bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiplication Operators on Cesàro Sequence Spaces
Authors: Komal B. S. , Pandoh Suruchi , Raj Kuldip
Published: December 2016

In this paper we characterize the compact, invertible and Fredholm multiplication operators on Cesàro sequence spaces.
Probabilistic Generalized Metric Spaces and Nonlinear Contractions
Authors: Mbarki Abderrahim , Naciri Rachid
Published: December 2016

We give a probabilistic generalization of the theory of generalized metric spaces [2]. Then, we prove a fixed point theorem for a self-mapping of a probabilistic generalized metric space, satisfying the very general nonlinear contraction condition without the assumption that the space is Hausdorff.
A Perspective Approach for Characterization of Lieb Concavity Theorem
Authors: Nikoufar Ismail
Published: December 2016

Lieb’s extension theorem holds for generalized p + q ∈ [0; 1] and Ando convexity theorem holds for q - r > 1. In this paper, we give a complete characterization for concavity or convexity of Lieb well known theorem in the case where p + q ≥ 1 or p+q ≤ 0. We also characterize some auxiliary results including Ando theorem for q-r ≤ 1.
Coupling Supercapacitors and Aeroacoustic Energy Harvesting for Autonomous Wireless Sensing in Aeronautics Applications
Authors: Monthéard Romain , Bafleur Marise , Boitier Vincent , Dollat Xavier , Nolhier Nicolas , Piot Estelle , Airiau Christophe , Dilhac Jean-Marie
Published: December 2016

This paper reports for the first time the experimental demonstration of a wireless sensor node only powered by an aeroacoustic energy-harvesting device, meant to be installed on an aircraft outside skin. Aeroacoustic noise is generated on purpose to serve as a means of converting mechanical energy from high velocity airflow into electrical energy. Results related to the physical characterization of the energy conversion process are presented. The proposed aeroacoustic transducer prototype, consisting in a rectangular cavity fitted with a piezoelectric membrane, is shown to deliver up to 2 mW AC power under Mach 0.5 airflow. Optimized power management electronics has been designed to interface with the transducer, including a self-powered Synchronized Switch Harvesting on Inductor (SSHI) interface circuit and an efficient buck-boost DC/DC converter. The design of micropower auxiliary circuits adds functionality while preserving high efficiency. This circuit stores energy in supercapacitors and is able to deliver a net output DC power close to 1 mW. A fully autonomous system has been implemented and tested, successfully demonstrating aeroacoustic power generation by supplying a battery-free wireless datalogger in conditions representative of an actual flight.
High Efficiency Vibration Energy Harvesting Through Combined Isolator and Absorber Approach
Authors: Marin Anthony , Garcia Anthony , Cruz Ricardo , Priya Shashank
Published: December 2016

Relative motion is required for vibration energy harvesting, such as magnet moving past the coil in inductive approach and tip-mass motion in piezoelectric approach. Typically, relative motion is created by amplifying the source displacement and storage of mechanical energy in an auxiliary vibrating mass. In this study, we propose a novel technique to create the relative motion without amplification of the original source displacement. The technique relies on cancelling the vibration at one location and transferring the source vibration directly to another location through combination of a vibration isolator with a vibration absorber. In this multi-degree of freedom configuration, the power is harvested from the displacement of the vibrating source rather than the displacement of an auxiliary mass. This configuration eliminates the need to capture relative motion with respect to an externally fixed component. A prototype was designed and fabricated based on this concept which was found to harvest 45 mW at 0.9 G base acceleration and weighed 462 g. Through analytical modeling it was determined that the prototype could generate 87 mW @ 1 G base acceleration, while weighing only 243 g. Also, an optimal balance between the bandwidth and the maximum power harvested was identified through parametric analysis.
Crede’s method in eye water finds a nanomedicine base: a potential candidate to control ophthalmia neonatorum
Authors: Roy Anupam , Shrivastava Shanker L. , Saha Suman , Khamrai Subhasish , Jana Malabendu , Mandal Santi M.
Published: December 2016

Lethal eye infections of newborns occur mostly due to their passage through the contaminated birth canal. In the pre-antibiotic era blindness from such infections was most challenging. This scenario changed after the 1880s with the use of Crede’s method (a drop of 2.0% silver nitrate solution into newborn’s eyes which was later reduced to 1.0%). This research is focused on finding the structure-function relationship between silver nitrate and tears which offer antimicrobial action. A reinvestigation of Crede’s method revealed a light-dependent instant formation of silver oxide nanoparticles (sizes 20–70 nm) with strong antimicrobial action against ocular pathogens. Nano-therapy would be the key reason behind the widely accepted use of silver nitrate eye drop as a prophylactic agent prior to the discovery of antibiotics. A scientific view on the age-old Crede’s method explores the use of nano-therapy as a prophylactic agent. When routine prophylaxis with topical antibiotics brings the risk of resistance, Crede’s method may, in the near future, offer a way to fight against ophthalmia neonatorum (ON) caused by antibiotic-resistant pathogens.
Synthesis and surface characterization of nanosized Y2O3:Eu and YAG:Eu luminescent phosphors which are useful in photodynamic therapy of cancer
Authors: Bakhmetyev Vadim V. , Minakova Tamara S. , Mjakin Sergey V. , Lebedev Lev A. , Vlasenko Anna B. , Nikandrova Anna A. , Ekimova Irina A. , Eremina Nina S. , Sychov Maxim M. , Ringuede Armelle
Published: December 2016

A series of finely dispersed Y
Geographical conceptualization of quality of life
Authors: Murgaš František
Published: December 2016

The conceptualization of quality of life in terms of geography is based on two assumptions. The first assumption is that the quality of life consists of two dimensions: subjective and objective. The subjective is known as ‘well-being’, while the objective is the proposed term ‘quality of place’. The second assumption is based on the recognition that quality of life is always a spatial dimension. The concept of quality of life is closely linked with the concept of a good life; geographers enriched this concept by using the term ‘good place’ as a place in which the conditions are created for a good life. The quality of life for individuals in terms of a good place overlaps with the quality of life in society, namely the societal quality of life. The geographical conceptualisation of quality of life is applied to settlements within the city of Liberec.
Formation of groupings of mayfly larvae (Ephemeroptera) in the area of small hydrological structures, in the streams of the Kamienica Nawojowska river basin (the Sądeckie Beskids, Poland)
Authors: Niechwiej Artur
Published: December 2016

Anthropogenic modification of abiotic factor in turn influencez biotic communities. The aim of this study was to characterise clusters of mayflies in selected streams of Kamienica Nawojowska river basin in conjunction with small, lateral hydrological structures that have been built in this area. There was an attempt to determine whether and to what extent small lateral hydrological structures affect larvae of mayflies in the examined mountain streams. An analysis of the taxonomic composition of mayfly clusters in the examined stream sections was carried out. For this purpose, the author described the taxonomic wealth, variation in the density of organisms, the domination structure within taxonomic groups and trophic functional groups, taxonomic variation (based on the Shannon-Winner factor), constancy of occurrence (according to the Szujecki formula) as well as faunistic similarity (according to the Jaccard formula). An emphasis was also placed on the species included in the Red List of Vulnerable and Endangered Species in Poland (2002). The obtained results indicate a high taxonomic richness and a large diversity of mayfly fauna on the examined stream sections. There were no significant differences, however, in this aspect between posts situated upstream and downstream from the hydrological structures. The formation of clusters was influenced not so much by small hydrological structures as by other abiotic factors such as the nature of the bottom substrate, the way in which the basin is used, the location of a particular post on a particular watercourse section as well as other anthropogenic activities (e.g. those related to forest management). A comparison of the obtained data with the results of the research conducted before the completion of major regulatory works in Kamienica Nawojowska river basin showed that the mayfly fauna had preserved a large taxonomic richness, although some changes had occurred in the structure of the clusters. However, further research related to this issue is needed, especially in other river basins of the Beskids.
Long-term decline in breeding abundance of Black-headed Gull (Chroicocephalus ridibundus) in the Czech Republic: a case study of a population trend at the Chomoutov lake
Authors: Poprach Karel , Machar Ivo , Maton Karel
Published: December 2016

The aim of this paper is to evaluate the long-term trend in breeding abundance of Black-headed Gull (Chroicocephalus ridibundus) at the Chomoutov lake, Czech Republic. In the period 1978-2014 (always between April 22 and May 10), we conducted 14 nest counts in the bird colony using the direct nest search method. In total, we counted 57,860 nests, from which 2,174 nests were found in the initial year 1978, the maximum number of nests (8,371) in 1993 and 3,304 nests in the last counting year 2014. The nests were located on the ground on an island elevated 2-3 m above the water level. In 1997, we found an unusually located nest on a nesting pad in a poplar tree (Populus sp.), 821 cm above the water level. In this paper, we point out the long-term decline in breeding abundance of Black-headed Gull in major breeding colonies in the Czech Republic, where the abundance declined by up to 95%, while numerous colonies have vanished completely. We discuss factors influencing the negative population trend of Black-headed Gull on the monitored site and in the entire Czech Republic.
Floristic diversity of midforest lakes (Sobibór Landscape Park, Poland)
Authors: Sender Joanna , Maślanko Weronika , Różańska-Boczula Monika , Garbowski Magda
Published: December 2016

Aquatic vegetation greatly impacts lake functions. Forest ecosystems surrounding lakes are effective protection zone of lakes and their associated flora and fauna. The presence of aquatic plants depends on many factors, including the chemical composition and acidity of water, the shape of the lake catchment, the angle of slope along shorelines and the management of surrounding lands. Natural ecosystems throughout Eastern Europe are threatened by anthropogenic activities. Aquatic systems and bogs are particularly sensitive to disturbances. The aim of the study was to determine the influence of land management, forest type and stand age on aquatic plant colonisation within lakes as well as to quantify and qualify the structure of macrophyte communities within two lakes, Płotycze Sobiborskie and Orchowe, located in the Sobibór Landscape Park in western Poland. Even though there were few bogs within the catchment areas and lake buffer zones, where they did occur they had the greatest effect on macrophyte presence. The results of this research indicate that in the absence of anthropogenic disturbances midforest water-bog complexes are relatively stable systems and preserve their natural character. The applied multi-criteria evaluation of macrophytes in the studied lakes and their surrounding buffer zones and catchment areas allowed the lakes to be characterised as lakes with a good ecological status.
Historical changes in dispersed kopanitse land type and changes in use of agricultural land on Kysuce region example
Authors: Barančok Peter , Barančoková Mária
Published: December 2016

Territory of Kysuce is characterised by a high proportion of the traditional agricultural landscape (TAL), which occupy almost 12% of the area. Two types of TAL were allocated here. The first type is represented by TAL with dispersed settlement. The second type is represented by TAL of arable land and grassland landscape. The largest representation has typical forms of anthropogenic relief (FAR). TALs represent the most diverse mosaic of man-made habitats and natural habitats too. In the past, there were the largest representations of arable land and regularly mown meadows. Currently, these areas are dominated by abandoned meadows (fallow meadows), occasionally grazed pastures and meadows. Arable land is represented only minimally. The large part of areas is overgrown by non-forest woody vegetation or passes to the forest vegetation. In this process of landscape changes, significant changes in biodiversity of the areas are realised. Successively, the species of segetal and ruderal vegetation are less represented and species of forest vegetation obtained greater representation. In the process of mapping and evaluation, FAR - shape and orientation of plots, types of balks and some of their basic characteristics - were monitored.
Attitudes of the involved subjects to the issue of biodiversity conservation in the Protected Area of the Malé Karpaty Mts (Results of personal interviews)
Authors: Moyzeová Milena , Izakovičová Zita
Published: December 2016

The aim of this paper is to evaluate the biodiversity from the stakeholders’ point of view as well as to identify the conflicts of interests and the ensuing problems between hunting and the development of other socio-economic activities in the central part of Protected Area of the Little Carpathians. The specified conflicts of interests between hunters, conservationists and farmers are followed by measures that may contribute to increase the biodiversity in this model territory.
Variability of seasonal and annual precipitation in Slovenia and its correlation with large-scale atmospheric circulation
Authors: Milošević Dragan D. , Savić Stevan M. , Pantelić Milana , Stankov Uglješa , Žiberna Igor , Dolinaj Dragan , Leščešen Igor
Published: December 2016

This paper examines temporal and spatial variability and trends of annual and seasonal precipitation in Slovenia and their relationship with three atmospheric circulation patterns represented by their indices: North Atlantic Oscillation index (NAOi), Mediterranean Oscillation index (MOi) andWestern Mediterranean Oscillation index (WeMOi). Data from 45 precipitation stations were used for the period 1963–2012.Mean annual precipitation varies from 736 mm in eastern Slovenia to 2,518 mm in northwestern Slovenia. A significant annual precipitation decrease (from −3% to −6% per decade) is observed in western Slovenia. Significant negative trends are observed in southwestern Slovenia in summer (from −4% to −10% per decade) and near the Adriatic coast in spring (from −6% to −10% per decade). Non-significant negative and positive trends are observed in winter and autumn, respectively. Results indicate significant correlations between winter precipitation and MOi (from −0.3 to −0.7), NAOi (from −0.3 to −0.6) andWeMOi (from 0.3 to 0.6). Significant We-MOi influence is observed in spring and autumn, while NAOi and MOi influence has not been detected. Annual precipitation and WeMOi are significantly correlated in central and eastern Slovenia, while significant NAOi and MOi influence is observed in western Slovenia (with the larger area covered by MOi influence).
Mineralogical and chemical characteristics of a powder and purified quartz from Yunnan Province
Authors: Zuo Ran-Fang , Du Gao-Xiang , Yang Wei-Gang , Liao Li-Bing , Li Zhaohui
Published: December 2016

For comprehensive utilization of powder quartz, a detailed mineralogical analysis is needed. In this paper, the minerals collected from a powder quartz deposit in Yunnan Province and its purification products were characterized by X-ray diffraction (XRD), chemical composition, and scanning electron microscopy (SEM) analyses. The raw powder quartz deposit had a simple mineral composition made of 85% quartz and 15% clay minerals kaolinite and illite with a trace amount of feldspar. It had narrow particle size distribution with whiteness of 81.4. The impurity minerals kaolinite and illite existed in the forms of aggregates with quartz or inclusions in quartz particles and could be easily removed. The mineralogical characterization suggested that the powder quartz deposit was formed by long-term weathering of feldspathic or felsic rocks, possible of pegmatitic origin.
Solventless synthesis of solketal with commercially available sulfonic acid based ion exchange resins and their catalytic performance
Authors: Esteban Jesús , García-Ochoa Félix , Ladero Miguel
Published: December 2016

As a means to valorize glycerol, the synthesis of solketal through a ketalization reaction with acetone was performed. Mild solventless conditions were applied to test the activity of different commercially available sulfonic ion exchange resins that had already been used for other applications, namely: Amberlyst 35dry, Amberlyst 36dry, Purolite CT275DR, Purolite CT276 and Lewatit GF101. Thorough characterization of the resins is herein provided and discussed, including acidity, elemental analysis, thermogravimetric, 13C-NMR, surface area and pore size distribution measurements. Lewatit GF101 showed the best performance reaching a yield to solketal of 47% after 6 h of operation at 313 K using a molar excess of acetone to glycerol of 4.5 to 1, owing to a greater availability of active centers as well as the ease of access to them than in the rest of the resins. Additionally, reutilization with and without regeneration was performed in up to five cycles, showing that Purolite CT276 had the lowest relative drop of its maximum activity, despite being the least active in each of the cycles.
Collection of Wild Helianthus anomalus and deserticola Sunflower from the Desert Southwest USA
Authors: Seiler Gerald J. , Marek Laura Fredrick
Published: December 2016

Genetic resources are the biological basis of global food security. Collection and preservation of wild relatives of important crop species such as sunflower provide the basic foundation to improve and sustain the crop. Acquisition through exploration is the initial step in the germplasm conservation process. There are 53 species of wild
Inheritance of Tribenuron-Methyl Tolerance in Sunflower
Authors: Demurin Ya. N. , Tronin A. S. , Pikhtyareva A. A.
Published: December 2016

The genetic stocks of SURES-1 and SURES-2 showed complete tolerance to tribenuron-methyl. No resistance were obtained after observation on 200,000 plants of four VNIIMK breeding lines grown on an experimental field with total area of 5 ha treated with Express at 1x rate. Potential frequency of a dominant gene for tolerance to tribenuron-methyl was estimated less than 5×10−6. Moreover screening both of 700 plants of 39 inbred lines of the genetic collection and 800 plants of M2 four breeding lines did not reveal any resistance. Tolerance to tribenuron-methyl in F1 and F2 in the crosses of SURES-1 and SURES-2 with VNIIMK breeding lines was controlled by one dominant gene. All recessive homozygous hybrid plants of sur sur genotype in the cross were dead with phytotoxicity index of 9 after Express treatment at any rate of tribenuron-methyl from 0.5x to 4x. Heterozygous hybrid plants of Sur sur genotype showed no injury symptoms at 0.5x rate and increasing level of phytotoxicity index of 4, 6 and 7 for 1x, 2x and 4x rates correspondingly. Dominant homozygous hybrid plants of Sur Sur genotype possessed no injury symptoms from 0.5x to 2x rates whereas the phytotoxicity index of 4 was observed at the 4x rate. Consequently there was no difference between dominant homozygote Sur Sur and heterozygote Sur sur with phytotoxicity index of 0 at 0.5x rate. Allelic interaction in a heterozygote Sur sur can vary from complete to partial dominance in accordance with increasing rate of tribenuron-methyl treatment estimating with the phenotypic scale of phytotoxicity index.
Effect of nitrogen fertilizer application timing on nitrogen use efficiency and grain yield of winter wheat in Ireland
Authors: Efretuei A. , Gooding M. , White E. , Spink J. , Hackett R.
Published: December 2016

The objectives of this work were to determine the effects of initiating application of fertilizer nitrogen (N) to winter wheat at different growth stages (GSs) on grain yield and N use efficiency (NUE). A factorial experiment was carried out in two growing seasons (2011 and 2012) with five timings of first N application (GS 24/26 [tillering], GS 30, GS 31, GS 32 or GS 37) and an unfertilized control, two sowing densities (100 and 400 seeds/m2) and a cattle slurry treatment (with or without slurry). The latter was included to simulate variation in soil N supply (SNS). Delaying the first application of N from the tillering stage until GS 30 had no significant effect on grain yield in either year. Further delaying the initial N application until GS 31 caused a significant yield reduction in 2011, in comparison to GS 30 application, but not in 2012. Differences in efficiency of recovery and use of fertilizer N by the crop among the first three application timings were small. There was no evidence to support alteration in the timing of the first application of N in response to low plant density. Slurry application did not influence SNS, so the interaction between SNS and fertilizer N application timing could not be determined. It is concluded that in order to maximise yield and NUE, the first N application should be applied to winter wheat between late tillering and GS 30 and that delaying the first N until GS 31 can lead to yield reductions compared to the yield obtained with earlier application.
Parental support for human papilloma virus vaccination by adolescents in Ibadan North Local Government Area, Ibadan, Nigeria
Authors: Dairo Magbagbeola David , Adeleke Moradeke Omoyemi , Salawu Adetokunbo Taophic , Adewole Ayobami David
Published: December 2016

Background:

Despite changing sexual norms and mores generally perceived to be permissive of sexual expression, parents continue to serve as gateways to uptake of reproductive health services and commodities in our cultural settings. However, their support for adolescent uptake of human papilloma virus (HPV) vaccine are not well explored and documented. This study aims to assess parental knowledge and awareness of HPV infection and cervical cancer and their support for HPV vaccination for their adolescent children.

Methods:

In a descriptive cross sectional study 612 parents from in Ibadan North Local Government Area were interviewed using a pre-tested semi structured interviewer administered questionnaire to assess the awareness of HPV infection and cervical cancer as well as parental support for the vaccine.

Results:

Only a few of the respondents were aware of HPV infection (10.5%) and the HPV vaccine (6.5%), respectively. About 64.3% of those that were aware of HPV knew it can be transmitted through sexual intercourse. However, 78.4% supported the administration of the vaccine to their adolescent daughters. Reported reasons for not supporting HPV vaccination were high cost of the vaccine (32.2%) and lack of awareness of the vaccine (49.2%). Earning a monthly income above the minimum wage of 18,000 Naira increases the likelihood of parental support for HPV vaccination uptake for adolescents (p<0.001).

Conclusion:

Ignorance and poverty remain as barriers to widespread coverage of the vaccine among adolescents. Health education and promotion on HPV infection and the HPV vaccine to the general public and subsidization of the vaccine to promote its uptake is advocated.
Perceived effectiveness and satisfaction of a community-based positive youth development program: findings based on high school students
Authors: Shek Daniel T.L. , Leung Janet T.Y. , Law Moon Y.M. , Chan Kies S.Y.
Published: December 2016

This study examined participants’ perceptions of a community-based positive youth development (PYD) program (the Project P.A.T.H.S.) based on the responses of 16,420 junior secondary students who joined the program in 2015. Subjective outcome evaluation approach was adopted to examine the students’ views of program content, program instructors, and program effectiveness. Consistent with previous studies, results showed that students generally perceived the program positively, and positive relationships were found amongst the three domains of evaluation. Multiple regression analyses showed that perceived program content and instructor qualities were significant predictors and could explain 35% of the variance in program effectiveness perceived by the participants. The present findings are basically consistent with previous subjective outcome evaluation findings derived from the school-based and community-based programs of the Project P.A.T.H.S. in Hong Kong.
Individual differences in intentional and unintentional exposure to online pornography among Hong Kong Chinese adolescents
Authors: Ma Cecilia M.S. , Shek Daniel T.L. , Lai Catie C.W.
Published: December 2016

The current study aimed to test how gender and religion affect unintentional and intentional exposure to online pornography in Chinese adolescents. A total of 1401 secondary school students (age range from 11 to 16 years) participated in the study. Findings from multivariate analyses show that males reported higher levels of unintentional and intentional exposure to online pornography than females. Significant differences were found in adolescents’ religiosity, with students who had religious beliefs reporting a lower level of unintentional exposure to online pornography than their counterparts without religious beliefs. In terms of intentional exposure to online pornography, adolescents were more likely to be exposed if they were male and had religious beliefs. Such differences were not found in females. This study demonstrated the influence of demographic characteristics on exposure to online pornography among Chinese adolescents.
A Novel Load Shedding Scheme for Voltage Stability
Authors: Damodhar Sunil S. , Krishna S.
Published: December 2016

Undervoltage load shedding serves to maintain voltage stability when a majority of loads are fast acting. An undervoltage load shedding scheme should address two tasks: the detection of voltage instability following a large disturbance and the determination of the amount of load to be shed. Additionally, in case of short-term voltage instability, the scheme should be fast. This paper proposes a method to predict voltage instability arising due to a large disturbance. The amount of load to be shed to maintain voltage stability is then determined from the Thevenin equivalent of the network as seen from the local bus. The proposed method uses local measurements of bus voltage and power, and does not require knowledge of the network. The method is validated by simulation of three test systems subjected to a large disturbance. The proposed scheme is fairly accurate in estimating the minimum amount of load to be shed to maintain stability. The method is also successful in maintaining stability in cases where voltage collapse is detected at multiple buses.
Hausa language names and ethnonyms
Authors: Newman Paul , Schuh Russell G.
Published: December 2016

The Hausa word
Entre verbe et adverbe : Grammaticalisation et dégrammaticalisation du marqueur épistémique umeengo/umeenga en kirundi (bantou, JD62)
Authors: Mberamihigo Ferdinand , de Schryver Gilles-Maurice , Bostoen Koen
Published: December 2016

La présente étude concerne l’évolution sémantique et formelle d’un adverbe épistémique du kirundi,
Three-Dimensional Reconstruction of Arterial-Lymphatic Vascular Complex (Vessel Within the Vessel) in Breast Tissue
Authors: Ivanov Ivan N. , Popovska Savelina L. , Ivanov Emilian A. , Iliev Sergey D. , Tonchev Pencho T.
Published: December 2016

The phenomenon “vessels within vessels” was initially described by Merchant S et al. as arteries found free-floating inside the lumen of veins. We have described another version of the “vessels within vessels”complex, composed of arteries found inside the lumen of lymphatic vessels. The purpose of the present study was to describe the structure of the lympho-arterial vascular complex in a breast tissue specimen from a male subject using three- dimensional tissue reconstruction. A histological specimen from a 64 year-old male subject diagnosed with gynecomastia was used. The tissue sample was sectioned in a multi-step manner. An overall of approximately 150pm thick tissue material was sampled. Immunostaining with anti-CD34 antibody and anti-podoplanin antibody was performed. Three-dimensional reconstruction of the vessel within the vessel structure was performed with “Reconstruct” software When the reconstruction of the breast parenchyma was revealed as a 3D image, it became apparent that the arterial vessel was situated inside the lymphatic vessel and could be followed along the entire length of the vascular segment studied. We have proved that these vascular complexes are not artificial phenomenon and do exist. The function of the vascular complexes is still uncertain, and is probably related to lymph propulsions in the initial collector vessels.
Multidrug Resistance Among Enterococci at a Tertiary Care Hospital in Northern Bulgaria
Authors: Popova Valentina P. , Sredkova Mariya P. , Hitkova Hristina H. , Ivanov Kaloyan T. , Popov Vladimir G.
Published: December 2016

Multidrug-resistant (MDR) enterococci are a growing threat. The aim of this study was to determine the species distribution and prevalence of multidrug resistance among 100 enterococcal strains, isolated from patients treated in the University Hospital in Pleven, Bulgaria. Susceptibility to 11 antimicrobial agents was determined, using the disc diffusion method according to the performance standards of Clinical Laboratory Standards Institute (CLS1), 2012. All isolates were screened for high-level aminoglycoside resistance and resistance to vancomycin according to the recommendations of CLS1, 2012. For strains with reduced susceptibility to vancomycin, minimal inhibitory concentrations (MIC) of glycopeptides were determined by Etest (Liofilchem, Italy) and by Vitek 2 automated system. Our results demonstrated decreased susceptibility of enterococci to almost all intensively used anti-enterococcal drugs. Resistance to both penicillins (ampicillin and penicillin) among E.faecium strains was significantly higher (83-87%) than among E.faecalis isolates (4-27%). HLGR was detected in 70% of E.faecium and 38% of E.faecalis isolates. All HLGR strains were foundtobemultiple-drug resistant. Of particular note was the emergence of concomitant resistance to 6 antimicrobials in almost 50% of E.faecium isolates. Despite the wide dissemination of MDR E.faecium strains penicillins in our hospital, acquired resistance to vancomycin was not found.
Effect of Aronia Melanocarpa Fruit Juice on Fearning and Memory in the Two-Way Active Avoidance Task in Rats
Authors: Valcheva-Kuzmanova Stefka , Eftimov Miroslav , Beleheva Iren , Tashev Roman , Beleheva Stiliana
Published: December 2016

Amnia melanocarpa fruits are one of the richest natural sources of phenolic substances, among them flavonoids, mainly from the subclass of anthocyanins. Flavonoids, which are constituents of Amnia melanocarpa fruit juice, have been found to localize in various brain regions that are important for memory. The aim of the present study was to investigate the learning and memory effects of Amnia melanocarpa fruit juice (AMFJ) in young/healthy male Wistarrats. AMFJ was applied orally for 21 and 30 days at a dose of 10 ml/kg b.w., and comparisons were made with saline-treated (10 ml/kg b.w.) controls. Learning and memory functions were evaluated, using the two-way active avoidance task (shuttle box). Administered for the two treatment periods, the juice significantly increased the number of avoidances on training days 1 and 2, as well as at the retention test (24 h after the 2ndtraining session). These effects were more pronounced in rats treated with AMFJ for 30 days. The learning and memory effects of AMFJ are probably due to its polyphenolic constituents. The findings from the present study suggest that AMFJ applied subchronically improved learning and memory in young/healthy rats.
The Place of Penetrating Keratoplasty in Corneal Diseases
Authors: Murgova Snejana V. , Balabanov Chavdar B. , Yordanov Georgi Y.
Published: December 2016

The aim of the study was to analyze the results from penetrating keratoplasties (PK) in patients with different comeal diseases. The retrospective study included 124 patients (130 eyes) who underwent penetrating keratoplasty at the Eye Clinic, Pleven, between 1990 and 2011. The patients were divided into four groups, according to the main indication for keratoplasty: 1 - bullous keratopathy - pseudophakic and aphakic bullous keratopathy (PBK and ABK); 2 - degeneration and dystrophy (including keratoconus); 3 - keratitis, scar, trauma; 4 - repeat keratoplasty. The main indications for penetrating keratoplasty included regraft - 27%, PBK - 22.62%, ABK - 11.9% and keratoconus - 10.71%, though the leading cause had been different at different periods of time. By the time of suture removal (8-9 months on the average) in the group of patients with bullous keratopathy, the percentages of clear grafts were as follows: 55.88% in the group of patients with bullous keratopathy, 97.44% in the group with comeal degeneration and dystrophies, and 60% in the group with keratitis, corneal scar and trauma. In patients with regrafts, For the whole period of the study, grafts failed in 61.54% of patients with one regraft, and in 50% of the cases with second and third regrafts. Penetrating keratoplasty proved a valuable method of treatment for a number of comeal diseases. The prognosis and outcome, however, depended on the pathology responsible for comeal blindness.
Comparison of Four Methods for Corneal Thickness Measurement
Authors: Marinova Teodora L. , Ivancheva Vesela , Peeva Svilena S. , Grupcheva Christina N.
Published: December 2016

The aim of the study was to evaluate the thickness of the normal cornea in order to establish correlation between four methods of measuring including: ultrasound pachymetry (USP), anterior segment optical coherence tomography (ASOCT), non-contact tono/pachymetry (TONOPACHY) and laser-scanning confocal microscopy (LSCM). The study was based on evaluating repeatability and comparability of four different methods formeasuring the corneal thickness. Non contact specular microscopy was first performed on all 27 patients (aged between 20 and 24 years) to evaluate corneal characteristics and confirm the absence of pathological changes. Each participant was examined by USP, ASOCT and TONOPACHY, and 13 eyes of 10 persons were also examined by LSCM. The values of average central corneal thickness measured by USP, ASOCT, TONOPACHY and LSCM were 532.20±4.5 pm, 553.33±12.1 pm, were 548.20±5.62 pm and 573.33±7.22 pm, respectively. There was a high correlation between the instruments. The mean differences for central corneal thickness measurements were 41.43±1.67 pm between USP and LSCM, 20.43±2.4 pm between USP and ASOCT, and 22.1 ±3.88 pm between USB and TONOPACHY. Anterior segment optical coherence tomography overestimated corneal thickness as compared with that measured by USP, which is believed to be a gold standard. Anterior segment optical coherence tomography had better agreement with USP, as compared with LSCM. However, the results of measured cornea thickness by TONOPACHY were very close to cornea thickness measured by ASOCT.
Etiology of Diabetic Foot Infection in Patients with Poorly Controlled Diabetes
Authors: Iliev Sergey D. , Beshev Lyubomir Ts. , Nedyalkov Kiril L. , Nguen Dobromir D. , Edreva-Besheva Valentina E. , Sredkova Mariya P. , Belcheva Yuliya M. , Dimitrova Emiliya J.
Published: December 2016

The aim of the study was to define the spectrum and susceptibility of microorganisms, isolated from diabetic foot ulcers in patients with poorly controlled diabetes, treated at the clinic of surgery, and compare microbial findings of specimens collected superficially and from deep tissues. The study included 19 patients with type 1 and 2 diabetes with clinical signs of infection. All patients were with poorly controlled diabetes and staged from 3rd to 5th grade according to the Wagner diabetic foot scale. Swab samples from non-debrided wounds and biopsy samples from deep tissues were collected from each patient. Specimens were inoculated on media for isolation of aerobic and anaerobic bacteria. Identification and susceptibility testing of the isolated oiganisms were performed by conventional methods, and VITEK 2 and mini API Systems (bioMerieux, France). A total of 88 bacterial isolates were cultured, comprising 56 clinical strains. Gram positive bacteria were the most common isolated organisms (53.57%), followed by Gram negative bacteria (26.78%) and anaerobic bacteria (19.64%). Staphylococcus aureus was the most common organism detected (10 strains), followed by Enterococcus spp. (7 strains), Escherichia coli (7 strains), Bacteroides spp. (6 strains) and various other organisms of low incidence. Polymicrobial infection was detected in 17 (89.47%) of the patients. In most of the cases infections were caused by 3 bacterial species. Mixed aerobic/anaerobic infections were detected in 9 (47.3%) patients. In 15 (78.94%) patients, there was a coincidence of bacterial findings from superficial and deep tissue samples. The strains isolated were susceptible to commonly used antimicrobials for treatment of diabetic foot infection. The predominant part of the diabetic foot infections were polymicrobial, caused by association between two or three microbial species. In half of the cases the infection was mixed. There was a good correlation between microbial findings from superficial swabs and deep tissue specimens when they were delivered to the microbiology laboratory immediately after collection.
An Angiosarcoma in the Right Atrium: A Case Report
Authors: Dumitru Nicoleta F. , Bartos Daniela I.
Published: December 2016

Angiosarcoma is a rare malignant tumor of vascular endothelial cell origin, accounting for 1-2 % of all sarcomas. We present a 24-year-old female patient, initially diagnosed and treated for tuberculous pleurisy for one month. Then transthoracic echocardiography (TTE) revealed a rare cause for the pleural and pericardial effusion - a tumoral mass apparently arising from the right atrium and extending into the upper vena cava. The patient presented with worsening dyspnea, stabbing pain in the right hemithorax and persistent, irritating cough, a recent history of haemoptysis, bilateral pleurisy and hemorrhagic pericardial effusion. The ECG showed sinus rhythm with negative T-waves in leads DI, Dll, aVL, V3 to V6. The TTE showed an irregularly shaped right atrial tumoral mass, not resembling a thrombus, which extended to the upper vena cava. The transesophageal echocardiography showed an invasion of the serous (parietal and visceral) pericardium and a dilated right atrium almost completely occupied by the tumoral mass. The CT scan revealed invasion of the upper vena cava ostium and anterior mediastinum with pretracheal adenopathies, and hemorrhagic pleural and pericardial effusion suggestive of a sarcoma. The histological examination and immunohistochemistry confirmed the diagnosis of angiosarcoma. Although a rare form of malignant tumor that affects the head, neck, breast, bone, liver, spleen and heart, angiosarcoma must be considered as a possible cause of pleural and pericardial effusion, especially in previously healthy young patients.
Assessment of the Effect of Treatment with Neoadjuvant Chemotherapy on Breast Cancer Axillary Lymph Node
Authors: Popovska Savelina L. , Ivanov Ivan N. , Dikov Dorian Y.
Published: December 2016

Neoadjuvant chemotherapy is the standard of care for patients with locally advanced breast cancer (LABS). The aim of this study was to determine the effects of neoadjuvant chemotherapy on metastatic and nonmetastatic breast cancer axillary lymph nodes (ALNs). Seventy-seven patients with LABS and cytologically documented ALN metastases were treated in two prospective trials. Patients had breast surgery with level I and level II axillary dissection followed by additional chemotherapy or radiation treatment. Clinical nodal status was determined by physical examination and compared with histological and immunohistochemical findings. The regressive changes in primary tumor and ALNs were achieved using scoring systems. Objective clinical response in primary tumor was seen in 48.05% of patients. Histologic evidence of regression was noted in 46 cases (59.75%), with complete histologic regression achieved in 5 cases (6.49%). The number of cases according to the ALNs regression scoring system was as follows: 0 grade - viable metastases without effect - 21 patients (30%); 1 grade - cytotoxic effect in metastases - 20 patients (28.58%), 2 grade - micrometastasis - only3 patients (4.28%); 3 grade - no residual metastatic disease - 1 patient (1.43%); 4 grade - negative ALNs before and after treatment - 25 patients (35.71%). Nodular fibrotic area and iron-loaded macrophages suggested previous presence of tumor metastasis. There was significant relationship between histologic regression in the primary tumor and the presence of effect of cytotoxic agents on ALNs metastases (r=0.9123; p<0.00001). As chemotherapy is widely used in the treatment of breast carcinoma, pathologists should be aware of chemotherapy-induced changes in metastatic and in non­metastatic ALNs.
Postoperative Outcomes of Elective Pancreatic Surgery in a Low-Volume Academic Surgical Clinic
Authors: Julianov Alexander E. , Karashmalakov Anatoli G. , Rachkov Ivan G. , Georgiev Yonko P.
Published: December 2016

According to the volume-outcome concept the postoperative outcome after major pancreatic surgery in high-volume institutions compares favorably to low- volume centers. However, it is not clear whether this is applicable to all low-volume institutions nowadays. The aim of the study was to evaluate the postoperative outcome after major elective pancreatic surgery in a low- volume academic surgical clinic. All consecutive elective major pancreatic cases operated within a 10-year period till October 2013 have been retrospectively reviewed. During the studied period, 36 patients (15 females, 21 males, mean age 54 years, age range 37-76) were scheduled for elective pancreatic surgery and underwent pancreatic resection (n=31, 18 proximal and 13 distal pancreatic resections) or complete pancreatic duct drainage procedure (n=5). Eleven patients had chronic pancreatitis and 25 patients had malignant or benign tumors. Vascular or adjacent organ resection was performed in 9 patients (29% of resections). The overall postoperative morbidity was 36% (n=13), and complications requiring re-operation occurred in 5 patients (14%). The median postoperative hospital stay was 11 days for patients without complications vs. 25 days for patients with any complication. There was no 60- day postoperative mortality or hospital readmission. Major elective pancreatic surgery can be safely performed today in a low-volume academic general surgical clinic, with postoperative outcomes similar to those reported by high-volume centers.
Risk Factors for Coronary Artery Diseases: A Study Among Patients With Ischemic Heart Disease in India (Kerala)
Authors: James Cyril , Attacheril Thankachan V. , Balakrishnan N. , Gaydarova Diana K. , Stancheva Nadya Y. , Gerchev Ivan P. , Ohri Shreya , Tisheva Snezhana T.
Published: December 2016

Coronary artery disease (CAD) is a condition that develops due to accumulation of atherosclerotic plaque in the epicardial coronary arteries, leading to myocardial ischemia. It is the leading cause of death worldwide and is a common complex disease. A study was carried out in a group of 496 patients with acute coronary syndrome or with angiographic or stress test evidence for coronary artery disease, admitted to the Department of Cardiology at Lourdes Heart Institute and Neuro Centre during the period June-August 2012. The risk factors studied were hypertension, diabetes mellitus, dyslipidemia, body mass index, smoking and family history of CAD. The results demonstrated that in both males and females of the Indian population studies, diabetes and dyslipidemia were major risk factors for CAD, while hypertension was not a major risk factor. Therefore, early detection and treatment of diabetes mellitus and dyslipidemia play a vital role in prevention of CAD in Indian population.
Rare Case of Human Visceral Linguatuliasis in Bulgaria Diagnosed on Biopsy Specimen
Authors: Mateva Svetlana A. , Nikolova Margarita R. , Karaivanov Milen P. , Marinova Petya E.
Published: December 2016

We report a rare case of visceral linguatuliasis in a 9-year-old boy. The diagnosis was made incidentally on a biopsy specimen obtained during laparotomy on account of an acute appendicitis. An encysted parasite was found in a mesenteric lymph node and diagnosed as Linguatula serrata larva mainly based on its typical appearance. The vermiform appendix showed only lymphoid hyperplasia and no features of inflammation. The patient made an uneventful recovery after the operation and was discharged. He is being followed up. To our knowledge this is the first officially reported case of human linguatuliasis in Bulgaria.
Genetic Polymorphisms, Plasma Levels of Lipoprotein (A) and its Possible Links with Degenerative Aortic Stenosis
Authors: Tomova Vesela D. , Rashev Tihomir R. , Atanasova Milena A.
Published: December 2016

Degenerative aortic stenosis is the second most common acquired valvular heart disease in adults (after mitral insufficiency) and the second most common cause for cardiac surgery (after coronary heart disease). The reasons for the occurrence of these diseases (congenital abnormality of the valve: bicuspid aortic valve disease, advanced renal failure, impaired calcium-phosphorus metabolism) have been established only in a small portion of these patients. The absence of a specific reason, causing calcification and narrowing of the aortic valve in recent years has challenged researchers to start investigating genetic factors that may correlate with the development of degenerative aortic stenosis. Regardless of the conducted studies, knowledge and identification of predictive genetic factors in the occurrence and progression of aortic stenosis are still insufficient. It is assumed that a specific genetic variant in the Lipoprotein (a) locus (LPA locus), reflected by the Lipoprotein (a) [Lp(a)] plasma levels, is connected to the pathology of aortic stenosis in multiethnic groups. The study of the genetic nature of aortic stenosis and significance of Lp( a) plasma levels and genetically determined variations of its structure associated with the manifestation and progression of valvular calcification in the future might provide predictive intervention. Similar studies relating to genetic polymorphisms in LPA locus, plasma concentrations of Lp(a) and their correlation with aortic stenosis have not beenconducted in Bulgaria so far.