Selected list of publications (1942-1993) of Professor Zhen YAO

1942YaoT,SPai.HeteropycnosisandchromatindiminutioninCosmocercasp.Sci-enceRecord1(1-2)197-202.1944PaiS,TYao.DieChromosomenderundifferenzirtenSomazellenandKeimba-bnzellenvonCosmocercasp.TheChineseJExpBiol2(1)1-8.1945aYaoT.StudiesontheorgainzerprobleminPelmatohydraoligactis.Ⅰ.Theinductionpotencyoftheimplantsandthenatureoftheinducedhydranth.JExpBiol21(3-4)147-50.1945bYaoT.StudiesontheorganizerprobleminPelmatohydraoligactis.Ⅱ.Theeffectofsomerespiratoryinhibitorsandstimulantsandofoxyge…     

Fifty years of entomological publications in the Revista de Biología Tropical

Over its fifty year history nearly twenty percent of the papers published in the Revista de Biología Tropical have been about insects and arachnids. In the 1950's papers on arthropods of medical importance were dominant, in the 1960's there was a poliferation of papers on bees, and in more recent years the subjects have become increasingly diverse. In terms of nationality of contributing authors, the journal appears to have become increasingly international in later years.     

List of publications on human biometeorology in Czechoslovakia (period 1920–1960)

International Journal of Biometeorology -     

Cryptic or pseudocryptic: can morphological methods inform copepod taxonomy? An analysis of publications and a case study of the Eurytemora affinis species complex

Interest in cryptic species has increased significantly with current progress in genetic methods. The large number of cryptic species suggests that the resolution of traditional morphological techniques may be insufficient for taxonomical research. However, some species now considered to be cryptic may, in fact, be designated pseudocryptic after close morphological examination. Thus the “cryptic or pseudocryptic” dilemma speaks to the resolution of morphological analysis and its utility for identifying species. We address this dilemma first by systematically reviewing data published from 1980 to 2013 on cryptic species of Copepoda and then by performing an in‐depth morphological study of the former Eurytemora affinis complex of cryptic species. Analyzing the published data showed that, in 5 of 24 revisions eligible for systematic review, cryptic species assignment was based solely on the genetic variation of forms without detailed morphological analysis to confirm the assignment. Therefore, some newly described cryptic species might be designated pseudocryptic under more detailed morphological analysis as happened with Eurytemora affinis complex. Recent genetic analyses of the complex found high levels of heterogeneity without morphological differences; it is argued to be cryptic. However, next detailed morphological analyses allowed to describe a number of valid species. Our study, using deep statistical analyses usually not applied for new species describing, of this species complex confirmed considerable differences between former cryptic species. In particular, fluctuating asymmetry (FA), the random variation of left and right structures, was significantly different between forms and provided independent information about their status. Our work showed that multivariate statistical approaches, such as principal component analysis, can be powerful techniques for the morphological discrimination of cryptic taxons. Despite increasing cryptic species designations, morphological techniques have great potential in determining copepod taxonomy.     

Do we need a Unique Scientist ID for publications in biomedicine?

BACKGROUND: The PubMed database contains nearly 15 million references from more than 4,800 biomedical journals. In general, authors of scientific articles are addressed by their last name and forename initial. DISCUSSION: In general, names can be too common and not unique enough to be search criteria. Today, Ph.D. students, other researchers and women publish scientific work. A person may not only have one name but several names and publish under each name. A Unique Scientist ID could help to address people in peer-to-peer (P2P) networks. As a starting point, perhaps PubMed could generate and manage such a scientist ID. SUMMARY: A Unique Scientist ID would improve knowledge management in science. Unfortunately in some of the publications, and then within the online databases, only one letter abbreviates the author's forename. A common name with only one initial could retrieve pertinent citations, but include many false drops (retrieval matching searched criteria but indisputably irrelevant).     

Cryoenzymology of β-galactosidase: Effects of cryosolvents

Experimental support for the use of fluid aqueous organic solvent systems and subzero temperatures in mechanistic studies of β-galactosidase is presented. The enzyme was stable and retained catalytic activity and structural integrity in 50% aqueous dimethyl sulfoxide and 60% aqueous methanol at 0°C; at lower temperatures higher concentrations of cosolvent may be successfully used. The effects of dimethyl sulfoxide on the catalytic and structural properties of the enzyme were investigated in detail. For the β-galactoside-catalyzed h ydrolysis ofo-nitrophenyl-β-D-galactoside the value ofk _cat decreased in a linear manner with increasing cosolvent concentration, whereasK _m increased exponentially. The decrease ink _cat paralleled the decrease in water concentration, consistent with rate-limiting hydrolysis of a galactosylenzyme intermediate. The increase inK _m is attributed to less favorable partitioning of the substrate to the active site in the cryosolvent compared to aqueous solution. ThepH*-rate profile for this reaction at 0°C in 50% dimethyl sulfoxide was similar to that in aqueous solution, withpK*₁=5.8 andpK*₂=8.0. Linear Arrhenius plots, with energies of activation of 13.9 and 16.0 kcal mol^?1, respectively, were obtained for the β-galactosidase-catalyzed hydrolysis ofo-nitrophenyl- andp-nitrophenyl-β-D-galactosides in 50% dimethyl sulfoxide at temperatures to ?57°C. Examination of the intrinsic fluorescence and ultraviolet spectra of the enzyme as a function of increasing cosolvent concentration showed no evidence for structural perturbation up to and including 50% dimethyl sulfoxide at 0°C. We conclude that these cryosolvent systems are suitable for mechanistic investigations of β-galactosidase, in particular for trapping intermediates at subzero temperatures.     

Catabolism of carotenoids: Involvement of peroxidase?

In primary leaves of barley allowed to senesce under natural conditions, carotenoids, like chlorophylls, disappear gradually. Commercial horse-radish peroxidase catalizes the oxidation of lutein to unknown colorless products. This reaction depends on the presence of 2,4 dichlorophenol. It is independent of peroxide but is nullified in the presence of catalase. Preparations of thylakoids from barley chloroplasts show an activity with features comparable to those of horse-radish peroxidase.Abbreviation DCP 2,4 Dichlorophenol     

Gibberellin: inhibitor of an inhibitor of...?

Gibberellin is an endogenous plant growth regulator. Here, we describe our present understanding of how gibberellin regulates plant growth, using recent results gained from studies of gibberellin-signalling mutants of Arabidopsis. These results show that a signalling pathway represses plant growth and that gibberellin releases this repression. In consequence, the well-known growth-promoting properties of gibberellin are due to its activity as an "inhibitor of an inhibitor" [Brian Pw. Sym Soc. Exp Bio 1957; 11:166-182 (Ref. 1)] of plant growth.     

Islands of Fertility: A Byproduct of Grazing?

Empirical work in arid shrubland systems has documented a distinct spatial pattern of soil nutrient distribution, with higher concentrations of nutrients under shrub canopies compared to bare ground interspaces between shrubs. This “fertile island” pattern is considered characteristic of arid ecosystems. However, recent work at a desertified shrubland site reported no island of fertility pattern for nitrogen inside a long-term grazing exclosure despite a strong fertile island pattern outside the exclosure, leading to a hypothesis that the pattern may be associated with grazing. In this paper we examine this hypothesis in two ways. First, we collected soil nitrogen data inside and outside two long-term livestock exclosures. Second, we examined published work on the fertile island pattern for nitrogen, phosphorus and carbon, and its association with livestock grazing. At the field sites, there was a strong fertile island pattern for soil nitrogen in the grazed area outside each exclosure but no fertile island pattern in the ungrazed area inside the fence. From the literature, we identified 49 studies, which represent 99 cases that examine differences in soil nutrients under and between shrubs (that is, tests of the fertile island pattern). In 92 cases, fertile islands were present for at least one of the nutrients. All cases where livestock grazing was present exhibited fertile island patterns for nitrogen and most did so for carbon and phosphorus. In contrast, fertile islands were less consistent where livestock grazing was absent; all nine cases that had been ungrazed for more than 30 years did not exhibit fertile islands for nitrogen. Our empirical data and literature review suggest that the fertile island pattern may be an artifact of grazing rather than an inherent property of arid shrublands. Further, we suggest that the grazing history of a site needs to be explicitly considered when documenting spatial patterns of soil nutrients in arid systems. This has significant implications for our understanding of soil nutrient dynamics in arid systems, the management of rangelands, and the potential for reversal of desertification.     

First steps of otolith formation of the zebrafish: role of glycogen?

The first steps of otolith formation were studied by electron microscopy in zebrafish embryos at different postfertilization (PF) time intervals. Between 19 and 22 h PF, the otic cavity contains glycogen particles derived by an apocrine process from the apical portions of the epithelial cells of the inner ear. The particles are arranged in parallel arrays, then in pseudocrystalloid structures, and finally in concentric arrays to form dense clusters referred to as "spherules". At 23 h PF, a group of "globules", consisting of modified aggregated "spherules" surrounded by several free "spherules", forms the nascent otolith. At 30 h PF, fused globules form a roughly spherical otolith. Spherules undergoing their process of modification and aggregation, are located in its central part, and constitute the so-called "nucleus". At 50 h PF, the otolith is a flattened hemisphere. It is made up of fused globules surrounded by two concentric layers whose organization is similar to that observed in the otolith of the adult fish. At this stage, calcium may be detected in the otolith except in its nucleus. We suggest that glycogen molecules found in the nascent otolith might allow the insertion of molecules such as glycoproteins (collagens) which are known to fix calcium. As a result, glycogen might play a key role in initiating the formation of otoliths and possibly that of other calcified tissues.