42 research outputs found

    Learning from Semantic Inconsistencies as the Origin of Dynamic Capabilities in MNCs: Evidence from Pharmaceutical MNCs

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    This paper focuses on origins of dynamic capabilities in multinational corporations (MNCs). Building on literature in the area of organizational memory and organizational learning, we investigate factors that contribute to subsidiaries of MNCs ability to detach themselves from obsolete knowledge and practices. To construct the theoretical framework, 11 extensive interviews with marketing and sales executives from three pharmaceutical MNCs operated in Iran were conducted. We test our hypotheses using statistical quantitative analysis of data related to 459 observations from subsidiaries of 51 pharmaceutical MNCs during years 2005-2009. We examine the quality of corrective actions taken by subsidiaries of pharmaceutical MNCs subsequent to subsidiaries failing to meet expected performance objectives. Our findings confirm a moderating role for internationalization, span, and the composition of human resources on the quality of corrective actions pursued

    Sugar beet (Beta vulgaris) guard cells responses to salinity stress: a proteomic analysis

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    Soil salinity is a major environmental constraint affecting crop growth and threatening global food security. Plants adapt to salinity by optimizing the performance of stomata. Stomata are formed by two guard cells (GCs) that are morphologically and functionally distinct from the other leaf cells. These microscopic sphincters inserted into the wax-covered epidermis of the shoot balance CO2 intake for photosynthetic carbon gain and concomitant water loss. In order to better understand the molecular mechanisms underlying stomatal function under saline conditions, we used proteomics approach to study isolated GCs from the salt-tolerant sugar beet species. Of the 2088 proteins identified in sugar beet GCs, 82 were differentially regulated by salt treatment. According to bioinformatics analysis (GO enrichment analysis and protein classification), these proteins were involved in lipid metabolism, cell wall modification, ATP biosynthesis, and signaling. Among the significant differentially abundant proteins, several proteins classified as “stress proteins” were upregulated, including non-specific lipid transfer protein, chaperone proteins, heat shock proteins, inorganic pyrophosphatase 2, responsible for energized vacuole membrane for ion transportation. Moreover, several antioxidant enzymes (peroxide, superoxidase dismutase) were highly upregulated. Furthermore, cell wall proteins detected in GCs provided some evidence that GC walls were more flexible in response to salt stress. Proteins such as L-ascorbate oxidase that were constitutively high under both control and high salinity conditions may contribute to the ability of sugar beet GCs to adapt to salinity by mitigating salinity-induced oxidative stress

    Salinity effects on guard cell proteome in chenopodium quinoa

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    Epidermal fragments enriched in guard cells (GCs) were isolated from the halophyte quinoa (Chenopodium quinoa Wild.) species, and the response at the proteome level was studied after salinity treatment of 300 mM NaCl for 3 weeks. In total, 2147 proteins were identified, of which 36% were differentially expressed in response to salinity stress in GCs. Up and downregulated proteins included signaling molecules, enzyme modulators, transcription factors and oxidoreductases. The most abundant proteins induced by salt treatment were desiccation-responsive protein 29B (50-fold), osmotin-like protein OSML13 (13-fold), polycystin-1, lipoxygenase, alpha-toxin, and triacylglycerol lipase (PLAT) domain-containing protein 3-like (eight-fold), and dehydrin early responsive to de-hydration (ERD14) (eight-fold). Ten proteins related to the gene ontology term “response to ABA” were upregulated in quinoa GC; this included aspartic protease, phospholipase D and plastid-lipid-associated protein. Additionally, seven proteins in the sucrose–starch pathway were upregulated in the GC in response to salinity stress, and accumulation of tryptophan synthase and L-methionine synthase (enzymes involved in the amino acid biosynthesis) was observed. Exogenous application of sucrose and tryptophan, L-methionine resulted in reduction in stomatal aperture and conductance, which could be advantageous for plants under salt stress. Eight aspartic proteinase proteins were highly upregulated in GCs of quinoa, and exogenous application of pepstatin A (an inhibitor of aspartic proteinase) was accompanied by higher oxidative stress and extremely low stomatal aperture and conductance, suggesting a possible role of aspartic proteinase in mitigating oxidative stress induced by saline conditions

    The study of upper gastrointestinal endoscopy in patients with inflammatory bowel disease and ulcerative colitis

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    زمینه و هدف: در بررسی های تشخیصی بیماری های التهابی روده، یکی از موارد تشخیصی انجام آندوسکوپی فوقانی است که علاوه بر تأیید تشخیص، در افتراق کولیت های نامشخص نیز کمک کننده است. هدف از این مطالعه بررسی لزوم انجام آندوسکوپی فوقانی در بیماران مبتلا به التهاب روده بوده است. روش بررسی: در این مطالعه توصیفی- تحلیلی تعداد 30 کودک در بیمارستان مرکز طبی به صورت سرشماری از مهر 1388 تا اسفند 1389 که به عنوان بیماری کرون و کولیت اولسراتیو به تشخیص قطعی رسیدند؛ تحت انجام آندوسکوپی فوقانی قرار گرفتند و داده ها با استفاده از نرم افزارSPSS و آزمون آماری t-test تجزیه و تحلیل شدند. یافته ها: از30 کودک با تشخیص بیماری التهابی روده، تعداد 15 بیمار دچار کرون و مابقی کولیت اولسراتیو داشتند. نتایج مطالعه حاضر حاکی از درگیری ماکروسکوپی مری در 93 بیماران، درگیری معده در 87 و درگیری دئودنوم در 26 بیماران با تشخیص کرون بود. در بیماران کولیت اولسراتیو درگیری مری 80، معده 66 و دئودنوم 20 بود. از نظر میکروسکوپی در بیماران کرون درگیری مری 94، درگیری معده 80 و در نهایت درگیری دئودنوم 47 مشاهده شد. در بیماران کولیت اولسراتیو از نظر میکروسکوپی 94 درگیری مری، 87 درگیری معده و 67 درگیری دئودنوم داشتند. نتیجه گیری: با توجه به درصد قابل توجه درگیری دستگاه گوارش فوقانی در بیماران با بیماری التهابی روده، انجام آندوسکوپی در تمام بیماران جدا از نوع و محل درگیری و بررسی هیستوپاتولوژیک کاری منطقی و لازم بنظر می رسد

    Human Induced Pluripotent Stem Cells Differentiation into Oligodendrocyte Progenitors and Transplantation in a Rat Model of Optic Chiasm Demyelination

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    BACKGROUND: This study aims to differentiate human induced pluripotent stem cells (hiPSCs) into oligodendrocyte precursors and assess their recovery potential in a demyelinated optic chiasm model in rats. METHODOLOGY/PRINCIPAL FINDINGS: We generated a cell population of oligodendrocyte progenitors from hiPSCs by using embryoid body formation in a defined medium supplemented with a combination of factors, positive selection and mechanical enrichment. Real-time polymerase chain reaction and immunofluorescence analyses showed that stage-specific markers, Olig2, Sox10, NG2, PDGFRα, O4, A2B5, GalC, and MBP were expressed following the differentiation procedure, and enrichment of the oligodendrocyte lineage. These results are comparable with the expression of stage-specific markers in human embryonic stem cell-derived oligodendrocyte lineage cells. Transplantation of hiPSC-derived oligodendrocyte progenitors into the lysolecithin-induced demyelinated optic chiasm of the rat model resulted in recovery from symptoms, and integration and differentiation into oligodendrocytes were detected by immunohistofluorescence staining against PLP and MBP, and measurements of the visual evoked potentials. CONCLUSIONS/SIGNIFICANCE: These results showed that oligodendrocyte progenitors generated efficiently from hiPSCs can be used in future biomedical studies once safety issues have been overcome

    Learning from Semantic Inconsistencies as the Origin of Dynamic Capabilities in MNCs: Evidence from Pharmaceutical MNCs

    No full text
    This paper focuses on origins of dynamic capabilities in multinational corporations (MNCs). Building on literature in the area of organizational memory and organizational learning, we investigate factors that contribute to subsidiaries of MNCs ability to detach themselves from obsolete knowledge and practices. To construct the theoretical framework, 11 extensive interviews with marketing and sales executives from three pharmaceutical MNCs operated in Iran were conducted. We test our hypotheses using statistical quantitative analysis of data related to 459 observations from subsidiaries of 51 pharmaceutical MNCs during years 2005-2009. We examine the quality of corrective actions taken by subsidiaries of pharmaceutical MNCs subsequent to subsidiaries failing to meet expected performance objectives. Our findings confirm a moderating role for internationalization, span, and the composition of human resources on the quality of corrective actions pursued

    Comparison of the Results of Three Observational Methods of Assessment of Musculoskeletal Disorders: A Case Study in the Steel Industry

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    Background and Objectives: Posture analysis methods are used for risk assessment of work activities in the incidence of musculoskeletal disorders. It is expected that the level of assessed risk for a certain job will be the same with different methods. This study aimed to investigate the correlation among three methods of RULA, QEC, and REBA. Methods: This descriptive cross-sectional study was performed on workers of 28 job groups in a steel complex. To evaluate the body position and postural stresses imposed on the workers, after taking pictures of different tasks, images were analyzed using RULA, QEC, and REBA methods and the risk levels were determined. Results: The correlation coefficient between RULA method and QEC and REBA methods was, respectively, 0.63 and 0.69, and it was calculated to be 0.56 between QEC and REBA methods, which was significant in all cases (p<0.01). Kappa agreement coefficient between RULA method and QEC and REBA methods was, respectively, 0.71 and 0.65, and it was calculated to be 0.36 between QEC and REBA methods, which was significant in all cases (p<0.01). Conclusion: The results of the present study provides a better understanding of different observational assessment methods of musculoskeletal disorders. These results could be beneficial, especially for ergonomic specialists in choosing assessment methods before adopting beneficial intervention measures
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