2,081 research outputs found

    Test of the purchasing power parity hypothesis by using panel structural break test for transition economies

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    This paper is aim to test the validity of the purchasing power parity hypothesis by analyzing the transition economies such as Bulgaria, Czech Republic, Hungary, Poland, Romania. For this purpose, the minimum LM unit root test with one structural break is applied to real exchange rate data.PPP, MADF, LM test.

    A Research on the Association between Corporate Governance and Corporate Performance in Turkish Energy Sector

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    Today’s harsh market conditions prompt companiesto allocate the highest level of emphasis on corporateperformance. However, in some cases interests of managementand shareholders may clash. Subsequently providing investorswith timely, accurate and valid information in today’s everchanging economic environment is vital for transparency. Aim ofthis paper is to measure the association between corporategovernance and corporate performance within companies in theenergy sector listed at Borsa Istanbul (formerly known asIstanbul Stock Exchange)

    Effect of management system and dietary yeast autolysate on the performance, slaughter and carcass characteristics of partridges (Alectoris chukar)

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    This study was conducted to determine the effects of management system (a floor housing (FH) versus a free-range housing (FRH) system) and dietary yeast autolysate (Saccharomyces cerevisiae) (1% versus 2% dietary supplement) on the performance, slaughter and carcass characteristics of partridges (Alectoris chukar). A total of 480 (240 for each management system) one-day-old male partridge chicks were randomly allocated to a control group and the two dietary groups per production system, each containing 80 chicks. Each dietary group was then divided into five replicate groups of 16 chicks. The study lasted 112 days. In terms of growth performance, partridges reared under FRH management system had a lower average daily live weight gain (ADG), a significantly higher feed intake (FI), and feed conversion ratio (FCR) compared to the control group. However, partridges fed diets with yeast autolysate had a significantly higher ADG, lower FI, and an improved FCR compared to the control group overall. The gizzard, leg, and wing percentages of the partridges reared in the FRH system were found to be significantly higher than those of partridges reared in the FH system, while the breast and abdominal fat percentages were found to be lower. Dietary supplementation with yeast autolysate significantly increased the cold carcass yield and breast percentage when compared to the control group, while wing and abdominal fat percentages were decreased. In general, best performance was observed in the dietary supplementation group of 1% yeast autolysate in terms of growth and carcass parameters. When considering the fact that partridges are gamebirds, that housing poultry in cage production systems has been prohibited in recent years and that there are positive effects associated with using yeast autolysate as a prebiotic, it is recommended that a free-range production system should be used for partridge breeding, with the addition of 1% yeast autolysate to the diet of the birds.Keywords: Carcass attributes, gamebird, growth, housing syste

    Macroanatomical and histological study of the structure of intercornual gland in Abaza (Capra Aegagrus) and Gurcu (Capra Falconeri) goats breeds

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    Background: The anatomical localisation of the odour glands, which increase activity during the reproduction period and help goat species to find each other, varies. Materials and methods: In our study, the anatomical and histological structures of the glands around the horn were examined in the Gurcu and Abaza goats, which are native breeds. In this study a total of 12 Abaza and Gurcu goat heads were used. Results: The area between the two horns and area at the back of the horns were shaved to remove all hair. The distance between the horns of both goat breeds was measured using an electronic calliper. The mean distance between the horns of the Abaza goats was determined as 36.80 ± 8.62 mm while this distance was 39.63 ± 4.10 mm for the Gurcu goats. Gland tissue that could not be seen anatomically under the skin was examined histologically. For the histological examination, skin samples were taken from the anterior, middle, right posterior and left posterior of the area between the two horns of both breeds. Crossman triple staining and haematoxylin and eosin staining were applied to the samples. Conclusions: Glandula intercornualis was found to be slightly caudal between the horns in both breeds and normal sebaceous glands were almost absent in the areas where these glands were found. Lobes and branched alveolar glands were located around the hair follicles

    The Meaning of Memory Safety

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    We give a rigorous characterization of what it means for a programming language to be memory safe, capturing the intuition that memory safety supports local reasoning about state. We formalize this principle in two ways. First, we show how a small memory-safe language validates a noninterference property: a program can neither affect nor be affected by unreachable parts of the state. Second, we extend separation logic, a proof system for heap-manipulating programs, with a memory-safe variant of its frame rule. The new rule is stronger because it applies even when parts of the program are buggy or malicious, but also weaker because it demands a stricter form of separation between parts of the program state. We also consider a number of pragmatically motivated variations on memory safety and the reasoning principles they support. As an application of our characterization, we evaluate the security of a previously proposed dynamic monitor for memory safety of heap-allocated data.Comment: POST'18 final versio

    Basics of factorization in a scalar Yukawa field theory

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    The factorization theorems of quantum chromodynamics (QCD) apply equally well to most simple quantum field theories that require renormalization but where direct calculations are much more straightforward. Working with these simpler theories is convenient for stress-testing the limits of the factorization program and for examining general properties of the parton density functions (pdfs) or other correlation functions that might be necessary for a factorized description of a process. With this view in mind, we review the steps of factorization in a real scalar Yukawa field theory for both deep inelastic scattering (DIS) and semi-inclusive deep inelastic scattering (SIDIS) cross sections. In the case of SIDIS, we illustrate how to separate the small transverse momentum region, where transverse momentum dependent (TMD) pdfs are needed, from a purely collinear large transverse momentum region, and we examine the influence of subleading power corrections. We also review the steps for formulating TMD factorization in transverse coordinate space, and we study the effect of transforming to the well-known b∗b_*-scheme. Within the Yukawa theory, we investigate the consequences of switching to a generalized parton model (GPM) approach, and compare with a fully factorized approach. Our results highlight the need to address similar or analogous issues in QCD.Comment: 39 pages, 46 figure

    Non-native insects dominate daytime pollination in a high-elevation Hawaiian dryland ecosystem

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    PREMISE OF THE STUDY: Over one-third of the native flowering plant species in the Hawaiian Islands are listed as federally threatened or endangered. Lack of sufficient pollination could contribute to reductions in populations, reproduction, and genetic diversity among these species but has been little studied. METHODS: We used systematic observations and manual flower treatments to quantify flower visitation and outcrossing dependency of eight native (including four endangered) plant species in a dryland ecosystem in Hawaii: Argemone glauca, Bidens menziesii, Dubautia linearis, Haplostachys haplostachya, Sida fallax, Silene lanceolata, Stenogyne angustifolia, and Tetramolopium arenarium. KEY RESULTS: During 576.36 h of flower observations, only insects visited the flowers. Out of all recorded flower visits, 85% were performed by non-native species, particularly the honeybee (Apis mellifera) and flies in the family Syrphidae. Some plant species received little visitation (e.g., S. angustifolia received one visit in 120 h of observation), whereas others were visited by a wide diversity of insects. The endangered plant species were visited by fewer visitor taxa than were the common native plant species. For six of the focal plant species, bagging of flowers to exclude pollinators resulted in significant reductions in seed set. CONCLUSIONS: The flower visitor community in this system, although heavily dominated by non-native insects, appears to be facilitating pollination for multiple plant species. Non-native insects may thus be sustaining biotic interactions otherwise threatened with disruption in this island ecosystem. This may be particularly important for the studied endangered plant species, which exhibit fewer partners than the more common plant species

    Antimicrobial and anti-inflammatory activity of chitosan-alginate nanoparticles: a targeted therapy for cutaneous pathogens.

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    Advances in nanotechnology have demonstrated potential application of nanoparticles (NPs) for effective and targeted drug delivery. Here we investigated the antimicrobial and immunological properties and the feasibility of using NPs to deliver antimicrobial agents to treat a cutaneous pathogen. NPs synthesized with chitosan and alginate demonstrated a direct antimicrobial activity in vitro against Propionibacterium acnes, the bacterium linked to the pathogenesis of acne. By electron microscopy (EM) imaging, chitosan-alginate NPs were found to induce the disruption of the P. acnes cell membrane, providing a mechanism for the bactericidal effect. The chitosan-alginate NPs also exhibited anti-inflammatory properties as they inhibited P. acnes-induced inflammatory cytokine production in human monocytes and keratinocytes. Furthermore, benzoyl peroxide (BP), a commonly used antiacne drug, was effectively encapsulated in the chitosan-alginate NPs and demonstrated superior antimicrobial activity against P. acnes compared with BP alone while demonstrating less toxicity to eukaryotic cells. Together, these data suggest the potential utility of topical delivery of chitosan-alginate NP-encapsulated drug therapy for the treatment of dermatologic conditions with infectious and inflammatory components

    Absence of native flower visitors for the endangered Hawaiian mint \u3ci\u3eStenogyne angustifolia\u3c/i\u3e: Impending ecological extinction?

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    If an organism becomes rare enough that it no longer participates in certain interspecific interactions, it can be said to have become ecologically extinct, even though it is still present. This form of extinction is much less recognized than global extinctions, although it may have ramifications for ecological community function. Here, we describe a case of possible or pending ecological extinction of an endemic Hawaiian plant. We performed over 120 h of systematic flower visitation observations of the endangered Hawaiian mint, Stenogyne angustifolia, in its wild habitat. The robust size and open shape of S. angustifolia flowers, along with their high accessibility, visibility, and nectar content, suggest that they are adapted to animal-mediated pollination. However, only one flower visitor was observed at our focal high-elevation study site: an individual of the non-native bee species Lasioglossum impavidum. Experimental pollination treatments indicate that S. angustifolia is self-compatible and demonstrates some autogamy, setting fruit and seed in the absence of pollinators. However, experimental additions of pollen increased fruit production, indicating that plants are pollen-limited and that lack of pollinators carries a reproductive cost for this species. Ecological communities throughout Hawaii are highly modified, and the distribution and diversity of the native pollinator community that occurred with S. angustifolia prior to these changes are wholly unknown. Nevertheless, the lack of visitation by native pollinators and extremely rare visitation by non-native pollinators suggest that this plant is today contributing little to pollination networks in its high-elevation habitat
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