Bird versus bat pollination in the genus Marcgravia and the description of a new species

A short account on the history of observations into the pollination ecology in Marcgravia ( Marcgraviaceae ) is given. The different pollination syndromes encountered in the genus are discussed. The circumstances of the discovery of a new species in southern Ecuador are presented. This new species, Marcgravia helverseniana , is described and is illustrated here for the first time.     

643. OXALIS MASSONIANA

The South African Oxalis massoniana T.M.Salter is illustrated and described, and its cultivation requirements are discussed. A brief account of Francis Masson's journeys of exploration at the Cape is given.     

Desmids from Pachmarhi,Madhya Pradesh,India

An illustrated account is given of 68 desmids from streams running below Pachmarhi plateau in Madhya Pradesh, India, Two varieties of Euastrum are new to science.     

The pollen of Dysoxylum (Meliaceae): the demise of Pseudocarapa

An account of the pollen morphology found in the genera Dysoxylum and Pseudocarapa (Meliaceae) is presented. Pollen grains are illustrated by means of electron and some light micrographs. The majority of taxa release grains as tetra-colporate monads. Tetrads have previously only been known in Pseudocarapa. They are also recorded here in three species of Dysoxylum. The taxonomic implications of this are discussed and Pseudocarapa is reduced to a synonym of Dysoxylum.     

Forced oscillations of DNA bases

This paper presents the results of a study of forced angular oscillations of DNA bases using a mathematical model that consists of two coupled nonlinear differential equations that take the effects of dissipation and the influence of an external periodic field into account. The calculation results are illustrated for the sequence of the gene that codes for interferon alpha 17 (IFNA17).     

Desmids from Bandhavgarh,Madhya Pradesh,India

An illustrated account of 71 desmids from perennial streams of Bandhavgarh, one of the important national parks of the country, is given. 10 forms marked with an asterix are recorded for the first time from India.     

Computer-assisted simulations of phosphofructokinase-1 kinetics using simplified velocity equations

Equations useful for simulating the kinetic behavior of phosphofructokinase are presented. The equations, which are based on the concerted transition (symmetry) model for allosteric enzymes, account for substrate inhibition by MgATP, cooperative binding by F-6-P, activation by F-2,6-P₂, and deinhibition by AMP. Velocity calculations can be performed using either a spreadsheet program (e.g., MS Excel) or a web-based program (e.g., Authorware). Both approaches are illustrated.     

915. HIERACIUM TOMENTOSUM

Hieracium tomentosum L. (Compositae: Lactuceae: Hieraciinae) is illustrated and described, the account of the species providing a fairly full synonymy, reference to types and the complication of grexes indicated. Frequently appearing under the name of Hieracium lanatum (L.) Vill., issues with the historical naming of this species are highlighted, together with those of naming many of the European hieracia. The species has been in cultivation in the British Isles for just short of three hundred years, and is apparently only currently available from three suppliers. Cultivation and propagation requirements are discussed. The artist of the plate and the figure, Gustavo Surlo, is the youngest Margaret Mee Fellowship Programme Artist Scholar to have illustrated in Curtis's Botanical Magazine. Having won the Artist Scholarship for 2018, this is his first plate in the Magazine.     

Some covariance models for longitudinal count data with overdispersion

A family of covariance models for longitudinal counts with predictive covariates is presented. These models account for overdispersion, heteroscedasticity, and dependence among repeated observations. The approach is a quasi-likelihood regression similar to the formulation given by Liang and Zeger (1986, Biometrika 73, 13-22). Generalized estimating equations for both the covariate parameters and the variance-covariance parameters are presented. Large-sample properties of the parameter estimates are derived. The proposed methods are illustrated by an analysis of epileptic seizure count data arising from a study of progabide as an adjuvant therapy for partial seizures.     

Functional morphology and evolutionary ecology

Functional morphology studies physico-chemical properties and biological roles of organs. If applied to fossils this approach is connected with specific methodological problems. The fields of application of functional morphology in paleontology are illustrated with examples. In a working concept it is shown how the results of functional morphology can be integrated into an account of the evolutionary ecology of fossil taxa.     

Phenomenological and molecular models of biological proton transfers

In this paper, the main models describing the transfer of a proton in a molecular system are presented. Models valid when the intersite coupling is weak (non-adiabatic and electronically adiabatic regimes) and strong (adiabatic regime) are described. We distinguish molecular models in which the rate constant is obtained by considering explicitly various degrees of freedom of the system and simpler, phenomenological models built to account for the kinetic isotope effect. The relations between the various models are discussed. Their application to specific systems is illustrated by several studies reported in the literature, with a special emphasis on biological systems.     

Development of gatekeeping strategies in confirmatory clinical trials

This paper discusses multiplicity issues arising in confirmatory clinical trials with hierarchically ordered multiple objectives. In order to protect the overall type I error rate, multiple objectives are analyzed using multiple testing procedures. When the objectives are ordered and grouped in multiple families (e.g. families of primary and secondary endpoints), gatekeeping procedures are employed to account for this hierarchical structure. We discuss considerations arising in the process of building gatekeeping procedures, including proper use of relevant trial-specific information and criteria for selecting gatekeeping procedures. The methods and principles discussed in this paper are illustrated using a clinical trial in patients with type II diabetes mellitus.     

毛茛目植物柄锈菌中国种的修订

作者对中国毛茛目植物(毛茛科,木通科和小檗科)上柄锈菌属的种进行了较详细的研究,对过去的错误报告和鉴定作了订正,共获得9个种,其中有3个新记录,即赛铁线莲柄锈菌Puccinia atragenes Hausm.,宽叶牛姆瓜柄锈菌Puccinia holboelliae-lat如liae Cumm.和鬼臼柄锈菌Puccinia podophylli Schw.。文中对每个种作了描述和讨论并附图和分种检索表。     

Structured population dynamics: continuous size and discontinuous stage structures

A nonlinear stochastic model for the dynamics of a population with either a continuous size structure or a discontinuous stage structure is formulated in the Eulerian formalism. It takes into account dispersion effects due to stochastic variability of the development process of the individuals. The discrete equations of the numerical approximation are derived, and an analysis of the existence and stability of the equilibrium states is performed. An application to a copepod population is illustrated; numerical results of Eulerian and Lagrangian models are compared.      

522. Anguloa Tognettiae

Summary.  A brief account of the genus Anguloa Ruiz & Pav. is given and the latest addition to the genus, Anguloa tognettiae Oakeley, is described and illustrated.