148 research outputs found

    External sources of clean technology: evidence from the clean development mechanism

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    New technology is fundamental to sustainable development. However, inventors from industrialized countries often refuse technology transfer because they worry about reverse-engineering. When can clean technology transfer succeed? We develop a formal model of the political economy of North–South technology transfer. According to the model, technology transfer is possible if (1) the technology in focus has limited global commercial potential or (2) the host developing country does not have the capacity to absorb new technologies for commercial use. If both conditions fail, inventors from industrialized countries worry about the adverse competitiveness effects of reverse-engineering, so technology transfer fails. Data analysis of technology transfer in 4,894 projects implemented under the Kyoto Protocol’s Clean Development Mechanism during the 2004–2010 period provides evidence in support of the model

    Congenital Hypothyroidism Long‐Term Follow‐up Project: Navigating the Rough Waters of a Multi‐Center, Multi‐State Public Health Project

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    The Region 4 Midwest Genetics Collaborative, made up of seven regional states (Illinois, Indiana, Kentucky, Michigan, Minnesota, Ohio, and Wisconsin), brought together pediatric endocrinologists, state laboratory experts, public health follow‐up specialists, and parents of children with congenital hypothyroidism (CH) to identify the three‐year follow‐up management and education patterns of primary care clinicians and pediatric endocrinologists in the care of children diagnosed with CH by state newborn screening (NBS) programs. Among a number of challenges, each state had different NBS methods, data systems, public health laws, and institutional review board (IRB) requirements. Furthermore, the diagnosis of CH was complicated by the timing of the NBS sample, the gestational age, weight, and co‐morbidities at delivery. There were 409 children with CH identified through NBS in 2007 in the seven state region. The clinician of record and the parents of these children were invited to participate in a voluntary survey. Approximately 64 % of clinician surveys were collected with responses to questions relating to treatment, monitoring practices, educational resources, genetic counseling, and services provided to children with confirmed CH and their families. Nearly one‐quarter (24 %) of parents surveyed responded to questions relating to treatment, education, genetic counseling, resources, and services they received or would like to receive. De‐identified data from six of the seven states were compiled for analysis, with one state being unable to obtain IRB approval within the study timeline. The data from this collaborative effort will improve state follow‐up programs and aid in developing three‐year follow‐up guidelines for children diagnosed with CH. To aid in the facilitation of similar public health studies, this manuscript highlights the challenges faced, and focuses on the pathway to a successful multi‐state public health endeavor.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147153/1/jgc40464.pd

    A Comprehensive Survey of Security Threats and their Mitigation Techniques for next-generation SDN Controllers

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    Software Dened Network (SDN) and Network Virtualization (NV) are emerged paradigms that simplied the control and management of the next generation networks, most importantly, Internet of Things (IoT), Cloud Computing, and Cyber-Physical Systems. The Internet of Things (IoT) includes a diverse range of a vast collection of heterogeneous devices that require interoperable communication, scalable platforms and security provisioning. Security provisioning to an SDN based IoT network pose a real security challenge leading to various serious security threats due to the connection of various heterogeneous devices having a wide range of access protocols . Furthermore, the logical centralized controlled intelligence of the SDN architecture represents a plethora of security challenges due to its single point of failure. it may throw the en tire network into chaos and thus expose it to various known and unknown security threats and attacks. security of SDN controlled IoT environment is still in infancy and thus remains the prime research agenda for both the industry and academia. This paper comprehensively reviews the current state-of-the-art security threats, vulnerabilities and issues at the control plane. Moreover, this paper contributes by presenting a detailed classfication of various security attacks on the control layer. A comprehensive state-of-the-art review of the latest mitigation techniques for various security breaches is also presented. Finally, the paper presents future research directions and challenges for further investigation down the line

    Tumor Cell Plasticity and Angiogenesis in Human Melanomas

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    Recent molecular studies provide evidence for a significant transcriptional plasticity of tumor cell subpopulations that facilitate an active contribution to tumor vasculature. This feature is accompanied by morphological changes both in vitro and in vivo. Herein, we investigated the morphological plasticity of tumor cells with special focus on vasculogenic mimicry and neovascularisation in human melanoma and mouse xenografts of human melanoma cell lines. In melanoma xenograft experiments, different vessel markers and green fluorescent protein expression were used to show how melanoma cells contribute to neovascularization. Additionally, we analyzed neovascularization in 49 primary melanomas and 175 melanoma metastases using immunostaining for blood (CD34) and lymphatic (D2–40) vessel-specific markers. We found significantly more lymphatic vessels in primary melanomas than in melanoma metastases (p<0.0001). In contrast to the near absence of lymphatic vessels within metastases, we found extensive blood micro-neovascularization. Blood micro-neovascularization was absent in micro metastases (less than 2 mm). A significant inverse correlation between Glut-1 expression (implying local hypoxia) and the presence of microvessels indicates their functional activity as blood vessels (p<0.0001). We suggest that the hypoxic microenvironment in metastases contributes to a phenotype switch allowing melanoma cells to physically contribute to blood vessel formation

    Melanoma Spheroids Grown Under Neural Crest Cell Conditions Are Highly Plastic Migratory/Invasive Tumor Cells Endowed with Immunomodulator Function

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    International audienceBACKGROUND: The aggressiveness of melanoma tumors is likely to rely on their well-recognized heterogeneity and plasticity. Melanoma comprises multi-subpopulations of cancer cells some of which may possess stem cell-like properties. Although useful, the sphere-formation assay to identify stem cell-like or tumor initiating cell subpopulations in melanoma has been challenged, and it is unclear if this model can predict a functional phenotype associated with aggressive tumor cells. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed the molecular and functional phenotypes of melanoma spheroids formed in neural crest cell medium. Whether from metastatic or advanced primary tumors, spheroid cells expressed melanoma-associated markers. They displayed higher capacity to differentiate along mesenchymal lineages and enhanced expression of SOX2, NANOG, KLF4, and/or OCT4 transcription factors, but not enhanced self-renewal or tumorigenicity when compared to their adherent counterparts. Gene expression profiling attributed a neural crest cell signature to these spheroids and indicated that a migratory/invasive and immune-function modulating program could be associated with these cells. In vitro assays confirmed that spheroids display enhanced migratory/invasive capacities. In immune activation assays, spheroid cells elicited a poorer allogenic response from immune cells and inhibited mitogen-dependent T cells activation and proliferation more efficiently than their adherent counterparts. Our findings reveal a novel immune-modulator function of melanoma spheroids and suggest specific roles for spheroids in invasion and in evasion of antitumor immunity. CONCLUSION/SIGNIFICANCE: The association of a more plastic, invasive and evasive, thus a more aggressive tumor phenotype with melanoma spheroids reveals a previously unrecognized aspect of tumor cells expanded as spheroid cultures. While of limited efficiency for melanoma initiating cell identification, our melanoma spheroid model predicted aggressive phenotype and suggested that aggressiveness and heterogeneity of melanoma tumors can be supported by subpopulations other than cancer stem cells. Therefore, it could be constructive to investigate melanoma aggressiveness, relevant to patients and clinical transferability

    Does vimentin help to delineate the so-called 'basal type breast cancer'?

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    <p>Abstract</p> <p>Background</p> <p>Vimentin is one of the cytoplasmic intermediate filament proteins which are the major component of the cytoskeleton. In our study we checked the usefulness of vimentin expression in identifying cases of breast cancer with poorer prognosis, by adding vimentin to the immunopanel consisting of basal type cytokeratins, estrogen, progesterone, and HER2 receptors.</p> <p>Methods</p> <p>179 tissue specimens of invasive operable ductal breast cancer were assessed by the use of immunohistochemistry. The median follow-up period for censored cases was 90 months.</p> <p>Results</p> <p>38 cases (21.2%) were identified as being vimentin-positive. Vimentin-positive tumours affected younger women (p = 0.024), usually lacked estrogen and progesterone receptor (p < 0.001), more often expressed basal cytokeratins (<0.001), and were high-grade cancers (p < 0.001). Survival analysis showed that vimentin did not help to delineate basal type phenotype in a triple negative (ER, PgR, HER2-negative) group. For patients with 'vimentin or CK5/6, 14, 17-positive' tumours, 5-year estimated survival rate was 78.6%, whereas for patients with 'vimentin, or CK5/6, 14, 17-negative' tumours it was 58.3% (log-rank p = 0.227).</p> <p>Conclusion</p> <p>We were not able to better delineate an immunohistochemical definition of basal type of breast cancer by adding vimentin to the immunopanel consisted of ER, PgR, HER2, CK5/6, 14 and 17 markers, when overall survival was a primary end-point.</p

    Breast adenocarcinoma liver metastases, in contrast to colorectal cancer liver metastases, display a non-angiogenic growth pattern that preserves the stroma and lacks hypoxia

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    Although angiogenesis is a prerequisite for the growth of most human solid tumours, alternative mechanisms of vascularisation can be adopted. We have previously described a non-angiogenic growth pattern in liver metastases of colorectal adenocarcinomas (CRC) in which tumour cells replace hepatocytes at the tumour-liver interface, preserving the liver architecture and co-opting the sinusoidal blood vessels. The aim of this study was to determine whether this replacement pattern occurs during liver metastasis of breast adenocarcinomas (BC) and whether the lack of an angiogenic switch in such metastases is due to the absence of hypoxia and subsequent vascular fibrinogen leakage. The growth pattern of 45 BC liver metastases and 28 CRC liver metastases (73 consecutive patients) was assessed on haematoxylin- and eosin-stained tissue sections. The majority of the BC liver metastases had a replacement growth pattern (96%), in contrast to only 32% of the CRC metastases (P&lt;0.0001). The median carbonic anhydrase 9 (CA9) expression (M75 antibody), as a marker of hypoxia, (intensity x % of stained tumour cells) was 0 in the BC metastases and 53 in the CRC metastases (P&lt;0.0001). There was CA9 expression at the tumour-liver interface in only 16% of the BC liver metastases vs 54% of the CRC metastases (P=0.002). There was fibrin (T2G1 antibody) at the tumour-liver interface in only 21% of the BC metastases vs 56% of the CRC metastases (P=0.04). The median macrophage count (Chalkley morphometry; KP-1 anti-CD68 antibody) at the interface was 4.3 and 7.5, respectively (P&lt;0.0001). Carbonic anhydrase 9 score and macrophage count were positively correlated (r=0.42; P=0.002) in all metastases. Glandular differentiation was less in the BC liver metastases: 80% had less than 10% gland formation vs only 7% of the CRC metastases (P&lt;0.0001). The liver is a densely vascularised organ and can host metastases that exploit this environment by replacing the hepatocytes and co-opting the vasculature. Our findings confirm that a non-angiogenic pattern of liver metastasis indeed occurs in BC, that this pattern of replacement growth is even more prevalent than in CRC, and that the process induces neither hypoxia nor vascular leakage

    Relationship between birth weight and retinal microvasculature in newborn infants

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    Objective: The purposes of this study were to determine the normal retinal microvasculature measurements in human infants who are born at term and to determine whether birth weight influences measurements of retinal microvasculature. Study Design: Retinal arteriole and venule measurements were obtained in a cohort of 24 infants who were born at term. Digital images of both the retinas were obtained using a digital retinal camera after pupillary dilation. Result: In all, 24 newborn infants born at term (12 females and 12 males) were analyzed in this study. The measured retinal arteriole diameters were from 66.8 to 147.8 Όm (mean, 94.2±19.6 Όm), and the venule diameters were from 102.0 to 167.8 Όm (mean, 135.2±19.1 Όm). Seven babies in the sample had low birth weight (LBW), while 17 babies were born with normal weight. Babies with lower birth weights had larger arteriole (113.1±17.9 Όm vs 86.4±14.4 Όm; P=0.0009) and venule diameters (151.7±14.9 Όm vs 128.4±16.9 Όm; P=0.0040). Conclusion: Retinal venules and arterioles in LBW babies are larger compared with those of normal-birth-weight babies. We postulate that the difference observed in our study was due to in utero pathophysiological changes that occurred in the cerebral circulation of growth-restricted fetuses

    Fibroblast growth factor signalling controls nervous system patterning and pigment cell formation in Ciona intestinalis

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    During the development of the central nervous system (CNS), combinations of transcription factors and signalling molecules orchestrate patterning, specification and differentiation of neural cell types. In vertebrates, three types of melanin-containing pigment cells, exert a variety of functional roles including visual perception. Here we analysed the mechanisms underlying pigment cell specification within the CNS of a simple chordate, the ascidian Ciona intestinalis. Ciona tadpole larvae exhibit a basic chordate body plan characterized by a small number of neural cells. We employed lineage-specific transcription profiling to characterize the expression of genes downstream of fibroblast growth factor signalling, which govern pigment cell formation. We demonstrate that FGF signalling sequentially imposes a pigment cell identity at the expense of anterior neural fates. We identify FGF-dependent and pigment cell-specific factors, including the small GTPase, Rab32/38 and demonstrated its requirement for the pigmentation of larval sensory organs
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