Systems analysis of iron metabolism: the network of iron pools and fluxes

Background  

Every cell of the mammalian organism needs iron as trace element in numerous oxido-reductive processes as well as for transport and storage of oxygen. The very versatility of ionic iron makes it a toxic entity which can catalyze the production of radicals that damage vital membranous and macromolecular assemblies in the cell. The mammalian organism maintains therefore a complex regulatory network of iron uptake, excretion and intra-body distribution. Intracellular regulation in different cell types is intertwined with a global hormonal signalling structure. Iron deficiency as well as excess of iron are frequent and serious human disorders. They can affect every cell, but also the organism as a whole.     

Increased hunting effort buffers against vole scarcity in an urban Kestrel Falco tinnunculus population

Capsule In years with low vole abundance birds visited hunting grounds more frequently and for longer.

Aims To describe diet composition, hunting behaviour, habitat choice and reproductive success of urban Kestrels during changing vole abundance.

Methods For five years, we studied the hunting effort of Kestrels in a medium-sized city during the breeding season. Pitfall traps were used for determining vole abundance. Kestrel diet composition was determined from pellet analyses. The number of eggs and offspring was recorded during at least two consecutive visits for each nest and each breeding stage.

Results In contrast to larger European cities, the Common Vole Microtus arvalis was a key part of the Kestrels' diet and did not fluctuate significantly according to vole availability. Reproductive success was quite high and stable throughout years with different vole abundance. In years of low vole abundance, the arrival frequency at hunting grounds and time spent there increased. During years with a low vole population, Kestrels had less hunting success and the rate of successful visits decreased. Therefore, Kestrels probably had to change hunting grounds more frequently. During low vole years Kestrels used less demanding techniques, e.g. perching, despite the lower success of these hunting techniques, to avoid extremely high energetic costs.

Conclusions An increase in hunting helps to maintain a proper diet and consequently reproductive success. Vole abundance did not change dramatically during the study period, as reported by studies from western and northern Europe. The proportion of ruderal habitats on the city periphery is higher than in more monotonous farmland habitats. Ruderal habitats can be important when Kestrels look for mammals other than voles, especially during vole scarcity.     

Shape based virtual screening and molecular docking towards designing novel pancreatic lipase inhibitors

Increase in obesity rates and obesity associated health issues became one of the greatest health concerns in the present world population. With alarming increase in obese percentage there is a need to design new drugs related to the obesity targets. Among the various targets linked to obesity, pancreatic lipase was one of the promising targets for obesity treatment. Using the in silico methods like structure based virtual screening, QikProp, docking studies and binding energy calculations three molecules namely zinc85531017, zinc95919096 and zinc33963788 from the natural database were reported as the potential inhibitors for the pancreatic lipase. Among them zinc95919096 presented all the interactions matching to both standard and crystal ligand and hence it can be further proceeded to drug discovery process.     

Sprint interval training (SIT) is an effective method to maintain cardiorespiratory fitness (CRF) and glucose homeostasis in Scottish adolescents

The present study examined the physiological impact of a school based sprint interval training (SIT) intervention in replacement of standard physical education (SPE) class on cardio-respiratory fitness (CRF) and glucose homeostasis during the semester following summer vacation. Participants (n=49) were randomly allocated to either intervention (SIT; n=26, aged 16.9 ± 0.3 yrs) or control group who underwent standard physical education (SPE; n=23, aged 16.8 ± 0.6 yrs). CRF (VO₂max) and glucose homeostasis were obtained prior-to and following 7 weeks of SIT exercise. Significant group x time interaction was observed for CRF (P < 0.01) with non-significant trends for fasting insulin (P= 0.08), and HOMA-IR (P=0.06). CRF decreased (P < 0.01) in SPE such that POST intervention CRF was significantly lower (P< 0.05) in SPE. Fasting plasma glucose (P < 0.01), insulin (P< 0.01) and HOMA-IR (P< 0.01) increased significantly amongst SPE. The main finding of the present study is that 7-weeks of SIT exercise is an effective method of maintaining (but not improving) CRF and fasting insulin homeostasis amongst school-going adolescents. SIT exercise demonstrates potential as a time efficient physiological adjunct to standard PE class in order to maintain CRF during the school term.     

The cDNA cloning and molecular evolution of reptile and pigeon lactate dehydrogenase isozymes

The cDNAs encoding lactate dehydrogenase isozymes LDH-A (muscle) and LDH-B (heart) from alligator and turtle and LDH-A, LDH-B, and LDH-C (testis) from pigeon were cloned and sequenced. The evolutionary relationships among vertebrate LDH isozymes were analyzed. Contrary to the traditional belief that the turtle lineage branched off before the divergence between the lizard/alligator and bird lineages, the turtle lineage was found to be clustered with either the alligator lineage or the alligator-bird clade, while the lizard lineage was found to have branched off before the divergence between the alligator/turtle and bird lineages. The pigeon testicular LDH-C isozyme was evidently duplicated from LDH-B (heart), so it is not orthologous to the mammalian testicular LDH-C isozymes.      

Supervised Lowess normalization of comparative genome hybridization data – application to lactococcal strain comparisons

Background

Visualising the evolutionary history of a set of sequences is a challenge for molecular phylogenetics. One approach is to use undirected graphs, such as median networks, to visualise phylogenies where reticulate relationships such as recombination or homoplasy are displayed as cycles. Median networks contain binary representations of sequences as nodes, with edges connecting those sequences differing at one character; hypothetical ancestral nodes are invoked to generate a connected network which contains all most parsimonious trees. Quasi-median networks are a generalisation of median networks which are not restricted to binary data, although phylogenetic information contained within the multistate positions can be lost during the preprocessing of data. Where the history of a set of samples contain frequent homoplasies or recombination events quasi-median networks will have a complex topology. Graph reduction or pruning methods have been used to reduce network complexity but some of these methods are inapplicable to datasets in which recombination has occurred and others are procedurally complex and/or result in disconnected networks.

Results

We address the problems inherent in construction and reduction of quasi-median networks. We describe a novel method of generating quasi-median networks that uses all characters, both binary and multistate, without imposing an arbitrary ordering of the multistate partitions. We also describe a pruning mechanism which maintains at least one shortest path between observed sequences, displaying the underlying relations between all pairs of sequences while maintaining a connected graph.

Conclusion

Application of this approach to 5S rDNA sequence data from sea beet produced a pruned network within which genetic isolation between populations by distance was evident, demonstrating the value of this approach for exploration of evolutionary relationships.