Multievent: an extension of multistate capture-recapture models to uncertain states

Capture-recapture models were originally developed to account for encounter probabilities that are less than 1 in free-ranging animal populations. Nowadays, these models can deal with the movement of animals between different locations and are also used to study transitions between different states. However, their use to estimate transitions between states does not account for uncertainty in state assignment. I present the extension of multievent models, which does incorporate this uncertainty. Multievent models belong to the family of hidden Markov models. I also show in this article that the memory model, in which the next state or location is influenced by the previous state occupied, can be fully treated within the framework of multievent models.     

A high conductance cationic channel from Phaseolus vulgaris roots incorporated into planar lipid bilayers

A previously undescribed plasma membrane cation channel from Phaseolus vulgaris bean roots was studied after its incorporation into planar lipid bilayers. The channel allows the passage of monovalent cations excluding the flux of both anions (Cl-) and divalent cations (Ca2+). The channel presents a high ( approximately 213 pS) conductance in (300 mM Kcis+)/ (150 mMKtrans+) conditions. The probability of opening (Po) is low at all the tested voltages, but it increases significantly at trans-negative potentials. Permeability ratios (Pcation/PK+) under bi-ionic conditions follow the sequence: K+ (1.0)>NH4+ (0.86)>Na+ (0.78). Under the same conditions, the conductance ratios (gamma cation/gamma K+) follow the sequence: NH4+ (1.1) > or = K+ (1.0)>Na+ (0.80). The low probability of opening exhibited by the channel upon its incorporation into a lipid bilayer makes it a candidate to regulation by (and therefore participation in) cellular signalling networks.     

Proline metabolism in response to nitrogen deficiency in French Bean plants (Phaseolus vulgaris L. cv Strike)

The objective of the present work was to determine the impact ofnitrogen deficiency on proline metabolism in French Bean plants(Phaseolus vulgaris L. cv. Strike). The nitrogen wasapplied to the nutrient solution in the form of NH₄NO₃ at1.45 mM (N1), 2.90mM (N2) and 5.80mM (N3, optimal level). Our results indicateNdeficiency is characterised by a decline in proline accumulation both in theroot and leaves, fundamentally because proline degradation is encouraged by thestimulation of the enzyme proline dehydrogenase. By contrast, under conditionsof adequate N (N3), proline levels rise due to the action of ornithine,suggesting predominance of the ornithine pathway over the glutamine pathway, inaddition to the inhibition of proline dehydrogenase activity.     

Analysis of the slow phases of the in vivo chlorophyll fluorescence induction curve. Changes in the redox state of Photosystem II electron acceptors and fluorescence emission from Photosystems I and II

An analysis of the photo-induced decline in the in vivo chlorophyll a fluorescence emission (Kautsky phenomenon) from the bean leaf is presented. The redox state of PS II electron acceptors and the fluorescence emission from PS I and PS II were monitored during quenching of fluorescence from the maximum level at P to the steady state level at T. Simultaneous measurement of the kinetics of fluorescence emission associated with PS I and PS II indicated that the ratio of PS I/PS II emission changed in an antiparallel fashion to PS II emission throughout the induction curve. Estimation of the redox state of PS II electron acceptors at given points during P to T quenching was made by exposing the leaf to additional excitation irradiation and determining the amount of variable PS II fluorescence generated. An inverse relationship was found between the proportion of PS II electron acceptors in the oxidised state and PS II fluorescence emission. The interrelationships between the redox state of PS II electron acceptors and fluorescence emission from PS I and PS II remained similar when the shape of the induction curve from P to T was modified by increasing the excitation photon flux density. The contributions of photochemical and non-photochemical quenching to the in vivo fluorescence decline from P to T are discussed.     

Psychrotolerant bacteria isolated from the leaf apoplast of cold-adapted wild plants improve the cold resistance of bean (Phaseolus vulgaris L.) under low temperature

We have isolated psychrotolerant bacteria from the leaf apoplast of cold-adapted wild plants and aimed to investigate their effect on the cold resistance of bean (Phaseolus vulgaris L.). Based on the findings of 16S rRNA gene sequence analysis, 20 isolates belonging to 5 bacteria species (Pseudomonas fragi, P. chloropaphis, P. fluorescens, P. proteolytica and Brevibacterium frigoritolerans) were identified in the leaf apoplastic fluid of Draba nemorosa, Galanthus gracilis, Colchicum speciousum, Scilla siberica, Erodium cicutarium, respectively. We have determined that 6 of the 20 isolates have exhibited ACC (1-aminocyclopropane-1-carboxylate) deaminase activity and secreted different extracellular proteins under cold condition (+4 °C) compared to normal growth condition (28 °C). The six isolates were then inoculated independently of each other to the leaves of 10-day-old bean seedlings growing under normal conditions (25/22 °C, 16/8 h photoperiod), and the inoculated and uninoculated (control) seedlings were transferred to cold (9/5 °C, 16/8 h photoperiod) for 3 days. The bacterial inoculations have decreased freezing injury, ice nucleating activity and lipid peroxidation content in parallel with the decrease of reactive oxygen species level such as O₂^.- and H₂O₂ in the inoculated seedlings compared to the control. In addition, the inoculations of the isolates have stimulated the activity of apoplastic antioxidant enzymes including superoxide dismutase, catalase, peroxidase, and glutathione reductase. The results show that the inoculations improve the cold resistance of bean seedlings and the psychrotolerant bacterial isolates can be evaluated within the group of plant growth promoting bacteria (PGPB) which can increase tolerance of cold-sensitive crops.     

Yield-forming effect of sandovit on field bean and its influence on the degree of damage to seeds by bruchus rufimanus

The paper presents the yield-forming effect of Sandovit on field bean. The field experiments, carried out in the experimental field of the Regional Experimental Centre in Boguchwala near Rzeszów, showed the significant effect this product has on accelerating the growth of plants and their yield. A significant difference was proved between the experimental object and the control one regarding the number of pods set on a plant and filling them with seeds. The result was an increase in the seed crop by 22.3% in relation to the control object. The effect of Sandovit on decreasing the degree of damage to the field bean seeds was also proved.     

Estimates of relatedness and inbreeding in goose strains from DNA fingerprints

The purpose of this study was to determine if DNA fingerprints (DFPs) could be used to estimate relatedness and inbreeding of strains of geese and to compare three methods of calculating relatedness indices. Strains included a control and selected strain from each of the Chinese and Synthetic (Chinese, Hungarian and Pilgrim) breeds. DFP patterns for each strain were based on individual DNA samples from six females, or on pooled DNA from 15 females different from those used for individual samples. Three relatedness indices were used, namely, genetic distance, modified Rogers distance and band sharing. All relatedness indices showed a closer relationship of strains within than between breeds. Correlation coefficients among relatedness indices were higher based on pooled DNA (r ≥|0·97|) than those based on individual DNA (r ≥|0·741). Inbreeding estimates were higher for selected compared with control strains. It appears that the use of DFPs to estimate relatedness, regardless of index used, and inbreeding can be valuable for studying geese where there is a limited breeding history.