Statistical evaluation of Ips typographus population density: a useful tool in protected areas and conservation-oriented forestry

Ips typographus (Col., Curculionidae, Scolytinae) occurring on Picea abies stems is a species characterised by large fluctuations in population numbers and causing frequent outbreaks. In protected areas, I. typographus is regarded as a sensitive bioindicator responsive to changes in forest health and vitality. In conservation-oriented forestry, attention is being paid to the ecological value of I. typographus beetles as ecosystem engineers and keystone species, driving forest natural regeneration and conversion. Despite many publications devoted to I. typographus, no accurate method for estimating the population density of this species has been developed. The objective of this study was to develop a statistical method for estimating I. typographus population density that enables calculation of estimation errors. The proposed method consists of two parts: tree-level analyses and stand-level analyses. Part one allows calculation of the total density of I. typographus infestation of each of P. abies selected stem (after selecting sample windfalls), part two allows estimation of the mean total infestation density of the stem in the area investigated. Linear regression functions were applied to part one and survey sampling to part two. The method is only marginally invasive because it involves debarking of one 0.5 m-long stem section on maximum 50 P. abies windfalls (trap trees can optionally be used). The developed method was employed to assess I. typographus population density in the ?wi?tokrzyskie Mountains in Central Poland in an area of ca. 4,000 ha. In 2010, in the area investigated, the mean total I. typographus infestation density of the P. abies stem was 440.6 maternal galleries/m² (from 358.7 to 522.6 maternal galleries/m² with ?? = 0.05; the relative error of estimation was 18.6%). The examined I. typographus population was in a progradation phase. The proposed method can be used in nature reserves, national parks and managed forests, mainly for scientific purposes.     

Growth factors effects on preimplantation development of mouse embryos exposed to tumor necrosis factor alpha

The success rates of assisted reproduction techniques are still unsatisfactory. Relatively few in vitro cultured embryos reach the blastocyst stage. The purpose of the study was to evaluate the protective potential of epidermal growth factor (EGF), insulin-like growth factors 1 and 2 (IGF-I, IGF-II) and stem cell factor (SCF) on in vitro development of pre-implantation mouse embryos exposed to tumor necrosis factor alpha (TNFalpha). C3B6F1 female mice were superovulated with 5 IU of pregnant mare serum gonadotropin (PMSG) and 48 h later with 5IU of equine chorionic gonadotropin (eCG). Following the second injection females were mated with DBA males. Two cell embryos were flushed out from the fallopian tubes 40 h after eCG administration. After retrieval, the embryos were divided into control and experimental media and incubated in groups of ten for 96 h (37 degrees C, 5%CO(2), in droplets of 50 microl under mineral oil). In the first part of experiment, the embryo development was tested in media containing EGF, IGF-I, IGF-II, SCF, TNF-alpha (1 to 1000 ng/ml). In the second part of the study, the development of embryos was examined in medium containing 100 ng/ml TNFalpha and one of following factors: IGF-I, IGF-II; EGF or SCF (100 ng/ml). During the culture embryos were examined at 24 hours intervals to assess the embryo development. Blastocyst rate was determined following 96 hours of culture. Evaluation of total blastocyst cell number (TB) and inner cell mass (ICM) was also performed. TNFalpha significantly reduced (p<0.05) the blastocyst rates as well as TB and ICM. The examined growth factors improved the development of embryos exposed to TNFalpha. Thus, in this study, the protective action of IGF-I and II, EGF and SCF against the detrimental influence of TNFalpha was demonstrated.     

Re(I)(tricarbonyl) complexes with the 2-(2-pyridyl)-N-methyl-benzimidazole, 2-(2-pyridyl)benzoxazole and 2-(2-pyridyl)benzothiazole ligands - syntheses, structures, electrochemical and spectroscopic studies

The reactions of Re(CO)₅Cl with the chelating ligands 2-(2-pyridyl)-N-methylbenzimidazole, 2-(2-pyridyl)benzoxazole and 2-(2-pyridyl)benzothiazole afforded neutral fac-Re(CO)₃(L)Cl and ionic complexes with structures confirmed by means of X-ray measurements. UV-vis absorption and emission properties have been studied at room and 77 K temperatures in order to determine the nature of the lowest electronically excited states. Electrochemical behaviour of the investigated fac-Re(CO)₃(L)Cl and complexes has been studied using cyclic and square-wave voltammetry. Preliminary results from the electrogenerated chemiluminescence studies of the ionic and the neutral fac-Re(CO)₃(MPBI)Cl complexes are briefly presented.     

The chaperone-usher pathway of bacterial adhesin biogenesis -- from molecular mechanism to strategies of anti-bacterial prevention and modern vaccine design

The chaperone-usher system determines the biogenesis of surface-exposed adhesive structures responsible for virulence of many Gram-negative bacteria. Investigations of the last 20 years have resolved the mechanism of this pathway on a structural level for different species of pathogenic bacteria. The purpose of this review is to present the molecular mechanisms of the biogenesis of adhesive structures assembled via the chaperone-usher pathway. The obtained mechanistic data allow one to propose potential strategies of anti-bacterial action. Additionally, the specific properties of the polymeric adhesive structures (pili and fimbriae) of the chaperone-usher system allow their use as effective and safe recombinant vaccines carrying foreign epitopes in thousands of copies on bacterial cell surface.     

The role of Salmonella and Yersinia in the pathogenesis of spondyloarthropathies and rheumatoid arthritis. I. Detection of bacteria, bacterial DNA, lipopolysaccharide and ECA antigen in synovial fluid or blood

To investigate the role of Salmonella and Yersinia in the pathogenesis of spondyloarthropathies and rheumatoid arthritis synovial specimens from 92 patients were analysed for the presence of bacterial DNA with the use of polymerase chain reaction and for the presence of lipopolysaccharide and enterobacterial common antigen (ECA) with the use of Dot-ELISA. In addition, peripheral blood samples were available for PCR analysis from 68 patients. Salmonella and Yersinia chromosomal DNA was not found in any of the synovial specimens and blood samples from the patients. All of the synovial fluids were also culture-negative. Salmonella LPS antigens were observed in 8 (8.6%), Yersinia in 20 (21.7%) and ECA antigens in 32 (34.9%) synovial specimens. Our findings revealed the presence of bacterial degradation products, but not bacteria from the genus Salmonella and Yersinia or their DNA in the synovial fluid or blood of patients with spondyloarthropathies and rheumatoid arthritis.     

Evaluation of usefulness for selected virulence markers for identifying pathogenic Yersinia enterocolitica strains. IV. Genes myfA and ureC

We check by polymerase chain reaction (PCR) the presence of gene ureC and myfA, encoding subunits of urease and Myf fimbriae, among clinical and food-originated strains of Yersinia to determine their usefulness as molecular virulence markers of Y. enterocolitica. The examinations were done on 130 clinical strains of Y. enterocolitica O:3/4 isolated in Poland from humans. All strains were obtained from stool and possessed the virulence plasmid pYV. In addition 40 isogenic, plasmid-cured strains were tested. The 52 strains including Y. enterocolitica (biotype 1A, 4, 2 and 1B), Y. pseudotuberculosis, Y. intermedia, Y. frederiksenii, Y. kristensenii, E. coli, Citrobatcer, Shigella and Salmonella were used as controls. The PCR assay resulted in detection of genes: ureC and myfA in genomic DNA of all 130 tested clinical strains of Y. enterocolitica pYV+, as well as in plasmid cured strains. Furthermore, ureC was found in all tested strains of Y. enterocolitica biotype A1 and in one strain of Y. intermedia and Y. kristensenii. In contrast to ureC, myfA was detected only in strains of Y. enterocolitica considered as pathogenic. Obtained results show, gene myfA seems to be the reliable virulence marker of Y. enterocolitica, whereas ureC is not recommended for identification of pathogenic strains of this species.     

The avoidance strategy of environmental constraints by an aquatic plant Potamogeton alpinus in running waters

Aquatic plants anchored in streams are under pressure from various constraints linked to the water flow and display strategies to prevent their damage or destruction. We assume that the responses of aquatic plants to fast‐water flow are a manifestation of a trade‐off consisting in either maximizing the resistance to damage (tolerance strategy) in minimizing the hydrodynamic forces (avoidance strategy), or both. Our main hypothesis was that Potamogeton alpinus demonstrate the avoidance strategy. We analyzed architecture traits of the modules of this clonal plant from slow‐ and fast‐flowing streams. In fast‐flowing waters, the avoidance strategy of P. alpinus is reflected by the following: (1) the presence of floating leaves that stabilize the vertical position of the stem and protect the inflorescence against immersion; (2) elongation of submerged leaves (weakens the pressure of water); and (3) shoot diameter reduction and increase in shoot density (weakens the pressure of water, increases shoot elasticity), and by contrast in slow‐water flow include the following: (4) the absence of floating leaves in high intensity of light (avoiding unnecessary outlays on a redundant organ); (5) the presence of floating leaves in low intensity of light (avoidance of stress caused by an insufficient assimilation area of submerged leaves).     

Variability of the Left Atrial Appendage in Human Hearts

Atrial fibrillation increases the risk of thrombus formation. It is commonly responsible for cerebral stroke whereas less frequently for pulmonary embolism. The aim of the study was to describe the morphology of the left atrial appendage in the human heart with respect to sex, age and weight. Macroscopic examination was carried out on 100 left appendages taken from the hearts of the patients aged 18–77, both sexes. All hearts preserved in 4% water solution of formaldehyde carried neither marks of coronary artery disease nor congenital abnormalities. Three axes of appendage orientation were performed. After the appendage had been cut off, morphological examination was performed in long and perpendicular axes. Measurements of the appendages were taken from anatomical specimens and their silicone casts. We classified the left atrial appendage into 4 morphological groups according to the number of lobes. Most left atrial appendages in female population were composed of 2 lobes. In the male group typically 2 or 3-lobed appendages were observed. The mean left atrial appendage orifice ranged from 12.0 to 16.0 mm and the most significant difference in the orifices between males and females was observed in LAA type 2 (about 3.3 mm). A smaller orifice and narrower, tubular shape of the LAA lobes could explain a higher risk of thrombus formation during nonvalvular atrial fibrillation in women. Knowledge of anatomical variability of the LAA helps diagnose some undefined echoes in the appendage during transesophageal echocardiographic examination.