207 research outputs found
Forensic Application of Larvae Analysis to Detect Chemicals in Muscle Tissue
Past events cannot be observed, that is where forensic toxicology comes into play regarding the detection of toxic amounts of chemicals. This is useful in the forensic science field because it allows death investigators to deduce if the body at the scene had been under the influence of any chemicals before death. The purpose of this research is to determine if maggots can uptake trace amounts of chemicals from muscle and to determine if this uptake can be detected and quantified. This research will specifically examine the toxicology of three common chemicals (alcohol, caffeine, and penicillin) as absorbed by fetal pig muscle. To do such, fetal pig thighs were removed and skinned then placed in individual solutions of alcohol, caffeine, or penicillin to soak for 24 hours. Once all the liquid was removed, maggots were placed on the muscle. Samples of maggots were collected every 12 hours for a total of 72 hours. The maggots were then frozen and later placed in a nitric acid digestion to create a liquid solution that was later analyzed using the GC-MS
Introduction : Bringing Institutions Back in the Study of Global Value Chains
This article introduces and summarizes the key questions and findings of this special issue of Global Policy on the role of domestic and international institutions in the study of global value chains (GVCs). The article starts by briefly introducing the concept of GVCs and the state-of-the-art of the existing literature focusing on the political implications of these landmark changes in the global economy. Then, we make a case for grounding this emerging literature more strongly into an ‘institutionalist’ perspective. More specifically, we argue that while a great deal of attention has been paid to intra-chain governance modes – that is, the different ways in which firms organize their cross-border production arrangements – the role external institutional forces play in structuring chain dynamics remains surprisingly under-researched. These observations invite an analytical perspective that brings institutions back into the study of GVCs. The contributions to the special issue focus on multiple causal pathways linking GVCs and various types of domestic- and international institutions. Altogether, these contributions underscore that the politics engendered by GVCs, as well as how they evolve, can only be fully understood by paying attention to the external institutional context in which they are embedded
Lipophilic Allergens, Different Modes of Allergen-Lipid Interaction and Their Impact on Asthma and Allergy
Molecular allergology research has provided valuable information on the structure and function of single allergenic molecules. There are several allergens in food and inhalant allergen sources that are able to interact with lipid ligands via different structural features: hydrophobic pockets, hydrophobic cavities, or specialized domains. For only a few of these allergens information on their associated ligands is already available. Several of the allergens are clinically relevant, so that it is highly probable that the individual structural features with which they interact with lipids have a direct effect on their allergenic potential, and thus on allergy development. There is some evidence for a protective effect of lipids delaying the enzymatic digestion of the peanut (Arachis hypogaea) allergen Ara h 8 (hydrophobic pocket), probably allowing this molecule to get to the intestinal immune system intact (sensitization). Oleosins from different food allergen sources are part of lipid storage organelles and potential marker allergens for the severity of the allergic reaction. House dust mite (HDM), is more often associated with allergic asthma than other sources of inhalant allergens. In particular, lipid-associated allergens from Dermatophagoides pteronyssinus which are Der p 2, Der p 5, Der p 7, Der p 13, Der p 14, and Der p 21 have been reported to be associated with severe allergic reactions and respiratory symptoms such as asthma. The exact mechanism of interaction of these allergens with lipids still has to be elucidated. Apart from single allergens glycolipids have been shown to directly induce allergic inflammation. Several—in parts conflicting—data exist on the lipid (and allergen) and toll-like receptor interactions. For only few single allergens mechanistic studies were performed on their interaction with the air-liquid interface of the lungs, in particular with the surfactant components SP-A and SP-D. The increasing knowledge on protein-lipid-interaction for lipophilic and hydrophobic food and inhalant allergens on the basis of their particular structure, of their capacity to be integral part of membranes (like the oleosins), and their ability to interact with membranes, surfactant components, and transport lipids (like the lipid transfer proteins) are essential to eventually clarify allergy and asthma development
Formation of nanoscale ferromagnetic MnAs crystallites in low-temperature grown GaAs
3 páginas, 3 figuras, 1 tabla.We report the formation of nanosize ferromagnetic MnAs crystallites imbedded in low-temperature grown GaAs using Mn+ ion implantation and subsequent annealing. The structural and magnetic properties of the crystallites have been characterized by transmission electron microscopy, electron beam induced x-ray fluorescence, and superconducting quantum interference device magnetometry. After an optimized thermal annealing at 750 °C, MnAs crystallites of 50 nm in size are formed. These nanomagnets show room temperature ferromagnetism.This work has been supported by QUEST, an
NSF Science and Technology center (Grant No.
DMR91.20007). P.J.W. is a postdoctoral fellow of the Deutsche
Forschungsgemeinschaft (DFG) J.M.G. is a postdoctoral
fellow of the Spanish Ministry of Education and Science.Peer reviewe
Lipid Mediators From Timothy Grass Pollen Contribute to the Effector Phase of Allergy and Prime Dendritic Cells for Glycolipid Presentation
Plant pollen are an important source of antigens that evoke allergic responses. Protein antigens have been the focus of studies aiming to elucidate the mechanisms responsible for allergic reactions to pollen. However, proteins are not the sole active agent present in pollen. It is known that pollen grains contain lipids essential for its reproduction and bioactive lipid mediators. These small molecular compounds are co-delivered with the allergens and hence have the potential to modulate the immune response of subjects by activating their innate immune cells. Previous reports showed that pollen associated lipid mediators exhibited neutrophil- and eosinophil-chemotactic activity and induced polarization of dendritic cells (DCs) toward a Th2-inducing phenotype. In our study we performed chemical analyses of the pollen associated lipids, that are rapidly released upon hydration. As main components we have identified different types of phytoprostanes (PhytoPs), and for the first time phytofurans (PhytoFs), with predominating 16-F1t-PhytoPs (PPF1-I), 9-F1t-PhytoPs (PPF1-II), 16-E1t-PhytoPs (PPE1-I) and 9-D1t-PhytoPs (PPE1-II), and 16(RS)-9-epi-ST-Δ14-10-PhytoFs. Interestingly 16-E1t-PhytoP and 9-D1t-PhytoPs were found to be bound to glycerol. Lipid-containing samples (aqueous pollen extract, APE) induced murine mast cell chemotaxis and IL-6 release, and enhanced their IgE-dependent degranulation, demonstrating a role for these lipids in the immediate effector phase of allergic inflammation. Noteworthy, mast cell degranulation seems to be dependent on glycerol-bound, but not free phytoprostanes. On murine dendritic cells, APE selectively induced the upregulation of CD1d, likely preparing lipid-antigen presentation to iNKT cells. Our report contributes to the understanding of the activity of lipid mediators in the immediate effector phase of allergic reactions but identifies a yet undescribed pathway for the recognition of pollen-derived glycolipids by iNKT cells
The globalisation strategies of five Asian tobacco companies : a comparative analysis and implications for global health governance
The global tobacco industry, from the 1960s to mid 1990s, saw consolidation and eventual domination by a small number of transnational tobacco companies (TTC). This paper draws together comparative analysis of five case studies in the special issue on \u27The Emergence of Asian Tobacco Companies: Implications for Global Health Governance.\u27 The cases suggest that tobacco industry globalisation is undergoing a new phase, beginning in the late 1990s, with the adoption of global business strategies by five Asian companies. The strategies were prompted foremost by external factors, notably market liberalisation, competition from TTCs and declining domestic markets. State protection and promotion enabled the industries in Japan, South Korea and China to rationalise their operations ahead of foreign market expansion. The TTM and TTL will likely remain domestic or perhaps regional companies, JTI and KT&G have achieved TTC status, and the CNTC is poised to dwarf all existing companies. This global expansion of Asian tobacco companies will increase competition which, in turn, will intensify marketing, exert downward price pressures along the global value chain, and encourage product innovation. Global tobacco control requires fuller understanding of these emerging changes and the regulatory challenges posed by ongoing globalisation
The Taiwan Tobacco and Liquor Corporation : To ‘join the ranks of global companies’
Until the late 1990s, the Taiwan Tobacco and Liquor Corporation (TTL) focused almost exclusively on serving the domestic market as a highly protected monopoly. This paper describes how the company has adopted a more outward looking strategy since 2000, with ambitions to become a regional, and eventually global, business by 2021. Drawing on company documents and industry sources, the paper argues that this shift in strategy was a direct reaction to the decline in domestic market share following liberalisation of the Taiwanese tobacco market and adoption of tougher domestic tobacco control measures. Market opening occurred as a result of pressure from the U.S. Trade Representative in the 1980s, as well as World Trade Organization membership in 2002. It is argued that TTL\u27s efforts to globalise operations have been limited by bureaucratic company management and structures, and ongoing political tension between Taiwan and China. However, the relative success of TTL\u27s alcohol branch, and potential détente as the Taiwanese government reaches out to improve relations with China, may provide TTL with new opportunities to achieve its goal of becoming a regional player with global ambitions. This article is part of the special issue \u27The Emergence of Asian Tobacco Companies: Implications for Global Health Governance.\u2
Japan Tobacco International: : To ‘be the most successful and respected tobacco company in the world’
Japan Tobacco International (JTI) is the international division of Japan Tobacco Incorporated, and the world's third largest transnational tobacco company. Founded in 1999, JTI's rapid growth has been the result of a global business strategy that potentially serves as a model for other Asian tobacco companies. This paper analyses Japan Tobacco Incorporated's global expansion since the 1980s in response to market opening, foreign competition, and declining share of a contracting domestic market. Key features of its global strategy include the on-going central role and investment by the Japanese government, and an expansion agenda based on mergers and acquisitions. The paper also discusses the challenges this global business strategy poses for global tobacco control and public health. This paper is part of the special issue 'The Emergence of Asian Tobacco Companies: Implications for Global Health Governance'.19 page(s
Pattern of mRNA expression of β-defensins in basal cell carcinoma
BACKGROUND: Although the human β-defensins hBDs today seem to have diverse functional activities in innate antimicrobial immunity, a few reports also indicated an altered expression of these antimicrobial peptides (AMPs) in tissues of cancers such as oral squamous cell carcinoma. The present work was aimed on the study of hBD gene expression in basal cell carcinoma (BCC) which is the most common cancer in humans. METHODS: Twenty-two non-ulcerated BCCs (12 nodular type, 10 superficial type) have been analysed for the presence of hBD (1–3) mRNA by quantitative real-time RT-PCR. As controls, non-lesional skin specimens of BCC patients as well as samples of healthy subjects were assessed by RT-PCR. RESULTS: hBD-1 levels in healthy controls and non-lesional skin of BCC patients were significantly (P < 0.05) higher than the levels observed in tumour tissue. Moreover, BCCs showed significantly (P < 0.05) increased mRNA expression of hBD-2 as compared to controls. There was no significant (P > 0.05) difference between lesional mRNA levels for hBD-3 and those levels observed in controls. The mRNA expression of hBDs (1–3) found in nodular and superficial BCCs did not significantly (P > 0.05) differ. CONCLUSION: The gene expression patterns of hBD-1 and hBD-2 are for the first time shown to be significantly altered in non-ulcerated BCCs as compared to intra-individual and inter-individual controls, respectively. The present findings may indicate that beside the antimicrobial activity of AMPs, hBDs may also play a role in the pathogenesis of BCC. However, functional and immunohistological studies investigating hBDs in patients with BCC are needed to confirm our data
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