The contribution of insect prey to the total nitrogen content of sundews (Drosera spp.) determined in situ by stable isotope analysis

The contribution of insect prey to total N in the carnivorous plants, Drosera rotundifolia and D. intermedia, was quantified in situ and without any experimental manipulation using natural abundance stable isotope analysis. Samples of D. rotundifolia and D. intermedia, insects and noncarnivorous reference plants were collected from three contrasting locations across Britain. The proportion of Drosera nitrogen obtained from insect prey was calculated by a mixing model using δ<sup>15</sup>N values from the different plant groups. The mean proportion of Drosera N derived from prey was 50%. There were significant differences in this proportion between sites, and significant differences within sites. There were significant differences between plant tissues and a significant negative relationship between the proportion of N derived from prey and the C : N ratio of Drosera tissues. There was little evidence of differences in prey capture/utilisation in response to N availability, possibly due to a limited range in available N between the sites. However, evidence of a positive benefit of prey capture was apparent through the decrease in C : N ratio with increasing prey N concentrations in the plants

Coagulation activity of stored blood at +4°C

U ovom je radu ispitana koagulaciona aktivnost uskladištene krvi na +4°C. Primijenjeno je osam koagulacionih testova, a promjene koagulacione aktivnosti prikazane su grafički. Testiranje je izvršeno odmah nakon vađenja krvi, te drugi, sedmi i četrnaesti dan. Rezultati autora uspoređeni su s rezultatima iz literature.The coagulation activity of blood stored at 4°C was investigated. Eight different clotting tests were used. The changes in the coagulation activity are presented graphically. The testing was performed .immediately after the blood was taken from the vein and then after the first, seventh and forteenth day of storage. The authors compare their results with the data reported in literature. On each figure the time of storage in days is marked on the abscissa. The ordinate indicates the clotting time in sec. (Fig. 1), the prothrombin time in sec. (Fig. 2), the prothrombin consumption test in sec. (Fig. 3), the number of platelets x 10-3 (Fig. 4), the tromboplastin generation test, % activity (Fig. 5), the antihemophilic globulin % (Fig. 6), factor V activity % (Fig. 7), factor VII activity % (Fig. 8)

International Veterinary Epilepsy Task Force recommendations for systematic sampling and processing of brains from epileptic dogs and cats

Traditionally, histological investigations of the epileptic brain are required to identify epileptogenic brain lesions, to evaluate the impact of seizure activity, to search for mechanisms of drug-resistance and to look for comorbidities. For many instances, however, neuropathological studies fail to add substantial data on patients with complete clinical work-up. This may be due to sparse training in epilepsy pathology and or due to lack of neuropathological guidelines for companion animals. The protocols introduced herein shall facilitate systematic sampling and processing of epileptic brains and therefore increase the efficacy, reliability and reproducibility of morphological studies in animals suffering from seizures. Brain dissection protocols of two neuropathological centres with research focus in epilepsy have been optimised with regards to their diagnostic yield and accuracy, their practicability and their feasibility concerning clinical research requirements. The recommended guidelines allow for easy, standardised and ubiquitous collection of brain regions, relevant for seizure generation. Tissues harvested the prescribed way will increase the diagnostic efficacy and provide reliable material for scientific investigations

phot1 inhibition of ABCB19 primes lateral auxin fluxes in the shoot apex required for phototropism

It is well accepted that lateral redistribution of the phytohormone auxin underlies the bending of plant organs towards light. In monocots, photoreception occurs at the shoot tip above the region of differential growth. Despite more than a century of research, it is still unresolved how light regulates auxin distribution and where this occurs in dicots. Here, we establish a system in Arabidopsis thaliana to study hypocotyl phototropism in the absence of developmental events associated with seedling photomorphogenesis. We show that auxin redistribution to the epidermal sites of action occurs at and above the hypocotyl apex, not at the elongation zone. Within this region, we identify the auxin efflux transporter ATP-BINDING CASSETTE B19 (ABCB19) as a substrate target for the photoreceptor kinase PHOTOTROPIN 1 (phot1). Heterologous expression and physiological analyses indicate that phosphorylation of ABCB19 by phot1 inhibits its efflux activity, thereby increasing auxin levels in and above the hypocotyl apex to halt vertical growth and prime lateral fluxes that are subsequently channeled to the elongation zone by PIN-FORMED 3 (PIN3). Together, these results provide new insights into the roles of ABCB19 and PIN3 in establishing phototropic curvatures and demonstrate that the proximity of light perception and differential phototropic growth is conserved in angiosperm

Implicating Calpain in Tau-Mediated Toxicity In Vivo

Alzheimer's disease and other related neurodegenerative disorders known as tauopathies are characterized by the accumulation of abnormally phosphorylated and aggregated forms of the microtubule-associated protein tau. Several laboratories have identified a 17 kD proteolytic fragment of tau in degenerating neurons and in numerous cell culture models that is generated by calpain cleavage and speculated to contribute to tau toxicity. In the current study, we employed a Drosophila tauopathy model to investigate the importance of calpain-mediated tau proteolysis in contributing to tau neurotoxicity in an animal model of human neurodegenerative disease. We found that mutations that disrupted endogenous calpainA or calpainB activity in transgenic flies suppressed tau toxicity. Expression of a calpain-resistant form of tau in Drosophila revealed that mutating the putative calpain cleavage sites that produce the 17 kD fragment was sufficient to abrogate tau toxicity in vivo. Furthermore, we found significant toxicity in the fly retina associated with expression of only the 17 kD tau fragment. Collectively, our data implicate calpain-mediated proteolysis of tau as an important pathway mediating tau neurotoxicity in vivo