Majority logic gate for magnetic quantum-dot cellular automata

We describe the operation of, and demonstrate logic functionality in, networks of physically coupled, nanometer-scale magnets designed for digital computation in magnetic quantum-dot cellular automata (MQCA) systems. MQCA offer low power dissipation and high integration density of functional elements and operate at room temperature. The basic MQCA logic gate, that is, the three-input majority logic gate, is demonstrated.     

Experimental results of using autologous rectus fascia sheath for venous patch grafts in dogs

Autologous vascular patch grafts developed from the internal rectus sheath were implanted onto the bilateral common iliac vein and jugular vein of 4 experimental beagle dogs. During the development and implanting of the grafts no technical difficulties or perioperative complications were encountered. The follow-up lasted 6 months and 3 months in the case of the common iliac vein grafts and the jugular grafts, respectively. In the postoperative period, the morphological and functional characteristics of the implanted venous sections were examined by Doppler ultrasonography and CT angiography. Normal patency was detected, and none of these check-ups showed obturation or stenosis. The histological survey showed no mesothelial cell layer, but the insides of the grafts showed total restructuring and were covered by a normal endothelial layer. No difference could be detected between samples harvested 3 and 6 months after implanting. The immunohistochemical examinations using anti-claudin-5 and anti-CD31 antibodies confirmed the preliminary results of the histological examinations that the luminal surfaces of the implanted grafts developed a differentiated monolayer endothelium which was free of degenerative and inflammatory signs. The control examinations show the suitability of the internal rectus sheath as a venous wall donor.     

Occurrence, clinical features and outcome of canine pancreatitis (80 cases)

Medical records of 80 dogs diagnosed with acute pancreatitis during a 4-year period were evaluated regarding history, breed predilection, clinical signs and additional examination findings. Cases were selected if compatible clinical symptoms, increased serum activity of amylase or lipase and morphologic evidence of pancreatitis by ultrasonography, laparotomy or necropsy were all present. Like in other studies, neutered dogs had an increased risk of developing acute pancreatitis. Although breed predilection was consistent with earlier reports, some notable differences were also observed. Apart from Dachshunds, Poodles, Cocker Spaniels and Fox Terriers, the sled dogs (Laikas, Alaskan Malamutes) also demonstrated a higher risk for pancreatitis according to our results. Concurrent diseases occurred in 56 dogs (70%), diabetes mellitus (n = 29, 36%) being the most common. Clinical signs of acute pancreatitis were similar to those observed in other studies. The study group represented a dog population with severe acute pancreatitis, having a relatively high mortality rate (40%) compared to data of the literature. Breed, age, gender, neutering and body condition had no significant association with the outcome. Hypothermia (p = 0.0413) and metabolic acidosis (p = 0.0063) correlated significantly with poor prognosis and may serve as valuable markers for severity assessment in canine acute pancreatitis.     

Microcystin-LR and Cylindrospermopsin Induced Alterations in Chromatin Organization of Plant Cells

Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-induced changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins induce the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister chromatid segregation during mitosis. Thus, MCY and CYN are probably inducing alterations of chromosome number. MCY induces programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR induces histone H3 hyperphosphorylation leading to incomplete chromatid segregation and the formation of micronuclei. CYN induces the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization.     

Decline of genetic diversity of sessile oak at the retracting (xeric) limits

Context

Genetic diversity of sessile oak (Quercus petraea) populations in Hungary was assessed close to the retracting, low-elevation, low-latitude (xeric) distribution limits.

Objective

We aimed at tracing an assumed effect of climatic factors on genetic diversity, particularly at the southern, low elevation limits of distribution.

Methods

Genetic diversity at isozyme-coding loci was analysed in populations, and related to the climate of the sites where the populations grow. A locus-wise analysis proved to be essential to follow responses.

Results

A climate-related cline was found at seven isoenzyme-coding gene loci. Declining allelic numbers and heterozygosity indicated lower diversity at warmer and drier sites. The majority of loci were responsive to precipitation factors, others to temperature. Genetic clustering was neither related to geographic distance nor to random or historic effects.

Conclusions

The results suggest that climatic stress may elicit a genetic diversity loss in populations, which may reduce their plasticity and adaptive potential. The selective pressure may override historic effects and gene flow. With respect to expected climate change, the correlation of diversity with some climatic factors gains specific importance. If supported by further investigations, the results might be utilised for reconsidering conservation strategies and rules for use of forest reproductive material.     

Barking in family dogs: An ethological approach

Although it is one of the most conspicuous features of dog behaviour, barking has received little attention from ethologists or from an applied perspective. In this review, an ethological look is taken at the communicative aspect of dog barking. Emerging new research has indicated that in the repertoire of dog vocalisations barking has unique features in showing wide ranges of acoustic parameters, such as frequency, tonality and rhythmicity. Barking has been shown to be context dependent, and provides information for humans about the inner state of the dog although there are few indications that barking is used for intra-species communication. It is assumed that dog barking emerged through selective processes in which human preferences for certain acoustic aspects of the vocalisation may have been paramount. A more experiment-oriented approach is required for the study of dog vocalisation that could shed light on the possible communicative function of these acoustic signals.     

Immunohistochemical detection of arteriolar hyperplasia in canine liver biopsy samples using the claudin-5 antibody

Claudins are key tight junctional proteins between adjacent epithelial, mesothelial or endothelial cells, which are responsible for the permeability of the paracellular space. This paper describes that the endothelial cells of normal hepatic arterioles, portal venules and portal lymphatics as well as the endothelium of sinusoids from dogs show strong membranous claudin-5 cross-reactivity. In 25 liver biopsy samples taken from dogs with portal vein hypoperfusion, an increased number of arterioles was detected in the portal areas (PAs) by the use of humanised anti-claudin-5 antibody. The increased number of hyperplastic hepatic arterioles per PA was 5-6, 8-12 and 15-20 in the case of small, medium-sized and large PAs, respectively. It is suggested that the claudin-5 marker can improve the detection of hepatic arteriolar proliferation in the PAs of liver samples.