasively from sections of fixed material without the need of an interference microscope. We used a computer model of the eye and calculated the most realistic spatial distribution of the refractive index gradient in the crystalline cone that would enable the eye to produce a sharp image on the retina. The animals are known to see well and on the basis of our computations we predict that for the eyes of the adult a maximum refractive index of 1.45-1.50 in the centre of the cone yields a better angular sensitivity and light absorption in a target receptor of the retina than if N(max) were 1.55. In juveniles with a narrower spatial separation between dioptric structures and retina, however, an N(max) of 1.50-1.55 gives a superior result. Our method to determine the most likely refractive index distribution in the cone without the need of fresh material and an interference microscope could be useful in the study of other invertebrate eyes that are known to possess good resolving power, but for a variety of reasons are not suitable for or will not permit direct refractive index measurements of their dioptric tissues to be taken.     

云南铁杉开花结实特性及其与环境因子的关系

以进入生殖阶段的8个天然云南铁杉(Tsuga dumosa)种群为对象, 对开花、结实植株(24个样株)的生长量进行测定, 并采用标准枝法对不同树冠层次与方位的开花及结实数量进行调查, 研究了开花结实规律和对其有主要影响的环境因子。结果表明: 云南铁杉雌、雄球花比为1:2, 雌球花转化为果实的数量仅占28%, 胸径为7 cm (树龄约25年)的植株最早进入开花结实阶段, 胸径为25-30 cm的植株开花结实量最高, 胸径为89 cm (树龄约200年)的植株开花结实最晚; 树冠不同层次与方位上开花结实数量有着明显的差异; 相关性分析得出植株胸径与开花结实量极显著相关(p < 0.01)、与冠幅显著相关, 生境中林分郁闭度与开花结实量、株高、胸径之间均呈负相关关系, 其中与结实量的相关性达显著水平; 主成分分析得出植株开花及结实主要受到温度因子、水分因子、光照因子协同作用的影响。云南铁杉雌雄球花的比例偏雄性、结实周期长、结实方式不经济、灾害性天气的影响是造成该种群逐渐走向濒危的主要原因。因此, 采用人工促进天然更新、建立母树林和种子园以提高种子的质量, 对云南铁杉种群的恢复和保护具有重要意义。     

Numerical Modeling of Skin Tissue Heating Using the Interval Finite Difference Method

Numerical analysis of heat transfer processes proceeding in a nonhomogeneous biological tissue domain is presented. In particular, the skin tissue domain subjected to an external heat source is considered. The problem is treated as an axially-symmetrical one (it results from the mathematical form of the function describing the external heat source). Thermophysical parameters of sub-domains (volumetric specific heat, thermal conductivity, perfusion coefficient etc.) are given as interval numbers. The problem discussed is solved using the interval finite difference method basing on the rules of directed interval arithmetic, this means that at the stage of FDM algorithm construction the mathematical manipulations are realized using the interval numbers. In the final part of the paper the results of numerical computations are shown, in particular the problem of admissible thermal dose is analyzed.     

Growth cone-growth cone interactions in cultures of rat sympathetic neurons

Growth cones of sympathetic neurons from the superior cervical ganglia of neonatal rats were studied using video-microscopy to determine events following contact between growth cones and other cell surfaces, including other growth cones and neurites. A variety of behaviors were observed to occur upon contact between growth cones. Most commonly, one growth cone would collapse and subsequently retract upon establishing filopodial contact with the growth cone of another sympathetic neuron. Contacts resulting in collapse and retraction were often accompanied by a rapid and transient burst of lamellipodial activity along the neurite 30-50 microns proximal to the retracting growth cone. In no instances did interactions between growth cones and either fibroblasts or red blood cells result in the growth cone collapsing, suggesting that a specific recognition event was involved. On several occasions, growth cones were seen to track other growth cones, although fasciculation was rare. In some cases, there was no obvious response between contacting growth cones. Growth cone-growth cone contact was almost four times more likely to result in collapse and retraction than was growth cone-neurite contact (45% vs 12%, respectively). These observations suggest that the superior cervical ganglion may be composed of neurons with different cell surface determinants and that these determinants are more concentrated on the surface of growth cones than on neurites. These results further suggest that contact-mediated inhibition of growth cone locomotion may play an important role in growth cone guidance.     

Receptor contacts of horizontal cells in the retina of the domestic cat.

The terminal aggregations of A- and B-type horizontal cells, stained by the Golgi-Colonnier method, have been analysed. The pattern of the aggregations is regular and is shown to be in register with the cone mosaic. Both tyes of horizontal cell are in contact with at least 80% of the cones above their dendritic fields. Therefore, the different horizontal cell classes cannot be selective for a special kind of cone but must have at least 60% of the cone input in common. Each A-type horizontal cell makes contacts with between 120 and 170 cones, and each B-type horizontal cell with 60-90 cones. An individual A-type horizontal cell occupies an average of 20% of the lateral elements of the triads in a cone pedicle, but an individual B-type cell fills only some 13%. Each and every cone is connected with several of both types of horizontal cell. An estimation of the number of rods converging onto a single axon terminal system showed that it could be as many as 3000.     

Seed cone anatomy of Cheirolepidiaceae (Coniferales): Reinterpreting Pararaucaria patagonica Wieland

? Premise of the study: Seed cone morphology and anatomy reflect some of the most important changes in the phylogeny and evolutionary biology of conifers. Reexamination of the enigmatic Jurassic seed cone Pararaucaria patagonica reveals previously unknown systematically informative characters that demonstrate affinities with the Cheirolepidiaceae. This paper documents, for the first time, internal anatomy for seed cones of this important extinct Mesozoic conifer family, which may represent the ghost lineage leading to modern Pinaceae. ? Methods: Morphology and anatomy of cones from the Jurassic La Matilde Formation in Patagonia are described from a combination of polished wafers and thin section preparations. New photographic techniques are employed to reveal histological details of thin sections in which organic cell wall remains are not preserved. Specific terminology for conifer seed cones is proposed to help clarify hypotheses of homology for the various structures of the cones. ? Key results: Specimens are demonstrated to have trilobed ovuliferous scale tips along with a seed enclosing pocket of ovuliferous scale tissue. Originally thought to represent a seed wing in P. patagonica, this pocket-forming tissue is comparable to the flap of tissue covering seeds of compressed cheirolepidiaceous cones and is probably the most diagnostic character for seed cones of the family. ? Conclusions: Pararaucaria patagonica is assigned to Cheirolepidiaceae, documenting anatomical features for seed cones of the family and providing evidence for the antiquity of pinoid conifers leading to the origin of Pinaceae. A list of key morphological and anatomical characters for seed cones of Cheirolepidiaceae is developed to facilitate assignment of a much broader range of fossil remains to the family. This confirms the presence of Cheirolepidiaceae in the Jurassic of the Southern Hemisphere, which was previously suspected from palynological records.     

重庆动物园亚洲象真菌性皮肤病的治疗探讨

重庆动物园亚洲象普遍发生一种皮肤病,表现为臀部、腰部或脖颈部等处皮肤不同程度的白斑、脱屑、皲裂、瘙痒和结痂等,严重妨碍动物生长发育,在应用特比萘芬等化学药物治疗效果不佳的情况下,于2008年经分离鉴定推测为小孢子菌真菌性皮肤病,自2009～2011年采用艾叶水剂外洗治疗,并以艾叶混合饲料饲喂动物,配合艾叶环境熏蒸消毒,取得良好的防治效果。初步表明艾叶为一种具有推广前景的防治动物皮肤病的中草药。     

Predation and protection in the macroevolutionary history of conifer cones

Conifers are an excellent group in which to explore how changing ecological interactions may have influenced the allocation of reproductive tissues in seed plants over long time scales, because of their extensive fossil record and their important role in terrestrial ecosystems since the Palaeozoic. Measurements of individual conifer pollen-producing and seed-producing cones from the Pennsylvanian to the Recent show that the relative amount of tissue invested in pollen cones has remained constant through time, while seed cones show a sharp increase in proportional tissue investment in the Jurassic that has continued to intensify to the present day. Since seed size in conifers has remained similar through time, this increase reflects greater investment in protective cone tissues such as robust, tightly packed scales. This shift in morphology and tissue allocation is broadly concurrent with the appearance of new vertebrate groups capable of browsing in tree canopies, as well as a diversification of insect-feeding strategies, suggesting that an important change in plant-animal interactions occurred over the Mesozoic that favoured an increase in seed cone protective tissues.     

Bacillus thuringiensis variety kurstaki x aizawai applied to spruce flowers reduced Dioryctria abietella (Lepidoptera: Pyralidae) infestation without affecting seed quality

We investigated the effects of Bacillus thuringiensis variety kurstaki x aizawai (Bt) on infestation levels of two lepidopteran insects as well as on seed quality in Norway spruce, Picea abies L. (Karst.) in central Sweden. Spruce flowers (female strobili) were sprayed with a 0.2% suspension (wt:wt) of the Bt preparation Turex 50 WP, 25,000 IU/mg in water. To expose even those lepidopteran larvae that feed exclusively embedded within the cone tissue, the Bt treatment was applied to open flowers, before they closed and developed into cones. The experimental design included three main factors: treatment (untreated control, water, or Bt), spruce genotype (three clones), and spraying time (spraying before, during, and after the phase of highest pollen receptivity). The Bt treatment reduced the proportion of cones infested by the cone worm Dioryctria abietella Den. et Schiff. (Lepidoptera: Pyralidae) from approximately 30 to 15%. There was no statistically significant treatment effect on the infestation rate of Cydia strobilella (L.) (Lepidoptera: Tortricidae). The Bt variety kurstaki x aizawai treatment caused no reduction in seed quality as measured by seed weight or percentage of nonfilled seeds. There was no difference in number of seeds per cone between the Bt-treated and untreated control cones. There was a significant effect of genotype on insect infestation rates, as well as on number of seeds per cone and seed weight. Neither level of insect damage nor any seed quality parameters were affected by time of application of the treatments.     

抗疫植物艾的本草考证及艾叶化学成分与抗菌抗病毒最新研究

艾叶为菊科蒿属植物艾(Artemisia argyi)的干燥叶。传统医学和现代医学均认为艾叶具有抵御微生物感染的功效。在体外,艾叶广谱抗菌抗病毒;在体内,艾灸、艾烟可调节多种免疫功能细胞和细胞因子,维持内环境稳定。自新冠肺炎疫情爆发以来,艾叶在疫情防控中发挥了重要作用,引起全社会的广泛关注。为进一步研究和开发艾的植物资源,本文从本草考证、资源分布、活性成分以及抗病毒抗菌活性和应用价值等方面对艾叶最新研究进行综述。     

Branching habit and the allocation of reproductive resources in conifers

Background and Aims Correlated relationships between branch thickness, branch density, and twig and leaf size have been used extensively to study the evolution of plant canopy architecture, but fewer studies have explored the impact of these relationships on the allocation of reproductive resources. This study quantifies pollen cone production in conifers, which have similar basic reproductive biology but vary dramatically in branching habit, in order to test how differences in branch diameter influence pollen cone size and the density with which they are deployed in the canopy. Methods Measurements of canopy branch density, the number of cones per branch and cone size were used to estimate the amount of pollen cone tissues produced by 16 species in three major conifer clades. The number of pollen grains produced was also estimated using direct counts from individual pollen cones. Key Results The total amount of pollen cone tissues in the conifer canopy varied little among species and clades, although vegetative traits such as branch thickness, branch density and pollen cone size varied over several orders of magnitude. However, branching habit controls the way these tissues are deployed: taxa with small branches produce small pollen cones at a high density, while taxa with large branches produce large cones relatively sparsely. Conclusions Conifers appear to invest similar amounts of energy in pollen production independent of branching habit. However, similar associations between branch thickness, branch density and pollen cone size are seen across conifers, including members of living and extinct groups not directly studied here. This suggests that reproductive features relating to pollen cone size are in large part a function of the evolution of vegetative morphology and branching habit.