The development of specific visual connections in the monkey and the goldfish: outline of a geometric theory of receptotopic structure.

The anatomical structure of the primate retino-striate system and the goldfish retino-tectal system are characterized by idealized geometrical domains. The physiological retinotopic mappings are then shown to be determined by the boundary conditions of the respective anatomical surfaces. This fact is interpreted as support for the “systems-matching” hypothesis of neural development of Gaze &; Keating. It is suggested that the development of specific neural mappings may be, in part, a variational problem in which two neural surfaces establish connections as “smoothly” as possible. Dirichlet's Principle supplies a quantitative definition of the term “smooth”—the average physiological magnification factor of the neural mapping is minimized, subject to the boundary conditions of the available tissue. Three developmental rules are formulated, which deal respectively with gross specificity, polarity, and detailed map construction. The latter rule, based on Dirichlet's Principle, supplies a link between the classical theory of fields and developmental neurobiology. Specific experimental tests are outlined in the goldfish visual system, and a general discussion of global approaches to neural structure and function is presented.     

粗秆高产小麦茎结构特性分析

以高产小麦(Triticum aestivum L.)新品种"兰考906-4"与北京大面积种植的小麦品种"京411"为实验材料,运用植物解剖学、化学和力学的理论与方法,对粗秆的高产小麦茎结构特性做了详细的比较研究.结果表明:粗秆的高产小麦品种茎秆在物理力学特性、维管束结构特征以及木质素含量等方面,均明显优于一般小麦品种.因此,在超高产小麦品种的育种中,重视外源基因的引进,改进茎秆的结构特性及提高木质素的含量等综合指标,可能是一个重要的选育方向.     

A Preliminary Study on the Wood Anatomy of Manglietia aromatica Dandy [

The present paper deals mainly with the wood structures of “Paramanglietia aromatica” Hu & Cheng and Paramichelia (Pierre) Hu of the Magnoliaceae. These wood structures are listed in Table Ⅰ. In comparison of their wood anatomical features with relsted genera[4], we find that (Ⅰ) the wood anatomy of the reduced genus “Para- manglietia” Hu et Cheng is still within the range of Manglietia Dandy and that (2 the wood anatomical features of Paramichelia (Pierre) Hu is very similar to those of Michelia L. and Tsoongiodendron Chun. We also find that the wood anatomy of Manylietia aromatica Dandy [“Parawanglietia aromatica” (Dandy) Hu & Cheng] is less similar to Manglietiastrum Law (see Table 1).     

The “acrostyle”: A newly described anatomical structure in aphid stylets

The recent demonstration that a plant virus could be retained on protein receptors located exclusively in a small area inside the common duct at the tip of aphid maxillary stylets indicated the possible existence of a distinct anatomical structure at this level. Since no distinct feature within the common duct of any aphid species has ever been reported in the literature, we first carefully re-examined the distal extremity of the maxillary stylets of Acyrthosiphon pisum using transmission- and scanning-electron microscopy. Here, we describe an area of the cuticle surface displaying a different structure that is limited to a “band” paving the bottom of the common duct in each opposing maxillary stylet. This band starts at the very distal extremity, adopts a “comma-like” shape as it continues up towards the salivary canal, reducing in width and disappearing before actually reaching it. Investigations on several aphid species led to the conclusion that this anatomical feature—which we have tentatively named the “acrostyle”—is highly conserved among aphids. We then produced an antibody recognizing a consensus peptide located in the middle of the RR-2 motif of cuticular proteins from A. pisum and showed that this motif is accessible specifically within the acrostyle, indicating a higher concentration of cuticular proteins. While it is clear that at least some viruses can use the acrostyle to interact with their aphid vectors to ensure plant-to-plant transmission, the role of this new “organ” in aphid biology is unknown and calls for further investigation in the near future.     

Links between the discovery of primates and anatomical comparisons with humans,the chain of being,our place in nature,and racism

I focus on the crucial links between the discovery of nonhuman primates by Westerners, discussions on our place in nature, the chain of being, racism, and the history of primate comparative anatomy and of so‐called “anatomical human racial studies.” Strikingly, for more than a millennium humans knew more about the internal anatomy of a single monkey species than about that of their own bodies. This is because Galen used monkeys to infer human anatomy, in line with the human‐animal continuity implied by the Greek notion of scala naturae. With the rise of Christianity, nonhuman primates were increasingly seen in a negative way. A more positive view emerged in the 14th century when nonhuman primates were directly studied/seen by Europeans, culminating in Tyson's 1699 work showing that chimps share more gross anatomical similarities with humans than with monkeys. However, the discomfort caused by this human‐chimp similarity then led to a new idea of animal‐human discontinuity, now related not to anatomy but to “civilization”: between Europeans vs. non‐Europeans + other primates. Moreover, Linnaeus' Systema Naturae and the emergence of “anatomical racial studies” influenced by Camper's craniology then led to even more extreme ideas, such as the notion that Europeans were both mentally and morphologically “ideal.” Unfortunately the biased and often incorrect “results” of such studies, combined with ideas based on Darwin's “struggle for survival”, became crucial in propaganda that lead to the rise of eugenics in the end of the 19th/first half of 20th centuries and that culminated in Nazism. Since the 1950s there has been an emphasis on the continuity/unity between all human groups and other primates, in great part influenced by what happened during World War 2. Reviews such as this one are, therefore, particularly necessary to illuminate and guard against attitudes against “the Other” and racist ideologies that are re‐emerging in modern political discourse across the globe.     

Bayberry wax and bayberries

The “wax” of various species of Myrica is not a true wax, but a vegetable tallow extracted from the surface of the fruits. The principal use of the “wax” is for Christmas candles, but it is also used in soap, ointments, leatherpolishing formulations, etching, and medicinals.     

Statistical Limitations on Molecular Evolution

Abstract

Complexity of functions evolving in an evolution process are expected to be limited by the time length of an evolution process among other factors. This paper outlines a general method of deriving function-complexity limitations based on mathematical statistics and independent from details of a biological or genetic mechanism of the evolution of the function. Limitations on the emergence of life are derived, these limitations indicate a possibility of a very fast evolution and are consistent with “RNA world” hypothesis. The discussed method is general and can be used to characterize evolution of more specific biological organism functions and relate functions to genetic structures. The derived general limitations indicate that a co-evolution of multiple functions and species could be a slow process, whereas an evolution of a specific function might proceed very fast, so that no trace of intermediate forms (species) is preserved in fossil records of phenotype or DNA structure; this is consistent with a picture of “punctuated equilibrium”.     

MICROMORPHOGENESIS DURING DIATOM WALL FORMATION PRODUCES SILICEOUS NANOSTRUCTURES WITH DIFFERENT PROPERTIES1

Micromorphogenesis within the silica deposition vesicle (SDV) of the diatom Pinnularia viridis (Nitzsh) Ehrenb. resulted in distinct silica nanostructures and layers within forming valves and girdle bands. These siliceous components were similarly disclosed following alkaline etching of mature valves/girdle bands, where their different susceptibilities to dissolution over time resulted from apparent differences in silica density and/or chemistry. The bulk of silica appeared to be deposited at the interface of the forming valve or girdle band with the silicalemma and occurred by the outward expansion of microfibrils of silica that aligned perpendicularly to the silicalemma. Microfibrils originated from both sides of the “silica lamella,” the first nanostructure formed within the SDV, and several silica species of distinct nanostructure and density resulted, including distinctive inner and outermost silica “coverings” of mature valves/girdle bands and the central and terminal nodules. Not all silica deposition and micromorphogenesis occurred in contact with the expanding silicalemma, but was somehow directed within the SDV cavity, and resulted in the distinct silica layers that lined the raphe fissures and poroids. Following alkaline etching, the inner surfaces of valves/girdle bands, as well as the silica layers lining the raphes, poroids, and slits, were determined to be significantly more resistant to alkaline etching than the exterior surfaces, while the outer silica coating and the nodules were quickly dissolved. The processes of micromorphogenesis must have exerted precise control over the chemical nature of the silica formed at different positions within the SDV and affected the overall structure and function of the diatom wall.     

Assembly of bacteriophage T4 head-related structures. Assembly of polyheads in vitro.

The fine structure of Z-discs from frog, chameleon, rabbit, rat and human muscles was studied. Our data lead us to conclude that the basket-weave (woven) lattice represents the fundamental en face pattern of the vertebrate Z-disc, regardless of the manner of fixation, and we suggest that the large and small-“square” lattices are fixation artifacts. We also find that the woven lattice pattern remains essentially unchanged throughout physiological ranges of resting sarcomere length, and is not detectably altered by active contraction. A model of the vertebrate Z-line, based on anatomical and possible functional considerations, is presented. It presumes that a thin filament, as it enters the Z-line, is continuous with three curved strands which unite with other I-filaments of the same sarcomere. The I-filaments and extending strands from the opposite sarcomere are proposed to be similarly arranged, with the main Z-line substance consisting of the two sets of strands from adjacent sarcomeres. The anatomical features of the Z-line and the phenomenon of “Z-line splitting” are explained by the proposed model. In addition, a potential hexagonal structural arrangement of the Z-line is retained so that a consistent geometrical organization persists throughout the entire sarcomere. Thus, the model also presents a means of understanding the recently suggested role of the Z-line in forming new sarcomeres.     

From Carlquist’s ecological wood anatomy to Carlquist’s Law: why comparative anatomy is crucial for functional xylem biology

All students of xylem structure–function relations need to be familiar with the work of Sherwin Carlquist. He studies xylem through the lens of the comparative method, which uses the appearance of similar anatomical features under similar conditions of natural selection to infer function. “Function” in biology implies adaptation; maximally supported adaptation inferences require experimental and comparative xylem scientists to work with one another. Engaging with comparative inferences of xylem function will, more likely sooner rather than later, bring one to the work of Sherwin Carlquist. To mark his 90th birthday, I highlight just a few examples of his extraordinarily perceptive and general comparative insights. One is “Carlquist’s Law”, the pervasive tendency for vessels to be solitary when background cells are conductive. I cover his pioneering of “ecological” wood anatomy, viewing xylem variation as reflecting the effects of selection across climate and habit variation. Another is the embolism vulnerability–conduit diameter relationship, one of the most widely invoked structure–function relationships in xylem biology. I discuss the inferential richness within the notion of Carlquistian paedomorphosis, including detailed functional inferences regarding ray cell orientation. My final example comes from his very recent work offering the first satisfactory hypothesis accounting for the geographical and histological distribution of scalariform perforation plates as an adaptation, including “Carlquist’s Ratchet”, why scalariform plates are adaptive but do not re-evolve once lost. This extraordinarily rich production over six decades is filled with comparative inferences that should keep students of xylem function busy testing for decades to come.     

Dictionary of protein secondary structure: Pattern recognition of hydrogen-bonded and geometrical features

For a successful analysis of the relation between amino acid sequence and protein structure, an unambiguous and physically meaningful definition of secondary structure is essential. We have developed a set of simple and physically motivated criteria for secondary structure, programmed as a pattern-recognition process of hydrogen-bonded and geometrical features extracted from x-ray coordinates. Cooperative secondary structure is recognized as repeats of the elementary hydrogen-bonding patterns “turn” and “bridge.” Repeating turns are “helices,” repeating bridges are “ladders,” connected ladders are “sheets.” Geometric structure is defined in terms of the concepts torsion and curvature of differential geometry. Local chain “chirality” is the torsional handedness of four consecutive C^α positions and is positive for right-handed helices and negative for ideal twisted β-sheets. Curved pieces are defined as “bends.” Solvent “exposure” is given as the number of water molecules in possible contact with a residue. The end result is a compilation of the primary structure, including SS bonds, secondary structure, and solvent exposure of 62 different globular proteins. The presentation is in linear form: strip graphs for an overall view and strip tables for the details of each of 10.925 residues. The dictionary is also available in computer-readable form for protein structure prediction work.     

Au Plasmonic Shofar Structures

Plasmonics - We demonstrate a simple two-step etching method to fabricate Au plasmonic shofars (“shofar” is the Hebrew name for certain types of curved and tapered horns, such as from a...     

Festuca rohlenae (Poaceae): A neglected taxon of the Montenegro

Abstract

Festuca porcii var. angustifolia is raised to the rank of a species under the new name F. rohlenae. It is an endemic of SE Dinarides in Montenegro, and it is most similar to the Carpathian F. porcii. Both species have the “broad‐leaved syndrome” and exhibit an intermediacy between “fine‐leaved” and “broad‐leaved” fescues. The comparative morpho‐anatomical data and the distribution map as well as basic ecological information of F. rohlenae are herewith presented.     

Indicators of hemeroby for the monitoring of landscapes in Germany

The article discusses the concepts of “closeness to nature” and “hemeroby”, and outlines a method to establish two indicators of hemeroby. Until now Germany's national land use monitoring systems have lacked an indicator to capture the naturalness respectively hemeroby of the landscape. Based on digital spatial data on land use (DLM-DE) and the mapping of potential natural vegetation, these indicators have now been estimated for the whole of Germany and illustrated cartographically. The indicators have been integrated into a land use monitoring system (IOER-Monitor). A hemeroby index that considers all hemeroby classes of a reference area (e.g. administrative unit and regular grid cell) is presented as well as an indicator named “Proportion of certain natural areas”. The results on hemeroby of several time-cuts can be used to estimate the cumulative impact of land use changes on the environmental status.     

“2020年后全球生物多样性框架”进展及展望

“2020年后全球生物多样性框架”是当前《生物多样性公约》谈判的焦点议题之一。本文阐述了框架制定的背景, 介绍了“2020年后全球生物多样性框架”不限成员名额工作组(Open Ended Working Group, OEWG),的谈判过程, 综合分析了缔约方在各有关磋商进程中的观点, 以及目前缔约方对框架各个要素的共识和分歧, 评估了框架的制定进展, 并就框架的设计提出四点展望: (1)阐明转型变革的具体实施路径; (2)平衡反映公约三大目标; (3)加强与其他全球治理进程的协同; (4)强化框架对全球及缔约方履约进展的评估和审查。最后提出对我国的建议: (1)及时更新国家生物多样性战略与行动计划(National Biodiversity Strategies and Action Plans, NBSAP); (2)加强国内生物多样性工作的协调; (3)继续加强生态环境执法和责任机制。为缔约方更好参与框架制定进程, 深入了解框架及其磋商进展提供参考, 并为下一步框架制定提供参考。     

Deconstructing the long-standing a priori assumption that serial homology generally involves ancestral similarity followed by anatomical divergence

It has long been assumed that serial homologues are ancestrally similar—polysomerism resulting from a “duplication” or “repetition” of forms—and then often diverge—anisomerism, for example, as they become adapted to perform different tasks as is the case with the forelimb and hind limbs of humans. However, such an assumption, with crucial implications for comparative, evolutionary, and developmental biology, and for evolutionary developmental biology, has in general not really been tested by a broad analysis of the available empirical data. Perhaps not surprisingly, more recent anatomical comparisons, as well as molecular knowledge of how, for example, serial appendicular structures are patterned along with different anteroposterior regions of the body axis of bilateral animals, and how “homologous” patterning domains do not necessarily mark “homologous” morphological domains, are putting in question this paradigm. In fact, apart from showing that many so-called “serial homologues” might not be similar at all, recent works have shown that in at least some cases some “serial” structures are indeed more similar to each other in derived taxa than in phylogenetically more ancestral ones, as pointed out by authors such as Owen. In this article, we are taking a step back to question whether such assumptions are actually correct at all, in the first place. In particular, we review other cases of so-called “serial homologues” such as insect wings, arthropod walking appendages, Dipteran thoracic bristles, and the vertebrae, ribs, teeth, myomeres, feathers, and hairs of chordate animals. We show that: (a) there are almost never cases of true ancestral similarity; (b) in evolution, such structures—for example, vertebra—and/or their subparts—for example, “transverse processes”—many times display trends toward less similarity while in many others display trends toward more similarity, that is, one cannot say that there is a clear, overall trend to anisomerism.     

Two-enzyme active transport in vitro with ph induced asymmetrical functional structures.: III. Discussions based on numerical treatments of the time-dependent evolutions

Three complementary models have been considered in which pH gradients (step function. linear pH or linear H^?) impose asymmetry on a two-enzyme mixture. If the “combined pH dependences” of enzymes is pro-asymmetrical, the pH gradient induces an asymmetrical distribution of potential activities (“latent” asymmetry of functional structure). When substrate is added, “developed” asymmetry of effective activities appears which results in “substrate space wave” and pumping when the catalysed reaction couple is “inversible”. It is shown that only one steady state exists for a given boundary condition and is attained when the “combined effective activity” of enzymes is nil: the stationary flux with symmetrical boundaries or the stationary load with moving boundaries is proportional to “effective global activities” of enzymes. “Equivalent square models” could be proposed that would be able to describe “functional” or “permanent” structure pumps as well. These models belong to the thermodynamic branch and the asymmetrical “space wave” substrate concentration profiles obtained must be distinguished from dissipative structures. It appears that such primary active transport pumps are chemical equivalents of heat pumps.     

The implicit rules of combat reflect the evolved function of combat: An evolutionary-psychological analysis of fairness and honor in human aggression

Aggression was a powerful selection pressure for our human ancestors. Aggressive contests would have selected not only for anatomical features (e.g., superior upper-body strength in adult males), but also for behavior-regulation adaptations for the conditional and cost-effective deployment of aggression. Here, we explore two concepts that appear to be part of the neurocognitive suite that regulates aggression. The first is the concept of a “fair fight”, which tags whether an aggressive bout can provide an unbiased estimate of the relative fighting ability of the combatants. The second concept is the “honorability” of a fighter, which tags whether an individual can be trusted to not inflict aggression in excess of what is needed to establish the relative fighting ability of the combatants. Eight predictions were derived from these hypotheses and tested experimentally with vignettes that varied relevant aspects of a fight. The results support the predictions. Fights are perceived as “fair” to the extent that the fighters avoid biased tactics that improve their probability of winning absent superior fighting ability (e.g., not attacking when the opponent is unprepared). Further, fighters are perceived as “honorable” when they minimize the danger to both combatants (e.g., not attacking after the opponent surrenders). We conclude by listing additional implications of the theory.     

The chelifores of sea spiders (Arthropoda,Pycnogonida) are the appendages of the deutocerebral segment

SUMMARY Within the last decade, gene expression patterns and neuro‐anatomical data have led to a new consensus concerning the long‐debated association between anterior limbs and neuromeres in the arthropod head. According to this new view, the first appendage in all extant euarthropods is innervated by the second neuromere, the deutocerebrum, whereas the anterior‐most head region bearing the protocerebrum lacks an appendage. This stands in contrast to the clearly protocerebrally targeted “antennae” of Onychophora and to some evidence for protocerebral limbs in fossil euarthropod representatives. Yet, the latter “frontal appendages” or “primary antennae” have most likely been reduced or lost in the lineage, leading to extant taxa. Surprisingly, a recent neuro‐anatomical study on a pycnogonid challenged this evolutionary scenario, reporting a protocerebral innervation of the first appendages, the chelifores. However, this interpretation was soon after questioned by Hox gene expression data. To re‐evaluate the unresolved controversy, we analyzed neuro‐anatomy and neurogenesis in four pycnogonid species using immunohistochemical techniques. We clearly show the postprotocerebral innervation of the chelifores, which is resolved as the plesiomorphic condition in pycnogonids when evaluated against a recently published comprehensive phylogeny. By providing direct morphological support for the deutocerebral status of the cheliforal ganglia, we reconcile morphological and gene expression data and argue for a corresponding position between the anterior‐most appendages in all extant euarthropods. Consequently, other structures have to be scrutinized to illuminate the fate of a presumptive protocerebral appendage in recent euarthropods. The labrum and the “frontal filaments” of some crustaceans are possible candidates for this approach.