The life histories and distribution of the centipedes Rhysida nuda togoensis and Ethmostigmus trigonopodus (Scolopendromorpha: Scolopendridae) in Nigeria

Observations on populations of Rhysida nuda togoensis and Ethmostigmus trigonopodus in Zaria, Nigeria, show that growth rates are very rapid and life cycles shorter than in centipedes from temperate regions. R. nuda togoensis reproduces when one year old and, in all probability, E. trigonopodus does so as well.
It is suggested that both species are enabled to continue feeding in damp areas after the rains have ended by virtue of their mobility and large size (with consequent greater resistance to desiccation). Increasing aridity drives them into crevices in the soil where a relatively rich fauna may persist through the dry season. The young appear at the beginning of the rains, thereby having the entire rainy season available for feeding.
The taxonomy of R. nuda togoensis is discussed and the distribution of both species in Nigeria is described. They are virtually absent from the dry sudan savanna vegetation belt.     

Three terrestrial Pleistocene coucals (Centropus: Cuculidae) from southern Australia: biogeographical and ecological significance

Coucals are large, predatory, primarily ground‐dwelling cuckoos of the genus Centropus, with 26 extant species ranging from Africa to Australia. Their evolutionary and biogeographical history are poorly understood and their fossil record almost non‐existent. Only one species (Centropus phasianinus) currently inhabits Australia, but there is now fossil evidence for at least three Pleistocene species. One of these (Centropus colossus) was described from south‐eastern Australia in 1985. Here we describe additional elements of this species from the same site, and remains of two further extinct species from the Thylacoleo Caves of the Nullarbor Plain, south‐central Australia. The skeletal morphology and large size of the three extinct species indicates that they had reduced capacity for flight and were probably primarily ground‐dwelling. The extinct species include the two largest‐known cuckoos, weighing upwards of 1 kg each. They demonstrate that gigantism in this lineage has been more marked in a continental context than on islands, contrary to the impression gained from extant species. The evolutionary relationships of the Australian fossil coucals are uncertain, but our phylogenetic analysis indicates a possible close relationship between one of the Nullarbor species and extant Centropus violaceus from the Bismarck Archipelago. The presence of three coucals in southern Australia markedly extends the geographical range of the genus from tropical Australia into southern temperate regions. This demonstrates the remarkable and consistent ability of coucals to colonize continents despite their very limited flying ability.     

不同产地红毛鸡(Centropus sinensis)氨基酸成分的分析

目的:评价不同产地红毛鸡药材的质量。方法:采用日立L-8800型全自动氨基酸分析仪测定12批不同产地红毛鸡总氨基酸的含量。结果:12个样品均含有17种总氨基酸,其中必需和半必需氨基酸占总氨基酸的49.42%～53.16%。结论:不同产地的红毛鸡均含有丰富的氨基酸,具有较高的药用价值,但含量随产地不同而异。     

Polymorphic microsatellite loci in pheasant coucal (Centropus phasianinus)

Little is known about the effect of male parental care and behavioural sex‐role reversal on the mating system of birds because genetic markers for species with these characteristics are lacking. We developed primers for nine polymorphic microsatellite loci in pheasant coucals (Centropus phasianinus). Eight of the primers were also polymorphic in African black coucals (Centropus grillii). Pheasant coucals are of particular interest in the study of evolutionary and behavioural ecology, because their sex‐role reversal and extensive male parental care suggests low levels of extra‐pair fertilizations, yet they have large testes indicating sperm competition.     

FIELD OBSERVATIONS ON CENTROPUS TOULOU INSULARIS ON ALDABRA ATOLL

Frith, C. B. 1975. Field observations on Centropus toulou insularis on Aldabra Atoll. Ostrich 46:251-257.

Details are presented of the nesting of a pair of Malagasy Coucals on Aldabra, with incidental observations of other pairs and nests. Courtship and copulation behaviour is very similar to that of the black Coucal Centropus grillii of Africa. Both sexes net build and incubate the eggs but these activities are performed very predominately by the male. Eggs are white and average 27,5 x 23.5 mm and 8,3 g. Two complete clutches of two and one of thee egg; were found and a doubtful early record of a four egg clutch is considered unlikely. There was an interval of at least 9 days between the laying of the two egg;, which hatched 7–8 days apart, incubation commencing with the first egg. The incubation of the second egg was 14 days, and the fledging period of both young about 19 days. Nestlings in the chamber produce a snake-like hissing noise, excrete a foul-smelling sticky fluid when handled and burst through the rear chamber wall as means of avoiding predation.

Both members of the pair were in the brown plumage generally considered to be the non-breeding plumage. It is suggested that the plumages of the Aldabran population of Centropus toulou are possibly more complex than previously considered or that the population may be dimorphic.     

A tale of the nearly tail‐less: the effects of Plio‐Pleistocene climate change on the diversification of the African avian genus Sylvietta

Sylvietta is a broadly distributed group of African species inhabiting a wide range of habitats and presents an interesting opportunity to investigate the historic mechanisms that have impacted the biogeography of African avian species. We collected sequence data from 50 individuals and used model‐based phylogenetic methods, molecular divergence estimates and ancestral area estimates to construct a time‐calibrated phylogeny and estimation of biogeographic history. We estimate a southern African origin for Sylvietta, with an initial divergence splitting the genus into two clades. The first consists of arid‐adapted species, with a southern African origin and subsequent diversification north into Ethiopia–Somalia. The second clade is estimated as having a Congolian forest origin with an eastward pattern of colonization and diversification as a result of Plio‐Pleistocene forest dynamics. Additionally, two members of the genus Sylvietta display interesting patterns of intraspecific diversification. Sylvietta rufescens is an arid‐adapted species inhabiting southern Africa, and we recover two subclades with a divergence dating to the Pleistocene, a unique pattern for avian species which may be explained via isolation in arid habitat fragments in the early Pleistocene. Second, Sylvietta virens, a species endemic to Afro‐tropical forests, is recovered with geographically structured genetic diversification across its broad range, an interesting result given that recent investigations of several avian forest species have found similar and substantial geographically structured genetic diversity relating to Plio‐Pleistocene forest fragmentation. Overall, Plio‐Pleistocene habitat cycling played a significant role in driving diversification in Sylvietta, and this investigation highlights the substantial impact of climate‐driven habitat dynamics on the history of sub‐Saharan species.     

辽宁鸟类分布新记录5种:小鸦鹃、雪鹀、 红翅凤头鹃、宝兴歌鸫和黄眉姬鹟北大核心CSCD

近年来,随着观鸟活动和鸟类科研工作在辽宁的持续开展(Baietal.2015,汤姆·滨客2016),辽宁各地不断发现鸟种分布新记录种(白清泉等2019)。2012至2020年间,在丹东、大连、抚顺等市先后发现小鸦鹃(Centropus bengalensis)、雪鹀(Plectrophenax nivalis)、红翅凤头鹃(Clamator coromandus)、宝兴歌鸫(Turdus mupinensis)和黄眉姬鹟(Ficedula narcissina)5种,经查阅相关资料(邱英杰等2006,郑光美2017),确定为辽宁省鸟类分布新记录种。     

Kinetic analysis of the action of tissue transglutaminase on peptide and protein substrates

Tissue transglutaminase (TGase) catalyzes transfer of gamma-acyl moieties of Gln residues in peptides or protein substrates to either water or amine nucleophiles through an acyl-enzyme intermediate formed from initial acyl-transfer to an active site Cys residue. Natural substrates for this enzyme include proteins (e.g., tau, alpha-synuclein, and huntingtin) whose TGase-promoted polymerization may be causative in neurodegenerative diseases. As part of a program to find inhibitors of TGase, we have undertaken kinetic and mechanistic studies of the enzyme from guinea pig (gpTGase) and humans (hTGase). Key findings of this study include: (i) gpTGase-catalyzed transamidation of Z-Gln-Gly by Gly-OMe proceeds essentially as described above but with the involvement of substrate inhibition by Gly-OMe. This phenomena, resulting from the binding of nucleophile to free enzyme, appears to be a common feature of TGase-catalyzed reactions. (ii) Solvent deuterium isotope effects for hydrolysis of Z-Gln-Gly by gpTGase are (D)(k(c)/K(m)) = 0.45 and (D)k(c) = 3.6. While the latter results from general catalysis of deacylation, the former originates purely from the reactant state, hydrogen fractionation factor of the active site thiol with no involvement of general catalysis of acylation. (iii) Studies of the transamidation of N,N-dimethylated casein by Gly-OMe and dansyl-cadaverine suggest a complex kinetic mechanism for both enzymes that reflects contributions from four reactions: Gln hydrolysis, intramolecular transpeptidation, intermolecular transpeptidation, and transamidation by added nucleophile.     

Isoenzyme analysis of Echinostoma liei: comparison and hybridization with other African species

Isoenzyme analysis was carried out on the laboratory strain of Echinostoma liei. The results were compared with those from a preliminary study on Echinostoma caproni, Echinostoma togoensis, and Echinostoma sp. (A. Voltz, J. Richard, B. Pesson, and J. Jourdane, 1986, Annales de Parasitologie Humaine et Comparée, 61, 617-623). Isoelectrofocusing showed characteristic phenotypes for phosphoglucomutase (PGM, EC 5.4.2.2) and glucosephosphate isomerase (GPI, EC 5.3.1.9). The four experimental strains were monomorphic. Their genotypes were defined. Isoenzyme analysis of F1-hybrids and their F2 descendants indicated the subunit structure of both isoenzymes and showed that they were encoded by independent genes. Finally, it also suggested that the four strains corresponded to variants of the same species.     

Zur Systematik der GattungCentropus (Mutationsstudien XXVIII.)

Zusammenfassung Centropus mindorensis ist ein völlig geschwärztes Allel vonC. viridis.Außerdem beherbergen die Philippinen noch 5Centropus-Arten, die sich folgendermaßen nach ihrer Verwandtschaft gruppieren lassen: I.C. bengalensis, II. a)C. sinensis, b)C. unirufus, c)C. melanops, d)C. steerii.Mutationsstudien XXVII: Journ. f. Orn. 1927, p. 574–579.     

Synthesis of N-unsubstituted, mono- and disubstituted carbohydrate-1-O-carbamates and their behaviour in glycoside syntheses

The syntheses of 44 1-carbamates from six different 1-O-unprotected carbohydrate derivatives (compounds 1-6), representing typical protecting pattern in glycoside synthesis, are described. The carbamate function is N-unsubstituted (compounds 1b-6b), mono- (compounds a: N-trichloroacetyl, c: N-monochloroacetyl, d: N-acetyl, e: N-ethyl, f: N-allyl, g: N-phenyl) or disubstituted (compounds h: imidazolyl, i: N-diethyl, j: N-diphenyl). Additionally, three N-chlorosulfonyl carbamates are synthesized and used as intermediates for the synthesis of N-unsubstituted compounds b. The accessibility of these compounds is described and compared. Some of the carbamates (1, 4, 5a-j) are used as model compounds for systematic investigations in glycoside syntheses. Selected experimental data (reaction conditions, anomeric ratios, rotation values, selected NMR data) are tabulated.     

Clonal analysis of early mammalian development

Various extrinsic markers have been used to label single cells in the early mouse embryo. However, they are appropriate only for short-term experiments because of their susceptibility to dilution. Studies on cell lineage and commitments have therefore depended mainly on exploiting genes as markers by combining cells from embryos that differ in genotype at particular loci. Tissue recombination and transplantation experiments using such indelible intrinsic markers have enabled the fate of different cell populations in the blastocyst to be determined with reasonable precision. The trophectoderm and inner cell mass (i.c.m.) give rise to distinct complementary groups of tissues in the later conceptus, as do the primitive endodermal and primitive ectodermal components of the more mature i.c.m. When cloned by blastocyst injection, single i.c.m. cells colonize only those parts of host conceptuses that are derived from their tissue of origin. Thus, while clonal descendants of early i.c.m. cells can contribute to all tissues other than those of trophectodermal origin, primitive endodermal and primitive ectodermal clones are restricted, respectively, to the extraembryonic endoderm versus all i.c.m. derivatives except the extraembryonic endoderm. Interestingly, individual primitive ectoderm cells can include both germ cells and somatic cells among their mitotic descendants. By using the genetically determined presence versus absence of cytoplasmic malic enzyme activity as a cell marker, the deployment of clones has been made visible in situ in whole-mount preparations of extraembryonic membranes. Very little mixing of donor and host cells was seen in either the endoderm of the visceral yolk sac or the mesodermal and ectodermal layers of the amnion. In contrast, mosaicism in the parietal endoderm was so fine grained that, in all except 1 of 15 fields from several specimens that were analysed, the arrangement of donor and host cells did not differ significantly from that expected on the basis of their random association.     

Complex-formation between cytochrome c and cytochrome c peroxidase. Kinetic studies

1. The kinetics of ferrocytochrome c peroxidation by yeast peroxidase are described. Kinetic differences between the older and more recent preparations of the enzyme most probably arise from differences in intrinsic turnover rates. 2. The time-courses of cytochrome c peroxidation by the enzyme follow essentially first-order kinetics in phosphate buffer. Deviations from first-order kinetics occur in acetate buffer, and are due to a higher enzymic turnover rate in this medium accompanied by a greater tendency to autocatalytic peroxidation of cytochrome c. 3. The kinetics of ferrocytochrome c peroxidation by yeast peroxidase are interpreted in terms of a mechanism postulating formation of reversible complexes between the peroxidase and both reduced and oxidized cytochrome c. Formation of these complexes is inhibited at high ionic strengths and by polycations. 4. Oxidized cytochrome c can act as a competitive inhibitor of ferrocytochrome c peroxidation by peroxidase. The K(i) for ferricytochrome c is approximately equal to the K(m) for ferrocytochrome c and thus probably accounts for the observed apparent first-order kinetics even at saturating concentrations of ferrocytochrome c. 5. The results are discussed in terms of a possible analogy between the oxidations of cytochrome c catalysed by yeast peroxidase and by mammalian cytochrome oxidase.     

Prediction of Individual Muscle Forces Using Lagrange Multipliers Method - A Model of the Upper Human Limb in the Sagittal Plane: II. Numerical Experiments and Sensitivity Analysis

Using the method of Lagrange multipliers an analytical solution of the optimization problem formulated for a two-dimensional, 3DOF model of the human upper limb has been described in Part I of this investigation. The objective criterion used is the following: [formula: see text], where F(i) -s are the muscle forces modelled and c(i) -s are unknown weight factors. This study is devoted to the numerical experiments performed in order to investigate which sets of the weight factors may predict physiologically reasonable muscle forces and joint reactions. A sensitivity analysis is also presented. The influence of: the gravity forces, different external loads applied to the hand, changes of the weight factors and of joint angle on the optimal solution is studied. A general conclusion may be drawn: using the above mentioned objective criterion, practically all motor tasks performed by the human upper limb may be described if the c(i) -s are properly chosen. These weight factors generally depend on the joint moments and must be different (their magnitudes as well as their signs) for agonistic muscles and for their antagonists.     

Characterization of Specific Membrane Fatty Acids as Chemotaxonomic Markers for Sulfate-Reducing Bacteria Involved in Anaerobic Oxidation of Methane

Membrane fatty acids were extracted from a sediment core above marine gas hydrates at Hydrate Ridge, NE Pacific. Anaerobic sediments from this environment are characterized by high sulfate reduction rates driven by the anaerobic oxidation of methane (AOM). The assimilation of methane carbon into bacterial biomass is indicated by carbon isotope values of specific fatty acids as low as m 103. Specific fatty acids released from bacterial membranes include C 16:1 y 5c , C 17:1 y 6c , and cyC 17:0 y 5,6 , all of which have been fully characterized by mass spectrometry. These unusual fatty acids continuously display the lowest i 13 C values in all sediment horizons and two of them are detected in high abundance (i.e., C 16:1 y 5c and cyC 17:0 y 5,6 ). Combined with microscopic examination by fluorescence in situ hybridization specifically targeting sulfate-reducing bacteria (SRB) of the Desulfosarcina/Desulfococcus group, which are present in the aggregates of AOM consortia in extremely high numbers, these specific fatty acids appear to provide a phenotypic fingerprint indicative for SRB of this group. Correlating depth profiles of specific fatty acid content and aggregate number in combination with pore water sulfate data provide further evidence of this finding. Using mass balance calculations we present a cell-specific fatty acid pattern most likely displaying a very close resemblance to the still uncultured Desulfosarcina/Desulfococcus species involved in AOM.     

Silver Staining for Nucleolar Organizing Regions of Vertebrate Chromosomes

Refinements to a simple, one-step silver staining technique for nucleolar organizing regions are described. These include fixation of silver stained material with sodium thiosulfate and standardization of silver development conditions for different groups of vertebrates. The central advantages to the method are that it is rapid, reliable, simple, and inexpensive. Additional benefits include (i) consistent and uniform silver staining of nucleolar organizing regions, (ii) few reduced silver deposits elsewhere on the chromosomes or on the slides, (iii) generally unaltered chromosome morphology after silver treatment, and (iv) relative permanence of Permounted preparations. The method works equally well on chromosomes made from cell cultures and from solid tissues of live specimens.     

Silver staining for nucleolar organizing regions of vertebrate chromosomes

Refinements to a simple, one-step silver staining technique for nucleolar organizing regions are described. These include fixation of silver stained material with sodium thiosulfate and standardization of silver development conditions for different groups of vertebrates. The central advantages to the method are that it is rapid, reliable, simple, and inexpensive. Additional benefits include (i) consistent and uniform silver staining of nucleolar organizing regions, (ii) few reduced silver deposits elsewhere on the chromosomes or on the slides, (iii) generally unaltered chromosome morphology after silver treatment, and (iv) relative permanence of Permounted preparations. The method works equally well on chromosomes made from cell cultures and from solid tissues of live specimens.