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Sample records for blood clot firmness

  1. Blood Clots

    Science.gov (United States)

    ... Index A-Z Blood Clots Blood clots are semi-solid masses of blood that can be stationary (thrombosis) ... treated? What are blood clots? Blood clots are semi-solid masses of blood. Normally, blood flows freely through ...

  2. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Blood Basics Blood Disorders Anemia Bleeding Disorders Blood Cancers Blood Clots Blood Clotting and Pregnancy Clots and ... Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood Clots ...

  3. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... For Patients Blood Disorders Blood Clots Blood Clotting & Pregnancy If you are pregnant, or you have just ... The risk of developing a blood clot during pregnancy is increased by the following: Previous blood clots ...

  4. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... 6, 2016, San Diego, CA Abstracts Registration Housing Travel Information Government Concierge View all meetings Publications Blood ... Blood Clots Blood Clotting and Pregnancy Clots and Travel DVT Myths vs. Facts Blood Detectives Find a ...

  5. Blood Clotting and Pregnancy

    Science.gov (United States)

    ... The risk of developing a blood clot during pregnancy is increased by the following: Previous blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple ...

  6. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... back to top How are Blood Clots in Pregnant Women Treated? Typically, blood clots are treated with ... you think you have one. If you are pregnant and have concerns about blood clots, talk with ...

  7. Blood Clots

    Science.gov (United States)

    ... Abstracts Archive View all Education ASH Academy The eLearning platform for hematologists ASH On Demand On-demand ... on the location of the clot and your health. If you are experiencing symptoms and suspect you ...

  8. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... pregnancy: Be aware of risk factors. Know your family history. Make sure your doctor knows about any ... blood clots or blood clotting disorders in your family. Remain active, with your doctor's approval. Be aware ...

  9. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... San Diego, CA Abstracts Registration Housing Travel Information Government Concierge View all meetings Publications Blood Current Issue ... clot. Blood clots in pregnant women tend to form in the deep veins of the legs or ...

  10. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... harming your baby. Jump To: Am I at Risk? The risk of developing a blood clot during pregnancy is ... prevent blood clots during pregnancy: Be aware of risk factors. Know your family history. Make sure your ...

  11. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... blood clots A genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) ... Programs and Awards ASH Agenda for Hematology Research Education For Clinicians For Trainees For Educators For Patients ...

  12. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are Blood ...

  13. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... genetic predisposition to blood clots Obesity Prolonged immobility (e.g., bedrest, long distance travel) Multiple births Increased maternal age Other medical illness (e.g., cancer, infection) back to top How are ...

  14. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... your members of Congress to support continued medical research funding Take Action Meetings ASH Workshop on Genome Editing July 14- ... U.S. Surgeon General has issued a Call to Action on DVT and PE to raise public ... research on the causes, prevention, and treatment. Blood clots ...

  15. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Housing Travel Information Government Concierge View all meetings Publications Blood Current Issue First Edition Abstracts Blood Advances ... reflect the most recent scientific research View all publications For Patients Blood Basics Blood Disorders Anemia Bleeding ...

  16. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and educational ... Studies Published in Blood Search Blood , the official journal of ASH, for the results of the latest ...

  17. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... in the field Hematology 2015 A collection of articles from the 2015 ASH Annual Meeting Education Program Blood: How I Treat A compendium of Blood articles updated to reflect the most recent scientific research ...

  18. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a ... If you find that you are interested in learning more about blood diseases and disorders, here are ...

  19. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Publications Blood Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a unique focus on scholarly and educational content The Hematologist Features Diffusion President's Column ASH Clinical News Society News Clinical News Features ASH Self- ...

  20. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... educational meetings and webinars ASH Image Bank Educational Web-based library of hematologic imagery In This Section: ... Blood Publishing Office . Patient Groups A list of Web links to patient groups and other organizations that ...

  1. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... If you find that you are interested in learning more about blood diseases and disorders, here are ... For Patients ASH Academy ASH On Demand ASH Image Bank Advocacy Action Alerts Policy News Advocacy Leadership ...

  2. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a unique focus ... ASH ASH Meeting on Hematologic Malignancies Consultative Hematology Course ASH Meeting on Lymphoma Biology ASH Workshop on ...

  3. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... flow and harming your baby. Jump To: Am I at Risk? The risk of developing a blood ... A Patient's Journey back to top Where Can I Find More Information? If you find that you ...

  4. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay current ... Blood The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards Membership ...

  5. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Meeting Abstracts 2016 Call for Abstracts 2016 Abstract Review Categories Abstracts Archive View all Education ASH Academy ... Current Issue First Edition Abstracts Blood Advances A peer-reviewed, online only, open access journal with a ...

  6. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... blood conditions. back to top Antiphospholipid Antibody Syndrome: A Patient's Journey back to top Where Can I ... and help move hematology forward. Learn more Find a Hematologist Search a database of practicing hematologists in ...

  7. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Clinical News Society News Clinical News Features ASH Self-Assessment Program A comprehensive resource to help stay ... Publications Blood The Hematologist ASH Clinical News ASH Self-Assessment Program Hematology , ASH Education Program About Awards ...

  8. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... techniques in the clinical application of genome editing technology MDS Summit Multiple dates and locations A complimentary ... of articles from the 2015 ASH Annual Meeting Education Program Blood: How I Treat A compendium of ...

  9. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Submit to Blood View all Annual Meeting Abstracts 2016 Call for Abstracts 2016 Abstract Review Categories Abstracts Archive View all Education ... ASH Workshop on Genome Editing July 14-15, 2016 Learn new techniques in the clinical application of ...

  10. Blood Clotting and Pregnancy

    Medline Plus

    Full Text Available ... Edition Abstracts Collections Submit to Blood View all Annual Meeting Abstracts 2016 Call for Abstracts 2016 Abstract Review ... Abstracts Registration Housing Schedule and Program 58th ASH ® Annual Meeting & Exposition December 3-6, 2016, San Diego, CA ...

  11. Cavitation damage in blood clots under HIFU

    Science.gov (United States)

    Weiss, Hope; Ahadi, Golnaz; Hoelscher, Thilo; Szeri, Andrew

    2010-11-01

    High Intensity Focused Ultrasound (HIFU) has been shown to accelerate thrombolysis, the dissolution of blood clots, in vitro and in vivo, for treatment of ischemic stroke. Cavitation in sonothrombolysis is thought to play an important role, although the mechanisms are not fully understood. The damage to a blood clot associated with bubble collapses in a HIFU field is studied. The region of damage caused by a bubble collapse on the fibrin network of the blood clot exposed to HIFU is estimated, and compared with experimental assessment of the damage. The mechanical damage to the network caused by a bubble is probed using two independent approaches, a strain based method and an energy based method. Immunoflourescent fibrin staining is used to assess the region of damage experimentally.

  12. Antithrombin, an Important Inhibitor in Blood Clots.

    Science.gov (United States)

    Zhu, Ying; Cong, Qing-Wei; Liu, Yue; Wan, Chun-Ling; Yu, Tao; He, Guang; He, Lin; Cai, Lei; Chou, Kuo-Chen

    2016-01-01

    Blood coagulation is healthy and lifesaving because it can stop bleeding. It can, however, be a troublemaker as well, causing serious medical problems including heart attack and stroke. Body has complex blood coagulation cascade to modulate the blood clots. In the environment of plasma, the blood coagulation cascade is regulated by antithrombin, which is deemed one of the most important serine protease inhibitors. It inhibits thrombin; it can inhibit factors IXa and Xa as well. Interestingly, its inhibitory ability will be significantly increased with the existence of heparin. In this minireview paper, we are to summarize the structural features of antithrombin, as well as its heparin binding modes and anti-coagulation mechanisms, in hopes that the discussion and analysis presented in this paper can stimulate new strategies to find more effective approaches or compounds to modulate the antithrombin. PMID:26411319

  13. Limitations of using synthetic blood clots for measuring in vitro clot capture efficiency of inferior vena cava filters

    Directory of Open Access Journals (Sweden)

    Robinson RA

    2013-05-01

    Full Text Available Ronald A Robinson, Luke H Herbertson, Srilekha Sarkar Das, Richard A Malinauskas, William F Pritchard, Laurence W GrossmanOffice of Science and Engineering Laboratories, Center for Devices and Radiological Health, US Food and Drug Administration, Silver Spring, MD, USAAbstract: The purpose of this study was first to evaluate the clot capture efficiency and capture location of six currently-marketed vena cava filters in a physiological venous flow loop, using synthetic polyacrylamide hydrogel clots, which were intended to simulate actual blood clots. After observing a measured anomaly for one of the test filters, we redirected the focus of the study to identify the cause of poor clot capture performance for large synthetic hydrogel clots. We hypothesized that the uncharacteristic low clot capture efficiency observed when testing the outlying filter can be attributed to the inadvertent use of dense, stiff synthetic hydrogel clots, and not as a result of the filter design or filter orientation. To study this issue, sheep blood clots and polyacrylamide (PA synthetic clots were injected into a mock venous flow loop containing a clinical inferior vena cava (IVC filter, and their captures were observed. Testing was performed with clots of various diameters (3.2, 4.8, and 6.4 mm, length-to-diameter ratios (1:1, 3:1, 10:1, and stiffness. By adjusting the chemical formulation, PA clots were fabricated to be soft, moderately stiff, or stiff with elastic moduli of 805 ± 2, 1696 ± 10 and 3295 ± 37 Pa, respectively. In comparison, the elastic moduli for freshly prepared sheep blood clots were 1690 ± 360 Pa. The outlying filter had a design that was characterized by peripheral gaps (up to 14 mm between its wire struts. While a low clot capture rate was observed using large, stiff synthetic clots, the filter effectively captured similarly sized sheep blood clots and soft PA clots. Because the stiffer synthetic clots remained straight when approaching the

  14. An optical approach for non-invasive blood clot testing

    Science.gov (United States)

    Kalchenko, Vyacheslav; Brill, Alexander; Fine, Ilya; Harmelin, Alon

    2007-02-01

    Physiological blood coagulation is an essential biological process. Current tests for plasma coagulation (clotting) need to be performed ex vivo and require fresh blood sampling for every test. A recently published work describes a new, noninvasive, in vivo approach to assess blood coagulation status during mechanical occlusion1. For this purpose, we have tested this approach and applied a controlled laser beam to blood micro-vessels of the mouse ear during mechanical occlusion. Standard setup for intravital transillumination videomicroscopy and laser based imaging techniques were used for monitoring the blood clotting process. Temporal mechanical occlusion of blood vessels in the observed area was applied to ensure blood flow cessation. Subsequently, laser irradiation was used to induce vascular micro-injury. Changes in the vessel wall, as well as in the pattern of blood flow, predispose the area to vascular thrombosis, according to the paradigm of Virchow's triad. In our experiments, two elements of Virchow's triad were used to induce the process of clotting in vivo, and to assess it optically. We identified several parameters that can serve as markers of the blood clotting process in vivo. These include changes in light absorption in the area of illumination, as well as changes in the pattern of the red blood cells' micro-movement in the vessels where blood flow is completely arrested. Thus, our results indicate that blood coagulation status can be characterized by non-invasive, in vivo methodologies.

  15. Clot Retraction: A Miniaturized Hemoretractometer for Blood Clot Retraction Testing (Small 29/2016).

    Science.gov (United States)

    Li, Zida; Li, Xiang; McCracken, Brendan; Shao, Yue; Ward, Kevin; Fu, Jianping

    2016-08-01

    Whole blood coagulation testing provides valuable diagnostic information on diseases such as bleeding disorders, heart attack, deep venous thrombosis, etc. On page 3926, J. Fu and co-workers develop a miniaturized hemoretractometer to measure clot contraction upon blood coagulation with good reproducibility and robustness. This device design shows great application potential in point-of-care testing. Photo credit: David Peyer from University of Michigan. PMID:27477258

  16. Some Important Milestones in the Field of Blood Clotting.

    Science.gov (United States)

    Doolittle, Russell F

    2016-01-01

    Several different kinds of 'milestone' in the field of blood coagulation are described from the middle decades of the 20th century. Although viewed from the standpoint of clotting per se, attention is also given to implications for innate immunity. The first milestone considered is the protracted saga of clotting dependence on vitamin K, an adventure that spanned more than five decades beginning in the 1920s. The second has to do with the discovery of a half-dozen 'new' clotting factors during the period immediately following World War II. A third pursues a narrower focus and examines the once mysterious transformation of fibrinogen into fibrin. Finally, the clinical treatment of classical hemophilia had a remarkable turning point in the 1960s as the result of simple but sensible measures. PMID:26667674

  17. Pro blood clotting activity of Scoparia dulcis in rats.

    Science.gov (United States)

    Ediriweera, E R H S S; Jayakody, J R A C; Ratnasooriya, W D

    2011-04-01

    Scoparia dulcis Linn (Family: Scrophulariaceae, Sinhala: WalKoththamalli) is a perennial herb growing in many tropical countries including Sri Lanka. Traditional Physicians in rural down south areas apply crushed S. dulcis plant on cuts and bruises to stop bleeding. S. dulcis may also have Rakta Sthambhana property. The study on effect of decoction (water extract) of S. dulcis on blood clotting time in rats was carried out to investigate this. Two groups of rats, 12 males and 42 females were used in this experimental study. Forty-two female rats were assigned into seven equal groups (n = 6/gp). Different doses of DE (25, 50, 100, 1000, 1500 mg/kg) (group 1-5) or 2 ml of distilled water (DW) (group 6) were orally administered. 0.1 ml of vitamin K was injected intramuscularly (group 7) as reference drug to seventh the group. Twelve male rats were assigned into two equal groups (n = 6/gp), 2 ml of distilled water (DW) and doses of DE (1500 mg/kg) were orally administered. Clotting time was determined on the Days 1, 2, and 7 using Lee and White method. In the DE treated groups with all doses, there was no reduction in clotting time on the Day 1 but a significant reduction of clotting time (P < 0.05) was observed on the Days 2 and 7. In the group treated with vitamin K, there was no significant reduction in clotting time on Day 1 or 2, but there was a significant reduction in clotting time on Day 7. It is concluded that S. dulcis has proclotting activity (rakthasthambhana property) and this was faster than vitamin K. PMID:22408315

  18. Aggregation of Red Blood Cells: From Rouleaux to Clot Formation

    CERN Document Server

    Wagner, C; Svetina, S

    2013-01-01

    Red blood cells are known to form aggregates in the form of rouleaux. This aggregation process is believed to be reversible, but there is still no full understanding on the binding mechanism. There are at least two competing models, based either on bridging or on depletion. We review recent experimental results on the single cell level and theoretical analyses of the depletion model and of the influence of the cell shape on the binding strength. Another important aggregation mechanism is caused by activation of platelets. This leads to clot formation which is life saving in the case of wound healing but also a major cause of death in the case of a thrombus induced stroke. We review historical and recent results on the participation of red blood cells in clot formation.

  19. Selective Light-Triggered Release of DNA from Gold Nanorods Switches Blood Clotting On and Off

    OpenAIRE

    de Puig, Helena; Cifuentes Rius, Anna; Flemister, Dorma; Salmaan H Baxamusa; Hamad-Schifferli, Kimberly

    2013-01-01

    Blood clotting is a precise cascade engineered to form a clot with temporal and spatial control. Current control of blood clotting is achieved predominantly by anticoagulants and thus inherently one-sided. Here we use a pair of nanorods (NRs) to provide a two-way switch for the blood clotting cascade by utilizing their ability to selectively release species on their surface under two different laser excitations. We selectively trigger release of a thrombin binding aptamer from one nanorod, in...

  20. Mesoscopic Modeling of Blood Clotting: Coagulation Cascade and Platelets Adhesion

    Science.gov (United States)

    Yazdani, Alireza; Li, Zhen; Karniadakis, George

    2015-11-01

    The process of clot formation and growth at a site on a blood vessel wall involve a number of multi-scale simultaneous processes including: multiple chemical reactions in the coagulation cascade, species transport and flow. To model these processes we have incorporated advection-diffusion-reaction (ADR) of multiple species into an extended version of Dissipative Particle Dynamics (DPD) method which is considered as a coarse-grained Molecular Dynamics method. At the continuum level this is equivalent to the Navier-Stokes equation plus one advection-diffusion equation for each specie. The chemistry of clot formation is now understood to be determined by mechanisms involving reactions among many species in dilute solution, where reaction rate constants and species diffusion coefficients in plasma are known. The role of blood particulates, i.e. red cells and platelets, in the clotting process is studied by including them separately and together in the simulations. An agonist-induced platelet activation mechanism is presented, while platelets adhesive dynamics based on a stochastic bond formation/dissociation process is included in the model.

  1. High-speed shaking of frozen blood clots for extraction of human and malaria parasite DNA

    OpenAIRE

    Mohammed Adan; Lebbad Marianne; Macharia Alex; Lundblom Klara; Färnert Anna

    2011-01-01

    Abstract Background Frozen blood clots remaining after serum collection is an often disregarded source of host and pathogen DNA due to troublesome handling and suboptimal outcome. Methods High-speed shaking of clot samples in a cell disruptor manufactured for homogenization of tissue and faecal specimens was evaluated for processing frozen blood clots for DNA extraction. The method was compared to two commercial clot protocols based on a chemical kit and centrifugation through a plastic sieve...

  2. Selective light-triggered release of DNA from gold nanorods switches blood clotting on and off.

    Directory of Open Access Journals (Sweden)

    Helena de Puig

    Full Text Available Blood clotting is a precise cascade engineered to form a clot with temporal and spatial control. Current control of blood clotting is achieved predominantly by anticoagulants and thus inherently one-sided. Here we use a pair of nanorods (NRs to provide a two-way switch for the blood clotting cascade by utilizing their ability to selectively release species on their surface under two different laser excitations. We selectively trigger release of a thrombin binding aptamer from one nanorod, inhibiting blood clotting and resulting in increased clotting time. We then release the complementary DNA as an antidote from the other NR, reversing the effect of the aptamer and restoring blood clotting. Thus, the nanorod pair acts as an on/off switch. One challenge for nanobiotechnology is the bio-nano interface, where coronas of weakly adsorbed proteins can obscure biomolecular function. We exploit these adsorbed proteins to increase aptamer and antidote loading on the nanorods.

  3. Selective light-triggered release of DNA from gold nanorods switches blood clotting on and off.

    Science.gov (United States)

    de Puig, Helena; Cifuentes Rius, Anna; Flemister, Dorma; Baxamusa, Salmaan H; Hamad-Schifferli, Kimberly

    2013-01-01

    Blood clotting is a precise cascade engineered to form a clot with temporal and spatial control. Current control of blood clotting is achieved predominantly by anticoagulants and thus inherently one-sided. Here we use a pair of nanorods (NRs) to provide a two-way switch for the blood clotting cascade by utilizing their ability to selectively release species on their surface under two different laser excitations. We selectively trigger release of a thrombin binding aptamer from one nanorod, inhibiting blood clotting and resulting in increased clotting time. We then release the complementary DNA as an antidote from the other NR, reversing the effect of the aptamer and restoring blood clotting. Thus, the nanorod pair acts as an on/off switch. One challenge for nanobiotechnology is the bio-nano interface, where coronas of weakly adsorbed proteins can obscure biomolecular function. We exploit these adsorbed proteins to increase aptamer and antidote loading on the nanorods. PMID:23894311

  4. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots.

    Science.gov (United States)

    Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

    2014-01-01

    Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1 ± 14.0, 251.0 ± 9.8, and 326.5 ± 14.5 nm and zeta potentials of 24.1 ± 0.5, 20.6 ± 1.9, and 15.3 ± 1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (P<0.05) (n=4) shorter than that of a clot induced by a phosphate-buffered solution (PBS) (clot/PBS) (63.6% ± 3.1%, 48.3% ± 6.2%, and 63.2% ± 4.7%, respectively). The ΔF2 values in the spectra of frequency shifts associated with the propagation of fibrin networks in the clot/ANPs and clot/FNPs were significantly lower than those of clot/PBS. Interestingly, texture profile analysis of the compressional properties showed significantly lower hardness and compressibility in clot/NPs and clot/ANPs (P<0.05 or better) (n=4) compared with

  5. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots.

    Science.gov (United States)

    Chung, Tze-Wen; Lin, Pei-Yi; Wang, Shoei-Shen; Chen, Yen-Fung

    2014-01-01

    Chitosan nanoparticles (NPs) decorated with adenosine diphosphate (ADP) (ANPs) or fibrinogen (FNPs) were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP) or FNP (clot/FNP) were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1 ± 14.0, 251.0 ± 9.8, and 326.5 ± 14.5 nm and zeta potentials of 24.1 ± 0.5, 20.6 ± 1.9, and 15.3 ± 1.5 mV (n=4), respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR) spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM) micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP), clot/ANP, and clot/FNP (at 0.05 wt%) were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc) of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM), were significantly (Pcompressibility in clot/NPs and clot/ANPs (Pcompression flow properties of the clot. Hence, ANPs have potential applications for preventing severe local hemorrhage. PMID:24729701

  6. Capture of lipopolysaccharide (endotoxin by the blood clot: a comparative study.

    Directory of Open Access Journals (Sweden)

    Margaret T Armstrong

    Full Text Available In vertebrates and arthropods, blood clotting involves the establishment of a plug of aggregated thrombocytes (the cellular clot and an extracellular fibrillar clot formed by the polymerization of the structural protein of the clot, which is fibrin in mammals, plasma lipoprotein in crustaceans, and coagulin in the horseshoe crab, Limulus polyphemus. Both elements of the clot function to staunch bleeding. Additionally, the extracellular clot functions as an agent of the innate immune system by providing a passive anti-microbial barrier and microbial entrapment device, which functions directly at the site of wounds to the integument. Here we show that, in addition to these passive functions in immunity, the plasma lipoprotein clot of lobster, the coagulin clot of Limulus, and both the platelet thrombus and the fibrin clot of mammals (human, mouse operate to capture lipopolysaccharide (LPS, endotoxin. The lipid A core of LPS is the principal agent of gram-negative septicemia, which is responsible for more than 100,000 human deaths annually in the United States and is similarly toxic to arthropods. Quantification using the Limulus Amebocyte Lysate (LAL test shows that clots capture significant quantities of LPS and fluorescent-labeled LPS can be seen by microscopy to decorate the clot fibrils. Thrombi generated in the living mouse accumulate LPS in vivo. It is suggested that capture of LPS released from gram-negative bacteria entrapped by the blood clot operates to protect against the disease that might be caused by its systemic dispersal.

  7. High-speed shaking of frozen blood clots for extraction of human and malaria parasite DNA

    Directory of Open Access Journals (Sweden)

    Mohammed Adan

    2011-08-01

    Full Text Available Abstract Background Frozen blood clots remaining after serum collection is an often disregarded source of host and pathogen DNA due to troublesome handling and suboptimal outcome. Methods High-speed shaking of clot samples in a cell disruptor manufactured for homogenization of tissue and faecal specimens was evaluated for processing frozen blood clots for DNA extraction. The method was compared to two commercial clot protocols based on a chemical kit and centrifugation through a plastic sieve, followed by the same DNA extraction protocol. Blood clots with different levels of parasitaemia (1-1,000 p/μl were prepared from parasite cultures to assess sensitivity of PCR detection. In addition, clots retrieved from serum samples collected within two epidemiological studies in Kenya (n = 630 were processed by high speed shaking and analysed by PCR for detection of malaria parasites and the human α-thalassaemia gene. Results High speed shaking succeeded in fully dispersing the clots and the method generated the highest DNA yield. The level of PCR detection of P. falciparum parasites and the human thalassaemia gene was the same as samples optimally collected with an anticoagulant. The commercial clot protocol and centrifugation through a sieve failed to fully dissolve the clots and resulted in lower sensitivity of PCR detection. Conclusions High speed shaking was a simple and efficacious method for homogenizing frozen blood clots before DNA purification and resulted in PCR templates of high quality both from humans and malaria parasites. This novel method enables genetic studies from stored blood clots.

  8. Blood Clots and Travel: What You Need to Know

    Science.gov (United States)

    ... Related Links Yellow Book chapter on DVT and travel Facts Clot Connect World Health Organization Information For... Media Policy Makers Language: English Español (Spanish) File Formats Help: How do I view different file formats (PDF, ...

  9. Adenosine diphosphate-decorated chitosan nanoparticles shorten blood clotting times, influencing the structures and varying the mechanical properties of the clots

    Directory of Open Access Journals (Sweden)

    Chung TW

    2014-03-01

    Full Text Available Tze-Wen Chung,1,3 Pei-Yi Lin,2 Shoei-Shen Wang,2 Yen-Fung Chen31Department of Biomedical Engineering, National Yang-Ming University, 2Department of Surgery, National Taiwan University Hospital, Taipei, Taiwan, Republic of China; 3Department of Chemical and Materials Engineering, National Yunlin University of Science and Technology, Yunlin, Taiwan, Republic of ChinaAbstract: Chitosan nanoparticles (NPs decorated with adenosine diphosphate (ADP (ANPs or fibrinogen (FNPs were used to fabricate hemostatic NPs that can shorten blood clotting time and prevent severe local hemorrhage. The structure and mechanical properties of the blood clot induced with ANP (clot/ANP or FNP (clot/FNP were also investigated. The NPs, ANPs, and FNPs, which had particle sizes of 245.1±14.0, 251.0±9.8, and 326.5±14.5 nm and zeta potentials of 24.1±0.5, 20.6±1.9, and 15.3±1.5 mV (n=4, respectively, were fabricated by ionic gelation and then decorated with ADP and fibrinogen. The zeta potentials and Fourier transform infrared (FTIR spectroscopy of the NPs confirmed that their surfaces were successfully coated with ADP and fibrinogen. The scanning electron microscope (SEM micrographs of the structure of the clot induced with "undecorated" chitosan NPs (clot/NP, clot/ANP, and clot/FNP (at 0.05 wt% were different, after citrated bloods had been recalcified by a calcium chloride solution containing NPs, ANPs, or FNPs. This indicated that many NPs adhered on the membrane surfaces of red blood cells, that ANPs induced many platelet aggregates, and that FNPs were incorporated into the fibrin network in the clots. Measurements of the blood clotting times (Tc of blood clot/NPs, clot/ANPs, and clot/FNPs, based on 90% of ultimate frequency shifts measured on a quartz crystal microbalance (QCM, were significantly (P<0.05 (n=4 shorter than that of a clot induced by a phosphate-buffered solution (PBS (clot/PBS (63.6%±3.1%, 48.3%±6.2%, and 63.2%±4.7%, respectively. The ∆F2

  10. C-Section Raises Risk of Blood Clots After Childbirth: Review

    Science.gov (United States)

    ... page: https://medlineplus.gov/news/fullstory_161301.html C-Section Raises Risk of Blood Clots After Childbirth: ... international studies found that women who had a C-section were four times more likely to develop ...

  11. High-Quality and -Quantity DNA Extraction from Frozen Archival Blood Clots for Genotyping of Single-Nucleotide Polymorphisms

    DEFF Research Database (Denmark)

    Bank, Steffen; Nexø, Bjørn Andersen; Andersen, Vibeke;

    2013-01-01

    Background: The recovery of biological samples for genetic epidemiological studies can be cumbersome. Blood clots are routinely collected for serological examinations. However, the extraction of DNA from blood clots can be difficult and often results in low yields. Aim: The aim was to compare...... the efficiency of commercial purification kits for extracting DNA from long-term frozen clotted blood. Methods: Serum tubes with clotted blood were stored at −20°C for 1 to 2.5 years before DNA extraction. DNA was extracted from 10 blood clot samples using PureGene (Qiagen) with and without glycogen, the QIAamp...... DNA Micro kit (Qiagen), and the Nucleospin 96 Blood kit (Macherey-Nagel). Furthermore, blood clots from 1055 inflammatory bowel disease patients were purified using the Maxwell 16 Blood purification kit (Promega). The DNA was extracted according to the manufacturers` instructions and real-time PCR...

  12. Effect of thiol derivatives on mixed mucus and blood clots in vitro.

    Science.gov (United States)

    Risack, L E; Vandevelde, M E; Gobert, J G

    1978-01-01

    The disintegrating effect of three reducing thiol derivatives: [sodium mercaptoethane sulphonate (Mesna), N-acetyl-L-cysteine (NAC) and dithio-1,4-threitol (DTT)] was investigated in vitro upon blood clots formed in the absence or in the presence of tracheobronchial secretions and compared with the effect of iso-osmotic saline solution. The amounts of haemoglobin released from the clots after 30 min incubation and the initial rates of haemoglobin release were compared for the different products at different concentrations. All three reducing agents showed some ability to disintegrate mixed clots to an extent depending on their concentration. After 30 min incubation, statistical analysis showed a highly significant difference in favour of Mesna at the three concentrations used, i.e. 0.1, 1.0 and 10 mmol/1. The initial rate of haemoglobin release in presence of Mesna was at all concentrations significantly higher than that of NAC or DTT. The effects on normal blood clots were much less pronounced. The effectiveness of Mesna in splitting up mixed blood and mucus clots in the management of patients who had inhaled blood is discussed.

  13. Effect of thiol derivatives on mixed mucus and blood clots in vitro.

    Science.gov (United States)

    Risack, L E; Vandevelde, M E; Gobert, J G

    1978-01-01

    The disintegrating effect of three reducing thiol derivatives: [sodium mercaptoethane sulphonate (Mesna), N-acetyl-L-cysteine (NAC) and dithio-1,4-threitol (DTT)] was investigated in vitro upon blood clots formed in the absence or in the presence of tracheobronchial secretions and compared with the effect of iso-osmotic saline solution. The amounts of haemoglobin released from the clots after 30 min incubation and the initial rates of haemoglobin release were compared for the different products at different concentrations. All three reducing agents showed some ability to disintegrate mixed clots to an extent depending on their concentration. After 30 min incubation, statistical analysis showed a highly significant difference in favour of Mesna at the three concentrations used, i.e. 0.1, 1.0 and 10 mmol/1. The initial rate of haemoglobin release in presence of Mesna was at all concentrations significantly higher than that of NAC or DTT. The effects on normal blood clots were much less pronounced. The effectiveness of Mesna in splitting up mixed blood and mucus clots in the management of patients who had inhaled blood is discussed. PMID:97741

  14. Honey Bee Venom (Apis mellifera Contains Anticoagulation Factors and Increases the Blood-clotting Time

    Directory of Open Access Journals (Sweden)

    Hossein Zolfagharian

    2015-12-01

    Full Text Available Objectives: Bee venom (BV is a complex mixture of proteins and contains proteins such as phospholipase and melittin, which have an effect on blood clotting and blood clots. The mechanism of action of honey bee venom (HBV, Apis mellifera on human plasma proteins and its anti-thrombotic effect were studied. The purpose of this study was to investigate the anti-coagulation effect of BV and its effects on blood coagulation and purification. Methods: Crude venom obtained from Apis mellifera was selected. The anti-coagulation factor of the crude venom from this species was purified by using gel filtration chromatography (sephadex G-50, and the molecular weights of the anti-coagulants in this venom estimated by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE. Blood samples were obtained from 10 rabbits, and the prothrombin time (PT and the partial thromboplastin time (PTT tests were conducted. The approximate lethal dose (LD values of BV were determined. Results: Crude BV increased the blood clotting time. For BV concentrations from 1 to 4 mg/mL, clotting was not observed even at more than 300 seconds, standard deviations (SDs = ± 0.71; however, clotting was observed in the control group 13.8 s, SDs = ± 0.52. Thus, BV can be considered as containing anti-coagulation factors. Crude BV is composed 4 protein bands with molecular weights of 3, 15, 20 and 41 kilodalton (kDa, respectively. The LD50 of the crude BV was found to be 177.8 μg/mouse. Conclusion: BV contains anti-coagulation factors. The fraction extracted from the Iranian bees contains proteins that are similar to anti-coagulation proteins, such as phospholipase A2 (PLA2 and melittin, and that can increase the blood clotting times in vitro.

  15. Zeolite-based hemostat QuikClot releases calcium into blood and promotes blood coagulation in vitro

    Institute of Scientific and Technical Information of China (English)

    Jing LI; Wei CAO; Xiao-xing LV; Li JIANG; Yue-jun LI; Wang-zhou LI; Shao-zong CHEN

    2013-01-01

    Aim:To examine the changes in electrolyte concentrations after addition of zeolite-based hemostat QuikClot in blood and the effects of zeolite on blood coagulation in vitro.Methods:Fresh blood was taken from healthy adult volunteers and sheep,and the electrolyte concentrations in blood were measured using a blood electrolyte analyzer.Zeolite Saline Solution (ZSS) was prepared by addition of 2 g zeolite to 0.9% NaCl solution (4,8,or 16 mL).The electrolytes in ZSS were measured using inductively coupled plasma atomic emission spectroscopy.The prothrombin time (PT) and activated partial thromboplastin time (APTT) of blood were measured using the test tube method.The activated clotting time (ACT) and clotting rate (CR) of blood were measured with Sonoclot Coagulation and Platelet Function Analyzer.Results:Addition of zeolite (50 and 100 mg) in 2 mL human blood significantly increased Ca2+ concentration,while Na+ and K+ concentrations were significantly decreased.Addition of zeolite (50 and 100 mg) in 0.9% NaCl solution (2 mL) caused similar changes in Ca2+ and Na+ concentrations.Si4+ (0.2434 g/L) and Al3+ (0.2575 g/L) were detected in ZSS (2 g/8 mL).Addition of ZSS in sheep blood shortened APTT in a concentration dependent manner,without changing PT.ZSS or aqueous solution of CaCl2 that contained Ca2+ concentration identical to that of ZSS significantly shortened ACT in human blood without significantly changing CR,and the effect of ZSS on ACT was not significantly different from that of CaCl2.Conclusion:Zeolite releases Ca2+ into blood,thus accelerating the intrinsic pathway of blood coagulation and shortening the clot formation time.

  16. Alteration of blood clot structures by interleukin-1 beta in association with bone defects healing

    Science.gov (United States)

    Wang, Xin; Friis, Thor E.; Masci, Paul P.; Crawford, Ross W.; Liao, Wenbo; Xiao, Yin

    2016-01-01

    The quality of hematomas are crucial for successful early bone defect healing, as the structure of fibrin clots can significantly influence the infiltration of cells, necessary for bone regeneration, from adjacent tissues into the fibrin network. This study investigated if there were structural differences between hematomas from normal and delayed healing bone defects and whether such differences were linked to changes in the expression of IL-1β. Using a bone defect model in rats, we found that the hematomas in the delayed healing model had thinner fibers and denser clot structures. Moreover, IL-1β protein levels were significantly higher in the delayed healing hematomas. The effects of IL-1β on the structural properties of human whole blood clots were evaluated by thrombelastograph (TEG), scanning electronic microscopy (SEM), compressive study, and thrombolytic assays. S-nitrosoglutathione (GSNO) was applied to modulate de novo hematoma structure and the impact on bone healing was evaluated in the delayed healing model. We found that GSNO produced more porous hematomas with thicker fibers and resulted in significantly enhanced bone healing. This study demonstrated that IL-1β and GSNO had opposing effects on clot architecture, the structure of which plays a pivotal role in early bone healing. PMID:27767056

  17. White blood cell deformation and firm adhesion

    Science.gov (United States)

    Szatmary, Alex; Eggleton, Charles

    2011-11-01

    For a white blood cell (WBC) to arrive at infection sites, it forms chemical attachments with activated endothelial cells. First, it bonds with P-selectin, which holds it to the wall, but weakly; this allows the WBC to roll under the shear flow of the blood around it. Later, the WBCs bond with the stronger intracellular adhesion molecule-1 (ICAM-1); it is these ICAM bonds that allow the WBCs to fully resist the flow and stop rolling, allowing them to crawl through the endothelial wall. We model this numerically. Our model uses the immersed boundary method to represent the interaction of the shear flow with the deformable cell membrane. Receptors are on the tips of microvilli-little fingers sticking off of the cell membrane. The microvilli also deform. The receptors stochastically form and break bonds with molecules on the wall. Using this method, the history of each microvillus and its bonds can be found, as well as the distribution of the adhesion traction forces and how all of these vary with the deformability of the white blood cell. At higher shear rates, the white blood cell membrane deforms more, increasing its contact area with the surface; this effect is larger for softer membranes. We investigate how the deformability of the WBC affects the ease with which it forms firm adhesion.

  18. Alkali treatment of microrough titanium surfaces affects macrophage/monocyte adhesion, platelet activation and architecture of blood clot formation

    Directory of Open Access Journals (Sweden)

    V Milleret

    2011-05-01

    Full Text Available Titanium implants are most commonly used for bone augmentation and replacement due to their favorable osseointegration properties. Here, hyperhydrophilic sand-blasted and acid-etched (SBA titanium surfaces were produced by alkali treatment and their responses to partially heparinized whole human blood were analyzed. Blood clot formation, platelet activation and activation of the complement system was analyzed revealing that exposure time between blood and the material surface is crucial as increasing exposure time results in higher amount of activated platelets, more blood clots formed and stronger complement activation. In contrast, the number of macrophages/monocytes found on alkali-treated surfaces was significantly reduced as compared to untreated SBA Ti surfaces. Interestingly, when comparing untreated to modified SBA Ti surfaces very different blood clots formed on their surfaces. On untreated Ti surfaces blood clots remain thin (below 15 mm, patchy and non-structured lacking large fibrin fiber networks whereas blood clots on differentiated surfaces assemble in an organized and layered architecture of more than 30 mm thickness. Close to the material surface most nucleated cells adhere, above large amounts of non-nucleated platelets remain entrapped within a dense fibrin fiber network providing a continuous cover of the entire surface. These findings might indicate that, combined with findings of previous in vivo studies demonstrating that alkali-treated SBA Ti surfaces perform better in terms of osseointegration, a continuous and structured layer of blood components on the blood-facing surface supports later tissue integration of an endosseous implant.

  19. Addition of a sequence from α2-antiplasmin transforms human serum albumin into a blood clot component that speeds clot lysis

    Directory of Open Access Journals (Sweden)

    Gataiance Sharon

    2009-03-01

    Full Text Available Abstract Background The plasma protein α2-antiplasmin (α2AP is cross-linked to fibrin in blood clots by the transglutaminase factor XIIIa, and in that location retards clot lysis. Competition for this effect could be clinically useful in patients with thrombosis. We hypothesized that fusion of N-terminal portions of α2-antiplasmin to human serum albumin (HSA and production of the chimeric proteins in Pichia pastoris yeast would produce a stable and effective competitor protein. Results Fusion protein α2AP(13-42-HSA was efficiently secreted from transformed yeast and purified preparations contained within a mixed population the full-length intact form, while fusions with longer α2AP moieties were inefficiently secreted and/or degraded. The α2AP(13-42-HSA protein, but not recombinant HSA, was cross-linked to both chemical lysine donors and fibrin or fibrinogen by factor XIIIa, although with less rapid kinetics than native α2AP. Excess α2AP(13-42-HSA competed with α2AP for cross-linking to chemical lysine donors more effectively than a synthetic α2AP(13-42 peptide, and reduced the α2AP-dependent resistance to fibrinolysis of plasma clots equally effectively as the peptide. Native α2AP was found in in vivo clots in rabbits to a greater extent than α2AP(13-42, however. Conclusion In this first report of transfer of transglutamination substrate status from one plasma protein to another, fusion protein α2AP(13-42-HSA was shown to satisfy initial requirements for a long-lasting, well-tolerated competitive inhibitor of α2-antiplasmin predicted to act in a clot-localized manner.

  20. Effect of anticoagulant administration on blood clotting and some hormones related to rat-fertility

    International Nuclear Information System (INIS)

    This study was performed using 30 mature male albino rats divided into 3 equal groups; control and two treated groups to assess the effect of anticoagulant (warfarin) administration on the level of some hormones related to fertility. The two treated groups were injected intraperitoneally every other day with 1 ml (0.03 mg)and 2 ml (0.06 mg)warfarin/ 100 g body weight respectively where, two specimens were taken from each group after two and four weeks. Clotting time (CT), prothrombin time (PT), partial prothrombin time (PTT) platelets count, fasting blood sugar (F.B.S), calcium levels in addition to triiodothyronine (T3), thyroxin (T4), insulin, corticosterone, and testosterone hormones were determined. The results showed that the intraperitoneal injection of warfarin caused significant increase in clotting time, prothrombin time , partial prothrombin time, platelets count and glucose level, while serum calcium level showed significant decrease. Intraperitoneal injection of warfarin caused significant decrease of insulin and significant increase of corticosterone, T3 showed significant decrease in high dose group while T4 showed significant decrease in small dose group. The high dose was associated with the highest level of testosterone hormone. these results denoted that warfarin anticoagulant had no negative effect on gonadal sex hormone and hence on male fertility

  1. Acute small bowel obstruction due to a large intraluminal blood clot after laparoscopic Roux-en-Y gastric bypass.

    Science.gov (United States)

    Green, Jessica; Ikuine, Tomoko; Hacker, Shoshana; Urrego, Hernan; Tuggle, Karleena

    2016-01-01

    Small bowel obstructions (SBOs) are a known perioperative complication of laparoscopic Roux-en-Y gastric bypass and common etiologies include internal hernia, port site hernia, jejunojejunostomy stricture, ileus and adhesions. Less commonly, SBO can be caused by superior mesenteric artery syndrome, intussusception and intraluminal blood clot. We present a case of SBO caused by intraluminal blood clot from jejunojejunostomy staple line bleeding in a patient with a normal coagulation profile. Computed tomography was used to elucidate the cause of perioperative SBO, and diagnostic laparoscopy was used to both diagnose and treat the complication. In this case, the intraluminal clot was evacuated laparoscopically by enterotomy, thrombectomy and primary closure without anastomotic revision since there was no evidence of continued bleeding. Administration of enoxaparin and Toradol post-operatively may have exacerbated mild intraluminal bleeding occurring at the stapled jejunojejunal anastomosis. Prompt recognition and treatment of perioperative SBO can prevent catastrophic consequences related to bowel perforation. PMID:27554828

  2. Acute small bowel obstruction due to a large intraluminal blood clot after laparoscopic Roux-en-Y gastric bypass

    Science.gov (United States)

    Green, Jessica; Ikuine, Tomoko; Hacker, Shoshana; Urrego, Hernan; Tuggle, Karleena

    2016-01-01

    Small bowel obstructions (SBOs) are a known perioperative complication of laparoscopic Roux-en-Y gastric bypass and common etiologies include internal hernia, port site hernia, jejunojejunostomy stricture, ileus and adhesions. Less commonly, SBO can be caused by superior mesenteric artery syndrome, intussusception and intraluminal blood clot. We present a case of SBO caused by intraluminal blood clot from jejunojejunostomy staple line bleeding in a patient with a normal coagulation profile. Computed tomography was used to elucidate the cause of perioperative SBO, and diagnostic laparoscopy was used to both diagnose and treat the complication. In this case, the intraluminal clot was evacuated laparoscopically by enterotomy, thrombectomy and primary closure without anastomotic revision since there was no evidence of continued bleeding. Administration of enoxaparin and Toradol post-operatively may have exacerbated mild intraluminal bleeding occurring at the stapled jejunojejunal anastomosis. Prompt recognition and treatment of perioperative SBO can prevent catastrophic consequences related to bowel perforation. PMID:27554828

  3. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus

    DEFF Research Database (Denmark)

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    /Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially......It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V...... documented case of hypoxia-induced pulmonary vasoconstriction and flow shift in a main pulmonary artery due to a complete intrinsic obstruction of the ipsilateral main bronchus. The condition is reversible, contingent on being relieved within a few days....

  4. A Simple, Inexpensive and Safe Method for DNA Extraction of Frigid and Clotted Blood Samples

    Directory of Open Access Journals (Sweden)

    Nasrin Mohammadi

    2015-07-01

    Full Text Available Background: Extraction of blood genomicDNAis one of the main approaches for clinical and molecular biology studies. Although several methods have been developed for extraction of blood genomic DNA, most of these methods consume long time and use expensive chemicals such as proteinase K and toxic organic solvent such as phenol and chloroform. The objective of this study was to developed easy and safe method forDNAextraction from clotted and frozen whole blood. This method has many advantages: time reducing, using inexpensive materials, without phenol and chloroform, achieving of high molecular weight and good quality genomicDNA.Materials and Methods: DNA extraction was performed by two methods (new and phenol-chloroform method. Then quantity and quality parameters were evaluated by 1% agarose gel electrophoresis, Nano drop analysis and efficiency of Polymerase Chain Reaction (PCR.Results: Extracted DNA from 500μL of blood samples were 457.7ng/μl and 212ng/μL and their purity (OD260/OD280 were 1.8 and 1.81 for new recommended and phenol–chloroform methods respectively. The PCR results indicated that D16S539 and CSF1PO loci were amplified.Conclusion: These results shown that this method is simple, fast, safe and most economical.

  5. Hemostatic, milk clotting and blood stain removal potential of cysteine proteases from Calotropis gigantea (L. R. Br. Latex

    Directory of Open Access Journals (Sweden)

    Omana Sukumaran Bindhu

    2014-01-01

    Full Text Available Introduction: Plant latex is a natural source of biologically active compounds and several hydrolytic enzymes responsible for their diverse health benefits. Recent past has witnessed substantial progress in understanding their supplementary industrial and pharmaceutical utility. Calotropis gigantea is one of the important latex producing plants belonging to asclepediaceae family with wide ethnopharmacological applications and is rich in proteolytic enzymes. Present study investigates hemostatic, milk clotting and blood stain removal potential of C. gigantea latex proteases. Materials and Methods: The protease activity of crude enzyme (CE, obtained by centrifugation followed by ammonium sulphate precipitation and dialysis, was assayed using casein as the substrate. Effect of pH, temperature and specific inhibitors on protease activity was determined. Native PAGE and in gel protease activity of CE was performed. Hemostatic (Fibrinogen polymerization, fibrinogen agarose plate and blood clot lysis assays, milk clotting and blood stain removal efficacies of CE were determined. Results: CE exhibited high caseinolytic activity. Enzyme activity was optimum at 37-50ºC and pH 8.0. Fibrinogen polymerization assay showed concentration dependent increase in turbidity indicating thrombin like activity which was further confirmed by fibrinogen agarose plate assays. Clot lysis assay indicated 92.41% thrombolysis by CE in 90 min. CE also revealed significantly high ratio of milk clotting to protease activity (Milk Clotting Index, MCI = 827.59 ± 1.52. Complete destaining of blood stained fabric was observed when incubated with 1% detergent incorporated with 0.1mg/ml CE. The study highlights and validates the compound application potential of latex cysteine proteases from C. gigantea.

  6. Highly Effective DNA Extraction Method from Fresh, Frozen, Dried and Clotted Blood Samples

    Directory of Open Access Journals (Sweden)

    Jaleh Barar

    2011-09-01

    Full Text Available Introduction: Today, with the tremendous potential of genomics and other recent advances in science, the role of science to improve reliable DNA extraction methods is more relevant than ever before. The ideal process for genomic DNA extraction demands high quantities of pure, integral and intact genomic DNA (gDNA from the sample with minimal co-extraction of inhibitors of downstream processes. Here, we report the development of a very rapid, less-hazardous, and high throughput protocol for extracting of high quality DNA from blood samples. Methods: Dried, clotted and ethylene diamine tetra-acetic acid (EDTA treated fresh and frozen blood samples were extracted using this method in which the quality and integrity of the extracted DNA were corroborated by agarose gel electrophoresis, PCR reaction and DNA digestion using restricted enzyme. The UV spectrophotometric and gel electrophoresis analysis resulted in high A260/A280 ratio (>1.8 with high intactness of DNA. Results: PCR and DNA digestion experiments indicated that the final solutions of extracted DNA contained no inhibitory substances, which confirms that the isolated DNA is of good quality. Conclusion: The high quality and quantity of current method, no enzymatic processing and accordingly its low cost, make it appropriate for DNA extraction not only from human but also from animal blood samples in any molecular biology labs.

  7. The effects of acclimatization on blood clotting parameters in exertional heat stress

    Directory of Open Access Journals (Sweden)

    Vesić Zoran

    2013-01-01

    Full Text Available Background/Aim. Exertional heat stress is a common problem in military services. Considering the coagulation abnormalities are of major importance in development of severe heat stroke, we wanted to examine changes in hemostatic parameters in soldiers during exertional heat stress test as well as the effects of a 10-day passive or active acclimatization in a climatic chamber. Methods. A total of 40 male soldiers with high aerobic capacity performed exertional heat stress test (EHST either in cool [20ºC, 16ºC wet bulb globe temperature (WBGT], or hot (40ºC, 29ºC, (WBGT environment, unacclimatized (U or after 10 days of passive (P or active (A acclimatization. Physiological strain was measured by tympanic temperatures (Tty and heart rates (HR. Platelet count (PC, antithrombin III (AT, and prothrombin time (PT were assessed in blood samples collected before and immediately after the EHST. Results. EHST in hot conditions induced physiological heat stress (increase in Tty and HR, with a significant increase in prothrombin time in the groups U and A. Platelet counts were significantly higher after the EHST compared to the basic levels in all the investigated groups, regardless environmental conditions and acclimatization state. Antithrombin levels were not affected by EHST whatsoever. Conclusion. In the trained soldiers, physiological heat stress caused mild changes in some serum parameters of blood clotting such as prothrombin time, while others such as antithrombin levels were not affected. Platelet counts were increased after EHST in all groups. A 10-day passive or active acclimatization in climatic chamber showed no effect on parameters investigated.

  8. Rosuvastatin Reduced Blood Clot Risk%罗苏伐他汀可减少血栓形成

    Institute of Scientific and Technical Information of China (English)

    吴河水; 洪班信

    2009-01-01

    A large trial of the cholesterol lowering drug rosuvastatin showed that giving1 it to healthy adults reduced their risk of blood clots (venous thromboembolism) by 43 per cent. This was the result of a subgroup analysis in the JUPITER trial2, and was published online on 28 March in The Lancet and presented at the American College of Cardiology's 58th Annual Scientific Sessions.

  9. Anti-thrombogenic properties of a nitric oxide-releasing dextran derivative: evaluation of platelet activation and whole blood clotting kinetics

    Science.gov (United States)

    Damodaran, Vinod B.; Leszczak, Victoria; Wold, Kathryn A.; Lantvit, Sarah M.; Popat, Ketul C.; Reynolds, Melissa M.

    2013-01-01

    Controlling platelet activation and clotting initiated by cardiovascular interventions remains a major challenge in clinical practice. In this work, the anti-thrombotic properties of a polysaccharide-based nitric oxide (NO)-releasing dextran derivative are presented. Total platelet adhesion, platelet morphology and whole blood clotting kinetics were used as indicators to evaluate the anti-clotting properties of this material. With a total NO delivery of 0.203±0.003 μmol, the NO-releasing dextran derivative (Dex-SNO) mixed with blood plasma demonstrated a significantly lower amount of platelet adhesion and activation onto a surface and reduced whole blood clotting kinetics. Nearly 75% reduction in platelet adhesion and a significant retention of platelet morphology were observed with blood plasma treated with Dex-SNO, suggesting this to be a potential anti-platelet therapeutic agent for preventing thrombosis that does not have an adverse effect on circulating platelets. PMID:24349705

  10. Does prior administration of enoxaparin influence the effects of levobupivacaine on blood clotting? Assessment using the Thrombelastograph.

    LENUS (Irish Health Repository)

    Leonard, S A

    2012-02-03

    The low molecular weight heparin, enoxaparin (by inhibition of factors Xa and IIa) and amide local anaesthetics (by altering platelet function) exert anti-clotting effects. Although these agents are often used in combination during the perioperative period, their potential interactive effect on clotting has not been defined. Blood from 10 ASA I-II patients who received enoxaparin 0.5 mg kg(-1) s.c. was studied using a Thrombelastograph (TEG) either alone or in combination with levobupivacaine (2.5 mg ml(-1) or 2.5 microg ml(-1)) or saline (50% dilution). In blood from patients who had received enoxaparin 0.5 mg kg(-1) s.c. 12 h previously, levobupivacaine 2.5 mg ml(-1) (but not 2.5 microg ml(-1)) produced significant changes in TEG clotting parameters (mean (SD) 15.7 (4.8) mm, 29.6 (25.6) mm, 34.4 (14.6) mm, 34.3 (12.2) degrees compared with control values of 6.1 (1.3) mm, 2.5 (0.5) mm, 63.5 (6.4) mm and 74.1 (2.9) degrees for r, K, MA, and alpha angle respectively).

  11. Fibrinolytic Activity and Dose-Dependent Effect of Incubating Human Blood Clots in Caffeic Acid Phenethyl Ester: In Vitro Assays

    Directory of Open Access Journals (Sweden)

    Abuzar Elnager

    2015-01-01

    Full Text Available Background. Caffeic acid phenethyl ester (CAPE has been reported to possess time-dependent fibrinolytic activity by in vitro assay. This study is aimed at investigating fibrinolytic dose-dependent activity of CAPE using in vitro assays. Methods. Standardized human whole blood (WB clots were incubated in either blank controls or different concentrations of CAPE (3.75, 7.50, 15.00, 22.50, and 30.00 mM. After 3 hours, D-dimer (DD levels and WB clot weights were measured for each concentration. Thromboelastography (TEG parameters were recorded following CAPE incubation, and fibrin morphology was examined under a confocal microscope. Results. Overall, mean DD (μg/mL levels were significantly different across samples incubated with different CAPE concentrations, and the median pre- and postincubation WB clot weights (grams were significantly decreased for each CAPE concentration. Fibrin removal was observed microscopically and indicated dose-dependent effects. Based on the TEG test, the Ly30 fibrinolytic parameter was significantly different between samples incubated with two different CAPE concentrations (15.0 and 22.50 mM. The 50% effective dose (ED50 of CAPE (based on DD was 1.99 mg/mL. Conclusions. This study suggests that CAPE possesses fibrinolytic activity following in vitro incubation and that it has dose-dependent activities. Therefore, further investigation into CAPE as a potential alternative thrombolytic agent should be conducted.

  12. Fatal dynamic hyperinflation secondary to a blood clot acting as a one-way valve at the internal orifice of a tracheostomy tube

    OpenAIRE

    Raschke RA

    2012-01-01

    We report the case of a patient who suffered fatal cardiopulmonary effects of a mobile blood clot adherent to the internal orifice of her tracheostomy tube. We believe the clot acted as a one-way valve, leading to dynamic hyperinflation and elevated intrinsic positive end expiratory pressure (iPEEP). This complication of a tracheostomy tube was suggested by clinical findings of expiratory wheezing, hypotension, increasing peak inspiratory pressure, and unusual but distinctive radiographic fin...

  13. Momordica charantia seed extract exhibits strong anticoagulant effect by specifically interfering in intrinsic pathway of blood coagulation and dissolves fibrin clot.

    Science.gov (United States)

    Manjappa, Bhagyalakshmi; Gangaraju, Sowmyashree; Girish, Kesturu S; Kemparaju, Kempaiah; Gonchigar, Sathish J; Shankar, Rohit L; Shinde, Manohar; Sannaningaiah, Devaraja

    2015-03-01

    The current study explores the anticoagulant and fibrin clot-hydrolyzing properties of Momordica charantia seed extract (MCSE). MCSE hydrolyzed casein with the specific activity of 0.780 units/mg per min. Interestingly, it enhanced the clot formation process of citrated human plasma from control 146 to 432 s. In addition, the intravenous injection of MCSE significantly prolonged the bleeding time in a dose-dependent manner from control 150 to more than 800 s, and strengthened its anticoagulant activity. Interestingly, MCSE specifically prolonged the clotting time of only activated partial thromboplastin time, but not prothrombin time, and revealed the participation of MCSE in the intrinsic pathway of the blood coagulation cascade. Furthermore, MCSE completely hydrolyzed both Aα and Bβ chains of the human fibrinogen and partially hydrolyzed the γ chain. However, it hydrolyzed all the chains (α polymer, α chain, β chain and γ-γ dimmers) of partially cross-linked human fibrin clot. The proteolytic activity followed by the anticoagulant effect of the MCSE was completely abolished by the 1,10-phenanthroline and phenyl methyl sulphonyl fluoride, but iodoacetic acid, EDTA, and ethylene glycol-N,N,N',N'-tetra acetic acid did not. Curiously, MCSE did not hydrolyze any other plasma proteins except the plasma fibrinogen. Moreover, MCSE was devoid of RBC lysis, edema and hemorrhagic properties, suggesting its nontoxic nature. Taken together, MCSE may be a valuable candidate in the treatment of blood clot/thrombotic disorders. PMID:25192240

  14. 77 FR 38838 - Compliance Policy Guide Sec. 230.110-Registration of Blood Banks, Other Firms Collecting...

    Science.gov (United States)

    2012-06-29

    ... Banks, Other Firms Collecting, Manufacturing, Preparing, or Processing Human Blood or Blood Products... Registration of Blood Banks, Other Firms Collecting, Manufacturing, Preparing, or Processing Human Blood or... INFORMATION: FDA issued the CPG entitled ``Sec. 230.110 Registration of Blood Banks, Other Firms...

  15. Vibrations and spatial patterns in biomimetic surfaces: using the shark-skin effect to control blood clotting.

    Science.gov (United States)

    Ramachandran, Rahul; Maani, Nazanin; Rayz, Vitaliy L; Nosonovsky, Michael

    2016-08-01

    We study the effect of small-amplitude fast vibrations and small-amplitude spatial patterns on various systems involving wetting and liquid flow, such as superhydrophobic surfaces, membranes and flow pipes. First, we introduce a mathematical method of averaging the effect of small spatial and temporal patterns and substituting them with an effective force. Such an effective force can change the equilibrium state of a system as well as a phase state, leading to surface texture-induced and vibration-induced phase control. Vibration and patterns can effectively jam holes in vessels with liquid, separate multi-phase flow, change membrane properties, result in propulsion and locomotion and lead to many other multi-scale, nonlinear effects including the shark-skin effect. We discuss the application of such effects to blood flow for novel biomedical 'haemophobic' applications which can prevent blood clotting and thrombosis by controlling the surface pattern at a wall of a vessel (e.g. a catheter or stent).This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. PMID:27354733

  16. Vibrations and spatial patterns in biomimetic surfaces: using the shark-skin effect to control blood clotting.

    Science.gov (United States)

    Ramachandran, Rahul; Maani, Nazanin; Rayz, Vitaliy L; Nosonovsky, Michael

    2016-08-01

    We study the effect of small-amplitude fast vibrations and small-amplitude spatial patterns on various systems involving wetting and liquid flow, such as superhydrophobic surfaces, membranes and flow pipes. First, we introduce a mathematical method of averaging the effect of small spatial and temporal patterns and substituting them with an effective force. Such an effective force can change the equilibrium state of a system as well as a phase state, leading to surface texture-induced and vibration-induced phase control. Vibration and patterns can effectively jam holes in vessels with liquid, separate multi-phase flow, change membrane properties, result in propulsion and locomotion and lead to many other multi-scale, nonlinear effects including the shark-skin effect. We discuss the application of such effects to blood flow for novel biomedical 'haemophobic' applications which can prevent blood clotting and thrombosis by controlling the surface pattern at a wall of a vessel (e.g. a catheter or stent).This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'.

  17. Factors affecting the lung perfused blood volume in patients with intrapulmonary clots after anti-coagulation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Munemasa, E-mail: radokada@yamaguchi-u.ac.jp [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Masuda, Yu [4th Grade of 6-year Medicine Doctor Program, Department of Medicine, Yamaguchi University Faculty of Medicine and Health Sciences 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Nakashima, Yoshiteru [Department of Radiology, Yamaguchi Grand Medical Center, Oosaki 77, Hofu, Yamaguchi 747-8511 (Japan); Nomura, Takafumi; Nakao, Sei [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan); Suga, Kazuyoshi [Department of Radiology, St Hills Hospital, Imamurakita 3-7-18, Ube, Yamaguchi 755-0155 (Japan); Kido, Shoji [Computer-aided Diagnosis and Biomedical Imaging Research Biomedical Engineering, Applied Medical Engineering Science Graduate School of Medicine, Yamaguchi University, Tokiwadai 2-16-1, Ube, Yamaguchi 755-8611 (Japan); Matsunaga, Naofumi [Department of Radiology, Yamaguchi University Graduate School of Medicine 1-1-1 Minamikogushi, Ube, Yamaguchi 755-8505 (Japan)

    2015-08-15

    Highlights: • Dual-energy CT can provide morphological and functional lung images in the same examination. • The subsequent dual-energy CT demonstrates the increased whole lung perfused blood volume (V{sub 120}) despite the residual intrapulmonary clots after treatment in one examination. • The increased whole lung perfusion (V{sub 120}) and a decreased low perfusion volume (V{sub 5}) result in the improvement in the low perfusion rate (%V{sub 5}) in the patients with acute pulmonary embolism after treatment. - Abstract: Objectives: Factors affecting the improvement in the lung perfused blood volume (LPBV) were evaluated based on the presence of intrapulmonary clots (IPCs) after anti-coagulation therapy using 64-slice dual-energy CT. Materials and methods: 96 patients exhibiting venous thromboembolism underwent initial and repeated LPBV examinations between December 2008 and July 2014. Fifteen patients were excluded due to pulmonary comorbidities, and a total of 81 patients were included in this study. Acute pulmonary embolism (PE) was diagnosed in 46 of the patients (56.7%). LPBV images were three-dimensionally reconstructed with two threshold ranges: 1–120 HU (V{sub 120}) and 1–5 HU (V{sub 5}), and the relative value of V{sub 5} per V{sub 120} expressed as %V{sub 5}. These values were subsequently compared with indicators of the severity of PE, such as the D-dimer level, heart rate and CT measurements. This study was approved by the local ethics committee. Results: In patients with IPCs, the D-dimer, V{sub 5} and %V{sub 5}values were significantly larger (p ≤ 0.01) in the initial LPBV, although these differences disappeared in subsequent LPBV after treatment. The right ventricular (RV) diameter, RV/left ventricular (RV/LV) diameter ratio and %V{sub 5} values were also significantly reduced, whereas the V{sub 5} value did not significantly decrease (p = 0.07), but V{sub 120} value significantly increased (p < 0.001) after treatment. However, in

  18. Abolished ventilation and perfusion of lung caused by blood clot in the left main bronchus: auto-downregulation of pulmonary arterial blood supply.

    Science.gov (United States)

    Afzelius, P; Bergmann, A; Henriksen, J H

    2015-01-01

    It is generally assumed that the lungs possess arterial autoregulation associated with bronchial obstruction. A patient with pneumonia and congestive heart failure unexpectedly developed frequent haemoptysis. High-resolution CT and diagnostic CT were performed as well as ventilation/perfusion (V/Q) scintigraphy with single-photon emission CT (SPECT)/CT. V/Q SPECT/CT demonstrated abolished ventilation due to obstruction of the left main bronchus and markedly reduced perfusion of the entire left lung, a condition that was completely reversed after removal of a blood clot. We present the first pictorially documented case of hypoxia-induced pulmonary vasoconstriction and flow shift in a main pulmonary artery due to a complete intrinsic obstruction of the ipsilateral main bronchus. The condition is reversible, contingent on being relieved within a few days. PMID:26374773

  19. 21 CFR 607.7 - Establishment registration and product listing of blood banks and other firms manufacturing human...

    Science.gov (United States)

    2010-04-01

    ... blood banks and other firms manufacturing human blood and blood products. 607.7 Section 607.7 Food and... Provisions § 607.7 Establishment registration and product listing of blood banks and other firms... permit any blood bank or similar establishment to ship blood products in interstate commerce. (b)...

  20. A comparative evaluation of the blood clot, platelet-rich plasma, and platelet-rich fibrin in regeneration of necrotic immature permanent teeth: A clinical study

    Directory of Open Access Journals (Sweden)

    Isha Narang

    2015-01-01

    Full Text Available Introduction: This study was designed as a clinical trial to evaluate and compare the regenerative potential of platelet-rich fibrin (PRF, platelet-rich plasma (PRP, and blood clot in immature necrotic permanent teeth with or without associated apical periodontitis. Methods: Access preparation was done under rubber dam isolation. Copious irrigation was done with 2.5% NaOCl and triple antibiotic paste was placed as an intracanal medicament. After 4 weeks, the cases were divided into four groups with five patients in each group. The study design had three test arms and one control arm. Group I in which mineral trioxide aggregate apexification was carried out and it was kept as control group to evaluate the regenerative potential of blood clot and platelet concentrates, Group II in which blood clot was used as scaffold in the canal, Group III in PRF was used as scaffold, and Group IV in which PRP carried on collagen was used as a scaffold. Results: The clinical and radiographic evaluation after 6 and 18 months was done by two independent observers who were blinded from the groups. The scoring was done as: None score was denoted by, Fair by 1, Good by 2, and Excellent by 3. The data were then analyzed statistically by Fisher′s exact test using Statistics and Data 11.1(PRP Using harvest Smart PReP2 which showed statistically significant values in Group III as compared to other Groups. Conclusion: PRF has huge potential to accelerate the growth characteristics in immature necrotic permanent teeth as compared to PRP and blood clot.

  1. Blood Clotting and Pregnancy

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    Full Text Available ... and webinars ASH Image Bank Educational Web-based library of hematologic imagery In This Section: Resources for ... locations A complimentary CME summit on the diagnosis, classification, and care of MDS. ASH Meeting on Hematologic ...

  2. Blood Clotting and Pregnancy

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    Full Text Available ... About Awards Membership ASH Foundation Global Initiatives Newsroom facebook twitter youtube linkedin Research In This Section Agenda ... About Awards Membership ASH Foundation Global Initiatives Newsroom facebook twitter youtube linkedin Copyright © 2016 by American Society ...

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    Full Text Available ... September 16-17, 2016, Chicago, IL Abstracts Registration Housing Schedule and Program 58th ASH ® Annual Meeting & Exposition ... 6, 2016, San Diego, CA Key Dates Registration Housing Travel Information Government Concierge View all meetings Publications ...

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    Full Text Available ... Patients Resources for Industry Professionals View all Guidelines & Quality Care Resources to help practitioners improve patient care ... vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening event that occurs when a DVT breaks ...

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  1. Blood Clotting and Pregnancy

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    Full Text Available ... Membership ASH Foundation Global Initiatives Newsroom facebook twitter youtube linkedin Research In This Section Agenda for Hematology ... Membership ASH Foundation Global Initiatives Newsroom facebook twitter youtube linkedin Copyright © 2016 by American Society of Hematology ...

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  5. Blood Clotting and Pregnancy

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    Full Text Available ... Institute Policy Statements Testimony & Correspondence Addressing Sickle Cell ... or in the pelvic area. This condition is known as deep vein thrombosis (DVT). Pulmonary embolism (PE) is a life-threatening event that ...

  6. Hypomethylation of serum blood clot DNA, but not plasma EDTA-blood cell pellet DNA, from vitamin B12-deficient subjects.

    Directory of Open Access Journals (Sweden)

    Eoin P Quinlivan

    Full Text Available Vitamin B12, a co-factor in methyl-group transfer, is important in maintaining DNA (deoxycytidine methylation. Using two independent assays we examined the effect of vitamin B12-deficiency (plasma vitamin B12<148 pmol/L on DNA methylation in women of childbearing age. Coagulated blood clot DNA from vitamin B12-deficient women had significantly (p<0.001 lower percentage deoxycytidine methylation (3.23±0.66%; n = 248 and greater [3 H]methyl-acceptance (42,859±9,699 cpm; n = 17 than DNA from B12-replete women (4.44±0.18%; n = 128 and 26,049±2,814 cpm; n = 11 [correlation between assays: r = -0.8538; p<0.001; n = 28]. In contrast, uncoagulated EDTA-blood cell pellet DNA from vitamin B12-deficient and B12-replete women exhibited similar percentage methylation (4.45±0.15%; n = 77 vs. 4.47±0.15%; n = 47 and [3 H]methyl-acceptance (27,378±4,094 cpm; n = 17 vs. 26,610±2,292 cpm; n = 11. Therefore, in simultaneously collected paired blood samples, vitamin B12-deficiency was associated with decreased DNA methylation only in coagulated samples. These findings highlight the importance of sample collection methods in epigenetic studies, and the potential impact biological processes can have on DNA methylation during collection.

  7. The Effect of Radioactive Lantern Mantle Powder and Bentonite-Zeoloite Minerals on the Volume of Blood Loss, Bleeding and Clotting Time

    Directory of Open Access Journals (Sweden)

    M Atefi

    2009-04-01

    Full Text Available ABSTRACT Introduction & Objective: Over the past decade the US army has widely studied new technologies for stopping sever hemorrhages and has introduced an effective Zeolite based hemostatic agent. On the other hand, Mortazavi and his colleagues previously reported the bio-stimulatory effects of the topical application of radioactive lantern mantle powder on wound healing. Their subsequent studies showed significant changes in some histological parameters concerning healing. In this light, here the bio-stimulatory effect of burned radioactive lantern mantles powder as well as two minerals bentonite and zeolite are presented. Materials & Methods: This experimental study was conducted in the center for radiological studies, Shiraz University of Medical Sciences in 2008. Fifty male Wistar rats were divided randomly into 5 groups of 10 animals each. Following anesthesia, animals’ tails were cut at a thickness of 5 mm by using a surgical scissor. No intervention was made on the animals of the 1st group. The 2nd to 4th group received topical non-radioactive lantern mantle powder, radioactive lantern mantle powder, Bentonite mineral or a mixture of Bentonite-Zeoliteat minerals respectively. After treatment with above mentioned agents, the volume of blood loss was measured using a scaled test-tube. The bleeding time and clotting time were also measured using a chronometer. SPSS software was used for statistical analysis. ANOVA was used for comparing the means of each parameter in the 5 groups. Results: The the volume of blood loss, bleeding and clotting times in control animals were 4.39±1.92 cc, 112.10±39.60 sec and 94.9±54.26 sec, respectively. In the 5th group in which the animals were treated with a mixture of Bentonite-Zeoliteat minerals, the volume of blood loss, bleeding and clotting times were 1.31±0.60 cc, 34.50±4.65 sec and 24.2±4.61 sec, respectively. Conclusion: This is the 1st investigation that studied the alterations of bleeding

  8. The development of a blood clotting response test for discriminating between difenacoum-resistant and susceptible Norway rats (Rattus norvegicus, Berk.).

    Science.gov (United States)

    Gill, J E; Kerins, G M; Langton, S D; MacNicoll, A D

    1993-01-01

    1. A new test for identifying levels of difenacoum resistance in the Norway rat is described, based upon the differential physiological response to difenacoum administration. 2. This test is based on changes in blood clotting activity over 4 days, following administration of the rodenticide difenacoum in conjunction with menadione (vitamin K3). 3. The anticoagulant effect is reduced only in rats that are resistant or tolerant to difenacoum. 4. This test procedure is quicker than traditional feeding tests, and identifies the degree of resistance in both laboratory and wild rats that have difenacoum resistance genes. PMID:8097452

  9. Synthesis, purification, and characterization of an Arg152 → Glu site-directed mutant of recombinant human blood clotting factor VII

    International Nuclear Information System (INIS)

    Coagulation factor VII circulates in blood as a single-chain zymogen of a serine protease and is converted to its activated two-chain form, factor VIIa, by cleavage of an internal peptide bond located at Arg152-Ile153. Previous studies using serine protease active-site inhibitors suggest that zymogen factor VII may possess sufficient proteolytic activity to initiate the extrinsic pathway of blood coagulation. In order to assess the putative intrinsic proteolytic activity of single-chain factor VII, the authors have constructed a site-specific mutant of recombinant human factor VII in which arginine-152 has been replaced with a glutamic acid residue. Mutant factor VII was purified in a single step from culture supernatants of baby hamster kidney cells transfected with a plasmid containing the sequence for Arg152 → Glu factor VII using a calcium-dependent, murine anti-factor VII monoclonal antibody column. The clotting activity of mutant factor VII was completely inhibited following incubation with dansyl-Glu-Gly-Arg chloromethyl ketone, suggesting that the apparent clotting activity of mutant factor VII was due to a contaminating serine protease. Immunoblots of mutant factor VII with human factor IXa revealed no cleavage, whereas incubation of mutant factor VII with human factor Xa resulted in cleavage of mutant factor VII and the formation of a lower molecular weight degradation product migrating at Mr∼40 000. The results are consistent with the proposal that zymogen factor VII possesses no intrinsic proteolytic activity toward factor X or factor IX

  10. In Vivo Quantification of Clot Formation in Extracorporeal Circuits

    CERN Document Server

    David, Omid

    2012-01-01

    Clot formation is a common complication in extracorporeal circuits. In this paper we describe a novel method for clot formation analysis using image processing. We assembled a closed extracorporeal circuit and circulated blood at varying speeds. Blood filters were placed in downstream of the flow, and clotting agents were added to the circuit. Digital images of the filter were subsequently taken, and image analysis was applied to calculate the density of the clot. Our results show a significant correlation between the cumulative size of the clots, the density measure of the clot based on image analysis, and flow duration in the system.

  11. Investigation of the effect of kaolin and tissue factor-activated citrated whole blood, on clot forming variables, as evaluated by thromboelastograph

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Andersen, S.;

    2008-01-01

    ), and maximum clot strength (amplitude [MA]) were evaluated, together with day-to-day variation, the coefficient of variance (CV%), and the effect of citrate storage time. RESULTS: Clot formation variables were equally affected by TF 1:17,000 and kaolin activation, whereas R was significantly longer when TF 1...

  12. Fibronectin adsorption on surface-modified polyetherurethanes and their differentiated effect on specific blood elements related to inflammatory and clotting processes.

    Science.gov (United States)

    Hugoni, Ludivine; Montaño-Machado, Vanessa; Yang, Meilin; Pauthe, Emmanuel; Mantovani, Diego; Santerre, J Paul

    2016-01-01

    After the introduction of a medical device into the body, adhesive proteins such as fibronectin (Fn) will adsorb to the surface of the biomaterial. Monocytes (MCs) will interact with these adsorbed proteins, and adopt either a proinflammatory and/or prowound healing phenotype, thereby influencing many blood interaction events including thrombogenesis. In this work, Fn adsorption as well as subsequent MC response and thrombus formation were investigated on two surfaces-modified polyetherurethanes (PEUs) using different surface modifiers: an anionic/dihydroxyl oligomeric (ADO) additive, known to enable cell adhesion, and a fluorinated polypropylene oxide oligomer (PPO), known to reduce platelet adhesion. Results indicated that at 24 h of MC culture, PEU-ADO and PEU-PPO promoted an anti-inflammatory character relative to the base PEU. Longer clotting times, based on a free hemoglobin assay, were also found on the two surface-modified PEUs relative to the native one, suggesting their potential for the reduction of thrombus formation. In presence of a Fn monolayer, the surface-modified PEUs conserved a lower thrombogenic character than the base PEU, and was however significantly decreased when compared to prior protein adsorption. Furthermore, Fn coatings increased the MC production levels of tumor necrosis factor-α and interleukin-10 at 24 h, while not affecting the anti-inflammatory effect of the modifications relative to the base PEU. This finding was most prominent on PEU-PPO, suggesting that the interaction of the adsorbed Fn with blood cells was different for the two additives. Hence, the results highlighted differentiating effects of Fn adsorption on specific blood activating processes related to inflammatory and thrombotic responses. PMID:27246517

  13. Acute induction of anomalous and amyloidogenic blood clotting by molecular amplification of highly substoichiometric levels of bacterial lipopolysaccharide

    Science.gov (United States)

    Mbotwe, Sthembile; Bester, Janette; Robinson, Christopher J.; Kell, Douglas B.

    2016-01-01

    It is well known that a variety of inflammatory diseases are accompanied by hypercoagulability, and a number of more-or-less longer-term signalling pathways have been shown to be involved. In recent work, we have suggested a direct and primary role for bacterial lipopolysaccharide (LPS) in this hypercoagulability, but it seems never to have been tested directly. Here, we show that the addition of tiny concentrations (0.2 ng l−1) of bacterial LPS to both whole blood and platelet-poor plasma of normal, healthy donors leads to marked changes in the nature of the fibrin fibres so formed, as observed by ultrastructural and fluorescence microscopy (the latter implying that the fibrin is actually in an amyloid β-sheet-rich form that on stoichiometric grounds must occur autocatalytically). They resemble those seen in a number of inflammatory (and also amyloid) diseases, consistent with an involvement of LPS in their aetiology. These changes are mirrored by changes in their viscoelastic properties as measured by thromboelastography. As the terminal stages of coagulation involve the polymerization of fibrinogen into fibrin fibres, we tested whether LPS would bind to fibrinogen directly. We demonstrated this using isothermal calorimetry. Finally, we show that these changes in fibre structure are mirrored when the experiment is done simply with purified fibrinogen and thrombin (±0.2 ng l−1 LPS). This ratio of concentrations of LPS : fibrinogen in vivo represents a molecular amplification by the LPS of more than 108-fold, a number that is probably unparalleled in biology. The observation of a direct effect of such highly substoichiometric amounts of LPS on both fibrinogen and coagulation can account for the role of very small numbers of dormant bacteria in disease progression in a great many inflammatory conditions, and opens up this process to further mechanistic analysis and possible treatment. PMID:27605168

  14. Acute induction of anomalous and amyloidogenic blood clotting by molecular amplification of highly substoichiometric levels of bacterial lipopolysaccharide.

    Science.gov (United States)

    Pretorius, Etheresia; Mbotwe, Sthembile; Bester, Janette; Robinson, Christopher J; Kell, Douglas B

    2016-09-01

    It is well known that a variety of inflammatory diseases are accompanied by hypercoagulability, and a number of more-or-less longer-term signalling pathways have been shown to be involved. In recent work, we have suggested a direct and primary role for bacterial lipopolysaccharide (LPS) in this hypercoagulability, but it seems never to have been tested directly. Here, we show that the addition of tiny concentrations (0.2 ng l(-1)) of bacterial LPS to both whole blood and platelet-poor plasma of normal, healthy donors leads to marked changes in the nature of the fibrin fibres so formed, as observed by ultrastructural and fluorescence microscopy (the latter implying that the fibrin is actually in an amyloid β-sheet-rich form that on stoichiometric grounds must occur autocatalytically). They resemble those seen in a number of inflammatory (and also amyloid) diseases, consistent with an involvement of LPS in their aetiology. These changes are mirrored by changes in their viscoelastic properties as measured by thromboelastography. As the terminal stages of coagulation involve the polymerization of fibrinogen into fibrin fibres, we tested whether LPS would bind to fibrinogen directly. We demonstrated this using isothermal calorimetry. Finally, we show that these changes in fibre structure are mirrored when the experiment is done simply with purified fibrinogen and thrombin (±0.2 ng l(-1) LPS). This ratio of concentrations of LPS : fibrinogen in vivo represents a molecular amplification by the LPS of more than 10(8)-fold, a number that is probably unparalleled in biology. The observation of a direct effect of such highly substoichiometric amounts of LPS on both fibrinogen and coagulation can account for the role of very small numbers of dormant bacteria in disease progression in a great many inflammatory conditions, and opens up this process to further mechanistic analysis and possible treatment. PMID:27605168

  15. 维持性血液透析患者血液灌流凝血的危险因素分析%Blood clotting during hemoperfusion plus hemodialysis in maintenance hemodialysis patients

    Institute of Scientific and Technical Information of China (English)

    张桂芝; 李寒; 王世相

    2010-01-01

    目的 了解维持性血液透析患者血液灌流凝血的发生情况,分析其危险因素.方法 对我院血液净化中心行血液灌流治疗的72例维持性血液透析患者进行回顾性研究,收集患者临床资料和生化指标,分析维持性血液透析患者血液灌流凝血的发生率及其危险因素.结果 72例维持性血液透析患者共进行血液灌流302例次,7例患者发生血液灌流凝血16例次,其中Ⅱ级凝血6例次,Ⅲ级凝血10例次.发生过血液灌流凝血的患者合并肿瘤、糖尿病、血管通路功能不良比例及血清低密度脂蛋白、脂蛋白a水平明显高于未发生过血液灌流凝血者,两组患者在年龄、性别、透析龄、超滤速度、机器温度、跨膜压、血肌酐、尿素氮、甘油三酯、总胆固醇、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇、脂蛋白a、血红蛋白、血小板及透析前APTT活化部分凝血酶活酶时间等方面相比,差异无统计学意义(P>0.05).凝血发生早期透析器呈现静脉压过低报警,凝血常发生在血液灌流1.5~2 h.结论 维持性血液透析患者常规行血液灌流治疗时存在凝血的风险.血液灌流联合血液透析过程中透析器呈现静脉压过低报警时应警惕凝血发生.合并肿瘤、糖尿病、血管功能不良比例及血清低密度脂蛋白、脂蛋白a水平增高的维持性血液透析患者联合血液灌流治疗时易发生凝血.%Objective To investigate the incidence, characteristic and risk factors of blood clotting during hemoperfusion plus hemodialysis in maintenance hemodialysis (MHD) patients. Methods From May 2008 to May 2009, a total of 72 cases of MHD patients in our blood purification center were enrolled in this retrospective study. The following data were collected: age, gender, dialysis duration, serum creatinine, lipid profile, etc. T test and x2 test were performed for statistics. Results 72 MHD patients performed 302 times of

  16. Preventing and Treating Blood Clots

    Science.gov (United States)

    ... Health Disparities and Cancer For Patient Advocates Public Policy Advocacy Cancer Awareness Dates Survivorship Blog About Us You ... Health Disparities and Cancer For Patient Advocates Public Policy Advocacy Cancer Awareness Dates Cancer.Net provides timely, comprehensive, ...

  17. Comparison of Topical Hemostatic Agents in a Swine Model of Extremity Arterial Hemorrhage: BloodSTOP iX Battle Matrix vs. QuikClot Combat Gauze

    Directory of Open Access Journals (Sweden)

    Huixi Li

    2016-04-01

    Full Text Available BloodSTOP iX Battle Matrix (BM and QuikClot Combat Gauze (CG have both been used to treat traumatic bleeding. The purpose of this study was to examine the efficacy and initial safety of both products in a swine extremity arterial hemorrhage model, which mimics combat injury. Swine (37.13 ± 0.56 kg, NBM = 11, NCG = 9 were anesthetized and splenectomized. We then isolated the femoral arteries and performed a 6 mm arteriotomy. After 45 s of free bleeding, either BM or CG was applied. Fluid resuscitation was provided to maintain a mean arterial pressure of 65 mmHg. Animals were observed for three hours or until death. Fluoroscopic angiography and wound stability challenge tests were performed on survivors. Tissue samples were collected for histologic examination. Stable hemostasis was achieved in 11/11 BM and 5/9 CG subjects, with recovery of mean arterial pressure and animal survival for three hours (p < 0.05, Odds Ratio (OR = 18.82 (0.85–415.3. Time to stable hemostasis was shorter for the BM-treated group (4.8 ± 2.5 min vs. 58 ± 20.1 min; Median = 2, Interquartile Range (IQR = 0 min vs. Median = 60, IQR = 120 min; p < 0.05 and experienced longer total stable hemostasis (175.2 ± 2.5 min vs. 92.4 ± 29.9 min; Median = 178, IQR = 0 min vs. Median = 120, IQR = 178 min; p < 0.05. Post-treatment blood loss was lower with BM (9.5 ± 2.4 mL/kg, Median = 10.52, IQR = 13.63 mL/kg compared to CG (29.9 ± 9.9 mL/kg, Median = 29.38, IQR = 62.44 mL/kg (p = 0.2875. Standard BM products weighed less compared to CG (6.9 ± 0.03 g vs. 20.2 ± 0.4 g (p < 0.05 and absorbed less blood (3.4 ± 0.8 g vs. 41.9 ± 12.3 g (p < 0.05. Fluoroscopic angiography showed recanalization in 5/11 (BM and 0/5 (CG surviving animals (p = 0.07, OR = 9.3 (0.41–208.8. The wound stability challenge test resulted in wound re-bleeding in 1/11 (BM and 5/5 (CG surviving animals (p < 0.05, OR = 0.013 (0.00045–0.375. Histologic evidence indicated no wound site, distal limb or major

  18. 血栓通注射液防治癌症相关静脉血栓的临床观察%Xueshuantong injection in prevention and treatment of the cancer-related venous blood clots

    Institute of Scientific and Technical Information of China (English)

    刘增刚; 于苏华; 邢建波

    2011-01-01

    Objective To observe the preventive and therapeutic effect of xueshuantong injection on cancer-related venous blood clots and the influence on the quality of cancer patients'life. Methods Four hundred and sixty cancer patients were randomly divided into two groups, 230 cases in the treatment group and 230 cases in the control group. Both groups received radiotherapy and chemotherapy, and to the treatment group, intravenous dripping of xueshuantong injection was added.The incidence rate of venous blood clots was observed and the quality of life was evaluated by Karnof-sky performance score(KPS).Results The incidence rate of venous blood clots was 1.15% in the treatment group,which was lower than that in the control group(16.96%),P<0.05.Cases experienced symptom inprovement were found more in the treatment group(118/230,51.30%)than in the control group(72/230,31.30%),P<0.05. Patients in stable condition were more in the treatment group(82/230,35.65%)than in the control group(47/230,20.43%),P<0.05. Conclusions Xueshuantong injection shows definite effect in preventing cancer-related venous blood clots and improving the quality of cancer patients'life.%目的 观察血栓通注射液对癌症相关静脉血栓的防治作用及对癌症患者生存质量的影响.方法 观察组230例患者在住院放化疗治疗的同时加用血栓通注射液静脉滴注,对照组230例仅做放、化疗,治疗结束后对两组患者静脉血栓的发生率及生活质量(Karnof - sky评分)进行评价.结果 观察组血栓发生率为1.15%,对照组血栓发生率为16.96%.Karnof-sky评分:观察组改善118例,稳定82例;对照组改善72例,稳定47例,两组比较差异有统计学意义(P<0.05).结论 血栓通注射液对癌症相关静脉血栓有预防作用,对该类癌症患者的生存质量有明显提高作用.

  19. Hybrid model of clot formation in flow

    Directory of Open Access Journals (Sweden)

    Tosenberger A.

    2015-01-01

    Full Text Available The process of blood coagulation and clot formation in vivo is not yet completely understood. One of the main questions related to haemostasis is why the clot stops growing in normal conditions before it completely obstructs the flow in the vessel, whereas, in pathologic cases, it can continue to grow, often with fatal consequences. Hence, revealing the mechanisms by which the clot grows and stops growing in the flow remains of great importance. In order to study this topic we have developed a hybrid DPD-PDE method where Dissipative Particle Dynamics (DPD is used to model plasma flow and platelets, while the protein regulatory network is described by a system of partial differential equations. The model describes the interaction between blood flow, platelet aggregation and plasma coagulation. As a result of modelling we propose a new mechanism of clot growth and growth arrest in flow. The developed model and its parts can be used as a base to modelling of different physiological phenomena related to cell-cell interactions and blood flows.

  20. Genomic DNA Isolation by Phenol/Chloroform Extracting Method from Sheep Blood Clot%酚/氯仿抽提法提取绵羊凝血块中基因组DNA

    Institute of Scientific and Technical Information of China (English)

    曹果清; 莫清珊; 陈凤仙

    2009-01-01

    [Objective] The aim was to establish the method of extracting genomic DNA from sheep blood clot on the basis of the improvement of method for extracting genomic DNA from tissues. [Method]The genomic DNA with complete primary structure and high purity was obtained from the sheep blood clot after the steps of cutting the sheep blood clot with ophthalmic scissors, cell lysis with tissue DNA extracts and digested by proteinase K, extracting with phenol/chloroform and precipitating with ethanol were performed. [Result]The concentration of the extracted DNA was 159.90±0.70 ng/μl and the ratio of the A260/A280 was 1.80+0.01. The sheep microsatellite locus of BM203 was amplified by using the extracted DNA from the sheep blood clot as template of PCR, and the PCR result was perfect. [Conclusion]This method is simple and feasible, the quantity and quality of the extracted DNA can satisfy the demands for the subsequent researches. It is worth to extending and using for reference.%[目的]对组织DNA提取方法进行改进,建立一种从绵羊凝血块中提取基因组DNA的方法.[方法]将绵羊凝血块用眼科剪剪碎,用组织DNA抽提液裂解细胞,用蛋白酶K消化后,经过酚/氯仿抽提,无水乙醇沉淀获得基因组DNA.用NanoDrop ND-1000微型分光光度计检测DNA浓度和纯度.用0.8%琼脂糖凝胶电泳检验基因组DNA的完整性.以绵羊微卫星位点BM203为扩增位点,分别以F:5′-GGGTGTGACATTTTGTTCCC-3′,R:5′-CTGCTCGCCACTAGTCCTTC-3′为上下游引物,进行PCR扩增试验.PCR产物用1.5%琼脂糖凝胶电泳检测.[结果]提取的DNA浓度为(159.90±0.70) ng/μl,A260/A280比值为1.80±0.01,分子完整,结果理想.以从凝血块中提取的DNA为模板,对绵羊BM203微卫星位点进行了PCR扩增,扩增产物条带整齐、明亮、特导性强,扩增效果好.[结论]该方法简单、实用,提取的DNA可满足后续相关研究对DNA质量的要求,值得推广借鉴.

  1. Reducing CBC Clotting Rates in the Neonatal Patient Care Areas.

    Science.gov (United States)

    McCoy, Jennifer; Tichon, Tanya; Narvey, Michael

    2016-01-01

    Performing a complete blood count (CBC) is a common test performed in neonatal intensive care. Samples reported as "clotted" are not able to be analyzed and require redraw. A perceived "high" clotting rate elicits frustration among team members and has negative effects on patient flow and patient satisfaction. Process mapping and a root cause analysis determined that an educational intervention was required to optimize blood collection skills of front-line nurses. Through four rapid PDSA cycles over a three year period, the neonatal patient care areas were able to decrease their CBC clotting rates from 30% (monthly rate when the problem was identified) to 16% (yearly average at the end of the project). The CBC clotting rates continue to decease over time due to the integration of a multi-faceted educational plan into biannual education days designed for current staff nurses, as well as into the orientation plan for newly hired and student nurses. PMID:27493749

  2. Detection of dengue virus RNA in blood clots by multiplex nested reverse transcription-PCR%多重套式RT-PCR检测患者凝血块中登革病毒RNA

    Institute of Scientific and Technical Information of China (English)

    张拥军; 黄萌; 翁育伟; 郑友限; 王金章

    2012-01-01

    目的 建立简便、灵敏、适合于全部血清型登革病毒核酸检测的多重套式RT- PCR体系,检测临床样品中登革病毒RNA,作为实验室辅助诊断的依据.方法 利用登革病毒标准株核酸,建立多重RT- PCR检测方法.提取患者凝血块总RNA,分别用一步法RT- PCR及多重套式RT PCR检测.结果 通过对检测体系进行优化,多重RT- PCR能够同时检测4种血清型登革病毒核酸.采用多重套式RT- PCR方法,从8例登革热患者凝血块中有4例检测到病毒RNA,而其它核酸检测方法仅检出1例阳性.结论 多重套式RT-PCR的方法能够从临床凝血块样品中检测到登革病毒核酸,并同时进行血清学分型,简化了登革病毒核酸检测步骤,有利于对临床样品开展病毒核酸检测.%Dengue is the most common vector borne viral disease of humans globally.Detection of viral RNA from suspected patient specimens is rapid,specific and confirmative in laboratory diagnosis of dengue infections during the acute phase.In this study,a multiplex nested reverse transcription PCR (RT-PCR) system was established for clinical specimens.While other nucleic acid amplification tests showed relatively low sensitivity,the multiplex nested RT PCR assay detected 4 cases among blood clots from 8 serologically confirmed dengue patients.These results suggested that blood clots of dengue patients could be used in laboratory diagnosis,and that the multiplex nested RT PCR assay,which simplified the detection procedure,could facilitate viral RNA detection of specimens in clinical laboratories.

  3. An Antithrombin-Heparin Complex Increases the Anticoagulant Activity of Fibrin Clots

    Directory of Open Access Journals (Sweden)

    Lesley J. Smith

    2008-01-01

    Full Text Available Clotting blood contains fibrin-bound thrombin, which is a major source of procoagulant activity leading to clot extension and further activation of coagulation. When bound to fibrin, thrombin is protected from inhibition by antithrombin (AT + heparin but is neutralized when AT and heparin are covalently linked (ATH. Here, we report the surprising observation that, rather than yielding an inert complex, thrombin-ATH formation converts clots into anticoagulant surfaces that effectively catalyze inhibition of thrombin in the surrounding environment.

  4. Establishment of a Rapid Method for Extracting Human Genomic DNA from Peripheral Clotted Blood%一种快速、经济提取外周凝血基因组DNA方法的建立

    Institute of Scientific and Technical Information of China (English)

    许丽娟; 马骁; 王洋阳; 王静; 潘晴; 刘梅

    2011-01-01

    Objective: To establish a rapid, economical method for extracting genotnic DNA from peripheral clotted blood. Methods: Explore a optimum homogenate condition, homogenate the clotted blood, extracting the genomic DNA by KI method. Use agarose gel electrophoresis, single PCR and multiplex PCR detect the genomic DNA extraction yield and quality. And compared with the traditional extraction methods, Proteinase K digestion method and KI method which extract DNA from anti-coagulated blood. Results: The optimum homogenate condition is 39000 rmp and 15 seconds. The genomic DNA was extracted under this condition has good integrity. There is no significant difference of purity and yield between this method and Proteinase K digestion and KI method. Single PCR and multiplex PCR also obtained good amplification results. Conclusion: Compared with traditional extraction methods (Proteinase K digestion method),this method can save time and cost, which can extract DNA rapidly,economical and effectively,and can be used in clinical and research analysis, and can solve the blood genomic DNA sources of some of the research institutions.%目的:建立一种经济、快速且高质量提取人体外周凝血DNA的方法.方法:摸索最佳的匀浆条件,对外周凝血块进行匀浆,采用KI法对匀浆液进行基因组DNA的提取,通过凝胶电泳、单重PCR和多重PCR检测凝血基因组DNA的提取产量和质量,并分别与常规的凝血基因组DNA提取方法,即蛋白酶K消化法,以及提取抗凝血基因组DNA的KI法进行比较分析.结果:最佳的匀浆条件为:39000 rmp,15秒.在此条件下提取的基因组DNA完整性好,纯度和产量与蛋白酶K消化法提取凝血DNA和KI法提取抗凝血DNA的结果相比,没有统计学差异.单重PCR和多重PCR也获得了理想的扩增结果.结论:与常规的外周凝血提取方法相比(蛋白酶K消化法),本方法节省了时间和成本,能快速、经济、有效地提取外周凝血基因组DNA,可

  5. Photoacoustic monitoring of clot formation during surgery and tumor surgery

    Science.gov (United States)

    Juratli, Mazen A.; Galanzha, Ekaterina I.; Sarimollaoglu, Mustafa; Nedosekin, Dmitry A.; Suen, James Y.; Zharov, Vladimir P.

    2013-03-01

    When a blood vessel is injured, the normal physiological response of the body is to form a clot (thrombus) to prevent blood loss. Alternatively, even without injury to the blood vessel, the pathological condition called thromboembolism may lead to the formation of circulating blood clots (CBCs), also called emboli, which can clog blood vessels throughout the body. Veins of the extremities (venous thromboembolism), lungs (pulmonary embolism ), brain (embolic stroke), heart (myocardial infarction), kidneys, and gastrointestinal tract are often affected. Emboli are also common complications of infection, inflammation, cancer, surgery, radiation and coronary artery bypass grafts. Despite the clear medical significance of CBCs, however, little progress has been made in the development of methods for real-time detection and identification of CBCs. To overcome these limitations, we developed a new modification of in vivo photoacoustic (PA) flow cytometry (PAFC) for real-time detection of white, red, and mixed clots through a transient decrease, increase or fluctuation of PA signal amplitude, respectively. In this work, using PAFC and mouse models, we present for the first time direct evidence that some medical procedures, such as conventional or cancer surgery may initiate the formation of CBCs. In conclusion, the PA diagnostic platform can be used in real-time to define risk factors for cardiovascular diseases, assist in the prognosis and potential prevention of stroke by using a well-timed therapy or as a clot count as a marker of therapy efficacy.

  6. Novel mechanisms that regulate clot structure/function.

    Science.gov (United States)

    Ariëns, Robert A S

    2016-05-01

    The structure and function of the blood clot has been associated with altered risk of thrombosis. Dense fibrin structures with small pores increase the risk of thrombosis, and have major functional consequences by increasing the resistance to fibrinolysis and altering the visco-elastic properties of the clot. However, while the structural changes to the overall fibrin network have been extensively characterised, little is known regarding the intrafibrillar structure of fibrin, the way protofibrils are arranged inside the fibrin fibers and the functional consequences of this. This brief paper aims to review recent findings regarding novel mechanisms that regulate fibrin intrafibrillar structure, including the degree of protofibril packing, their functional consequences, and the effects of FXIII activation on clot structure and thrombosis. It is concluded that fibrin intrafibrillar structure represents a major novel mechanism that influences clot structure and stability. Future studies are required to investigate the role of fibrin intrafibrillar structure in the functional characteristics of the blood clot, and in diseases of bleeding and thrombosis.

  7. Dietary supplementation with dried chicory root triggers changes in the blood serum proteins engaged in the clotting process and the innate immune response in growing pigs.

    Science.gov (United States)

    Lepczynski, A; Herosimczyk, A; Ozgo, M; Skomial, J; Taciak, M; Barszcz, M; Berezecka, N

    2015-02-01

    The aim of the study was to characterize the systemic immune and metabolic alterations in the blood serum of growing pigs in response to a dietary supplementation with 4% of dried chicory roots. This was achieved by examining the influence of the experimental diet on serum protein changes especially these related with immunology and lipid metabolism. Serum proteins with the isoelectric point ranging from pH 3.0 to 10.0 were separated using high resolution two-dimensional electrophoresis. As a result, we found that experimental diet triggered significant changes in 37 protein spots. Of these, 14 were up-regulated, whereas 23 showed down-regulation. Of 37 significantly altered protein spots, 24 were successfully identified, representing 14 distinct gene products. Implementation of the dried chicory roots into the diet of growing pigs caused a significant down-regulation of apolipoprotein C-II complement component C6, C-reactive protein, CD14 antigen, C4b binding protein α and β chains, and fibrinogen. Piglets fed experimental diet had similar IgA, IgG and IgM concentrations, although the level of IgM tended to be lower compared to the control group. It is concluded that diet supplemented with 4% of dried chicory root may exert anti-inflammatory properties and affect lipid metabolism in growing pigs. PMID:25716964

  8. The clot burden score, the Boston Acute Stroke Imaging Scale, the cerebral blood volume ASPECTS, and two novel imaging parameters in the prediction of clinical outcome of ischemic stroke patients receiving intravenous thrombolytic therapy

    Energy Technology Data Exchange (ETDEWEB)

    Sillanpaa, Niko; Hakomaki, Jari; Lahteela, Arto; Dastidar, Prasun; Soimakallio, Seppo [Tampere University Hospital, Medical Imaging Center, Tampere (Finland); Saarinen, Jukka T.; Numminen, Heikki; Elovaara, Irina [Tampere University Hospital, Department of Neurology, Tampere (Finland); Rusanen, Harri [Oulu University Hospital, Department of Neurology, Oulu (Finland)

    2012-07-15

    Recently two classification methods based on the location and the extent of thrombosis detected with CT angiography have been introduced: the Boston Acute Stroke Imaging Scale (BASIS) and the clot burden score (CBS). We studied the performance of BASIS and CBS in predicting good clinical outcome (mRS {<=}2 at 90 days) in an acute (<3 h) stroke cohort treated with intravenous thrombolytic therapy. Eighty-three consecutive patients who underwent multimodal CT were analyzed. Binary logistic regression model was used to assess how BASIS, CBS, and cerebral blood volume (CBV) ASPECTS predict favorable clinical outcome. Diagnostic sensitivities and specificities were calculated and compared. Patients with low CBS and CBV ASPECTS scores and major strokes according to BASIS had significantly higher admission NIHSS scores, larger perfusion defects, and more often poor clinical outcome. In logistic regression analysis, CBV ASPECTS, CBS and BASIS were significantly associated with the clinical outcome. The performance of BASIS improved when patients with thrombosis of the M2 segment of the middle cerebral artery were classified as having minor stroke (M1-BASIS). In the anterior circulation, the sum of CBS and CBV ASPECTS (CBSV) proved to be the most robust predictor of favorable outcome. CBV ASPECTS and CBS had high sensitivity but moderate to poor specificity while BASIS was only moderately sensitive and specific. CBS, BASIS, and CBV ASPECTS are statistically robust and sensitive but unspecific predictors of good clinical outcome. Two new derived imaging parameters, CBSV and M1-BASIS, share these properties and may have increased prognostic value. (orig.)

  9. 动态检测乙型肝炎患者凝血指标的临床分析*%Dynamic detection of hepatitis B patients for blood clotting index:Clinical analysis

    Institute of Scientific and Technical Information of China (English)

    余晓红; 马珍珍; 吕宏迪; 冯雨; 谢琳; 杨廷桐

    2015-01-01

    Objective To explore the clinical significance of dynamic detection of blood coagulation function in the patients with hepatitis B and cirrhosis of the liver. Methods The 182 cases of hepatitis B patients (78 cases of chronic hepatitis B,56 acute hepatitis B,cirrhosis in 48 cases) and 100 cases of in the same period normal physical body as control were collected their plasma for testing. Japanese sysmex ca7000 automatic blood coagulation instrument and auxiliary reagents were adopted for test:PT, (plasma prothrombin time),TT(thrombin time),FIB(content of fibrinogen) and APTT (activated clotting time live enzymes) and other indicators. Results Acute hepatitis B group compared with normal control group in the plasma PT,APTT,TT, FIB,there was no significant difference (P>0.05),no statistical significance. And chronic hepatitis B,liver cirrhosis group compared with normal control group,the plasma FIB content had the varying degree reduction (P<0.05),the significant differences had statistical significance;plasma PT,APTT,TT measurements had different levels of extended(P<0.05),the significant difference was statistically significant. Conclusion Blood coagulation function in patients with hepatitis B index changing with the illness and the abnormal change and dynamic detection of blood coagulation function indicators has help-guide to the patient's diagnosis ,treatment and prognosis judgement.%目的:探讨乙型肝炎及其肝硬化患者凝血功能动态检测的临床意义。方法收集182例乙肝患者(其中急性乙肝56例,慢性乙肝78例,肝硬化48例)和100例同期体检正常的对照者血浆进行检测。采用日本sysmex ca7000全自动血凝仪及配套试剂,检测:PT(血浆凝血酶原时间)、TT(凝血酶时间)、FIB(纤维蛋白原的含量)和APTT(活化部分凝血活酶时间)等指标。结果急性乙肝组与正常对照组相比,血浆PT、APTT、TT、FIB差异无显著性(P>0.05),无统计

  10. Analysis of clot formation with acoustic radiation force

    Science.gov (United States)

    Viola, Francesco; Longo, Diane M.; Lawrence, Michael B.; Walker, William F.

    2002-04-01

    Inappropriate blood coagulation plays an important role in diseases including stroke, heart attack, and deep vein thrombosis (DVT). DVT arises when a blood clot forms in a large vein of the leg. DVT is detrimental because the blood flow may be partially or completely obstructed. More importantly, a potentially fatal situation may arise if part of the clot travels to the arteries in the lungs, forming a pulmonary embolism (PE). Characterization of the mechanical properties of DVT could improve diagnosis and suggest appropriate treatment. We are developing a technique to assess mechanical properties of forming thrombi. The technique uses acoustic radiation force as a means to produce small, localized displacements within the sample. Returned ultrasound echoes are processed to estimate the time dependent displacement of the sample. Appropriate mechanical modeling and signal processing produce plots depicting relative mechanical properties (relative elasticity and relative viscosity) and force-free parameters (time constant, damping ratio, and natural frequency). We present time displacement curves of blood samples obtained during coagulation, and show associated relative and force-free parameter plots. These results show that the Voigt model with added mass accurately characterizes blood behavior during clot formation.

  11. Randomized Comparison of the Therapeutic Effect of Acupuncture, Massage, and Tachibana-Style-Method on Stiff Shoulders by Measuring Muscle Firmness, VAS, Pulse, and Blood Pressure

    Directory of Open Access Journals (Sweden)

    Kazuhiro Tachibana

    2012-01-01

    Full Text Available To compare the therapeutic efficacy of acupuncture, massage, and Tachibana-Ryojutsu (one of Japanese traditional body balance therapy techniques (SEITAI, on stiff shoulders, the subjects’ muscle firmness, blood pressure, pulse, VAS, and body temperature were measured before and after the treatment. Forty-seven volunteer subjects gave written informed consent to participate in this study. The subjects were randomly divided into three groups to receive acupuncture, massage, or Tachibana-Ryojutsu. Each therapy lasted for 90 seconds. The acupuncture treatment was applied by a retaining-needle at GB-21, massage was conducted softly on the shoulders, and Tachibana-Ryojutsu treated only the muscles and joints from the legs to buttocks without touching the shoulders or backs. The study indicated that the muscle firmness and VAS of the Tachibana-Ryojutsu group decreased significantly in comparison with the acupuncture and massage groups after treatment.

  12. Inherited Control and Firm Performance

    OpenAIRE

    Francisco Pérez-González

    2006-01-01

    I use data from chief executive officer (CEO) successions to examine the impact of inherited control on firms? performance. I find that firms where incoming CEOs are related to the departing CEO, to a founder, or to a large shareholder by either blood or marriage underperform in terms of operating profitability and market-to-book ratios, relative to firms that promote unrelated CEOs. Consistent with wasteful nepotism, lower performance is prominent in firms that appoint family CEOs who did no...

  13. Effects observation of Yaokang capsule to decrease pain caused by blood clotting prolapse of lower back intervertebral disc%腰康胶囊减轻淤血性腰椎间盘突出症痛痛的疗效观察

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Background:The prolapse of the lower back intervertebral disc is a common clinical disease,the national research of recent years found that non-operation methods were important in treating the prolapse of the intervertebral discs,especially the Chinese medicine has significant effects.Yaokang capsule is made from 7 herbs as Earth worm, Frankincense and Myrrh etc it used on blood clotting prolapse of lower back intervertebral disc and satisfactory effects were achieved. Objective:To discuss the treating effects of Yaokang capsule to decrease pain caused by blood clotting prolapse of lower back intervertebral disc. Design:100 cases of prolapse of lower back intervertebral disc were randomly divided into treating group and control group.There was no difference of ages,sexes and complications between the two groups(P< 0.05).The treating effects were determined according to the scoring methods of Chinese medicine and related standards, Chi-squared test was used in statistics. Unit: Anyang District Hospital of Puyang City.

  14. Fibrinogen concentrate improves clot strength in patients with haematological malignancies requiring platelet transfusion

    DEFF Research Database (Denmark)

    Munk-Andersen, H; Schenk, B; Larsen, O H;

    2016-01-01

    BACKGROUND: Patients with bone marrow failure secondary to chemotherapy often develop thrombocytopenia and require platelet transfusion. Fibrinogen plays an important role in platelet aggregation and the establishment of the primary haemostatic plug. OBJECTIVES: To compare the effects of in vivo...... platelet transfusion on clot firmness in thrombocytopenic patients with in vitro-performed fibrinogen concentrate substitution. MATERIALS AND METHODS: Thirty patients with haematological malignancy admitted for platelet transfusion were included. Haemostatic effects from platelet transfusion and ex vivo...... addition of fibrinogen concentrate at three different doses were evaluated by thromboelastometry, with clot firmness as the primary endpoint (A30 ExTEM assay). Secondary endpoints were other thromboelastometry parameters, thrombin generation parameters, activated partial thromboplastin time (APTT...

  15. What Are Rare Clotting Factor Deficiencies?

    Science.gov (United States)

    ... Pictures Young Voices Compendium of Assessment Tools Educational Games Video Library Find a Treatment Centre Haemophilia Journal About Bleeding Disorders Bleeding Disorders The Clotting Process Drugs That Can Cause Bleeding Hemophilia How Do You ...

  16. Fractal dimension (df) as a new structural biomarker of clot microstructure in different stages of lung cancer.

    Science.gov (United States)

    Davies, Nia Anne; Harrison, Nicholas Kim; Morris, Roger H Keith; Noble, Simon; Lawrence, Matthew James; D'Silva, Lindsay Antonio; Broome, Laura; Brown, Martin Rowan; Hawkins, Karl M; Williams, Phylip Rhodri; Davidson, Simon; Evans, Phillip Adrian

    2015-11-25

    Venous thromboembolism (VTE) is common in cancer patients, and is the second commonest cause of death associated with the disease. Patients with chronic inflammation, such as cancer, have been shown to have pathological clot structures with modulated mechanical properties. Fractal dimension (df) is a new technique which has been shown to act as a marker of the microstructure and mechanical properties of blood clots, and can be performed more readily than current methods such as scanning electron microscopy (SEM). We measured df in 87 consecutive patients with newly diagnosed lung cancer prior to treatment and 47 matched-controls. Mean group values were compared for all patients with lung cancer vs controls and for limited disease vs extensive disease. Results were compared with conventional markers of coagulation, fibrinolysis and SEM images. Significantly higher values of df were observed in lung cancer patients compared with controls and patients with extensive disease had higher values than those with limited disease (p< 0.05), whilst conventional markers failed to distinguish between these groups. The relationship between df of the incipient clot and mature clot microstructure was confirmed by SEM and computational modelling: higher df was associated with highly dense clots formed of smaller fibrin fibres in lung cancer patients compared to controls. This study demonstrates that df is a sensitive technique which quantifies the structure and mechanical properties of blood clots in patients with lung cancer. Our data suggests that df has the potential to identify patients with an abnormal clot microstructure and greatest VTE risk.

  17. Influence of styptic fiber on clotting time in rabbits

    Institute of Scientific and Technical Information of China (English)

    LU Jun; JIANG Su-yun

    2008-01-01

    Objective To explore the influence of styptic fiber on clotting time in rabbits so as to provide experiment data for its development. Methods Onto 0.1 mL aliquots of citrated anti-coagulant rabbit blood placed in a surfacial plate 25 ul of 0.2 mol·L-1 CaCl2 solution was dropped, and mixed well with glass stirrer;the resulting mixture was immediately capped with a piece of styptic fiber (test product group) or absorptive gelatin sponge(positive control group) of 2 cm diameter. Then, the surficial plate was rinsed with 30ml of purified water at 5, 10, 20, 30, 40 and 50 min after capping; the rinsings were allowed to stand for 1 h and were subjected to OD determination at a wavelength of 541 nm. The above procedure was repeated twice, the average value of the twice experiments was taken for evaluation of the hemostatic effect of test product. For negative control group, all procedures except for capping were same as the test product group. The haemostatic effect was judged by percent OD relative to OD at 0 min in negative control group (OD 0 min) (OD 0 min was considered as 100% );if OD value at a time was less than 80% of OD 0 min, it should be designated as primary clotting time(PCT), less than 20 96 as complete clotting time(CCT). Results The measured PCT was 20min for both negative and positive control groups;CCT was 50, 30 and 5 min for negative control, positive control and test product groups, respectively, showing the test styptic fiber had a CCT 8 times shorter than untreated blood, 10 times shorter than negative control and 6 times shorter than positive control. Conclusions The test styptic fiber has powerful hemostatic effect.

  18. Evaluation of the effects of levobupivacaine on clotting and fibrinolysis using thromboelastography.

    LENUS (Irish Health Repository)

    Leonard, S A

    2012-02-03

    Amide local anaesthetics inhibit platelet function. We hypothesized that residual anaesthetic in the epidural space could decrease efficacy of an epidural blood patch in preventing postdural puncture headache. Levobupivacaine has recently been approved for epidural anaesthesia. Its effects on coagulation have not previously been studied. The aim of this study was to determine the effects of levobupivacaine on clotting using thromboelastography. Ten ASA Class I volunteers were studied. Venous blood samples were analysed using a Haemoscope 2000D TEG analyser. Whole blood, a 50% saline control and two levobupivacaine solutions (2.5 mg mL(-1) and 2.5 microg mL(-1) in blood) were compared. The former reproduces that produced in the epidural space by blood (20 mL for an epidural blood patch) and levobupivacaine 0.5% (20 mL). The latter approximates plasma concentrations following epidural injection of levobupivacaine 0.5% (20 mL). P < 0.05 was considered significant. Maximum amplitude (MA), a measure of clot strength, is decreased by levobupivacaine 2.5 mg mL(-1). Levobupivacaine 2.5 mg mL(-1) decreases clot strength and may reduce efficacy of a prophylactic epidural blood patch.

  19. Fibrin clots keep non-adhering living cells in place on glass for perfusion or fixation.

    Science.gov (United States)

    Forer, Arthur; Pickett-Heaps, Jeremy

    2005-09-01

    We describe a method to hold living cells in place that ordinarily do not adhere to glass coverslips. The method, developed for insect spermatocytes but with application to other cell types, consists of embedding cells in a fibrin clot that forms after the enzyme thrombin cleaves the blood protein fibrinogen. The method permits continuous observation of living cells as they are treated with and recover from drug or other treatments: when held in the clot the living cells remain in place and keep their shapes when perfused with drugs that ordinarily cause drastic shape changes, and they remain in place and keep their shapes through lysis/fixation procedures. We describe how to place live cells in a fibrin clot and how subsequently to perfuse them. PMID:16095930

  20. Tranexamic acid combined with recombinant factor VIII increases clot resistance to accelerated fibrinolysis in severe hemophilia A

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Sørensen, Hanne Thykjær; Norengaard, Lisbeth;

    2007-01-01

    BACKGROUND: Most patients with severe hemophilia A suffer from a profoundly compromised hemostatic response. In addition to both the delayed and slow development of a clot, previous studies have documented that severe hemophilia A is also associated with reduced clot stability. OBJECTIVES: We...... examined whether the clot stability in hemophiliacs could be improved by treatment with tranexamic acid (TXA) in combination with recombinant factor VIII (rFVIII). PATIENTS/METHODS: Baseline blood samples were obtained from eight males with severe hemophilia A. Thereafter, a bolus injection of r...... the elasticity curve increased 5-fold after rFVIII and 24-fold after addition of TXA. CONCLUSIONS: The study demonstrates that simultaneous treatment with TXA and rFVIII significantly improves the clot stability in patients with hemophilia A. Udgivelsesdato: December...

  1. Transfusion packages for massively bleeding patients: the effect on clot formation and stability as evaluated by Thrombelastograph (TEG)

    DEFF Research Database (Denmark)

    Johansson, Per Ingemar; Bochsen, L.; Stensballe, J.;

    2008-01-01

    We investigated the effect of administering a transfusion package encompassing 5 red blood cells (RBC), 5 fresh frozen plasma (FFP), and 2 platelet concentrates (PC) on clot formation and stability as evaluated by Thrombelastograph (TEG) in 10 patients presenting with massive bleeding. Blood...

  2. Blood in the semen

    Science.gov (United States)

    ... by swelling or infection of the prostate or seminal vesicles. The problem may occur after a prostate biopsy . ... blood and if any clots formed in the seminal vesicles. Depending on the cause, other symptoms that may ...

  3. Brillouin spectroscopy of clotting dynamics in a model system

    Science.gov (United States)

    Bustamante-Lopez, Sandra C.; Traverso, Andrew J.; Yakovlev, Vladislav V.; Meissner, Kenith E.

    2016-02-01

    Keys to successful treatment of disease include early diagnosis and timely treatment. It is hypothesized that early clotting events may contribute to a pro-thrombotic state that exacerbates atherothrombotic vascular disease. Brillouin spectroscopy involves inelastic coupling of light with phonons and enables viscoelastic characterization of samples at the microscale. In this work, we apply Brillouin spectroscopy to a model fibrinogen-thrombin clotting system with the goal of measuring clotting dynamics at the microscale and providing characterization that is not possible with standard rheometric techniques. Here, the clotting dynamics of the model clotting system are measured at various fibrinogen and thrombin concentrations.

  4. The Influence of a Micropolar Fluid on Peristaltic Transport in an Annulus: Application of the Clot Model

    Directory of Open Access Journals (Sweden)

    Kh. S. Mekheimer

    2008-01-01

    Full Text Available A serious pathological condition is encountered when some blood constituents deposited on the blood vessels get detached from the wall, join the blood stream again and form a clot. Study of the peristaltic transport of a micropolar fluid in an annular region is investigated under low Reynolds number and long wavelength approximations. We model a small artery as a tube having a sinusoidal wave travelling down its wall and a clot model inside it. Closed form solutions are obtained for the velocity and the microrotation components, as well as the stream function, and they contain new additional parameters, namely, δ, the height of the clot, N, the coupling number and m, the micropolar parameter. The pressure rise and friction force on the inner and the outer tubes have been discussed for various values of the physical parameters of interest.

  5. Do some of physiotherapy and rehabilitation programs improve the health state of patients suffering from cerebral clot?

    Directory of Open Access Journals (Sweden)

    Ayad OMAR

    2014-09-01

    Full Text Available Cerebral stroke represents one of the most important diseases resulting from blood clot in the middle cerebral artery, this is due to atherosclerotic clot and the brain has area of deprived blood , therefore blood becomes unable to pass the clot, in this case leads to total or partial paralysis. Rehabilitation programs are one of the most effective therapies for cerebral stroke. These pr ograms include rehabilitation exercises, therapeutic massage and kinet otherapy. The present study deals with the application of organized rehabilitation program and identify it's effect on the movement system and joints. This study examined the effect of rehabilitation program to improve the efficiency of the Locomotor system of patient who complain of cerebral stroke.

  6. Heparin Therapy during Extracorporeal Circulation: Deriving an Optimal Activated Clotting Time during Cardiopulmonary Bypass for Isolated Coronary Artery Bypass Grafting

    OpenAIRE

    Palmer, Kenneth; Ridgway, Tim; Al-Rawi, Omar; Poullis, Michael

    2012-01-01

    Bull’s seminal work on heparin therapy during cardiopulmonary bypass (CPB) was carried out over 30 years ago and has not been updated in the modern era. No correlation with postoperative blood loss was performed. The optimal activated clotting time (ACT) with regard to blood loss has not been established for patients undergoing CPB. A minimum ACT of 400 is based on the lack of visible formation of clots in the CPB circuit. The effect of heparin dose, sensitivity, metabolism, patient size, ele...

  7. {sup 99m}Tc-NC100668, a new tracer for imaging venous thromboemboli: pre-clinical biodistribution and incorporation into plasma clots in vivo and in vitro

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, David [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden); Lewis, Joanne; Battle, Mark; Lear, Rochelle; Farrar, Gill; Barnett, D.J.; Godden, Vanessa; Oliveira, Alexandra; Coombes, Catherine [Grove Centre, Research and Development, GE Healthcare Bio-Sciences, Little Chalfont (United Kingdom); Ahlstroem, Haakan [Uppsala University Hospital, Institution of Oncology, Radiology and Clinical Immunology, Section of Radiology, Uppsala (Sweden)

    2006-11-15

    {sup 99m}Tc-NC100668 is a new radiotracer being developed to aid the diagnosis of thromboembolism. The structure of NC100668 is similar to a region of human {alpha}{sub 2}-antiplasmin, which is a substrate for factor XIIIa (FXIIIa). The purpose of this study was to confirm the uptake of {sup 99m}Tc-NC100668 into forming plasma clot and to establish the biodistribution of {sup 99m}Tc-NC100668 in Wistar rats. The in vitro plasma clot uptake of {sup 99m}Tc-NC100668 and other compounds with known affinities to FXIIIa was measured using a plasma clot assay. The biodistribution and blood clot uptake of radioactivity of {sup 99m}Tc-NC100668 in normal Wistar rats and those bearing experimentally induced deep vein thrombi were investigated. The in vitro uptake of {sup 99m}Tc-NC100668 was greater than that for [{sup 14}C]dansyl cadaverine, a known substrate of FXIIIa in the plasma clot assay. The biodistribution of {sup 99m}Tc-NC100668 in male and female Wistar rats up to 24 h p.i. showed that radioactivity was rapidly excreted, predominantly into the urine, with very little background tissue retention. In vivo the uptake and retention of {sup 99m}Tc-NC100668 into the blood clot was greater than could be accounted for by non-specific accumulation of the radiotracer within the blood clot. {sup 99m}Tc-NC100668 was retained by plasma clots in vitro and blood clots in vivo. No significant tissue retention which could interfere with the ability to image thrombi in vivo was observed. This evidence suggests that {sup 99m}Tc-NC100668 might be useful in the detection of thromboembolism. (orig.)

  8. Influence of open surgical and endovascular abdominal aortic aneurysm repair on clot quality assessed by ROTEM® test

    Directory of Open Access Journals (Sweden)

    Šarac Momir

    2016-01-01

    Full Text Available Introduction/Aim. The disturbances in hemostasis are often in open surgical repair (OR and endovascular repair (EVAR of an abdominal aortic aneurysm (AAA. These changes may influence the perioperative and early postoperative period inducing serious complications. The aim of this study was to compare the impact of OR and EVAR of AAA on clot quality assessed by rotational thromboelastometry (ROTEM® tests. Methods. The study included 40 patients who underwent elective AAA surgery and were devided into two groups (the OR and the EVAR group - 20 patients in each group. The ROTEM ® test was performed in 4 points: point 1 - 10 min before starting anesthesia in both groups; point 2 - 10 min after aortic clapming in the OR group and 10 min after the stent-graft trunk release in the EVAR group; point 3 - 10 min after the releasing of aortic clamp in the OR group and 10 min after stentgraft placement and releasing the femoral clamp in the EVAR group; point 4 - one hour after the procedure in both groups. Three ROTEM® tests were performed as: extrinsically activated assay with tissue factor (EXTEM, intrinsically activated test using kaolin (INTEM, and extrinsically activated test with tissue factor and the platelet inhibitor cytochalasin D (FIBTEM. All tests included the assessment of the maximum clot firmness (MCF and the platelet component of clot strength was presented as maximal clot elasticity (MCE. Results. No significant difference in age, gender and diameter of AAA between groups was found. The time required for the procedure was significantly longer and loss of blood was greater in the OR group than in the EVAR group (p < 0.001. The significant deviation of MCF values in EXTEM test was found mainly in the point 3 (p ≤ 0.004 with significant difference between groups (p < 0.001. A significant difference of MCF values in INTEM test between groups was found in the points 3 and 4 (p < 0.001, which were dose-dependent by heparin sulfate. The MCF

  9. Changes in clot lysis levels of reteplase and streptokinase following continuous wave ultrasound exposure, at ultrasound intensities following attenuation from the skull bone

    Directory of Open Access Journals (Sweden)

    Roijer Anders

    2008-08-01

    Full Text Available Abstract Background Ultrasound (US has been used to enhance thrombolytic therapy in the treatment of stroke. Considerable attenuation of US intensity is however noted if US is applied over the temporal bone. The aim of this study was therefore to explore possible changes in the effect of thrombolytic drugs during low-intensity, high-frequency continuous-wave ultrasound (CW-US exposure. Methods Clots were made from fresh venous blood drawn from healthy volunteers. Each clot was made from 1.4 ml blood and left to coagulate for 1 hour in a plastic test-tube. The thrombolytic drugs used were, 3600 IU streptokinase (SK or 0.25 U reteplase (r-PA, which were mixed in 160 ml 0.9% NaCl solution. Continuous-wave US exposure was applied at a frequency of 1 MHz and intensities ranging from 0.0125 to 1.2 W/cm2. For each thrombolytic drug (n = 2, SK and r-PA and each intensity (n = 9 interventional clots (US-exposed, n = 6 were submerged in thrombolytic solution and exposed to CW-US while control clots (also submerged in thrombolytic solution, n = 6 were left unexposed to US. To evaluate the effect on clot lysis, the haemoglobin (Hb released from each clot was measured every 20 min for 1 hour (20, 40 and 60 min. The Hb content (mg released was estimated by spectrophotometry at 540 nm. The difference in effect on clot lysis was expressed as the difference in the amount of Hb released between pairs of US-exposed clots and control clots. Statistical analysis was performed using Wilcoxon's signed rank test. Results Continuous-wave ultrasound significantly decreased the effects of SK at intensities of 0.9 and 1.2 W/cm2 at all times (P 2 and at 1.2 W/cm2, following 40 min exposure at 0.3, 0.6, 0.9 and at 1.2 W/cm2, and following 60 min of exposure at 0.05 0.3, 0.6, 0.9 and at 1.2 W/cm2 (all P Conclusion Increasing intensities of CW-US exposure resulted in increased clot lysis of r-PA-treated blood clots, but decreased clot lysis of SK-treated clots.

  10. Thrombin-Accelerated Quick Clotting Serum Tubes: An Evaluation with 22 Common Biochemical Analytes

    Directory of Open Access Journals (Sweden)

    Wai-Yoong Ng

    2013-01-01

    Full Text Available Clot activator serum tubes have significantly improved turnaround times for result reporting compared to plain tubes. With increasing workload and service performance expectations confronting clinical laboratories with high-volume testing and with particular emphasis on critical analytes, attention has focussed on preanalytical variables that can be improved. We carried out a field study on the test performance of BD vacutainer rapid serum tubes (RSTs compared to current institutional issued BD vacutainer serum separator tubes (SSTs in its test result comparability, clotting time, and stability on serum storage. Data from the study population (n=160 of patients attending outpatient clinics and healthy subjects showed that results for renal, liver, lipids, cardiac, thyroid, and prostate biochemical markers were comparable between RSTs and SSTs. Clotting times of the RSTs were verified to be quick with a median time of 2.05 min. Analyte stability on serum storage at 4°C showed no statistically significant deterioration except for bicarbonate, electrolytes, and albumin over a period of 4 days. In conclusion, RSTs offered savings in the time required for the clotting process of serum specimens. This should translate to further trimming of the whole process from blood collection to result reporting without too much sacrifice on test accuracy and performance compared to the current widely used SSTs in most clinical laboratories.

  11. A comparative study of tissue factor and kaolin on blood coagulation assays using rotational thromboelastometry and thromboelastography.

    Science.gov (United States)

    Peng, Henry T; Grodecki, Richard; Rizoli, Sandro; Shek, Pang N

    2016-01-01

    Rotational thromboelastometry (ROTEM) and thromboelastography (TEG) have been increasingly used to diagnose acute coagulopathy and guide blood transfusion. The tests are routinely performed using different triggering activators such as tissue factor and kaolin, which activate different pathways yielding different results. To optimize the global blood coagulation assays using ROTEM and TEG, we conducted a comparative study on the activation methods employing tissue factor and kaolin at different concentrations as well as standard reagents as recommended by the manufacturer of each device. Key parameter values were obtained at various assay conditions to evaluate and compare coagulation and fibrinolysis profiles of citrated whole blood collected from healthy volunteers. It was found that tissue factor reduced ROTEM clotting time and TEG R, and increased ROTEM clot formation time and TEG K in a concentration-dependent manner. In addition, tissue factor affected ROTEM alpha angle, and maximum clot firmness, especially in the absence of kaolin activation, whereas both ROTEM and TEG clot lysis (LI30, CL30, and LY30) remained unaffected. Moreover, kaolin reduced ROTEM clotting time and TEG R and K, but to a lesser extent than tissue factor, in-tem and ex-tem. Correlations in all corresponding parameters between ROTEM and TEG were observed, when the same activators were used in the assays compared with lesser correlations between standard kaolin TEG and ROTEM (INTEM/EXTEM). The two types of viscoelastic point-of-care devices provide different results, depending on the triggering reagent used to perform the assay. Optimal assay condition was obtained to reduce assay time and improve assay accuracy. PMID:26340454

  12. Identification of quantitative trait loci for fibrin clot phenotypes: the EuroCLOT study

    DEFF Research Database (Denmark)

    Williams, Frances M K; Carter, Angela M; Kato, Bernet;

    2009-01-01

    OBJECTIVE: Fibrin makes up the structural basis of an occlusive arterial thrombus, and variability in fibrin phenotype relates to cardiovascular risk. The aims of the current study from the EU consortium EuroCLOT were to (1) determine the heritability of fibrin phenotypes and (2) identify QTLs as...

  13. Platelets and fibrin strands during clot retraction.

    Science.gov (United States)

    Morgenstern, E; Korell, U; Richter, J

    1984-03-15

    The ultrastructure of platelet fibrin contacts (PFC) and the course of the strands was investigated in serial sections of retracted clots with the help of specimen tilting. We found after retraction in a test tube as well as under isometric conditions in the resonance thrombograph, after HARTERT, an uniform type of PFC. The side to side contact between platelet surface and fibrin strands displayed a 15 nm wide space which was bridged of 10 - 30 nm by filamentary structure. In each case the direction of the fibrin strands changed on contact with the platelet surface (bend). These bends recurred if the adhering strands ran over a longer distance on the platelet surface. The bends can be explained by non-directional movement of the platelets or of their pseudopodia. Microfilaments (actomyosin) which run straight in pseudopodia and often also twisted in the platelet body support this assumption. The described mechanism - contact of the thrombin activated platelets with fibrin strands and simultaneous nondirectional movement of the platelets which bind further sections of the adhering strands to their surface - would provide a more satisfactory explanation for the retraction of the clot to 1/10 of its original volume. PMID:6539004

  14. Efficacy and spatial distribution of ultrasound-mediated clot lysis in the absence of thrombolytics.

    Science.gov (United States)

    Ammi, Azzdine Y; Lindner, Jonathan R; Zhao, Yan; Porter, Thomas; Siegel, Robert; Kaul, Sanjiv

    2015-06-01

    Ultrasound and microbubble (MB) contrast agents accelerate clot lysis, yet clinical trials have been performed without defining optimal acoustic conditions. Our aim was to assess the effect of acoustic pressure and frequency on the extent and spatial location of clot lysis. Clots from porcine blood were created with a 2-mm central lumen for infusion of lipid-shelled perfluorocarbon MBs (1×10(7) ml(-1)) or saline. Therapeutic ultrasound at 0.04, 0.25, 1.05, or 2.00 MHz was delivered at a wide range of peak rarefactional acoustic pressure amplitudes (PRAPAs). Ultrasound was administered over 20 minutes grouped on-off cycles to allow replenishment of MBs. The region of lysis was quantified using contrast-enhanced ultrasound imaging. In the absence of MBs, sonothrombolysis did not occur at any frequency. Sonothrombolysis was also absent in the presence of MBs despite their destruction at 0.04 and 2.00 MHz. It occurred at 0.25 and 1.05 MHz in the presence of MBs for PRAPAs > 1.2 MPa and increased with PRAPA. At 0.25 MHz the clot lysis was located in the far wall. At 1.05 MHz, however, there was a transition from far to near wall as PRAPA was increased. The area of clot lysis measured by ultrasound imaging correlated with that by micro-CT and quantification of debris in the effluent. In conclusion, sonothrombolysis with MBs was most efficient at 0.25 MHz. The spatial location of sonothrombolysis varies with pressure and frequency indicating that the geometric relation between therapeutic probe and vascular thrombosis is an important variable for successful lysis clinically. PMID:25809056

  15. Influence of Interleukin-1 Beta on Platelet-Poor Plasma Clot Formation: A Potential Impact on Early Bone Healing.

    Directory of Open Access Journals (Sweden)

    Xin Wang

    Full Text Available Hematoma quality (especially the fibrin matrix plays an important role in the bone healing process. Here, we investigated the effect of interleukin-1 beta (IL-1β on fibrin clot formation from platelet-poor plasma (PPP.Five-milliliter of rat whole-blood samples were collected from the hepatic portal vein. All blood samples were firstly standardized via a thrombelastograph (TEG, blood cell count, and the measurement of fibrinogen concentration. PPP was prepared by collecting the top two-fifths of the plasma after centrifugation under 400 × g for 10 min at 20°C. The effects of IL-1β cytokines on artificial fibrin clot formation from PPP solutions were determined by scanning electronic microscopy (SEM, confocal microscopy (CM, turbidity, and clot lysis assays.The lag time for protofibril formation was markedly shortened in the IL-1β treatment groups (243.8 ± 76.85 in the 50 pg/mL of IL-1β and 97.5 ± 19.36 in the 500 pg/mL of IL-1β compared to the control group without IL-1β (543.8 ± 205.8. Maximal turbidity was observed in the control group. IL-1β (500 pg/mL treatment significantly decreased fiber diameters resulting in smaller pore sizes and increased density of the fibrin clot structure formed from PPP (P < 0.05. The clot lysis assay revealed that 500 pg/mL IL-1β induced a lower susceptibility to dissolution due to the formation of thinner and denser fibers.IL-1β can significantly influence PPP fibrin clot structure, which may affect the early bone healing process.

  16. Your Guide to Preventing and Treating Blood Clots

    Science.gov (United States)

    ... Clinical Preventive Services Clinical Decision Support U.S. Preventive Services Task Force Improving Primary Care Practice Health IT Integration Health Care/System Redesign Clinical-Community Linkages Care ...

  17. New polymorphic variants of human blood clotting factor IX

    Energy Technology Data Exchange (ETDEWEB)

    Surin, V.L.; Luk`yanenko, A.V.; Tagiev, A.F.; Smirnova, O.V. [Hematological Research Center, Moscow (Russian Federation); Plutalov, O.V.; Berlin, Yu.A. [Shemyakin Institute of Bioorganic Chemistry, Moscow (Russian Federation)

    1995-04-01

    The polymorphism of Alu-repeats, which are located in the introns of the human factor IX gene (copies 1-3), was studied. To identify polymorphic variants, direct sequencing of PCR products that contained appropriate repeats was used. In each case, 20 unrelated X chromosomes were studied. A polymorphic Dra I site was found near the 3{prime}-end of Alu copy 3 within the region of the polyA tract. A PCR-based testing system with internal control of restriction hydrolysis was suggested. Testing 81 unrelated X chromosomes revealed that the frequency of the polymorphic Dra I site is 0.23. Taq I polymorphism, which was revealed in Alu copy 4 of factor IX gene in our previous work, was found to be closely linked to Dra I polymorphism. Studies in linkage between different types of polymorphisms of the factor IX gene revealed the presence of a rare polymorphism in intron a that was located within the same minisatellite region as the known polymorphic insertion 50 bp/Dde I. However, the size of the insertion in our case was 26 bp. Only one polymorphic variant was found among over 150 unrelated X chromosomes derived from humans from Moscow and its vicinity. 10 refs., 4 figs., 1 tab.

  18. ICT, Complementary Firm Strategies and Firm Performance

    OpenAIRE

    Rasel, Fabienne

    2016-01-01

    This doctoral thesis analyses from different perspectives the relationship between information and communication technologies (ICT), complementary firm strategies and firm performance. One chapter examines the role of ICT and decentralized workplace organization for productivity. Two chapters analyse the association between firms' ICT use, international trade activities and productivity. The empirical analyses are based on data from firms located in Germany from the manufacturing or service s...

  19. 21 CFR 173.150 - Milk-clotting enzymes, microbial.

    Science.gov (United States)

    2010-04-01

    ... HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.150 Milk-clotting enzymes, microbial... of cheese in accordance with the following prescribed conditions: (a) Milk-clotting enzyme is derived... minimum required to produce its intended effect in the production of those cheeses for which it...

  20. Globalization and Multiproduct Firms

    OpenAIRE

    Nocke, Volker; Yeaple, Stephen

    2013-01-01

    We present an international trade model of multiproduct firms where firms differ in their endowment of managerial resources and in how effectively these resources can be used in making production more efficient. The model gives rise to a trade-off between conglomerate and specialization strategies of firms, yielding testable predictions on the relationship between firm size, scope and productivity. More efficient firms become exporters, but not all exporters are large and not all large firms ...

  1. Strong Firms Lobby, Weak Firms Bribe

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Feldmann, Sven E.; Lassen, David Dreyer

    We use survey responses by firms to examine the firm-level determinants and effects of political influence, their perception of corruption and prevalence of bribe paying. We find that: (a) measures of political influence and corruption/bribes are uncorrelated at the firm level; (b) firms...... that are larger, older, exporting, government-owned, are widely held and/or have fewer competitors, have more political influence, perceive corruption to be less of a problem and pay bribes less often; (c) influence increases sales and government subsidies and in general makes the firm have a more positive view...

  2. Specialized proresolving lipid mediators in patients with coronary artery disease and their potential for clot remodeling.

    Science.gov (United States)

    Elajami, Tarec K; Colas, Romain A; Dalli, Jesmond; Chiang, Nan; Serhan, Charles N; Welty, Francine K

    2016-08-01

    Inflammation in arterial walls leads to coronary artery disease (CAD). Because specialized proresolving lipid mediators (SPMs; lipoxins, resolvins, and protectins) stimulate resolution of inflammation in animal models, we tested whether n-3 fatty acids impact SPM profiles in patients with CAD and promote clot remodeling. Six patients with stable CAD were randomly assigned to either treatment with daily 3.36 g Lovaza for 1 yr or without. Targeted lipid mediator-metabololipidomics showed that both groups had absence of resolvin D1 (RvD1), RvD2, RvD3, RvD5 and resolvin E1-all of which are present in healthy patients. Those not taking Lovaza had an absence of aspirin-triggered resolvin D3 (AT-RvD3) and aspirin-triggered lipoxin B4 (AT-LXB4). Lovaza treatment restored AT-RvD3 and AT-LXB4 and gave levels of RvD6 and aspirin-triggered protectin D1 (AT-PD1) twice as high (resolvin E2 ∼5 fold) as well as lower prostaglandins. Principal component analysis indicated positive relationships for patients with CAD who were receiving Lovaza with increased AT-RvD3, RvD6, AT-PD1, and AT-LXB4 SPMs identified in Lovaza-treated patients with CAD enhanced ∼50% at 1 nM macrophage uptake of blood clots. These results indicate that patients with CAD have lower levels and/or absence of specific SPMs that were restored with Lovaza; these SPMs promote macrophage phagocytosis of blood clots. Together, they suggest that low vascular SPMs may enable progression of chronic vascular inflammation predisposing to coronary atherosclerosis and to thrombosis.-Elajami, T. K., Colas, R. A., Dalli, J., Chiang, N., Serhan, C. N., Welty, F. K. Specialized proresolving lipid mediators in patients with coronary artery disease and their potential for clot remodeling. PMID:27121596

  3. What Is Combined Deficiency of Vitamin K-Dependent Clotting Factors?

    Science.gov (United States)

    ... Pool Deficiencies Home About Bleeding Disorders What is combined deficiency of vitamin K-dependent clotting factors? Inherited combined deficiency of the vitamin K-dependent clotting factors ( ...

  4. C-reactive protein prolongs blood coagulation time in phospholipids-dependent coagulation tests

    Directory of Open Access Journals (Sweden)

    L D Kozmin

    2003-01-01

    Full Text Available C-refctive protein prolongs blood coagulation time in phospholipids-dependent coagulation tests. O.P. Bliznukov, L.D. Kostin, A.J. Martinov, T.A. Lisitsina, T.M. Reshetnyak, V.J. Lauga Objective. To study influence of different CRP forms on blood clotting time in standard phospholipid clotting tests. Material and methods. Purified native CRP. monomeric CRP (0-1.6 M, immune complexes of native CRP and rabbit polyclonal anti-CRP antibodies (1.6 M were added to blood plasma of healthy donors. Blood clotting time was registered using optical coagulometer. Phospholipid dependent prothrombin time (PT, activated partial tromboplastin time (APTT, kaolin clotting time (KCT with kaolin and ellagic acid, dilute Russel viper venom time (dRVVT were determined. Results. Native CRP was able to increase blood clotting time in all mentioned clotting tests, excluding prothrombin time. CRP influence on blood clotting time showed a concentration dependence. Polyclonal rabbit anti-CRP antibodies had no inhibitory effect on CRP prolonged blood clotting time. Monomeric CRP (0-1.6 M had no influence on blood clotting time in all phospholipid-dependent clotting tests.

  5. Problems concerning ovine milk clotting aptitude

    Directory of Open Access Journals (Sweden)

    M. Martini

    2003-01-01

    Full Text Available A comparative study of the lactodynamographic parameters was carried out on ovine milk. Besides evaluating the repeatability and reproducibility of the analytical method, the influence of some variables such as the genetic type (three breeds, the kind of milk (whole or skimmed, and its concentration after reconstitution (12g or 20g /100 ml was evaluated. The working plan involved 6 laboratories for the final statistic analyses, by the use of freeze-dried milk samples (adequately reconstituted on the basis of established methods from Sardinia, Comisana, and Massese ewes. All the considered variability factors showed a highly significant effect (P<0.001 on the lactodynamographic parameters considered. In particular, Massese ewe milk showed the shortest curd speed (k20 and the best coagulum strength (a30 and a45, although clotting time (CT was the highest one. The same trend was registered for skimmed milk and for the most concentrated one (20g. Repeatability values within laboratories were 96% and 97% for CT and k20, lowering for a30 e a45, (respectively 87% and 85%. Much lower coefficients were found for the among laboratories reproducibility, ranging from a maximum of 58% for CT to a minimum of 18% for k20. The wide variability observed indicates that lactodynamographic parameters are comparable only within the same lab. Further investigation is needed to compare different labs in order to obtain more homogeneous results.

  6. Evaluation of ovine milk clotting aptitude

    Directory of Open Access Journals (Sweden)

    A. Caroli

    2010-01-01

    Full Text Available A comparative study of the lactodynamographic parameters was carried out on ovine milk. Besides evaluating the repeatability and reproducibility of the analytical method, the influence of some variables such as the genetic type (three breeds, the kind of milk (whole or skimmed, and its concentration after reconstitution (12g or 20g /100 ml was evaluated. The working plan involved 6 laboratories for the final statistic analyses, by the use of freeze-dried milk samples (adequately reconstituted on the basis of established methods from Sardinia, Comisana, and Massese ewes. All the considered variability factors showed a highly significant effect (P<0.001 on the lactodynamographic parameters considered. In particular, Massese ewe milk showed the shortest curd speed (k20 and the best coagulum strength (a30 and a45, although clotting time (CT was the highest one. The same trend was registered for skimmed milk and for the most concentrated one (20g. Repeatability values within laboratories were 96% and 97% for CT and k20, lowering for a30 e a45, (respectively 87% and 85%. Much lower coefficients were found for the among laboratories reproducibility, ranging from a maximum of 58% for CT to a minimum of 18% for k20. The wide variability observed indicates that lactodynamographic parameters are comparable only within the same lab. Further investigation is needed to compare different labs in order to obtain more homogeneous results.

  7. Tumour imaging by the detection of fibrin clots in tumour stroma using an anti-fibrin Fab fragment.

    Science.gov (United States)

    Obonai, Toshifumi; Fuchigami, Hirobumi; Furuya, Fumiaki; Kozuka, Naoyuki; Yasunaga, Masahiro; Matsumura, Yasuhiro

    2016-01-01

    The diagnosis of early and aggressive types of cancer is important for providing effective cancer therapy. Cancer-induced fibrin clots exist only within lesions. Previously, we developed a monoclonal antibody (clone 102-10) that recognizes insoluble fibrin but not fibrinogen or soluble fibrin and confirmed that fibrin clots form continuously in various cancers. Here, we describe the development of a Fab fragment probe of clone 102-10 for tumour imaging. The distribution of 102-10 Fab was investigated in genetically engineered mice bearing pancreatic ductal adenocarcinoma (PDAC), and its effect on blood coagulation was examined. Immunohistochemical and ex vivo imaging revealed that 102-10 Fab was distributed selectively in fibrin clots in PDAC tumours 3 h after injection and that it disappeared from the body after 24 h. 102-10 Fab had no influence on blood coagulation or fibrinolysis. Tumour imaging using anti-fibrin Fab may provide a safe and effective method for the diagnosis of invasive cancers by detecting fibrin clots in tumour stroma.

  8. Clotting mechanism in beagles irradiated by 4.5 Gy γ-rays

    International Nuclear Information System (INIS)

    Objective: To explore the clotting mechanism in beagles irradiated by 4.5 Gy γ-rays after treatment with supportive care, or supportive care and combined cytokines. Methods: Sixteen beagles were divided into irradiation control group, Supportive care group and combined cytokines treatment group. Platelet aggregation test, thrombelastography (TEG) and the time measurement were analyzed in vitro. Results: In irradiation group and supportive care group, the platelet aggregation rates in beagles were decreased markedly and the k value of TEG was increased 7 d post-irradiation, while those indexes in combined cytokines treatment group changed little. At 14 d post-irradiation, each parameter of TEG in irradiated group changed obviously. The values of r, k, r + k and M were elevated significantly, clotting time and the maximum coagulation time of thrombus delayed, the Ma value was decreased markedly, and the maximum elasticity amplitude of thrombus was diminished. All parameters in combined cytokines treatment group were better than those in supportive care group. The thrombin time was prolonged obviously in irradiated group 14 d post-irradiation, while the thrombin time was the longest at 2-3 weeks post irradiation in supportive care group and combined cytokines treatment group (P>0.05). Conclusions: Cytokines could improve the platelet aggregation and the blood clotting functions of beagles suffering from acute radiation sickness. (authors)

  9. Foreign Firms, Domestic Wages

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Markusen, James R.; Schjerning, Bertel

    Foreign-owned firms are often hypothesized to generate productivity "spillovers" to the host country, but both theoretical micro-foundations and empirical evidence for this are limited. We develop a heterogeneous-firm model in which ex-ante identical workers learn from their employers in proportion...... to the firm?s productivity. Foreign-owned firms have, on average, higher productivity in equilibrium due to entry costs, which means that low-productivity foreign firms cannot enter. Foreign firms have higher wage growth and, with some exceptions, pay higher average wages, but not when compared to similarly...... large domestic firms. The empirical implications of the model are tested on matched employer-employee data from Denmark. Consistent with the theory, we find considerable evidence of higher wages and wage growth in large and/or foreign-owned firms. These effects survive controlling for individual...

  10. Clotting of mammalian fibrinogens by papain: A re-examination

    OpenAIRE

    Doolittle, RF

    2014-01-01

    © 2014 American Chemical Society. Papain has long been known to cause the gelation of mammalian fibrinogens. It has also been reported that papain-fibrin is insoluble in dispersing solvents like strong urea or sodium bromide solutions, similar to what is observed with thrombin-generated clots in the presence of factor XIIIa and calcium. In those old studies, both the gelation and subsequent clot stabilization were attributed to papain, although the possibility that the second step might be du...

  11. Colombia Firm Energy Market

    OpenAIRE

    Peter Cramton; Steven Stoft

    2007-01-01

    A firm energy market for Colombia is presented. Firm energy—the ability to provide energy in a dry period—is the product needed for reliability in Colombia’s hydro-dominated electricity market. The firm energy market coordinates investment in new resources to assure that sufficient firm energy is available in dry periods. Load procures in an annual auction enough firm energy to cover its needs. The firm energy product includes both a financial call option and the physical capability to supply...

  12. Lasting power of new clotting proteins.

    Science.gov (United States)

    Powell, Jerry S

    2014-12-01

    Hemophilia is a genetic disease caused by a deficiency of one of the coagulation proteins. The term usually refers to either hemophilia A, factor VIII (FVIII), with an incidence of ∼1 in 5000 male births, or hemophilia B, factor IX (FIX), with an incidence of ∼1 in 30 000 male births. When severe, the disease leads to spontaneous life-threatening bleeding episodes. Current therapy requires frequent intravenous infusions of therapeutic factor concentrates. Most patients administer the infusions at home every few days and must limit their physical activities to avoid bleeding when the factor activity levels are below normal. In March 2014, a new therapeutic FIX preparation was approved for clinical use in Canada and the United States and, in June 2014, a new FVIII preparation was approved for clinical use in the United States. Over the next couple of years, other new factor products for FIX, FVIIa, and FVIII, which are currently in late stages of clinical trials, will likely also be approved. These new factors have been engineered to extend their half-life in circulation, thus providing major therapeutic advances for patients with hemophilia primarily by allowing treatment with fewer infusions per month. In the clinical trials so far, >500 patients have successfully used these extended half-life products regularly for >1 year to prevent spontaneous bleeding, to treat successfully any bleeding episodes, and to provide effective coagulation for major surgery. Essentially all infusions were well tolerated and effective. These promising new therapies should allow patients to use fewer infusions to maintain appropriate clotting factor activity levels in all clinical settings. PMID:25696879

  13. Computational Study of Thrombus Formation and Clotting Factor Effects under Venous Flow Conditions.

    Science.gov (United States)

    Govindarajan, Vijay; Rakesh, Vineet; Reifman, Jaques; Mitrophanov, Alexander Y

    2016-04-26

    A comprehensive understanding of thrombus formation as a physicochemical process that has evolved to protect the integrity of the human vasculature is critical to our ability to predict and control pathological states caused by a malfunctioning blood coagulation system. Despite numerous investigations, the spatial and temporal details of thrombus growth as a multicomponent process are not fully understood. Here, we used computational modeling to investigate the temporal changes in the spatial distributions of the key enzymatic (i.e., thrombin) and structural (i.e., platelets and fibrin) components within a growing thrombus. Moreover, we investigated the interplay between clot structure and its mechanical properties, such as hydraulic resistance to flow. Our model relied on the coupling of computational fluid dynamics and biochemical kinetics, and was validated using flow-chamber data from a previous experimental study. The model allowed us to identify the distinct patterns characterizing the spatial distributions of thrombin, platelets, and fibrin accumulating within a thrombus. Our modeling results suggested that under the simulated conditions, thrombin kinetics was determined predominantly by prothrombinase. Furthermore, our simulations showed that thrombus resistance imparted by fibrin was ∼30-fold higher than that imparted by platelets. Yet, thrombus-mediated bloodflow occlusion was driven primarily by the platelet deposition process, because the height of the platelet accumulation domain was approximately twice that of the fibrin accumulation domain. Fibrinogen supplementation in normal blood resulted in a nonlinear increase in thrombus resistance, and for a supplemented fibrinogen level of 48%, the thrombus resistance increased by ∼2.7-fold. Finally, our model predicted that restoring the normal levels of clotting factors II, IX, and X while simultaneously restoring fibrinogen (to 88% of its normal level) in diluted blood can restore fibrin generation to

  14. Procurement with specialized firms

    DEFF Research Database (Denmark)

    Schottmüller, Christoph; Boone, Jan

    2016-01-01

    This paper analyzes optimal procurement mechanisms when firms are specialized. The procurement agency has incomplete information concerning the firms’ cost functions and values high quality as well as low price. Lower type firms are cheaper (more expensive) than higher type firms when providing l...

  15. Procurement with specialized firms

    DEFF Research Database (Denmark)

    Boone, Jan; Schottmüller, Christoph

    2016-01-01

    This paper analyzes optimal procurement mechanisms when firms are specialized. The procurement agency has incomplete information concerning the firms’ cost functions and values high quality as well as low price. Lower type firms are cheaper (more expensive) than higher type firms when providing low...

  16. Transformation of Manufacturing Firms to Servitisation Firms

    DEFF Research Database (Denmark)

    Lin, Chih-Cheng; Ma, Zheng; Tanev, Stoyan

    2014-01-01

    a traditional manufacturing firm to service-oriented firms is the conspicuous lack of publications in this research stream. Applying a case study research approach, this study explores the transformation model for manufacturing SMEs to servitisation firms by adopting a network approach, and reveals......It is crucial for the manufacturing SMEs to reconsider their business strategy in order to be able to launch customer-centric solutions. This ability is associated with a paradigm shift from a product-orientation to service-orientation. One of the major challenges to success in transforming...

  17. Intra-firm trade, exporting, importing, and firm performance

    OpenAIRE

    Haller, Stefanie A.

    2012-01-01

    This paper examines firm heterogeneity in terms of size, wages, capital intensity, and productivity between domestic and foreign-owned firms that engage in intra-firm trade, firms that export and import, firms that import only, and firms that export only. As previously documented, heterogeneity between different groups of trading firms is substantial. Taking into account intra-firm trade in addition to exporting and importing yields new insights into the productivity advantage previously esta...

  18. Input reallocation within firms

    OpenAIRE

    Vandenbussche, Hylke; Viegelahn, Christian

    2016-01-01

    This paper documents the within firm reallocation of inputs and outputs as a result of a trade policy shock on the input side. A unique firm-input level dataset for India with information on different raw material inputs used in production, enables us to identify firms with imported inputs subject to trade policy. To guide the empirics, we first develop a back-bone model of heterogeneous firms that source inputs from abroad. We find that affected firms engage in input reallocation and lower t...

  19. Performance of Patenting Firms

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar; Nielsen, Anders Østergaard

    2000-01-01

    Most countries focus on industries with high technology and the governments grant subsidies to innovating firms. However, there has been remarkable few studies of the performance of innovative firms or industries. This study examines the performance of patent active firms compared to the non-patenting...... firms within the manufacturing sector in Denmark. Performance is measured both by growth in employment as well as in the return on equity and profit share in turnover. The results suggest that differences in performance of patenting and non-patenting firms are very small, which questions the political...

  20. Unusual clotting dynamics of plasma supplemented with iron(III).

    Science.gov (United States)

    Jankun, Jerzy; Landeta, Philip; Pretorius, Etheresia; Skrzypczak-Jankun, Ewa; Lipinski, Bogusław

    2014-02-01

    Iron salts are used in the treatment of iron deficiency anemia. Diabetic patients are frequently anemic and treatment includes administration of iron. Anemic patients on hemodialysis are at an increased risk of thromboembolic coronary events associated with the formation of dense fibrin clots resistant to fibrinolysis. Moreover, in chronic kidney disease patients, high labile plasma iron levels associated with iron supplementation are involved in complications found in dialyzed patients such as myocardial infarction. The aim of the present study was to investigate whether iron treatment is involved in the formation of the fibrin clots. Clotting of citrated plasma supplemented with Fe(3+) was investigated by thromboelastometry and electron microscopy. The results revealed that iron modifies coagulation in a complex manner. FeCl(3) stock solution underwent gradual chemical modification during storage and altered the coagulation profile over 29 days, suggesting that Fe(3+) interacts with both proteins of the coagulation cascade as well as the hydrolytic Fe(3+) species. Iron extends clotting of plasma by interacting with proteins of the coagulation cascade. Fe(3+) and/or its hydrolytic species interact with fibrinogen and/or fibrin changing their morphology and properties. In general FeCl(3) weakens the fibrin clot while at the same time precipitating plasma proteins immediately after application. Fe(3+) or its derivatives induced the formation of insoluble coagulums in non-enzymatic reactions including albumin and transferrin. Iron plays a role in coagulation and can precipitate plasma proteins. The formation of coagulums resistant to lysis in non‑enzymatic reactions can increase the risk of thrombosis, and extending clotting of plasma can prolong bleeding.

  1. Firming up inequality

    OpenAIRE

    Song, Jae; Price, David J.; Guvenen, Fatih; Bloom, Nick

    2015-01-01

    Earnings inequality in the United States has increased rapidly over the last three decades, but little is known about the role of firms in this trend. For example, how much of the rise in earnings inequality can be attributed to rising dispersion between firms in the average wages they pay, and how much is due to rising wage dispersion among workers within firms? Similarly, how did rising inequality affect the wage earnings of different types of workers working for the same employ...

  2. Immigration and Firm Expansion

    OpenAIRE

    William W. Olney

    2008-01-01

    Research generally focuses on how immigration affects native workers, while the impact of immigration on domestic firms is often overlooked. This paper addresses this important omission by examining whether firms respond to immigration by expanding their production activities within a city in order to utilize the abundant supply of low-skilled workers. Using data on immigration and the universe of establishments in U.S. cities, the results indicate that firms respond to immigration at the ext...

  3. Thermodynamics of firms' growth.

    Science.gov (United States)

    Zambrano, Eduardo; Hernando, Alberto; Fernández Bariviera, Aurelio; Hernando, Ricardo; Plastino, Angelo

    2015-11-01

    The distribution of firms' growth and firms' sizes is a topic under intense scrutiny. In this paper, we show that a thermodynamic model based on the maximum entropy principle, with dynamical prior information, can be constructed that adequately describes the dynamics and distribution of firms' growth. Our theoretical framework is tested against a comprehensive database of Spanish firms, which covers, to a very large extent, Spain's economic activity, with a total of 1,155,142 firms evolving along a full decade. We show that the empirical exponent of Pareto's law, a rule often observed in the rank distribution of large-size firms, is explained by the capacity of economic system for creating/destroying firms, and that can be used to measure the health of a capitalist-based economy. Indeed, our model predicts that when the exponent is larger than 1, creation of firms is favoured; when it is smaller than 1, destruction of firms is favoured instead; and when it equals 1 (matching Zipf's law), the system is in a full macroeconomic equilibrium, entailing 'free' creation and/or destruction of firms. For medium and smaller firm sizes, the dynamical regime changes, the whole distribution can no longer be fitted to a single simple analytical form and numerical prediction is required. Our model constitutes the basis for a full predictive framework regarding the economic evolution of an ensemble of firms. Such a structure can be potentially used to develop simulations and test hypothetical scenarios, such as economic crisis or the response to specific policy measures. PMID:26510828

  4. Audits of private firms

    OpenAIRE

    Langli, John Christian; Svanström, Tobias

    2013-01-01

    Private and public firms differ across a number of important dimensions. Public firms are under scrutiny by stock exchanges, regulators, and market participants and they share the feature of separation of ownership and control. Private firms, in contrast, are much less regulated, the nature of their agency problems is different, they are less exposed to market forces, litigation and publicity, and they operate in a much more opaque information environment. The greater heterogeneit...

  5. Firm Ownership and Philanthropy

    OpenAIRE

    Chai, D.H.

    2010-01-01

    This paper empirically examines the relationship between firm ownership structure and corporate charitable donations. Using a panel data set of 1,017 listed Korean firms, we find that larger firms with higher advertising intensity and lower export intensity 'give' relatively more, suggesting that charitable donations are both strategic and discretionary corporate expenditures. In addition, the study explores the effects of ownership structure on corporate philanthropy. We find a positive rela...

  6. Thermodynamics of firms' growth

    CERN Document Server

    Zambrano, Eduardo; Fernandez-Bariviera, Aurelio; Hernando, Ricardo; Plastino, Angelo

    2015-01-01

    The distribution of firms' growth and firms' sizes is a topic under intense scrutiny. In this paper we show that a thermodynamic model based on the Maximum Entropy Principle, with dynamical prior information, can be constructed that adequately describes the dynamics and distribution of firms' growth. Our theoretical framework is tested against a comprehensive data-base of Spanish firms, which covers to a very large extent Spain's economic activity with a total of 1,155,142 firms evolving along a full decade. We show that the empirical exponent of Pareto's law, a rule often observed in the rank distribution of large-size firms, is explained by the capacity of the economic system for creating/destroying firms, and can be used to measure the health of a capitalist-based economy. Indeed, our model predicts that when the exponent is larger that 1, creation of firms is favored; when it is smaller that 1, destruction of firms is favored instead; and when it equals 1 (matching Zipf's law), the system is in a full mac...

  7. The euglobulin clot lysis time to assess the impact of nanoparticles on fibrinolysis

    Energy Technology Data Exchange (ETDEWEB)

    Minet, Valentine, E-mail: valentine.minet@unamur.be; Alpan, Lutfiye; Mullier, François [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium); Toussaint, Olivier [Laboratory of Cellular Biochemistry and Biology (URBC) (Belgium); Lucas, Stéphane [University of Namur (UNamur), Research Centre for the Physics of Matter and Radiation (PMR-LARN), Namur Nanosafety Center NNC, NAmur Research Institute for Life Sciences NARILIS (Belgium); Dogné, Jean-Michel; Laloy, Julie, E-mail: julie.laloy@unamur.be [University of Namur – UNamur, Department of Pharmacy, Namur Thrombosis and Hemostasis Center (NTHC), Namur Nanosafety Center (NNC), NAmur Research Institute for Life Sciences NARILIS (Belgium)

    2015-07-15

    Nanoparticles (NPs) are developed for many applications in various fields, including nanomedicine. The NPs used in nanomedicine may disturb homeostasis in blood. Secondary hemostasis (blood coagulation) and fibrinolysis are complex physiological processes regulated by activators and inhibitors. An imbalance of this system can either lead to the development of hemorrhages or thrombosis. No data are currently available on the impact of NPs on fibrinolysis. The objectives of this study are (1) to select a screening test to study ex vivo the impact of NPs on fibrinolysis and (2) to test NPs with different physicochemical properties. Euglobulin clot lysis time test was selected to screen the impact of some NPs on fibrinolysis using normal pooled plasma. A dose-dependent decrease in the lysis time was observed with silicon dioxide and silver NPs without disturbing the fibrin network. Carbon black, silicon carbide, and copper oxide did not affect the lysis time at the tested concentrations.

  8. Alignment of the Fibrin Network Within an Autologous Plasma Clot.

    Science.gov (United States)

    Gessmann, Jan; Seybold, Dominik; Peter, Elvira; Schildhauer, Thomas Armin; Köller, Manfred

    2016-01-01

    Autologous plasma clots with longitudinally aligned fibrin fibers could serve as a scaffold for longitudinal axonal regrowth in cases of traumatic peripheral nerve injuries. Three different techniques for assembling longitudinally oriented fibrin fibers during the fibrin polymerization process were investigated as follows: fiber alignment was induced by the application of either a magnetic field or-as a novel approach-electric field or by the induction of orientated flow. Fiber alignment was characterized by scanning electron microscopy analysis followed by image processing using fast Fourier transformation (FFT). Besides FFT output images, area xmin to xmax, as well as full width at half maximum (FWHM) of the FFT graph plot peaks, was calculated to determine the relative degree of fiber alignment. In addition, fluorescently labeled human fibrinogen and mesenchymal stem cells (MSCs) were used to visualize fibrin and cell orientation in aligned and nonaligned plasma clots. Varying degrees of fiber alignment were achieved by the three different methods, with the electric field application producing the highest degree of fiber alignment. The embedded MSCs showed a longitudinal orientation in the electric field-aligned plasma clots. The key feature of this study is the ability to produce autologous plasma clots with aligned fibrin fibers using physical techniques. This orientated internal structure of an autologous biomaterial is promising for distinct therapeutic applications, such as a guiding structure for cell migration and growth dynamics.

  9. Foreign Firms, Domestic Wages

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Schjerning, Bertel; R. Markusen, James

    2013-01-01

    Three types of theories have been used to explain the wage premium in foreign firms: the theories of heterogeneous workers, heterogeneous learning, and heterogeneous firms. We set up a model that explicitly encompasses two of these theories, and that can illustrate the third. This unifying framew...

  10. Corruption and firm performance: Evidence from Greek firms

    OpenAIRE

    Athanasouli, Daphne; Goujard, Antoine; Sklias, Pantelis

    2012-01-01

    This article investigates the relationship between corruption and firm performance in Greece using firm level data. Corruption is overall negatively associated with firm size and growth at the firm level. We focus on the effect of ‘administrative corruption’, whereby firms engage in corrupt practices and bribery of government officials. We contrast the firm experience of corruption and the contextual experience of corruption at the sectoral level and find that the latter, contextual corruptio...

  11. Does Corporate Governance Influence Firm Value? Evidence from Indian Firms

    OpenAIRE

    Kumar, Jayesh

    2004-01-01

    This paper examines empirically the effects of ownership structure on the firm performance for a panel of Indian corporate firms, from a corporate governance perspective. We examine the effect of interactions between corporate, foreign, institutional, and directorial ownership on firm performance. Using firm level panel data framework, we show that a large fraction of cross-sectional variation, in firm performance, can be explained by unobserved firm heterogeneity. We also provide evidence th...

  12. Firming Up Inequality

    OpenAIRE

    Jae Song; Price, David J.; Fatih Guvenen; Nicholas Bloom; Till von Wachter

    2015-01-01

    Earnings inequality in the United States has increased rapidly over the last three decades, but little is known about the role of firms in this trend. For example, how much of the rise in earnings inequality can be attributed to rising dispersion between firms in the average wages they pay, and how much is due to rising wage dispersion among workers within firms? Similarly, how did rising inequality affect the wage earnings of different types of workers working for the same employer—men vs. w...

  13. Global Sourcing and Firm Selection

    OpenAIRE

    Kohler, Wilhelm; Smolka, Marcel

    2013-01-01

    Which firms find it optimal to integrate their input suppliers into the firm boundaries of control (vertical integration)? Which firms choose to expand their sourcing activities across the national border (offshoring)? This letter provides novel evidence on these questions based on a Spanish firm-level data set. We find that firms selecting into strategies of vertical integration and of offshoring tend to have been more productive ex ante than firms choosing not to do so. This finding is in l...

  14. Global Sourcing and Firm Selection

    DEFF Research Database (Denmark)

    Kohler, Wilhelm; Smolka, Marcel

    2014-01-01

    We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms.......We analyze the sourcing strategies of firms active in the Spanish manufacturing sector. We show that firms that select strategies of vertical integration and of foreign sourcing ex post tend to have been more productive, ex ante, than other firms....

  15. Firm Financial Policy

    Directory of Open Access Journals (Sweden)

    Alexandru NEGREA

    2014-11-01

    Full Text Available Financial policy outlines the main directions of action of the financial activity. In determining financial policy, managers must take into consideration interests of all stakeholders, given the political, social, financial and monetary context of the firm, but also the technical and technological one. In addition, the educational, environmental and scientific context must be considered when establishing the financial policy, as it also influences the latter. Therefore, within financial policy, managers must identify and adopt those financial decisions that can positively influence the future development of the firm. Present studies intended as a tool for those interested in the future of the firm, e.g. employers, employees, banks, insurance companies, service providers, etc. It details directions of actions used by managers within financial policy in order to increase firm profits.

  16. High-throughput proteomic characterization of plasma rich in growth factors (PRGF-Endoret)-derived fibrin clot interactome.

    Science.gov (United States)

    Anitua, Eduardo; Prado, Roberto; Azkargorta, Mikel; Rodriguez-Suárez, Eva; Iloro, Ibon; Casado-Vela, Juan; Elortza, Felix; Orive, Gorka

    2015-11-01

    Plasma rich in growth factors (PRGF®-Endoret®) is an autologous technology that contains a set of proteins specifically addressed to wound healing and tissue regeneration. The scaffold formed by using this technology is a clot mainly composed of fibrin protein, forming a three-dimensional (3D) macroscopic network. This biomaterial is easily obtained by biotechnological means from blood and can be used in a range of situations to help wound healing and tissue regeneration. Although the main constituent of this clot is the fibrin scaffold, little is known about other proteins interacting in this clot that may act as adjuvants in the healing process. The aim of this study was to characterize the proteins enclosed by PRGF-Endoret scaffold, using a double-proteomic approach that combines 1D-SDS-PAGE approach followed by LC-MS/MS, and 2-DE followed by MALDI-TOF/TOF. The results presented here provide a description of the catalogue of key proteins in close contact with the fibrin scaffold. The obtained lists of proteins were grouped into families and networks according to gene ontology. Taken together, an enrichment of both proteins and protein families specifically involved in tissue regeneration and wound healing has been found.

  17. Information theory of firm

    OpenAIRE

    Ledenyov, Dimitri O.; Ledenyov, Viktor O.

    2015-01-01

    The article formulates the information theory of firm, introduces the concept of firm as an operating system, which controls the firm’s operation by the means of the information resources processing, in an analogy with the operating system at a microprocessor in the computing devices, represents the director as an information processing element, describes the board of directors as the electronically-scanned electronically-steered phased array radar, considers the scientific problem of strateg...

  18. The market for firms

    DEFF Research Database (Denmark)

    Davis, Jerome Dean; Keiding, Hans

    2010-01-01

    In this paper, the pricing and sale of firms is approached from the owners' point of view. It is shown that there are very strong ex ante owner incentives to set prices of firm products or services below their short- term profit maximizing levels, since low prices signal low costs and as a conseq......In this paper, the pricing and sale of firms is approached from the owners' point of view. It is shown that there are very strong ex ante owner incentives to set prices of firm products or services below their short- term profit maximizing levels, since low prices signal low costs...... and as a consequence a higher sales value of the firm. Buyers take this signaling into consideration, but irrespective of their countermoves, the equilib- rium result may be a lowering of ex ante product prices, and an ex post market overvaluation of the firm. This model is utilized to suggest possible explanations...... to one of the more puzzling initial public offer (IPO) phenomena: the long run underperformance of IPO equities....

  19. How Entrepreneurial Firms Prosper while Larger Firms Crumble

    OpenAIRE

    Shukla, P K

    2009-01-01

    Many firms are facing great difficulty surviving the declining financial markets in Fall 2008. As larger firms take drastic measures to control and cut costs while forecasting declining revenue, entrepreneurial firms view the same marketplace in a more positive light. What separate these two types of firms is their differing levels of entrepreneurial intensity.An entrepreneurial grid positions firms upon two dimensions: Frequency of Entrepreneurship and Degree of Entrepreneurship (innovativen...

  20. PARTIAL PURIFICATION OF MILK-CLOTTING ENZYME FROM THE SEEDS OF MORINGA OLEIFERA

    Directory of Open Access Journals (Sweden)

    Amna E. Tajalsir

    2014-08-01

    Full Text Available The aim of the present study was to search for milk clotting substitute from different parts (flowers, seeds, stem, leaves, ripe and unripe fruits of Moringa oleifera. The samples were blended and extracted using different types of extracting solutions. The most reliable, quick and efficient enzyme extracting solution was found to be 5% NaCl in 100 mM sodium acetate buffer, pH 5.0, which was used throughout the study. The milk clotting activity was only observed in the seeds extract while the other parts were either deficient or has very low milk clotting activity. Thus, the moringa seeds were used as source of milk clotting enzyme. The extracted proteins were fractionated with ammonium sulfate at concentration of 20, 30, 40, 50 and 60 %. Highest milk clotting activity was observed in the 20 % fraction. This fraction was assumed to contain the clotting enzymes and characterized for its heating stability (30 – 90°C and optimum temperature (30 – 90°C. The results demonstrated that moringa seeds milk clotting enzyme is stable up to 50°C with an optimum milk clotting activity of 70°C. The high ratio of milk-clotting to proteolytic activity of the partially purified enzyme indicates the potential of this enzyme as suitable rennet substitute in dairy industry. However, further study is needed to completely purify and characterize this promising milk clotting enzyme from moringa seeds.

  1. Collaborative Communities of Firms

    DEFF Research Database (Denmark)

    Bøllingtoft, Anne; Müller, Sabine; Ulhøi, John Parm;

    2011-01-01

    Both small and medium-size entrepreneurial firms face liabilities such as resource scarcity and scale diseconomies, making it difficult for them to innovate on a continuous basis. In response, experimentation with new ways of organizing for innovation has increased. One successful result is an or...... of collaborative communities of firms from different sectors: the U.S.-based Blade.org and two Denmark-based communities, the Kalundborg Industrial Symbiosis and MG50. Implications for the theory and practice of organization design are discussed....... is an organizational model called the collaborative community of firms. This chapter addresses an important organizational role in a collaborative community, that of the shared services provider. The shared services provider acts as a facilitator in the community, helping member firms collaborate with one another...... and developing strategic initiatives that aid the community as a whole. We discuss the facilitator role of the shared services provider, contrasting it with the coordinator role found in other multi-firm organizations, and we show how shared services providers function by describing three examples...

  2. Global sourcing of family firms

    OpenAIRE

    Horgos, Daniel

    2010-01-01

    In Europe, a huge share of firms is family owned. Since family firms are known to be more risk averse concerning international transactions, an interesting question emerges: Do family firms adopt a different international sourcing pattern. Altering the Gloubal Sourcing model of Antràs and Helpman, this theoretical contribution adopts a family firm's perspective. The model shows that family firms tend to decrease international procurement. In the headquarter intensive sector, where FDI coexist...

  3. Global Sourcing of Familiy Firms

    OpenAIRE

    Horgos, Daniel

    2010-01-01

    In Europe, a huge share of firms is family owned. Since family firms are known to be more risk averse concerning international transactions, an interesting question emerges: Do family firms adopt a different international sourcing pattern. Altering the Gloubal Sourcing model of Antràs and Helpman, this theoretical contribution adopts a family firm's perspective. The model shows that family firms tend to decrease international procurement. In the headquarter intensive sector, where FDI coexist...

  4. The Multinational Firm

    DEFF Research Database (Denmark)

    Morgan, Glenn; Hull Kristensen, Peer; Whitley, Richard

    In contrast to the traditional view of multinational firms as cohesive rational actors maximizing the use of resources across national boundaries, the contributors to this volume argue that they are complex social arenas where competing groups draw on resources from their own socially-embedded lo......In contrast to the traditional view of multinational firms as cohesive rational actors maximizing the use of resources across national boundaries, the contributors to this volume argue that they are complex social arenas where competing groups draw on resources from their own socially......-embedded locations in developing new transnational social relationships. As firms seek to manage across national and institutional boundaries, they stretch their existing capacities and routines and develop new sets of transnational social relationships through different groups competing and cooperating...

  5. Foreign Firms, Domestic Wages

    OpenAIRE

    Malchow-Møller, Nikolaj; Markusen, James R.; Schjerning, Bertel

    2013-01-01

    Many papers have documented a wage premium in foreign-owned and large firms. However, there is very little formal theory in the literature and empirical analyses are typically not based on hypotheses which are rigorously derived from theory. This paper contributes to the theory-empirics gap by developing a model that allows for two “pure” explanations for the wage premium. The first is a heterogenous-worker explanation along the lines of Yeaple (2005), where firms that select more scaleintens...

  6. Industry segment effects and firm effects on firm performance in single industry firms

    OpenAIRE

    Houthoofd, Noël; Hendrickx, Jef

    2012-01-01

    The purpose of the paper is to identify the sources of variation in firm performance. This is one of the cornerstones of strategy research, i.e. the relative importance of industry and firm level effects on firm performance. Multilevel analysis is well suited to analyze variance in performance when the data are hierarchically structured (industry segments consist of firms, firms operate within the context of industry segments). The Belgian industry studied is a service industry that consists ...

  7. Travail et pouvoir d’agir d’Yves Clot

    Directory of Open Access Journals (Sweden)

    Jacques Leplat

    2008-11-01

    Full Text Available Yves Clot est titulaire de la Chaire de psychologie du travail du Conservatoire National des Arts et Métiers (CNAM au sein duquel il dirige l’équipe de clinique de l’activité. Cet ouvrage est le second qu’il publie dans cette collection, le premier « La fonction psychologique du travail » est paru en 1999. Entre les deux s’inscrivent un grand nombre de publications, dont beaucoup avec d’autres chercheurs, comme on pourra le constater en consultant la bibliographie de ce livre. Ce denier réun...

  8. Whom do new firms hire?

    DEFF Research Database (Denmark)

    2015-01-01

    Using the matched employer-employee data set for Denmark and information on the founders of new firms, we analyze the hiring choices of all new firms that entered from 2003 to 2010. We develop a theoretical model in which the quality of a firm’s employees determines its average cost, a firm......, and firm size influence the wages firms pay to their early hires. We find that beginning with the time of entry, larger firms consistently pay higher wages to their new hires. These are firms with greater survival prospects at the time of entry based on the pre-entry backgrounds of their founders...... and that grow at greater rates over time, both of which are predictive of the wages paid to new hires from the time of entry onward. Our findings suggest workers are allocated to firms according to their abilities, which can give rise to enduring firm capabilities....

  9. Which firms use measures?

    DEFF Research Database (Denmark)

    Pedersen, Esben Rahbek Gjerdrum; Sudzina, Frantisek

    2012-01-01

    Purpose – The purpose of this paper is to outline the anatomy of firms which adopt comprehensive performance measurement (PM) systems in order to gain an understanding of how internal (organisational capabilities) and external (perceived environmental uncertainties) factors shape performance meas...

  10. Foreign Firms, Domestic Wages

    DEFF Research Database (Denmark)

    Malchow-Møller, Nikolaj; Markusen, James R.; Schjerning, Bertel

    Many papers have documented a wage premium in foreign-owned and large firms. However, there is very little formal theory in the literature and empirical analyses are typically not based on hypotheses which are rigorously derived from theory. This paper contributes to the theory-empirics gap by de...

  11. MEASURING INDUSTRY AND FIRM EFFECTS IN FOOD AND AGRIBUSINESS FIRMS

    OpenAIRE

    Schumacher, Sara K.; Boland, Michael A.

    2003-01-01

    Managers craft strategies that, if successfully implemented, can improve profitability and financial performance over time. Can firms repeat their performance over time? If so, then a manager who crafted a successful strategy could expect her/his firm to achieve greater profitability relative to other firms within its industry. The objective of this study was to compare business performance (accounting profitability) for publicly traded and cooperatively-owned food and agribusiness firms. We ...

  12. Corporate Ownership Structure and Firm Performance: Evidence from Greek Firms

    OpenAIRE

    Panayotis Kapopoulos; Sophia Lazaretou

    2006-01-01

    The Berle-Means thesis (1932) implies that diffuse ownership adversely affects firm performance. This paper tries to investigate whether there is strong evidence to support the notion that variations across firms in observed ownership structures result in systematic variations in observed firm performance. We test this hypothesis by assessing the impact of the structure of ownership on corporate performance, measured by profitability, using data for 175 Greek listed firms. Following Demsetz a...

  13. Calibrated automated thrombin generation measurement in clotting plasma.

    Science.gov (United States)

    Hemker, H Coenraad; Giesen, Peter; Al Dieri, Raed; Regnault, Véronique; de Smedt, Eric; Wagenvoord, Rob; Lecompte, Thomas; Béguin, Suzette

    2003-01-01

    Calibrated automated thrombography displays the concentration of thrombin in clotting plasma with or without platelets (platelet-rich plasma/platelet-poor plasma, PRP/PPP) in up to 48 samples by monitoring the splitting of a fluorogenic substrate and comparing it to a constant known thrombin activity in a parallel, non-clotting sample. Thus, the non-linearity of the reaction rate with thrombin concentration is compensated for, and adding an excess of substrate can be avoided. Standard conditions were established at which acceptable experimental variation accompanies sensitivity to pathological changes. The coefficients of variation of the surface under the curve (endogenous thrombin potential) are: within experiment approximately 3%; intra-individual: AVK, heparin(-likes), direct inhibitors]. In PRP, it is diminished in von Willebrand's disease, but it also shows the effect of platelet inhibitors (e.g. aspirin and abciximab). Addition of activated protein C (APC) or thrombomodulin inhibits thrombin generation and reflects disorders of the APC system (congenital and acquired resistance, deficiencies and lupus antibodies) independent of concomitant inhibition of the procoagulant pathway as for example by anticoagulants.

  14. Staying Active and Healthy: Blood Thinners

    Medline Plus

    Full Text Available Referenced Links: Review the following links for additional information on this topic: • Blood Thinner Pills: Your Guide to Using Them Safely ... the following related programs are offered for your review: Preventing Blood Clots After Hip or Knee Surgery ...

  15. Combination of recombinant factor VIIa and fibrinogen corrects clot formation in primary immune thrombocytopenia at very low platelet counts

    DEFF Research Database (Denmark)

    Larsen, Ole H; Stentoft, Jesper; Radia, Deepti;

    2013-01-01

    Haemostatic treatment modalities alternative to platelet transfusion are desirable to control serious acute bleeds in primary immune thrombocytopenia (ITP). This study challenged the hypothesis that recombinant activated factor VII (rFVIIa) combined with fibrinogen concentrate may correct whole...... blood (WB) clot formation in ITP. Blood from ITP patients (n = 12) was drawn into tubes containing 3·2% citrate and corn trypsin inhibitor 18·3 μg/ml. WB [mean platelet count 22 × 10(9) /l (range 0-42)] was spiked in vitro with buffer, donor platelets (+40 × 10(9) /l), rFVIIa (1 or 4 μg/ml), fibrinogen...... (1 or 3 mg/ml), or combinations of rFVIIa and fibrinogen. Coagulation profiles were recorded by tissue factor (0·03 pmol/l) activated thromboelastometry. Coagulation in ITP was characterized by a prolonged clotting time (CT, 1490 s (mean)) and a low maximum velocity (MaxVel, 3·4 mm × 100/s...

  16. The Innovative Capacity of Firms

    Directory of Open Access Journals (Sweden)

    Neely Andy

    2014-11-01

    Full Text Available Innovation is widely accepted as a crucial competitive weapon in today's global market place. Yet the levels of innovation achieved by different firms, even within the same industry, can vary widely. The key question raised by this observation is why. Why are some firms more innovative than others? What are the factors that determine a firm's capacity to innovate and how can these be managed to enhance the firm's innovative potential? This paper sets out to address these and related issues. It reports the results of a study of competitiveness and innovation of firms in the East of England. In the paper it is argued that the innovative capacity of a firm is a function of the firm's culture, resources, competences and networks. Justification for this framework is provided by a review of the relevant literature and a series of case studies examining the capacity to innovate of a sample of firms in the East of England.

  17. Alternative theories of the firm

    OpenAIRE

    Staněk, Jan

    2014-01-01

    This thesis is focusing on alternative theories of the firm and their distinctions to the traditional neoclassical theory of profit maximization. It goes back to perception of the firm in the society and to development of theoretical concepts of the firm, as well as to different points of view of profit or satisfaction principle. You will learn more about the reason which triggered the beginnings of alternative theories of the firm like separation of ownership and control, which was one of th...

  18. Matching Firms, Managers, and Incentives

    OpenAIRE

    Bandiera, Oriana; Guiso, Luigi; Prat, Andrea; Sadun, Raffaella

    2009-01-01

    We provide evidence on the match between firms, managers and incentives using a new survey designed for this purpose. The survey contains information on a sample of executives’ risk preferences and human capital, on the explicit and implicit incentives they face and on the firms they work for. We model a market for managerial talent where both firms and managers are heterogeneous. Following the sources of heterogeneity observed in the data, we assume that firms differ by ownership structure a...

  19. Board diversity in family firms

    OpenAIRE

    Menozzi, Anna; Fraquelli, Giovanni; Novara, Jolanda de

    2015-01-01

    The paper deals with diversity as a key factor to improve the board of directors’ decision process in family firms. The empirical literature about board diversity points at the positive impact of diversity on board functioning and firm performance. The paper uses a statistical diversity index to capture the heterogeneity of board of directors and put it in relation with firm performance, as measured by firm profitability. The empirical analysis is based on a newly collected panel of 327 famil...

  20. Belgian firms visiting CERN

    CERN Multimedia

    FP Department

    2009-01-01

    25 – 26 MAY 2009 09.00 to 17.00 Monday 25 May 09.00 to 17.00 Tuesday 26 May Individual interviews will take place in technicians’ offices. The firms will contact relevant users/technicians but any user wishing to make contact with a particular firm is welcome to use the contact details which are available from each departmental secretariat or from the GS Department web pages here. List of Companies:Automation Services and Consulting BVBA Burrick NV, (PLC) Cissoid DB Engineering Design, Drafting & Services BVBA Entelec Control Systems GILLAM-Fei S.A. HPC ICSENSE IWT – Enterprise Europe Flanders Jema SA Mecasoft SA SA Polmans Rapid-Torc Resarm Engineering Plastics SA Sentera Europa NV SLC BVBA Stocker Industrie SA Technord Tecnubel Winlock BVBA For further information please contact Caroline Laignel (GS-DI 73722) or Karine Robert (GS-SEM-LS 74407).

  1. Entrepreneurship and the Firm

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul; Klein, Peter G.

    While characteristically "Austrian" themes such as entrepreneurship, economic calculation, tacit knowledge and the temporal structure of capital are clearly relevant to the business firm, Austrian economists have said relatively little about management, organization and strategy. This work features...... topics. These include knowledge management, authority and hierarchy, modularity, corporate restructuring, telecommunications regulation and competitive advantage. They clearly show how Austrian ideas can usefully engage, challenge and extend more mainstream perspectives on economic organization....... 12 chapters that all seek to advance the understanding of these issues by drawing on Austrian ideas. Building on existing research in transaction cost economics, agency theory, evolutionary economics and the resource-based theory of the firm, the authors cover a wide range of theoretical and applied...

  2. Inside the Family Firm

    OpenAIRE

    Bennedsen, Morten; Nielsen, Kasper; Pérez-González, Francisco; Wolfenzon, Daniel

    2005-01-01

    This paper uses a unique dataset from Denmark to investigate (1) the role of family characteristics in corporate decision making, and (2) the consequences of these decisions on firm performance. We focus on the decision to appoint either a family or an external chief executive officer (CEO). We show that a departing CEO’s family characteristics have a strong predictive power in explaining CEO succession decisions: family CEOs are more frequently selected the larger the size of the family, the...

  3. Innovation in Family Firms

    DEFF Research Database (Denmark)

    Filser, Matthias; Brem, Alexander; Gast, Johanna;

    2016-01-01

    , organizational culture and behaviour, resources, and innovation and strategy. Second, based on a thorough literature review the major research avenues are reflected. The comparison of the results of both analyses showed the following areas for future research on family firm innovation: members‘ individual human...... capital and their leadership behaviour, openness to externals, cross-country comparisons, and finally the family‘s functional integrity on innovation performance....

  4. Foreign Firms Partner Up

    Institute of Scientific and Technical Information of China (English)

    DAVID HENDRICKSON

    2006-01-01

    @@ There is an important strategic adjustment occurring on the part of foreign dairy companies seeking to capitalize on the China market. Rather than going it alone,with local partnerships little more than an entry mechanism,global giants such as Danone,Arla, and Fonterra are taking advantage of the country's more relaxed foreign investment rules by upping their stakes in established local firms and expanding the role they play in business and industrial operations.

  5. Socially Responsible Firms

    OpenAIRE

    Renneboog, L.D.R.; Liang, H; Ferrell, A.

    2014-01-01

    In the corporate finance tradition starting with Berle & Means (1923), corporations should generally be run so as to maximize shareholder value. The agency view of corporate social responsibility (CSR) generally considers CSR as a managerial agency problem and a waste of corporate resources, since corporate insiders do good with other people’s money. We evaluate this agency view using large-scale datasets with global coverage (59 countries) on firm-level corporate engagement and compliance wi...

  6. 7 CFR 58.436 - Rennet, pepsin, other milk clotting enzymes and flavor enzymes.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Rennet, pepsin, other milk clotting enzymes and flavor enzymes. 58.436 Section 58.436 Agriculture Regulations of the Department of Agriculture (Continued... clotting enzymes and flavor enzymes. Enzyme preparations used in the manufacture of cheese shall be...

  7. Biological variation in tPA-induced plasma clot lysis time

    NARCIS (Netherlands)

    S. Talens (Simone); J.J.M.C. Malfliet (Joyce); G. Rudež (Goran); H.M.H. Spronk (Henri); N.A.H. Janssen (N. A H); P. Meijer (Piet); C. Kluft (Cornelius); M.P.M. de Maat (Moniek); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractHypofibrinolysis is a risk factor for venous and arterial thrombosis, and can be assessed by using a turbidimetric tPA-induced clot lysis time (CLT) assay. Biological variation in clot lysis time may affect the interpretation and usefulness of CLT as a risk factor for thrombosis. Suffici

  8. Growth of hydroxyapatite on physiologically clotted fibrin capped gold nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Sastry, T P; Sundaraseelan, J; Swarnalatha, K; Sobhana, S S Liji; Makheswari, M Uma; Sekar, S; Mandal, A B [Central Leather Research Institute, Chennai-600020, Tamilnadu (India)], E-mail: sastrytp@hotmail.com, E-mail: abmandal@hotmail.com

    2008-06-18

    The growth of hydroxyapatite (HAp) on physiologically clotted fibrin (PCF)-gold nanoparticles is presented for the first time by employing a wet precipitation method. Fourier transform infrared (FTIR) spectroscopy confirmed the characteristic functionalities of PCF and HAp in the PCF-Au-HAp nanocomposite. Scanning electron microscopy (SEM) images have shown cuboidal nanostructures having a size in the range of 70-300 nm of HAp, whereas 2-50 nm sized particles were visualized in high-resolution transmission electron microscopy (TEM). Energy-dispersive x-ray (EDX) and x-ray diffraction (XRD) studies have confirmed the presence of HAp. These results show that gold nanoparticles with PCF acted as a matrix for the growth of HAp, and that PCF-Au-HAp nanocomposite is expected to have better osteoinductive properties.

  9. Polymorphism of clotting factors in Hungarian patients with Raynaud's phenomenon.

    Science.gov (United States)

    Shemirani, Amir-Houshang; Szomják, Edit; Balogh, Emese; András, Csilla; Kovács, Dóra; Acs, Judit; Csiki, Zoltán

    2011-01-01

    Patients with primary Raynaud's phenomenon may have a genetically determined risk for clotting factors that predispose them to aberrant microvascular thrombosis. We investigated the prevalence of factor V substitution of G to A at position 1691 (FVLeiden), prothrombin G20210A, and methyltetrahydrofolate reductase C677T mutations in these patients. Two hundred (158 women, 42 men, mean age of 42.4 ± 13.7 years) consecutive patients with primary Raynaud's phenomenon and 200 age-sex-matched healthy controls of Hungarian origin were included in a case-control study. The prevalence of methyltetrahydrofolate reductase C677T homozygous among patients was significantly lower than in the control group (odds ratio 0.4, 95% confidence interval 0.2-0.9, P Raynaud's phenomenon and control subjects. FVLeiden, prothrombin G20210A, and polymorphism, prothrombin G20210A mutations have no apparent effect on the etiology of primary Raynaud's phenomenon.

  10. Corporate Governance and Firm Performance: Results from Greek Firms

    OpenAIRE

    Toudas, Kanellos; Karathanassis, George

    2007-01-01

    In this paper, we construct a Governance Index for a sample of Greek companies quoted on the Athens Stock Exchange. We then classify firms, using each firm governance index, into three governance portfolios. Furthermore, the Fama and French model, extended to include a momentum variable, is tested for each of the three governance portfolios. Our findings suggest that most of the firms in our sample are semi-democracies followed by democracies and dictatorships respectively. Good governance ap...

  11. Firm-Specific Learning and the Nature of the Firm

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn

    2007-01-01

    This article discusses the limits of a purely transaction cost explanation of the existence of the firm by pointing to additional factors. A simple heuristic model shows that firm-specific learning effects can overcome the costs of monitoring employees, and explain the existence of the firm even...... in the absence of transaction costs related to the market mode of organisation. Comparing the relative importance of transaction cost and capabilities explanations for the existence of the firm, there is no a priori reason to assume the supremacy of one type of explanation over the other. We argue...

  12. Firm Level Determinants of Investment in the Kenyan Manufacturing Firm

    Directory of Open Access Journals (Sweden)

    Augustus S. Muluvi

    2011-09-01

    Full Text Available This study uses firm level data to investigate the investment behavior in the Kenyan manufacturing firms. Using Probit and Tobit regression models the results shows that factors determining the decision to invest are different from those determining the share invested. Overall the results shows low levels of investment by Kenyan manufacturing firms and the importance of firm level data in explaining the investment behavior. On the policy front the paper observes the role of government in the provision of stable macroeconomic policies, affordable credit and basic infrastructure in order to attract investment in this sector.

  13. Danish firms visit CERN

    CERN Multimedia

    FP Department

    2011-01-01

    30 – 31 JANUARY 2012 09:00 to 17:00 Monday 30 January 09:00 to 17:00 Tuesday 31 January Individual interviews will take place in technicians’ offices. The firms will contact relevant users/technicians but any user wishing to make contact with a particular firm is welcome to use the contact details available from the secretariat of their department or from the GS Department web page. List of Companies: · Axcon APS · BB Electronics A/S · B.Rustfrit Stal A/S · CIM Industrial Systems A/S · Danfysik A/S · Develco A/S · Eletronic A/S · GPV Group · Innoware A/S · JLI Vision A/S · NECAS A/S· NKT Cables A/S · Noliac A/S · Prodan A/S · Röttger’s Vaerktoj A/S · Vengcon APS For further information please contact Claudia Bruggmann Furlan  GS-IS-LS 73312 or Caroline Laignel GS-DI 73722.

  14. How to Assess Fibrinogen Levels and Fibrin Clot Properties in Clinical Practice?

    Science.gov (United States)

    Undas, Anetta

    2016-06-01

    Fibrin formed from fibrinogen is the main component of thrombi. Clot structure is characterized by fiber thickness and pore size, which differs within a given clot and between individuals. Plasma clot architecture is largely determined by the quantity and quality of fibrinogen. Plasma fibrinogen concentrations are most commonly measured in citrated plasma using the Clauss method. However, several factors, including instrument type and reagent, may affect results. Other approaches to express the ability of fibrinogen to clot involve prothrombin time-derived or clottable protein assays, while fibrinogen antigen levels in clinical settings are measured using immunological or precipitation assays. Fibrin clot permeability (reflected by the Darcy constant, K s) being proportional to a buffer volume percolating through a clot under a given hydrostatic pressure is now the most commonly used measure of clot structure. Low K s values indicating tightly packed fibrin structure have been shown to be associated with venous and arterial thrombotic complications, while high K s might contribute to bleeding disorders. The measurement of K s, however, is not standardized and validated. This review summarizes the current knowledge on practical aspects of the measurement of fibrinogen levels and K s in patients. PMID:27071050

  15. Lead Directorship and Firm Performance

    OpenAIRE

    OuYang, Bo

    2013-01-01

    This paper empirically explores the role of the lead directors in the corporate governance system and strives to empirically examine the association between the lead directorship and firm performance. I measure firm performance by three empirical proxies: Tobin’s Q, returns on assets (ROA) and stock returns. I explore the research question on the relationship between lead directorship and firm performance in both cross-sectional and inter-temporal contexts. The sample consists of S & P 500 fi...

  16. Should firms employ personalized pricing?

    OpenAIRE

    Matsumura, Toshihiro; Matsushima, Noriaki

    2013-01-01

    The recent developments in information technology (IT) have enabled firms to employ personalized pricing. Should all firms employ personalized pricing even though the adaptation costs of such pricing strategies are not high? This paper theoretically demonstrates a situation in which all firms do not always employ personalized pricing even though the fixed costs to do so is zero. The model is based on those of Thisse and Vives (1988) and Shaffer and Zhang (2002). Our model incorporates the fac...

  17. Director Characteristics and Firm Performance

    OpenAIRE

    Gantenbein, Pascal; Volonté, Christophe

    2011-01-01

    The traditional methodology examining optimal boards relates a simple board variable (e.g., independence or board demography) to firm performance, however, ig- noring other board characteristics. This paper investigates how the education and business experience of directors affect firm performance. The sample consists of 1,574 directorships from 224 listed firms in Switzerland. Using OLS and including control variables, the results show that graduates of minor Swiss universities are negativel...

  18. Geographical Vibrancy and Firm Performance

    OpenAIRE

    Ovtchinnikov , Alexei; Cooper, Michael

    2015-01-01

    Recent work has shown that where a firm is located matters for such things as dividend and investment policy, governance, liquidity, equity and debt issuance, and risk exposure. These effects seem to exist, in part, because of managements' desire to minimize agency problems related to monitoring and relationship building that vary as a function of firm distance from agents. The authors expand the current location literature by showing that firm location characteristics, not just distance per ...

  19. Controlling Shareholders and Firm Value

    OpenAIRE

    Borja Larraín; Matías Tapia

    2012-01-01

    We study the relationship between firm value and ownership concentration in a market where firms are controlled by large shareholders. We set up an equilibrium model with private benefits of control and bargaining between large shareholders. With simulated data from the model we are able to match approximately the value-concentration relationship observed among Chilean firms in 1990-2009. The model also delivers novel predictions regarding the relationship between investor protection and: (1)...

  20. Exploring Marketing in Micro Firms

    OpenAIRE

    WÀgar, Karolina; Björk, Peter; Ravald, Annika; West, Björn

    2007-01-01

    Purpose - The purpose of the paper is to explore the practice of marketing in micro firms. Which are the challenges micro firms encounter and how do they handle them? Methodology - The research methodology is based on the theory-in-use approach (Zaltman, Heffring & LeMasters 1982) in order to inductively explore the practice of marketing in micro firms. The empirical findings rest on ten case studies, where data has been generated through repeated interactions with each case. Find...

  1. Effects of calcium-modified titanium implant surfaces on platelet activation, clot formation, and osseointegration.

    Science.gov (United States)

    Anitua, Eduardo; Prado, Roberto; Orive, Gorka; Tejero, Ricardo

    2015-03-01

    The clinical success of load bearing dental and orthopedic implants relies on adequate osseointegration. Because of its favorable properties, titanium is generally considered as the material of choice. Following implant placement, titanium surfaces establish an ionic equilibrium with the surrounding tissues in which calcium plays major roles. Calcium is a cofactor of the coagulation cascade that mediates plasma protein adsorption and intervenes in a number of other intra and extracellular processes relevant for bone regeneration. In this study, titanium surfaces were modified with calcium ions (Ca(2+) surfaces) and their responses to in vitro and in vivo models were analyzed. Unlike unmodified surfaces, Ca(2+) surfaces were superhydrophilic and induced surface clot formation, platelet adsorption and activation when exposed to blood plasma. Interestingly, in vivo osseointegration using a peri-implant gap model in rabbit demonstrated that Ca(2+) surfaces significantly improved peri-implant bone volume and density at 2 weeks and bone implant contact at 8 weeks as compared to the unmodified controls. The combination of Ca(2+) surfaces with plasma rich in growth factors produced significantly more bone contact already at 2 weeks of implantation. These findings suggest the importance of the provisional matrix formation on tissue integration and highlight the clinical potential of Ca(2+) titanium surfaces as efficient stimulators of implant osseointegration.

  2. [Guidelines for certification of Activated clotting time (ACT) according to the EN ISO 22870 standards].

    Science.gov (United States)

    Lasne, Dominique; Bauters, Anne; Le Querrec, Agnès; Bourdin, Carole; Voisin, Sophie

    2015-01-01

    Point of care testing (POCT) must comply with regulatory requirements according to standard EN ISO 22870, which identify biologists as responsible for POCT. Activated clotting time (ACT) is mandatory to monitor on whole blood, anticoagulation achieved by unfractionated heparin during cardiopulmonary bypass (CPB) or cardiac catheterization. This test has no equivalent in the laboratory. With the aim to help the multidisciplinary groups for POCT supervision when they have to analyse the wish of medical departments to use ACT and to help the biologists to be in accordance with the standard, we present the guidelines of the GEHT (Groupe d'étude d'hémostase et thrombose) subcommittee "CEC et Biologie délocalisée" for the certification of ACT. These guidelines are based on the SFBC guidelines for the certification of POCT and on the analysis of the literature to ascertain the justification of clinical need and assess the analytical performance of main analyzers used in France, as well as on a survey conducted with French and Belgian biologists.

  3. Knowledge management in the firm

    DEFF Research Database (Denmark)

    Rasmussen, Palle; Nielsen, Peter

    2011-01-01

    , transforming and utilizing various kinds of knowledge as a firm-specific asset is a very important element of firm competitiveness and innovative performance. In managing knowledge learning and innovation learning approaches are central. The paper identifies various approaches to learning and strategies...... to innovation and illustrates how combinations of these might benefit firm performance. It also stresses the preconditions of employee involvement and participation to knowledge management and not least the importance of interaction with environmental resources. To improve performance firms should be aware...

  4. Experiences of Emerging Economy Firms

    DEFF Research Database (Denmark)

    Vissak, Tiia; Zhang, Xiaotian

    2015-01-01

    Experiences of Emerging Economy Firms investigates the different elements of the experiences of emerging economy firms and sheds essential light on a large variety of aspects associated with their functioning in both home and host contexts. For example, firms must be able to overcome the liability...... of foreign and emerging issues when they expand their activities in various contexts, enter, exit, and re-enter overseas markets; they have to overcome institutional barriers, adapt the cultural challenges in foreign markets, undergo the impact of large multinational firms from developed economies...

  5. Credit rationing and firm size

    Directory of Open Access Journals (Sweden)

    G. CALCAGNINI

    2013-10-01

    Full Text Available This paper examines the likelihood of credit rationing faced by firms of different size. Contrary to common thought, several recent contributions on this topic argue that, when rationing credit, size alone is not a sufficient condition for discriminating between firms. We show that this result can be predicted using a framework based on the Stiglitz-Weiss model. In particular, in an environment of asymmetric information, we highlight how the likelihood of credit rationing depends upon the shape of the distribution function of project returns, especially its asymmetry and Kurtosis. Our empirical results do not support the hypothesis that small firms face more credit rationing than larger firms.

  6. Patenting activities and firm performance : Does firm size matter?

    NARCIS (Netherlands)

    Andries, P.; Faems, D.L.M.

    2013-01-01

    Whereas prior research has provided valuable insights into the willingness of small and medium-sized enterprises (SMEs) and large firms to engage in patenting, a comparison of the performance implications of patenting activities across small and large firms is still lacking. This gap is important be

  7. Scientific Auditing Firms

    CERN Document Server

    Sarma, Gopal P

    2016-01-01

    The "crisis of reproducibility" has been a significant source of controversy, heated debate, and calls for reform to institutional science in recent years. As a long-term solution to address both the present crisis and future obstacles, I propose the creation of a new form of research organization whose purpose would be to conduct random audits of the scientific literature. I suggest that data analytics of a digitized scientific corpus may play a critical role in allowing broadly educated scientists to identify linchpin results to investigate in further detail across all disciplines. I argue that a simple "mock" trial run of a simplified auditing firm consisting of several researchers over a short time period would provide valuable insight into the feasibility of this proposal.

  8. Inside the Family Firm

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Nielsen, Kasper; Pérez-González, Francisco;

    2005-01-01

    This paper uses a unique dataset from Denmark to investigate (1) the role of family characteristics in corporate decision making, and (2) the consequences of these decisions on firm performance. We focus on the decision to appoint either a family or an external chief executive officer (CEO). We...... show that a departing CEO's family characteristics have a strong predictive power in explaining CEO succession decisions: family CEOs are more frequently selected the larger the size of the family, the higher the ratio of male children and when the departing CEOs had only had one spouse. We...... then analyze the impact of family successions on performance. We overcome endogeneity and omitted variables problems of previous papers in the literature by using the gender of a departing CEO's first-born child as an instrumental variable (IV) for family successions. This is a plausible IV as male first...

  9. Measuring Firm Performance

    DEFF Research Database (Denmark)

    Assaf, A. George; Josiassen, Alexander; Gillen, David

    2014-01-01

    Set in the airport industry, this paper measures firm performance using both desirable and bad outputs (i.e. airport delays). We first estimate a model that does not include the bad outputs and then a model that includes bad outputs. The results show important differences in the efficiency...... and productivity results depending on whether bad outputs are or are not included in the model. The differences reflect the resource cost to society and the potential cost to an airport if such externalities were internalized. Finally, the paper provides measures of shadow prices for the bad output, in our case...... airport delay, and discusses the results in terms of several interesting trends affecting US airports....

  10. Risk-taking and Firm Growth

    OpenAIRE

    Xu, Peng

    2015-01-01

    Using firm data from 2002-2012, we examine the relationship between capital structure and risk taking, and between risk taking and firm performance of small and medium-sized enterprises and large private firms. Domestically-owned entrepreneurial private firms are more risk averse than domestically-owned affiliated private firms. Foreign-owned affiliated private firms are much more risk taking than domestically-owned private firms. However, leverage is not strongly associated with less corpora...

  11. Firm Traits and Web Based Disclosures in Top Nigerian Firms

    Directory of Open Access Journals (Sweden)

    Bello Ayuba

    2016-02-01

    Full Text Available The use of the internet as a medium of dissemination of information to stakeholders is increasingly gaining grounds. This study extends existing literature on web disclosures by investigating the characteristics that predict the extent of web-based disclosures. In this study, corporate websites of top Nigerian firms are used as sources of data, while a regression analysis is employed to examine the extent of prediction. Results indicate that the firm size and industry type are significant determinants of web disclosures. However, other firm traits such as ownership dispersion and financial performance do not significantly explain the extent of internet disclosures. The study recommends that a regulatory template for corporate web disclosures be put in place by government regardless of the size or industry classification of the firm. This is with a view to considerably reduce agency conflicts arising from information asymmetry in publicly listed firms in Nigeria.

  12. 体外循环术对先天性心脏病儿童围术期凝血功能的影响及临床意义%Study on the clinical significance and effect of cardiopulmonary bypass on intraoperative blood clotting function in pediatric patients with congenital heart disease

    Institute of Scientific and Technical Information of China (English)

    冯永健; 杨宁; 董斌; 徐远久

    2015-01-01

    目的观察先天性心脏病儿童行体外循环术中凝血功能的变化,并分析其监测的应用价值。方法选取2012年1月至2013年12月间30例先天性心脏病体外循环术患儿为研究组,并且选取同期15例先天性心脏病非外循环术患儿为对照组。观察两组患儿手术前后的凝血功能变化。结果研究组患儿手术前后凝血指标比较差异无统计学意义( P >0.05);研究组患儿术后24 h 凝血指标显著低于对照组,差异有统计学意义( P 0. 05). The changes in blood coagula-tion parameters in patients of study group in 24 h after surgery were significantly lower than those of control group,and the difference was statisti-cally significant( P < 0. 05). The difference in PLT counts in 3 h after surgery in patients with Fallot′s tetralogy and ventricular septal defect im-mediately after surgery and 3 h after surgery was statistically significant( P < 0. 05). The difference in levels of FIB in patients with Fallot′s tetral-ogy and patients with ventricular septal defect at immediately and 24 h after surgery was statistically significant( P < 0. 05). Conclusion The application of bypass circulation is better than traditional non - cardiopulmonary bypass in surgical treatment of patients with Fallot′s tetralogy and ventricular septal defect in pediatric patients with congenital heart disease,it had certain impact on coagulation parameters,but they return to nor-mal in 24 h after surgery. It is important to strengthen the monitoring of clinical coagulation parameters,hence it can better guide surgeons in oper-ations,thereby it may reduce the risk of surgery,and it is important to apply in clinical practice.

  13. Quality control in audit firm

    OpenAIRE

    Dostálová, Milena

    2008-01-01

    Thesis deals with the quality control of audit firms in accordance with international regulations. Defining the requirements for quality based on the Code of Ethics and the International quality standard ISQC1. Part of this work is the practical demonstration of ISQC1 in the smaller audit firm. For comparison, there is a description of quality control in the U.S.

  14. Does internationalization foster firm performance?

    NARCIS (Netherlands)

    van den Berg, Marcel

    2014-01-01

    The research in this dissertation concerns the impact of internationalization of business activities on several dimensions of firm performance. We show that the productivity ranking by trade status of Dutch manufacturing firms in increasing order of productivity is: non-traders, importers, exporters

  15. Relationship Lending and Firm Innovativeness

    NARCIS (Netherlands)

    Giannetti, C.

    2009-01-01

    This study investigates the effects of relationship lending on firm innovativeness using a panel of Italian manufacturing firms. In order to disentangle the impact of bank ties on the discovery phase from that in the introduction phase of new technologies, the analysis proceeds in two steps, estimat

  16. Competitive Advantage of Interconnected Firms

    DEFF Research Database (Denmark)

    Nell, Phillip Christopher; Andersson, Ulf

    We model the complex interplay between firm-level variables, notably capabilities and performance, and relationship-level variables: relationship-specific assets and network context. We test how the network context of individual exchange relationships as well as firm-level capabilities jointly af...

  17. Dividend Policy of German Firms

    NARCIS (Netherlands)

    Goergen, M.; Renneboog, L.D.R.; Correia Da Silva, L.

    2004-01-01

    German firms pay out a lower proportion of their cash flows than UK and US firms.However, on a published profits basis, the pattern is reversed.Company law provisions and accounting policies account for these conflicting results.A partial adjustment model is used to estimate the implicit target payo

  18. Development and comparison of a minimally-invasive model of autologous clot pulmonary embolism in Sprague-Dawley and Copenhagen rats

    Directory of Open Access Journals (Sweden)

    Sanapareddy Nina

    2010-02-01

    Full Text Available Abstract Background Experimental models of pulmonary embolism (PE that produce pulmonary hypertension (PH employ many different methods of inducing acute pulmonary occlusion. Many of these models induce PE with intravenous injection of exogenous impervious objects that may not completely reproduce the physiological properties of autologous thromboembolism. Current literature lacks a simple, well-described rat model of autlogous PE. Objective: Test if moderate-severity autologous PE in Sprague-Dawley (SD and Copenhagen (Cop rats can produce persistent PH. Methods blood was withdrawn from the jugular vein, treated with thrombin-Ca++ and re-injected following pretreatment with tranexamic acid. Hemodynamic values, clot weights and biochemical measurements were performed at 1 and 5 days. Results Infusion of clot significantly increased the right ventricular peak systolic pressure to 45-55 mm Hg, followed by normalization within 24 hours in SD rats, and within 5 days in COP rats. Clot lysis was 95% (24 hours and 97% (5 days in SD rats and was significantly lower in COP rats (70%, 24 hours; 87% 5 days. Plasma D-dimer was elevated in surgical sham animals and was further increased 8 hours after pulmonary embolism. Neither strain showed a significant increase in bronchoalveolar chemotactic activity, myeloperoxidase activity, leukocyte infiltration, or chemokine accumulation, indicating that there was no significant pulmonary inflammation. Conclusions Both SD and COP rats exhibited near complete fibrinolysis of autologous clot PE within 5 days. Neither strain developed persistent PH. Experimental models of PE designed to induce sustained PH and a robust inflammatory response appear to require significant, persistent pulmonary vascular occlusion.

  19. Thromboelastography to Monitor Clotting/Bleeding Complications in Patients Treated with the Molecular Adsorbent Recirculating System

    OpenAIRE

    Schuepbach, Reto A; Renner, Eberhard L; Beat Müllhaupt; Marco Maggiorini; Markus Béchir; Stover, John F.; Reto Stocker; Jörg Bösiger; Bachli, Esther B.

    2011-01-01

    Background. The Molecular Adsorbent Recirculating System (MARS) has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS ...

  20. T2* "susceptibility vessel sign" demonstrates clot location and length in acute ischemic stroke.

    Directory of Open Access Journals (Sweden)

    Olivier Naggara

    Full Text Available OBJECTIVES: The aim of our study was to evaluate, in acute ischemic stroke patients, the diagnostic accuracy of the MRI susceptibility vessel sign (SVS against catheter angiography (DSA for the detection of the clot and its value in predicting clot location and length. MATERIALS AND METHODS: We identified consecutive patients (2006-2012 admitted to our center, where 1.5 T MRI is systematically implemented as first-line diagnostic work-up, with: (1 pre-treatment 6-mm-thick multislice 2D T2* sequence; (2 delay from MRI-to-DSA 94%. Inter- and intra-observer ICC was excellent for clot length as measured on T2* (ĸ ≥ 0.97 and as measured on DSA (ĸ ≥ 0.94. Correlation between T2* and DSA for clot length was excellent (ICC: 0.88, 95%CI: 0.81-0.92; Bland & Altman: mean bias of 1.6% [95%CI: -4.7 to 7.8%], Passing & Bablok: 0.91. CONCLUSIONS: SVS is a specific marker of clot location in the anterior and posterior circulation. Clot length greater than 6 mm can be reliably measured on T2*.

  1. Novel fibrin clot components : identification, characterization and function

    NARCIS (Netherlands)

    S. Talens (Simone)

    2013-01-01

    textabstractThe main goal of blood coagulation is to diminish blood loss and to support vessel damage repair. The initial step in primary hemostasis is the adhesion of platelets to the exposed subendothelial extracellular matrix which contains several adhesive macromolecules such as collagen, von Wi

  2. Multifrequency acoustics as a probe of mesoscopic blood coagulation dynamics

    Science.gov (United States)

    Ganesan, Adarsh; Rajendran, Gokulnath; Ercole, Ari; Seshia, Ashwin

    2016-08-01

    Coagulation is a complex enzymatic polymerisation cascade. Disordered coagulation is common in medicine and may be life-threatening yet clinical assays are typically bulky and/or provide an incomplete picture of clot mechanical evolution. We present the adaptation of an in-plane acoustic wave device: quartz crystal microbalance with dissipation at multiple harmonics to determine the time-evolution of mesoscale mechanical properties of clot formation in vitro. This approach is sensitive to changes in surface and bulk clot structure in various models of induced coagulopathy. Furthermore, we are able to show that clot formation at surfaces has different kinetics and mechanical strength to that in the bulk, which may have implications for the design of bioprosthetic materials. The "Multifrequency acoustics" approach thus enables unique capability to portray biological processes concerning blood coagulation.

  3. Firm-specific learning and the investment behavior of large and small firms

    OpenAIRE

    Wenli Li; Weinberg, John A.

    1999-01-01

    We examine a model of the size distribution and growth of firms whereby firms learn about idiosyncratic productivity parameters. Aggregate shocks, by adding noise to learning at the firm level, can produce differentiated response across firms with their reactions depending on the position of the firms in their individual life cycle. In particular, young firms, which are smaller on average than older firms, can 'overreact' to aggregate shocks. Such differences across firm sizes and ages, which...

  4. Firm Search for External Knowledge

    DEFF Research Database (Denmark)

    Sofka, Wolfgang; Grimpe, Christoph

    2012-01-01

    The innovation performance of modern firms is increasingly determined by their ability to search and absorb external knowledge. However, after a certain threshold firms "oversearch" their environment and innovation performance declines. In this paper, we argue that prior literature has largely...... ignored the institutional context that provides or denies access to external knowledge at the country level. Combining institutional and knowledge search theory, we suggest that the market orientation of the institutional environment and the magnitude of institutional change influence when firms begin...... for external knowledge while higher magnitudes of institutional change decrease it. Our results provide important insights for management on how to adapt search strategies to the institutional context....

  5. Dividend Policy of German Firms

    OpenAIRE

    M. Goergen; Renneboog, L.D.R.; Correia Da Silva, L.

    2004-01-01

    German firms pay out a lower proportion of their cash flows than UK and US firms.However, on a published profits basis, the pattern is reversed.Company law provisions and accounting policies account for these conflicting results.A partial adjustment model is used to estimate the implicit target payout ratio and the speed of adjustment of dividends towards a long run target payout ratio. We find that German firms do not base their dividend decisions on published earnings, but on cash flows.The...

  6. Board Effectiveness in Small Firms

    OpenAIRE

    Söderqvist, Anette; WÀgar, Karolina

    2010-01-01

    Purpose: This study investigates boards of directors in small firms and explores the link between board effectiveness and the composition, roles and working styles of the boards. Design/methodology/approach: The study analyses data from a telephone survey of boards in 45 small firms. The survey included both the CEO and the chairperson of the board. Findings: The study identifies three groups of small firms: ‘paperboards’, ‘professional boards’, and ‘management ...

  7. Firm Sustainability Performance Index Modeling

    Directory of Open Access Journals (Sweden)

    Che Wan Jasimah Bt Wan Mohamed Radzi

    2015-12-01

    Full Text Available The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling. Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learning, and business strategy. Based on the both Bayesian and classical methodology, we confirmed that knowledge management and business strategy have significant impact on firm sustainability performance index.

  8. Directors' human capital, firm strategy, and firm performance

    OpenAIRE

    Volonté, Christophe; Gantenbein, Pascal

    2016-01-01

    Ideally, corporations are directed by boards whose directors provide valuable human capital that match the firms’ strategy. We investigate how directors’ human capital (international experience, industrial know-how, CEO experience, and financial know-how) affects firm performance including the firm’s strategy (diversification and internationalization) and how human capital is related to acquisition strategies (non-diversifying and international acquisitions). Our sample consists of 560 firm-y...

  9. New Firm Growth: Exploring Processes and Paths

    OpenAIRE

    Garnsey, E.; Stam, Erik; Heffernan, P.; Hugo, O.

    2003-01-01

    textabstractThis paper provides a new methodology for the diachronic study of new firm growth, theoretically grounded in the work of Penrose (1995). We show that a model of firm growth as an unfolding process makes possible draw simple, measurable inferences from firm level to aggregate evidence on growth paths of new firms, expressed as propositions. Metrics on growth paths of new firms in three longitudinal samples of new firms are examined for evidence at the aggregate level consistent wit...

  10. The Role of Firm Ownership on Internationalization

    DEFF Research Database (Denmark)

    Hobdari, Bersant; Gregoric, Aleksandra; Sinani, Evis

    2011-01-01

    This paper investigates how different types of owners influence the extent of firm internationalization, measured by the share of firm exports in total sales. The results of the analysis carried out using firm level data of Estonian and Slovenian firms, show that the firms under the control...... in internationalization process. Finally, high market share also leads to increased internationalization through exports as firms seek to expand in foreign markets after having dominated the domestic ones....

  11. Public/private transitions and firm financing

    OpenAIRE

    Huynh, Kim P.; Paligorova, Teodora; Petrunia, Robert

    2013-01-01

    A large body of empirical literature investigates differences in financing structures across firms. Private firms' financing receives little attention due to the lack of data. Using administrative confidential data on the universe of Canadian corporate firms, we compare financing relationships for private and public firms. Leverage ratios are lower for public firms and the difference is almost entirely driven by private firms' stronger reliance on short-term debt. We also find that private an...

  12. The Contribution of Pin End-Cup Interactions to Clot Strength Assessed with Thrombelastography.

    Science.gov (United States)

    Nielsen, Vance G

    2016-01-01

    Viscoelastic methods have been developed to assess the contribution of plasma proteins and platelets to coagulation in vitro to guide clinical transfusion therapy. One of the cardinal precepts of determining clot strength is making sure that the viscoelastic technique includes complete exposure of the plastic pin in the testing chamber with the fluid analyzed so as to assure maximal interaction of the cup wall with the pin surface. However, the various contributions of the pin surface area to final clot strength have not been investigated. That is, it is not clear what is more important in the in vitro determination of clot strength, the surface area shared between the cup and pin filled with fluid or the final viscoelastic resistance of the gel matrix formed. Thus, the purpose of this investigation was to determine the clot strength when only the tip of the pin was engaged with plasma thrombus and to compare these values with clot strength values obtained when the pin was completely in plasma. After determining the minimal amount of plasma required to cover a pin tip in a thrombelastographic system (30 μL), clot strength (elastic modulus, G) was determined in plasma samples of 30 or 360 μL final volume (n = 12 per condition) after tissue factor activation. The G value with 30 μL volume was 1057 ± 601 dynes/cm (mean ± SD; 95% confidence interval, 675-1439 dynes/cm), which was (P = 0.0015) smaller than the G value associated with 360-μL sample volumes, that was 1712 ± 48 dynes/cm (confidence interval, 1681-1742 dynes/cm). In conclusion, these data demonstrate that clot strength is not determined by a simple ratio of surface area of pin and cup to volume of sample, but rather strength is importantly influenced by the viscoelastic resistance of the fluid assessed.

  13. Web traffic and firm performance

    DEFF Research Database (Denmark)

    Farooq, Omar; Aguenaou, Samir

    2013-01-01

    Does the traffic generated by websites of firms signal anything to stock market participants? Does higher web-traffic translate into availability of more information and therefore lower agency problems? And if answers to above questions are in affirmative, does higher web-traffic traffic translate...... into better firm performance? This paper aims to answer these questions by documenting a positive relationship between the extent of web-traffic and firm performance in the MENA region during the 2010. We argue that higher web-traffic lowers the agency problems in firms by disseminating more information...... to stock market participants. Consequently, lower agency problems translate into better performance. Furthermore, we also show that agency reducing role of web-traffic is more pronounced in regimes where information environment is already bad. For example, our results show stronger impact of web...

  14. Highly Effective DNA Extraction Method from Fresh, Frozen, Dried and Clotted Blood Samples

    OpenAIRE

    Jaleh Barar; Sina Atashpaz; Abolfazl Barzegari; Vala Kafil; Sepideh Zununi Vahed; Farzaneh Soltanzad; Sara Samadi Shams

    2011-01-01

    Introduction: Today, with the tremendous potential of genomics and other recent advances in science, the role of science to improve reliable DNA extraction methods is more relevant than ever before. The ideal process for genomic DNA extraction demands high quantities of pure, integral and intact genomic DNA (gDNA) from the sample with minimal co-extraction of inhibitors of downstream processes. Here, we report the development of a very rapid, less-hazardous, and high throughput protocol for e...

  15. 42 CFR 410.63 - Hepatitis B vaccine and blood clotting factors: Conditions.

    Science.gov (United States)

    2010-10-01

    ... furnishing fee paid the previous year increased by the percentage increase in the consumer price index for... factors to control bleeding for hemophilia patients competent to use these factors without medical...

  16. A feasible strategy for preventing blood clots in critically ill patients with acute kidney injury (FBI)

    DEFF Research Database (Denmark)

    Robinson, Sian I.; Zincuk, A.; Larsen, U. L.;

    2014-01-01

    BACKGROUND: Previous pharmacokinetic trials suggested that 40 mg subcutaneous enoxaparin once daily provided inadequate thromboprophylaxis for intensive care unit patients. Critically ill patients with acute kidney injury are at increased risk of venous thromboembolism and yet are often excluded...... from these trials. We hypothesized that for critically ill patients with acute kidney injury receiving continuous renal replacement therapy, a dose of 1 mg/kg enoxaparin subcutaneously once daily would improve thromboprophylaxis without increasing the risk of bleeding. In addition, we seek to utilize...... urine output prior to discontinuing dialysis, and low neutrophil gelatinase-associated lipocalin in dialysis-free intervals, as markers of renal recovery. METHODS/DESIGN: In a multicenter, double-blind randomized controlled trial in progress at three intensive care units across Denmark, we randomly...

  17. Firm Sustainability Performance Index Modeling

    OpenAIRE

    Che Wan Jasimah Bt Wan Mohamed Radzi; Hashem Salarzadeh Jenatabadi; Maisarah Binti Hasbullah

    2015-01-01

    The main objective of this paper is to bring a model for firm sustainability performance index by applying both classical and Bayesian structural equation modeling (parametric and semi-parametric modeling). Both techniques are considered to the research data collected based on a survey directed to the China, Taiwan, and Malaysia food manufacturing industry. For estimating firm sustainability performance index we consider three main indicators include knowledge management, organizational learn...

  18. Innovation Strategies and Firm Performance

    OpenAIRE

    Karlsson, Charlie; Tavassoli, Sam

    2015-01-01

    This paper analyzes the effect of various innovation strategies of firms on their future performance, captured by labour productivity. Using five waves of the Community Innovation Survey in Sweden, we have traced the innovative behaviour of firms over a decade, i.e. from 2002 to 2012. We distinguish between sixteen innovation strategies, which compose of Schumpeterian four types of innovations, i.e. process, product, marketing, and organizational (simple innovation strategies) plus various co...

  19. The nature of the firm

    OpenAIRE

    Xin LI

    2009-01-01

    This paper is intended to propose a relationship-based theory of the firm (R’BT), an alternative to the transaction cost theory. The R’BT takes relationship disharmony (rather than transaction costs) as its basic unit of analysis of the nature of the firm, and argues relationship disharmony derives from conflict of interests, a problem faced by any human organizations; to reduce the conflict of interests, the best way is to harmonize relationships by mutually accommodating or i...

  20. Dividend Policy in Regulated Firms

    OpenAIRE

    rondi, laura; Cambini, Carlo; bremberger, francisca; GUGLER, Klaus

    2013-01-01

    We study the impact of different regulatory and ownership regimes on the dividend policy of regulated firms. Using a panel of 106 publicly traded European electric utilities in the period 1986-2010, we link payout and smoothing decisions to the implementation of different regulatory mechanisms (cost plus vs. incentive regulation) and to firm ownership (state vs. private). After controlling for the potential endogeneity of the regulatory mechanism, our results show that utilities subject to i...

  1. Consumer Networks and Firm Reputation

    DEFF Research Database (Denmark)

    Huck, Steffen; Lünser, Gabriele K.; Tyran, Jean-Robert

    Arguing that consumers are the carriers of firms' reputations, we examine the role of consumer networks for trust in markets that suffer from moral hazard. When consumers are embedded in a network, they can exchange information with their neighbours about their private experiences with different ...... sellers. We find that such information exchange fosters firms' incentives for reputation building and, thus, enhances trust and efficiency in markets. This efficiency-enhancing effect is already achieved with a rather low level of network density...

  2. A Serpin Released by an Entomopathogen Impairs Clot Formation in Insect Defense System

    Science.gov (United States)

    Hao, YouJin; Balasubramanian, Natesan; Jing, Yingjun; Montiel, Rafael; Faria, Tiago Q.; Brito, Rui M.; Simões, Nelson

    2013-01-01

    Steinernema carpocapsae is an entomopathogenic nematode widely used for the control of insect pests due to its virulence, which is mainly attributed to the ability the parasitic stage has to overcome insect defences. To identify the mechanisms underlying such a characteristic, we studied a novel serpin-like inhibitor (sc-srp-6) that was detected in a transcriptome analysis. Recombinant Sc-SRP-6 produced in Escherichia coli had a native fold of serpins belonging to the α-1-peptidase family and exhibited inhibitory activity against trypsin and α-chymotrypsin with Ki of 0.42×10−7 M and 1.22×10−7 M, respectively. Functional analysis revealed that Sc-SRP-6 inhibits insect digestive enzymes, thus preventing the hydrolysis of ingested particles. Moreover, Sc-SRP-6 impaired the formation of hard clots at the injury site, a major insect defence mechanism against invasive pathogens. Sc-SRP-6 does not prevent the formation of clot fibres and the activation of prophenoloxidases but impairs the incorporation of the melanin into the clot. Binding assays showed a complex formation between Sc-SRP-6 and three proteins in the hemolymph of lepidopteran required for clotting, apolipophorin, hexamerin and trypsin-like, although the catalytic inhibition occurred exclusively in trypsin-like. This data allowed the conclusion that Sc-SRP-6 promotes nematode virulence by inhibiting insect gut juices and by impairing immune clot reaction. PMID:23874900

  3. Firm Culture and Leadership as Firm Performance Predictors: a Resource-Based Perspective

    OpenAIRE

    Wilderom, C.P.M.; van den Berg, P.

    2000-01-01

    In this study, we tested part of the resource-based view of the firm by examining two 'soft' resources, firm culture and top leadership, as predictors of 'hard' or bottom-line firm performance.Transformational top leadership was found to predict firm performance directly while the link between firm culture and firm performance was indirect: via transformational top leadership.Firm culture was operationalized as the employees' views about the degree of optimization of four organizational pract...

  4. The spider hemolymph clot proteome reveals high concentrations of hemocyanin and von Willebrand factor-like proteins.

    Science.gov (United States)

    Sanggaard, Kristian W; Dyrlund, Thomas F; Bechsgaard, Jesper S; Scavenius, Carsten; Wang, Tobias; Bilde, Trine; Enghild, Jan J

    2016-02-01

    Arthropods include chelicerates, crustaceans, and insects that all have open circulation systems and thus require different properties of their coagulation system than vertebrates. Although the clotting reaction in the chelicerate horseshoe crab (Family: Limulidae) has been described in details, the overall protein composition of the resulting clot has not been analyzed for any of the chelicerates. The largest class among the chelicerates is the arachnids, which includes spiders, ticks, mites, and scorpions. Here, we use a mass spectrometry-based approach to characterize the spider hemolymph clot proteome from the Brazilian whiteknee tarantula, Acanthoscurria geniculata. We focused on the insoluble part of the clot and demonstrated high concentrations of proteins homologous to the hemostasis-related and multimerization-prone von Willebrand factor. These proteins, which include hemolectins and vitellogenin homologous, were previously identified as essential components of the hemolymph clot in crustaceans and insects. Their presence in the spider hemolymph clot suggests that the origin of these proteins' function in coagulation predates the split between chelicerates and mandibulata. The clot proteome reveals that the major proteinaceous component is the oxygen-transporting and phenoloxidase-displaying abundant hemolymph protein hemocyanin, suggesting that this protein also plays a role in clot biology. Furthermore, quantification of the peptidome after coagulation revealed the simultaneous activation of both the innate immune system and the coagulation system. In general, many of the identified clot-proteins are related to the innate immune system, and our results support the previously suggested crosstalk between immunity and coagulation in arthropods.

  5. The spider hemolymph clot proteome reveals high concentrations of hemocyanin and von Willebrand factor-like proteins.

    Science.gov (United States)

    Sanggaard, Kristian W; Dyrlund, Thomas F; Bechsgaard, Jesper S; Scavenius, Carsten; Wang, Tobias; Bilde, Trine; Enghild, Jan J

    2016-02-01

    Arthropods include chelicerates, crustaceans, and insects that all have open circulation systems and thus require different properties of their coagulation system than vertebrates. Although the clotting reaction in the chelicerate horseshoe crab (Family: Limulidae) has been described in details, the overall protein composition of the resulting clot has not been analyzed for any of the chelicerates. The largest class among the chelicerates is the arachnids, which includes spiders, ticks, mites, and scorpions. Here, we use a mass spectrometry-based approach to characterize the spider hemolymph clot proteome from the Brazilian whiteknee tarantula, Acanthoscurria geniculata. We focused on the insoluble part of the clot and demonstrated high concentrations of proteins homologous to the hemostasis-related and multimerization-prone von Willebrand factor. These proteins, which include hemolectins and vitellogenin homologous, were previously identified as essential components of the hemolymph clot in crustaceans and insects. Their presence in the spider hemolymph clot suggests that the origin of these proteins' function in coagulation predates the split between chelicerates and mandibulata. The clot proteome reveals that the major proteinaceous component is the oxygen-transporting and phenoloxidase-displaying abundant hemolymph protein hemocyanin, suggesting that this protein also plays a role in clot biology. Furthermore, quantification of the peptidome after coagulation revealed the simultaneous activation of both the innate immune system and the coagulation system. In general, many of the identified clot-proteins are related to the innate immune system, and our results support the previously suggested crosstalk between immunity and coagulation in arthropods. PMID:26621385

  6. Merger incentives and the failing firm defense

    NARCIS (Netherlands)

    Bouckaert, J.M.C.; Kort, P.M.

    2014-01-01

    The merger incentives between profitable firms differ fundamentally from the incentives of a profitable firm to merge with a failing firm. We investigate these incentives under different modes of price competition and Cournot behavior. Our main finding is that firms strictly prefer exit of the faili

  7. Ex-vivo response to blood products and haemostatic agents after paediatric cardiac surgery

    DEFF Research Database (Denmark)

    Hvas, Anne-Mette; Andreasen, Jo B; Christiansen, Kirsten;

    2013-01-01

    cardiac surgery. The haemostatic potential of various factor concentrates (fibrinogen concentrate, recombinant factor VIIa and factor XIII), fresh frozen plasma (FFP), pooled platelets and tranexamic acid was investigated. After surgery, the coagulation profiles revealed significantly prolonged clotting...... of fibrinogen concentrate, FFP or tranexamic acid improved clot stability significantly. Whole blood coagulation was significantly impaired after cardiac surgery in children. Ex-vivo studies showed a total reversal of the coagulopathy after addition of pooled platelets and significantly improved clot stability...... after addition of fibrinogen concentrate, FFP and tranexamic acid, respectively....

  8. Quality Signaling, Advertising and Firm Numbers

    OpenAIRE

    Tsui, Hsiao-Chien; Lin, Yi-Shiun

    2013-01-01

    This paper investigates whether low-quality firms can pretend through advertising to be high-quality firms, which is a signal of product quality, when the number of firms increases. We assume that consumers remain loyal to high-quality firms after purchasing high-quality products and will therefore not patronize low-quality firms, which pretend through advertising to be high-quality firms. Our results indicate that the possibility of low-quality firms entering the high-quality market declines...

  9. Process Ambidexterity for Entrepreneurial Firms

    Directory of Open Access Journals (Sweden)

    Sonia D. Bot

    2012-04-01

    Full Text Available Technology-based entrepreneurial firms must effectively support both mainstream exploitation and new-stream exploration in order to remain competitive for the long term. The processes that support exploitation and exploration initiatives are different in terms of logistics, payoff horizons, and capabilities. Few firms are able to strike a balance between the two, where mainstream exploitation usually trumps new-stream exploration. The ultimate goal is for the firm to operate effectively in a repeatable, scalable, and systematic manner, rather than relying on good luck and hoping either to come up with the next innovation or for the product to function according to its requirements. This article builds on the author’s years of experience in building businesses and transforming medium and large-sized, entrepreneurial technology firms, leading large-scale breakthrough and sustained performance improvements by using and evolving Lean Six Sigma methodologies, and reviews of technology innovation management and entrepreneurship literature. This article provides a process-based perspective to understanding and addressing the issues on balancing mainstream exploitation and new-stream exploration in medium and large-sized entrepreneurial firms and extending it to startups. The resulting capability is known as process ambidexterity and requires disciplined, agile, and lean business management.

  10. In Vitro impairment of whole blood coagulation and platelet function by hypertonic saline hydroxyethyl starch

    Directory of Open Access Journals (Sweden)

    Görlinger Klaus

    2011-02-01

    Full Text Available Abstract Background Hypertonic saline hydroxyethyl starch (HH has been recommended for first line treatment of hemorrhagic shock. Its effects on coagulation are unclear. We studied in vitro effects of HH dilution on whole blood coagulation and platelet function. Furthermore 7.2% hypertonic saline, 6% hydroxyethylstarch (as ingredients of HH, and 0.9% saline solution (as control were tested in comparable dilutions to estimate specific component effects of HH on coagulation. Methods The study was designed as experimental non-randomized comparative in vitro study. Following institutional review board approval and informed consent blood samples were taken from 10 healthy volunteers and diluted in vitro with either HH (HyperHaes®, Fresenius Kabi, Germany, hypertonic saline (HT, 7.2% NaCl, hydroxyethylstarch (HS, HAES6%, Fresenius Kabi, Germany or NaCl 0.9% (ISO in a proportion of 5%, 10%, 20% and 40%. Coagulation was studied in whole blood by rotation thrombelastometry (ROTEM after thromboplastin activation without (ExTEM and with inhibition of thrombocyte function by cytochalasin D (FibTEM, the latter was performed to determine fibrin polymerisation alone. Values are expressed as maximal clot firmness (MCF, [mm] and clotting time (CT, [s]. Platelet aggregation was determined by impedance aggregrometry (Multiplate after activation with thrombin receptor-activating peptide 6 (TRAP and quantified by the area under the aggregation curve (AUC [aggregation units (AU/min]. Scanning electron microscopy was performed to evaluate HyperHaes induced cell shape changes of thrombocytes. Statistics: 2-way ANOVA for repeated measurements, Bonferroni post hoc test, p Results Dilution impaired whole blood coagulation and thrombocyte aggregation in all dilutions in a dose dependent fashion. In contrast to dilution with ISO and HS, respectively, dilution with HH as well as HT almost abolished coagulation (MCFExTEM from 57.3 ± 4.9 mm (native to 1.7 ± 2.2 mm (HH 40

  11. Multiple-product firms and product switching

    OpenAIRE

    Andrew B. Bernard; Redding, Stephen; Peter K. Schott

    2010-01-01

    This paper examines the frequency, pervasiveness, and determinants of product switching by US manufacturing firms. We find that one-half of firms alter their mix of five-digit SIC products every five years, that product switching is correlated with both firm- and firm-product attributes, and that product adding and dropping induce large changes in firm scope. The behavior we observe is consistent with a natural generalization of existing theories of industry dynamics that incorporates endogen...

  12. Bundling and joint marketing by rival firms

    OpenAIRE

    Jeitschko, Thomas D.; Jung, Yeonjei; Kim, Jaesoo

    2014-01-01

    We study joint marketing arrangements by competing firms who engage in price discrimination between consumers who patronize only one firm (single purchasing) and those who purchase from both competitors (bundle purchasers). Two types of joint marketing are considered. Firms either commit to a component-price that applies to bundle-purchasers and then firms set stand-alone prices for single purchasers; or firms commit to a rebate off their stand alone price that will be applied to bundle-purch...

  13. THE INTERNAL COSTS OF THE FIRM

    OpenAIRE

    Monica Dudian; Aurelia Ştefănescu; Rodica Gherghina; Ioana Duca

    2007-01-01

    The Economics of the firm is affecting in the latest year of a changing perspective, from the firm like production function and market actor to internal organization of the firm. Producing suppose resource allocation by the entrepreneurs or/and managers and cooperation between individuals inside the firm. The existence of the firm like institution implies transaction costs, agency costs, the costs of creating incitation and the costs of reducing flexibility. In addition, the existence of the ...

  14. The Case of Japanese Manufacturing Firms

    OpenAIRE

    Ando, Mitsuyo; Akie IRIYAMA

    2009-01-01

    This paper examines how international production/distribution networks provide individual firms with exporting/importing responsiveness to exchange rate movements. With the micro-data of Japanese manufacturing firms from 1994 to 2004, we find that firms' exports tend to respond to exchange rate movements, in particular (1) when firms are large in size, (2) when majority-owned affiliates are dominant among their foreign affiliates, and (3) when their intra-firm trade ratio is moderately high. ...

  15. The Relationship between Offshoring Strategies and Firm Performance: Impact of innovation, absorptive capacity and firm size

    NARCIS (Netherlands)

    M.W. Roza-van Vuren (Marja)

    2011-01-01

    textabstractHow do offshoring strategies impact firm performance? And how are innovation, absorptive capacity and firm size influencing this relationship? This research investigates how firms of varying size, well-established firms and growing firms may profit from relocating business activities to

  16. Firm Culture and Leadership as Firm Performance Predictors : a Resource-Based Perspective

    NARCIS (Netherlands)

    Wilderom, C.P.M.; van den Berg, P.

    2000-01-01

    In this study, we tested part of the resource-based view of the firm by examining two 'soft' resources, firm culture and top leadership, as predictors of 'hard' or bottom-line firm performance.Transformational top leadership was found to predict firm performance directly while the link between firm

  17. A demographic approach to firm dynamics: formation of new firms and survival of old ones

    NARCIS (Netherlands)

    Nijkamp, P.; Geenhuizen, van M.

    1995-01-01

    This paper introduces a new approach to firm dynamics, named demography of firms. It is the study of demographic events in a population of firms. Thepaper argues that withina demographic approach, attention should be paid to a broad range of firm dynamics, including both new firm formation and survi

  18. Human Capital in New Firms

    OpenAIRE

    Müller, Bettina

    2009-01-01

    This dissertation is a collection of three stand-alone research papers on the composition of human capital in newly founded firms. The papers are all empirical but they are closely related to two theoretical approaches. The first approach is the jack-ofall-trades model by Lazear (2005) and the second the O-ring theory introduced by Kremer (1993) and applied to new firms by Fabel (2004a,b) and Fabel and Weber (2005). Besides contributing to the search of stylised facts about the effects of the...

  19. Clot resolution after 3 weeks of anticoagulant treatment of pulmonary embolism: Comparison of computed tomography and perfusion scintigraphy

    NARCIS (Netherlands)

    Van Es, J.; Douma, Renee; Kamphuisen, P.W.; Gerdes, V.E.A.; Verhamme, P.; Wells, P.S.; Bounameaux, H.; Lensing, A.W.A.; Büller, H.R.

    2013-01-01

    Introduction: Little is known about the natural history of clot resolution in the initial weeks of anticoagulant therapy in patients with acute pulmonary embolism (PE). Aim: To assess clot resolution of acute PE with either computed tomography pulmonary angiography (CT-scan) or perfusion scintigraph

  20. Clot resolution after 3 weeks of anticoagulant treatment for pulmonary embolism : comparison of computed tomography and perfusion scintigraphy

    NARCIS (Netherlands)

    van Es, J.; Douma, R. A.; Kamphuisen, P. W.; Gerdes, V. E. A.; Verhamme, P.; Wells, P. S.; Bounameaux, H.; Lensing, A. W. A.; Bueller, H. R.

    2013-01-01

    Introduction Little is known about the natural history of clot resolution in the initial weeks of anticoagulant therapy in patients with acute pulmonary embolism (PE). Clot resolution of acute PE was assessed with either computed tomography pulmonary angiography scan (CT-scan) or perfusion scintigra

  1. Drivers of Discretionary Firm Donations in Brazil

    Directory of Open Access Journals (Sweden)

    Rodrigo Bandeira-de-Mello

    2008-10-01

    Full Text Available Discretionary firm donation is usually related to the stakeholder theory and corporate social performance. Although theoretical explanations for this social behavior are pervasive in related literature, empirical modeling remains underdeveloped. We developed an explanatory structural model of discretionary firm donation using firm and industry level indicators. Unlike previous research, we estimated the explanatory power of the construct we called stakeholder orientation. Our tentative model was tested on a Brazilian sample of 101 publicly traded donor firms, using data on firm donations to social projects and to political candidates in electoral campaigns. The main results suggest that discretionary donation seems to be a strategy for managing conflicting claims in highly stakeholder oriented firms; the characteristics of the firm are more important than industry effects in explaining firm donations; and large firms, showing slack resources, and with a less concentrated ownership structure tend to engage in discretionary donation more intensively.

  2. Mathematical Model of Extrinsic Blood Coagulation Cascade Dynamic System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The blood coagulation system is very important to life. This paper presents a mathematical blood coagulation model for the extrinsic pathway. This model simulates clotting factor VIII, which plays an important role in the coagulation mechanism. The mathematical model is used to study the equilibrium stability, orbit structure, attractors and global stability behavior, with conclusions in accordance with the physiological phenomena. Moreover, the results provide information about blood related illnesses, which can be used for further study of the coagulation mechanism.

  3. Numerical Simulation of the Coagulation Dynamics of Blood

    OpenAIRE

    Bodnár, T.; Sequeira, A.

    2008-01-01

    The process of platelet activation and blood coagulation is quite complex and not yet completely understood. Recently, a phenomenological meaningful model of blood coagulation and clot formation in flowing blood that extends existing models to integrate biochemical, physiological and rheological factors, has been developed. The aim of this paper is to present results from a computational study of a simplified version of this coupled fluid-biochemistry model. A generalized Newtonian model with...

  4. Improving the firm's environmental conduct

    DEFF Research Database (Denmark)

    Knudsen, Thorbjørn; Koed Madsen, Tage

    2001-01-01

    lead to strategic advantage and, thus, economic gains at the firm level. In view of the great importance of this claim, the purpose of the present article was to apply resource-based insights in order to develop this reasoning further and provide an empirical test of three hypotheses related...

  5. Firm default and aggregate fluctuations

    NARCIS (Netherlands)

    Jacobson, Tor; Linde, Jesper; Roszbach, Kasper

    2013-01-01

    This paper studies the relationship between macroeconomic fluctuations and corporate defaults while conditioning on industry affiliation and an extensive set of firm-specific factors. By using a panel data set for virtually all incorporated Swedish businesses over 1990-2009, a period which includes

  6. Small firm transformation through IS

    NARCIS (Netherlands)

    Levy, Margi; Powell, Philip

    2008-01-01

    Globally, Small and Medium-sized Enterprises (SMEs) are encouraged, particularly by governments, to embrace c-business. Fully adopting e-business involves substantial change in firms, both internally and externally. However, there is little understanding of the mechanisms by which such business tran

  7. JOINT VENTURES AMONG EXPORTING FIRMS

    OpenAIRE

    CHAUDHURI, Prabal Ray

    2000-01-01

    In this paper we examine the incentive for joint venture formation among exporting firms. We show that an increase in domestic demand increases the incentive for joint venture formation. An increase in world price, however, can either increase or decrease the incentive for joint venture formation.

  8. Characterization of partially purified milk-clotting enzyme from sunflower (Helianthus annuus) seeds.

    Science.gov (United States)

    Nasr, Assia I A M; Mohamed Ahmed, Isam A; Hamid, Omer I A

    2016-09-01

    This study was aimed to extract milk-clotting enzyme from sunflower seeds and to determine its potentiality for manufacturing white soft cheese from cows and goats milk. The seeds were blended and extracted using two types of buffers and milk-clotting and proteolytic activities were evaluated. The enzyme was partially purified using ammonium sulfate fractionation techniques. Results indicated that sunflower seeds extracted with 5% NaCl in 50 mmol/L acetate buffer, pH 5.0, had the highest milk-clotting activity (MCA) and lowest coagulation time compared to that extracted with only acetate buffer (pH 5.0). Ammonium sulfate at 30-50% saturation purified the enzyme to 4.3 folds with MCA of 241.0 U/mL and final enzyme yield of 10.9%. The partially purified enzyme was characterized by SDS-PAGE that showed two bands with molecular weight of 120 and 62 kDa. When compared with other plant enzymes, the partially purified sunflower enzyme was found to have higher milk-clotting activity and lower proteolytic activity. Also, both milk sources and enzyme types significantly affected the cheese yield and curd formation time. The cheese made from cow milk using sunflower enzyme had higher yield compared to that obtained using commercial rennet, whereas the opposite was observed when using goat milk.

  9. Characterization of partially purified milk-clotting enzyme from sunflower (Helianthus annuus) seeds.

    Science.gov (United States)

    Nasr, Assia I A M; Mohamed Ahmed, Isam A; Hamid, Omer I A

    2016-09-01

    This study was aimed to extract milk-clotting enzyme from sunflower seeds and to determine its potentiality for manufacturing white soft cheese from cows and goats milk. The seeds were blended and extracted using two types of buffers and milk-clotting and proteolytic activities were evaluated. The enzyme was partially purified using ammonium sulfate fractionation techniques. Results indicated that sunflower seeds extracted with 5% NaCl in 50 mmol/L acetate buffer, pH 5.0, had the highest milk-clotting activity (MCA) and lowest coagulation time compared to that extracted with only acetate buffer (pH 5.0). Ammonium sulfate at 30-50% saturation purified the enzyme to 4.3 folds with MCA of 241.0 U/mL and final enzyme yield of 10.9%. The partially purified enzyme was characterized by SDS-PAGE that showed two bands with molecular weight of 120 and 62 kDa. When compared with other plant enzymes, the partially purified sunflower enzyme was found to have higher milk-clotting activity and lower proteolytic activity. Also, both milk sources and enzyme types significantly affected the cheese yield and curd formation time. The cheese made from cow milk using sunflower enzyme had higher yield compared to that obtained using commercial rennet, whereas the opposite was observed when using goat milk. PMID:27625777

  10. Plasma Clot Lysis Time and Its Association with Cardiovascular Risk Factors in Black Africans

    NARCIS (Netherlands)

    Z. de Lange (Zelda); M. Pieters (Marlien); J.C. Jerling (Johann); A. Kruger (Annamarie); D.C. Rijken (Dingeman)

    2012-01-01

    textabstractStudies in populations of European descent show longer plasma clot lysis times (CLT) in patients with cardiovascular disease (CVD) than in controls. No data are available on the association between CVD risk factors and fibrinolytic potential in black Africans, a group undergoing rapid ur

  11. Thromboelastography to Monitor Clotting/Bleeding Complications in Patients Treated with the Molecular Adsorbent Recirculating System

    Directory of Open Access Journals (Sweden)

    Esther B. Bachli

    2011-01-01

    Full Text Available Background. The Molecular Adsorbent Recirculating System (MARS has been shown to clear albumin-bound toxins from patients with liver failure but might cause bleeding complications potentially obscuring survival benefits. We hypothesized that monitoring clotting parameters and bed-side thromboelastography allows to reduce bleeding complications. Methods. Retrospective analysis of 25 MARS sessions during which clotting parameters were monitored by a standardized protocol. Results. During MARS therapy median INR increased significantly from 1.7 to 1.9 platelet count and fibrinogen content decreased significantly from 57 fL−1 to 42 fL−1 and 2.1 g/L to 1.5 g/L. Nine relevant complications occurred: the MARS system clotted 6 times 3 times we observed hemorrhages. Absent thrombocytopenia and elevated plasma fibrinogen predicted clotting of the MARS system (ROC 0.94 and 0.82. Fibrinolysis, detected by thromboelastography, uniquely predicted bleeding events. Conclusion. Bed-side thromboelastography and close monitoring of coagulation parameters can predict and, therefore, help prevent bleeding complications during MARS therapy.

  12. Ultrasonographic imaging of abomasal milk clotting and abomasal diameter in healthy and diarrheic calves.

    Science.gov (United States)

    Kirchner, Daniela; Schwedhelm, Lea; Wenge, Julia; Steinhöfel, Ilka; Heinrich, Christian; Coenen, Manfred; Bachmann, Lisa

    2015-11-01

    In case of diarrhea calves are treated with oral rehydration solutions (ORS), which are known to increase abomasal pH and inhibit milk clotting in vitro. Nevertheless, recent studies have shown that ORS with HCO3(-) ≤ 62 mmol/L do not interfere with abomasal milk clotting in healthy calves. However, in diarrheic calves, feeding ORS and milk simultaneously may disturb abomasal curd formation and exacerbate diarrhea due to faster abomasal passage of ingesta. Therefore, the aim of the present study was to ultrasonographically examine abomasal milk clotting and diameter after feeding milk and milk replacer (MR) with and without ORS to healthy and diarrheic calves. Abomasal curd formation and diameter in healthy and diarrheic calves were ultrasonographically imaged before and after feeding milk, MR and ORS prepared in milk or MR. Feeding mixtures of milk or MR with ORS did not cause any remarkable differences in the ultrasonographic images of abomasal content. Moreover, abomasal milk clotting was not disturbed due to diarrhea. Statistically significant differences of abomasal diameter after feeding between healthy and diarrheic calves indicated that abomasal emptying is delayed in diarrheic calves. Hence, further studies are needed to determine reasons for decelerated abomasal passage in calves suffering from diarrhea.

  13. Firm Based Trade Models and Turkish Economy

    Directory of Open Access Journals (Sweden)

    Nilüfer ARGIN

    2015-12-01

    Full Text Available Among all international trade models, only The Firm Based Trade Models explains firm’s action and behavior in the world trade. The Firm Based Trade Models focuses on the trade behavior of individual firms that actually make intra industry trade. Firm Based Trade Models can explain globalization process truly. These approaches include multinational cooperation, supply chain and outsourcing also. Our paper aims to explain and analyze Turkish export with Firm Based Trade Models’ context. We use UNCTAD data on exports by SITC Rev 3 categorization to explain total export and 255 products and calculate intensive-extensive margins of Turkish firms.

  14. Entrepreneurship and the Economics of the Firm

    DEFF Research Database (Denmark)

    Foss, Nicolai Juul

    The study of entrepreneurship and the study of economic organizing lack contact. In fact, the modern theory of the firm virtually ignores entrepreneurship, while the literature on entrepreneurship often sees little value in the economic theory of the firm. In contrast, we argue in this chapter that...... entrepreneurship theory and the theory of the firm can be usefully integrated, and that doing so would improve both bodies of theory. Adding the entrepreneur to the theory of the firm provides a dynamic view that the overly static analysis of firm organizing cannot support. Moreover, adding the firm to the study...... of the entrepreneur provides important clues to how we can understand entrepreneurship....

  15. Segmentation, Reconstruction, and Analysis of Blood Thrombus Formation in 3D 2-Photon Microscopy Images

    Directory of Open Access Journals (Sweden)

    Xu Zhiliang

    2010-01-01

    Full Text Available We study the problem of segmenting, reconstructing, and analyzing the structure growth of thrombi (clots in blood vessels in vivo based on 2-photon microscopic image data. First, we develop an algorithm for segmenting clots in 3D microscopic images based on density-based clustering and methods for dealing with imaging artifacts. Next, we apply the union-of-balls (or alpha-shape algorithm to reconstruct the boundary of clots in 3D. Finally, we perform experimental studies and analysis on the reconstructed clots and obtain quantitative data of thrombus growth and structures. We conduct experiments on laser-induced injuries in vessels of two types of mice (the wild type and the type with low levels of coagulation factor VII and analyze and compare the developing clot structures based on their reconstructed clots from image data. The results we obtain are of biomedical significance. Our quantitative analysis of the clot composition leads to better understanding of the thrombus development, and is valuable to the modeling and verification of computational simulation of thrombogenesis.

  16. Correlation of fibrinogen level and absorbance change in both PT and APTT clotting curves on BCSXP

    Institute of Scientific and Technical Information of China (English)

    Xiaojie Zhang; Bing Bai

    2008-01-01

    Objective: To investigate the correlation of fibrinogen level and absorbance change in both PT and APTT clotting curves on BCSXP Analyzer. Methods:A serial of standard fibrinogen and 250 patient plasma samples with different qualities(normal, hemolysis,icterus, and lipemia) were run on BCSXP for assays PT, APTT and Fibrinogen. The absorbance change(DeltaA) from baseline to plateau in clotting curve was retrieved and analyzed on its correlation with the Fibrinogen result. Influence of plasma quality and PT/APTT result on this correlation was also studied respectively. Results:Both PT-DeltaA and APTT-DeltaA showed good linear regression with fibrinogen level in the sample, with Re close to 0.90 in both standard and patient samples. Hemolysis(H), itcterus(1) and lipemia(L) of the sample with valid clotting curves were found to have no significant difference in this correlation from normal(N) sample(R2: 0.83H, 0.92I 0.81L and 0.79N in PT; 0.89H, 0.95I, 0.91L and 0.89N in APTT) in either PT or APTT curve. PT or APTT result also has little impact on this correlation(0.71 in range 7 ~ 10 sec, 0.56 in10 ~ 20 sec, and 0.70 in 20 sec~; R2 in APTT: 0.88 in 20~30 sec,0.92 in 30~40 sec, and 0.95 in 40 sec~). Conclusion:The absorbance change in either PT or APTT clotting curve correlates well with the fibrinogen level in plasma, which is independent of plasma quality PT or APTT results. The absorbance change can be used as an alternative way to roughly estimate fibrinogen level in either PT or APTT clotting curve when the result of clauss-based fibrinogen measurement is not available.

  17. Real firms, transaction costs and firm development: a suggested formalisation

    OpenAIRE

    McHardy, J.P.; Dietrich, M.; Krafft, J.

    2015-01-01

    The motivation of this discussion is threefold: to integrate transaction costs (TCs) into a standard model of the firm; to examine the interaction between organisational factors (i.e. TCs) and standard demand-cost factors; and to analyse key propositions of transaction cost economics with the general model. Two sets of results are derived. First, when analysis is based on significant interaction between organisational effort and production costs two possible organisational solutions can exist...

  18. Diversification and firm performance: A study of Indian manufacturing firms

    OpenAIRE

    Ravichandran, Archana; Bhaduri, Saumitra

    2015-01-01

    The advantages and disadvantages of diversification and its impact on productivity or performance of a firm have been debated upon by academics and business professionals all over, although views on the topic still differ widely. While popular views are that related diversification increases value and unrelated diversification decreases value, the results of research conducted on the effects of overall diversification (without distinguishing between related and unrelated diversification) on p...

  19. Extraction of mRNA from coagulated horse blood and analysis of inflammation-related cytokine responses to coagulation

    DEFF Research Database (Denmark)

    Bovbjerg, Kirsten Katrine Lindegaard; Heegaard, Peter M. H.; Skovgaard, Kerstin

    2010-01-01

    available. Here, a protocol for RNA extraction from highly clotted blood was optimized and the regulation of a number of cytokine genes compared to stabilized blood was studied. Whole blood samples from 10 clinically healthy horses were incubated for 24 hours at 37°C and RNA was extracted from...

  20. Heterogeneity in Firm Performance During Economic Crisis

    Directory of Open Access Journals (Sweden)

    Sergio Bruni

    2014-06-01

    Full Text Available What happens to firms during periods of deep economic crisis? Did different types of firms perform differently under the economic crisis? With the aid of a rich database and focusing on the literature regarding the growth of firms, this paper investigates the relative profitability performance of Italian firms during the current economic crisis, exploring those factors, which help certain firms to do relatively better even in the slowdown period. Some preliminary results show that the Italian firms that are relatively young in age, with relatively better current liquidity and more focused on domestic market have performed better than other firms. Furthermore, firms operating in high-tech and in highly concentrated sectors have enjoyed a better performance in this period.

  1. Do foreign-owned firms pay more?

    OpenAIRE

    Harrison, Ann E.; Scorse, Jason

    2008-01-01

    This paper uses Indonesian data to analyze the impact of foreign ownership on wages. After controlling for worker and firm characteristics, we find that foreign firms pay a wage premium, which is larger for skilled relative to unskilled workers.

  2. How do Economic Crises Impact Firm Boundaries?

    DEFF Research Database (Denmark)

    Foss, Kirsten

    2010-01-01

    may impact these variables and change efficient firm boundaries. The various theories of the firm have difficulties explaining how firms efficiently adapt their boundaries to such prominent characteristics of economic crisis as declining demand and increased costs of external finance. However, all......How economic crises impact the boundaries of firms has been offered virtually no attention in the literature on the theory of the firm. I review the best-known theories of the firm and identify the variables that matter for the explanation of firm boundaries. I then examine how an economic crisis...... these theories stress uncertainty as an antecedent of firm organization, and as uncertainty is also an important characteristic of an economic crisis I examine how uncertainty is allowed to play out in the various theories in order to identify what predictions we can derive from the theory regarding changes...

  3. International Strategies of Non-Dominant Firms

    OpenAIRE

    Briance Mascarenhas

    1986-01-01

    There has been a growing interest in how follower firms can compete with industry leaders. This article documents the use of international strategies by some non-dominant firms to avoid direct competition with industry leaders. Twenty-five cases of international strategies used by non-dominant firms in a variety of industries were cluster analyzed to identify common strategies. Seven different strategies were identified together with their attendant firm characteristics, stage of industry int...

  4. Does Labour Diversity affect Firm Productivity?

    DEFF Research Database (Denmark)

    Parrotta, Pierpaolo; Pozzoli, Dario; Pytlikova, Mariola

    Using a matched employer-employee dataset, we analyze how workforce diversity in cultural background, education and demographic characteristics affects productivity of firms in Denmark. Implementing a structural estimation of the firms' production function (Ackerberg et al., 2006) we find...... that labor diversity in education significantly enhances a firm's value added. Conversely, diversity in ethnicity and demographics induces negative effects on firm productivity. Hence, the negative effects, coming from communication and integration costs connected to a more culturally and demographically...

  5. Spanish Multinational Firm and its Internationalization Process

    OpenAIRE

    David de Matías Batalla

    2015-01-01

    The article responds to the need to study and analyze the evolution of the Spanish multinational firm in order to be able to identify the characteristics of success and what kind of factors are drivers to internationalize the activities in the Spanish economy. The first part reviews the evolution of the Spanish firm internationalization; meanwhile the second part describes the characteristics of Spanish multinational firm, resulted of a survey of 166 Spanish multinational firms.

  6. Industry-specific firm growth and agglomeration

    OpenAIRE

    Duschl, Matthias; Scholl, Tobias; Brenner, Thomas; Luxen, Dennis; Raschke, Falk

    2013-01-01

    This paper studies the industry-specific relationship between industrial clustering and firm growth. The literature usually considers industrial clusters as positive for the general economic development of regions. In particular, their relationship with the formation rate of new firms and the survival rate of existing firms is well documented. However, the impact of agglomeration effects on growth prospects of firms is less clear. Because of the heterogeneity of industries, different agglomer...

  7. The Equity Ownership Structure of Thai Firms

    OpenAIRE

    Wiwattanakantang, Yupana

    2001-01-01

    This paper examines the ownership structure of listed Thai firms in 1996. The ownership structure is concentrated. In 82.59 percent of the firms in the sample, the largest shareholders are also controlling shareholders. The controlling shareholders are mainly families. Foreign investors form the second largest group of controlling shareholders. More of the controlling shareholders use a simple ownership pattern to control the firms. Only in 21.27 percent of the firms, the controlling sharehol...

  8. International Taxation and Multinational Firm Location Decisions

    OpenAIRE

    Barrios Cobos, Salvador; Huizinga, Harry; Laeven, Luc; Gaëtan J.A. Nicodème

    2008-01-01

    Using a large international firm-level data set, we estimate separate effects of host and parent country taxation on the location decisions of multinational firms. Both types of taxation are estimated to have a negative impact on the location of new foreign subsidiaries. In fact, the impact of parent country taxation is estimated to be relatively large, possibly reflecting its international discriminatory nature. For the cross-section of multinational firms, we find that parent firms tend to ...

  9. Three Essays on Age and Firm Performance

    OpenAIRE

    Zeller, Jonas

    2014-01-01

    Old captains at the helm: Chairman age and firm performance Urs Waelchli and Jonas Zeller December, 2012 This paper examines whether the chairmen of the board (COBs) impose their life-cycles on the firms over which they preside. Using a large sample of unlisted firms we find a robust negative relation between COB age and firm performance. COBs age much like ‘ordinary’ people. Their cognitive abilities deteriorate and they experience significant shifts in motivation. Deteriorating cog...

  10. ICT and Household-Firm Relations

    OpenAIRE

    Lindbeck, Assar; Wikström, Solveig

    1999-01-01

    This paper discusses how ICT and emerging electronic commerce in consumer products influence the relative efficiency in production of households and firms, resulting in changes in the division of tasks between these two types of agents. Increased information and competence of households, in combination with stiffer competition among firms, will also increase the power of households relative to firms, at least in a long-term perspective with free entry of firms. Households will also get more p...

  11. Risk/Return Performance of Diversified Firms

    OpenAIRE

    Richard A. Bettis; Vijay Mahajan

    1985-01-01

    Based on a sample of 80 firms, this paper examines the risk/return performance of related and unrelated diversified firms at the level of accounting data. The results suggest that although on the average related diversified firms outperform unrelated diversified firms, related diversification offers no guarantee of a favorable risk/return performance. (Many low performers are related diversifiers.) In fact, different diversification strategies can result in similar risk/return performance. Ho...

  12. Quality, Size and Performance of Audit Firms

    OpenAIRE

    Yahn-Shir Chen; Joseph Hsu; Mei-Ting Huang; Ping-Sen Yang

    2013-01-01

    This study examines the relations between audit quality, audit firm size, and financial performance. This study estimates audit quality of audit firms from human capital-related factors, such as educational level of auditors, work experience of auditors, and professional training. From the perspective of market segmentation, the sample is divided into three categories: national, regional, and local firms. Empirical results report a positive association between audit firm size and audit qualit...

  13. Dynamic capabilities in small software firms

    OpenAIRE

    Kivelä, Marianne

    2007-01-01

    In this dissertation we study dynamic capabilities in small software firms. Small software firms find themselves in highly complex and turbulent environments that require dynamic capabilities to build, integrate and configure resources. While the literature describes a portfolio of such dynamic capabilities that can help firms to adapt to changing conditions, we could not find many definitions, models and studies on these capabilities suitable with particular focus on small software firms. Fu...

  14. Blood-induced joint damage: from mechanisms to clinical practice

    NARCIS (Netherlands)

    Jansen, N.W.D.

    2008-01-01

    Blood-induced joint damage is an arthropathy which evolves as a consequence of joint bleeding (or: haemarthroses). These joint bleeds can occur as a consequence of joint trauma, such as intra-articular fracture or ligament rupture, but in patients suffering from the clotting disorder haemophilia, jo

  15. Reputational penalties to firms in antitrust investigations

    NARCIS (Netherlands)

    Broek, van den S.; Kemp, R.G.M.; Verschoor, W.F.C.; Vries, de A.

    2012-01-01

    We estimate the impact of legal penalties imposed on Dutch listed firms targeted by competition authorities from 1998 to 2008 on a firm's stock market value. On average, firms lose 2.3 percent of their market values when an antitrust investigation is uncovered. This corresponds to a total value loss

  16. New Firm Growth: Exploring Processes and Paths

    NARCIS (Netherlands)

    E. Garnsey; F.C. Stam (Erik); P. Heffernan; O. Hugo

    2003-01-01

    textabstractThis paper provides a new methodology for the diachronic study of new firm growth, theoretically grounded in the work of Penrose (1995). We show that a model of firm growth as an unfolding process makes possible draw simple, measurable inferences from firm level to aggregate evidence on

  17. Agility in a small software firm

    DEFF Research Database (Denmark)

    Schmidt, Thomas; Mathiassen, Lars

    2009-01-01

    Small software firms are vulnerable to environmental uncertainty. While agile methods and other technologies offer suggestions to this challenge, we know little about how these firms combine project and firm level capabilities to effectively respond to changes. On this backdrop, we examine a small...

  18. Independent Directors Human Capital and Firm Internationalization

    OpenAIRE

    Hsiang-Lan Chen

    2014-01-01

    This study examines the effect of independent directors? human capital (independent directors? educational level, CEO experience and international experience) on firms? decisions toward internationalization. Using a panel of electronics firms in Taiwan, the results show that independent directors? CEO experience and international experience are positively and significantly related to firm internationalization. Independent directors? educational level is positively, but not significantly, asso...

  19. Structure, Employment and Performance in Biotech Firms

    DEFF Research Database (Denmark)

    Valentin, Finn; Dahlgren, Johan Henrich; Lund Jensen, Rasmus

    2006-01-01

    .g. universities, firms and venture capital. That makes DDFs a sensitive "seismograph" for the ability of the Danish innovation system to foster new science-based technologies.Key words: Employment, Biotechnology, Firm size distribution, Industry structure,Firm performanceJEL Codes: J21, L11, L22, L25, L65, O57...

  20. Firm-Level Corruption in Vietnam

    DEFF Research Database (Denmark)

    Rand, John; Tarp, Finn

    This paper uses a unique panel dataset on firm-level corruption. It contains quantitative information on bribe payments by a sample of formal and informal Vietnamese firms. We show that bribe incidence is highly associated with firm-level differences in (i) visibility, (ii) sunk costs, (iii...

  1. The Dividend Policy of German Firms

    NARCIS (Netherlands)

    Andres, C.; Betzer, A.; Goergen, M.; Renneboog, L.D.R.

    2008-01-01

    Abstract: German firms pay out a lower proportion of their cash flows, but a higher proportion of their published profits than UK and US firms. We estimate partial adjustment models and report two major findings. First, German firms base their dividend decisions on cash flows rather than published e

  2. The Dividend Policy of German Firms

    NARCIS (Netherlands)

    Andres, C.; Betzer, A.; Goergen, M.; Renneboog, L.D.R.

    2008-01-01

    German firms pay out a lower proportion of their cash flows, but a higher proportion of their published profits than UK and US firms. We estimate partial adjustment models and report two major findings. First, German firms base their dividend decisions on cash flows rather than published earnings as

  3. Finding the "Right Staff" in Small Firms

    Science.gov (United States)

    Barrett, Rowena; Neeson, Robyn; Billington, Leo

    2007-01-01

    Purpose: The purpose of this paper is to explore what owners of small firms are looking for from new employees. The aim is to pursue this in light of the debate around formality and informality of small firm HRM, exploring the extent to which the small firms studied had formalized HRM practices. Design/methodology/approach: The data reported here…

  4. Family firm research——A review

    Institute of Scientific and Technical Information of China (English)

    Qiang; Cheng

    2014-01-01

    This article reviews family firm studies in the finance and accounting literature,primarily those conducted using data from the United States and China. Family owners have unique features such as concentrated ownership, long investment horizon, and reputation concerns. Given the distinguishing features of family ownership and control, family firms face unique agency conflicts. We discuss the agency problems in family firms and review the findings of recent family firm studies. We call for more research to understand the unique family effects and encourage more research on Chinese family firms.Part I of the article discusses the fundaments of family firms: the prevalence of and the agency conflicts within family firms. Part II summarizes the findings of recent U.S. family firm studies. It reviews the evidence on the family firm premium(how, which, and when family firms are associated with a valuation premium), the manifestation of the agency conflict between majority and minority shareholders in family firms, earnings quality and corporate disclosure, and the determinants of family ownership and control. Part III discusses the prevalence and characteristics of Chinese family firms and reviews the findings of related studies. The article concludes with some suggestions for future research.

  5. Firm Exit, Technological Progress and Trade

    DEFF Research Database (Denmark)

    Schröder, Philipp; Sørensen, Allan

    The dynamics of export market exit and firm closure have found limited attention in the new heterogeneous-firms trade literature. In fact, several of the predictions on firm survival and exit stemming from this new class of models are at odds with the stylized facts. Empirically, higher...

  6. The Internationalisation of Service Firms

    DEFF Research Database (Denmark)

    Blagoeva, Denitsa Hazarbassanova

    specificities may be universal axes around which all MNCs, both manufacturing and service ones, configure themselves internally and externally across geographic locations. We do not in fact know that services are different from manufacturing - some empirical evidence suggests they are (e.g. Laanti, Mc......The question the thesis aims at resolving is: How do the value creation logics of firms impact their internationalisation? The overall aim of this PhD project is to explore and test an approach to understanding the internationalisation of service firms, based not on opposing them to manufacturing......Dougal and Baume, 2009), some - that they are not (e.g., Terpstra and Yu, 1988). What we do know is that services are very important. They generate roughly 80% of GDP in the United States and the European Union, and the proportion is well over 50% in most countries, industrial and developing alike (International...

  7. Communication in an "Officeless firm"

    OpenAIRE

    Burchell, Brendan J.; LAI, YI

    2008-01-01

    New technologies permit new types of organisations. This article describes and analyses one such organisation, an "officeless firm", where all employees work from their own homes and there is no central office. Drawing upon observations and interviews, the modes of communication and the nature of the interpersonal relationships that have permitted this organisation to succeed are described, along with the challenges that face this organisation in the future as it attempts to grow.

  8. Constitutional orders in multinational firms

    DEFF Research Database (Denmark)

    Hull Kristensen, Peer; Morgan, Glenn

    Multinationals are faced with the problem of how to coordinate different actors and stop `fiefdoms' emerging that inhibits the achievement of transnational cooperation? We identify this as a problem of `constitutional ordering' in the firm. Drawing on Varieties of Capitalism approaches, we explore...... how multinationals from different contexts seek to create constitutional orders. We argue that the models which exist appear to be destructive of coordination. We explore the implications for MNCs....

  9. Why Firms Purchase Property Insurance?

    OpenAIRE

    Daniel Aunon-Nerin; Paul Ehling

    2007-01-01

    We investigate whether corporate finance incentives aect the extent of corporate hedging with property insurance. Using a database that contains detailed insurance information, we show that rms buy property insurance to reduce the expected costs of distress. Further, we document a scale effect: large rms purchase less insurance per unit of property. This is consistent with the notion that expected bankruptcy costs fall as firm size increases. We also show that the dividend payout ratio exerts...

  10. Optimization of firm's tax liability

    OpenAIRE

    Švihálek, Pavel

    2012-01-01

    The thesis is divided in two basic parts. The first part includes structure of the tax system in the Czech Republic, explanation of tax definitions and characteristics of Czech tax system. The goal of the first part is to clarify the tax system, tax base calculation and factors that influence its amount. The second part is structured more practically and should offer several possibilities of how to optimize the firm's tax liability, with focus on the corporate income tax.

  11. Investment financing in cooperative firms

    Directory of Open Access Journals (Sweden)

    Gaetano Cuomo

    2015-04-01

    Full Text Available By general agreement, one of the main obstacles to the growth of producer cooperatives is difficult investment financing, due to inadequate Capitalisation levels and the resulting inability to lodge sufficient collateral with lenders. Moreover, worker-owned firms are considered not very reliable because they suffer from problems of moral hazard and insufficient commitment. Unfortunately, the literature on this issue is not extensive and has weaknesses that are highlighted in the paper. By means of its critical analysis, it is possible to provide evidence that the funding difficulties caused by the particular structure of cooperative firms can be effectively tackled by creating an institutional framework within which cooperatives would be offered a wider range of organizational options comparable to those open to traditional enterprises. Finally, it is proved that the willingness of the members to fund the operations of their cooperative with loan capital may not be enough to mobilize external credit. For member financings to persuade potential providers of funds to place trust in a firm, third-party claims must necessarily qualify as senior debt and be repaid before the claims of the partners are settled.

  12. TYPOLOGY OF KNOWLEDGE-BASED FIRMS - INFLUENCES ON THE VALUE OF THE FIRM

    OpenAIRE

    Bogdan Marza

    2009-01-01

    As Michael Porter states that there are three main stages of economic competitiveness that a nation may go through, so we can say by analogy that there are three stages of firm competitiveness: firms based on classical inputs, investment firms and firms based on innovation and knowledge - modern organizations.

  13. Chondrogenic differentiation of marrow clots after microfracture with BMSC-derived ECM scaffold in vitro.

    Science.gov (United States)

    Wei, Bo; Jin, Chengzhe; Xu, Yan; Du, Xiaotao; Yan, Chao; Tang, Cheng; Ansari, Mujtaba; Wang, Liming

    2014-10-01

    Repairing articular cartilage by combining microfracture and various scaffolds has been extensively performed in in vivo animal models. We previously described a novel extracellular matrix (ECM) scaffold for cartilage tissue engineering. The aim of this study was to investigate the effect of a bone marrow-derived mesenchymal stem cells-derived ECM (BMSC-dECM) scaffold on the chondrogenic differentiation of marrow clots following microfracture in vitro. In this study, we manufactured the BMSC-dECM scaffold using a freeze-drying method. To obtain the marrow clots, a full-thickness cartilage defect was established and microholes were created in the trochlear groove of New Zealand white rabbits. The samples were divided and cultured in vitro for 1, 2, 4, and 8 weeks. The samples included a culture of the marrow clot alone (Group 1), a culture of the marrow clot with transforming growth factor-beta 3 (TGF-β3) (Group 2), a culture of the composite of the BMSC-dECM scaffold and the marrow clot alone (Group 3), and a culture of the composite with TGF-β3 (Group 4). A smooth and glossy surface was observed in Group 2 and Group 4 over time, but the surface for Group 4 was larger from week 1 onward. Compressive strength gradually increased in Groups 2 and 4, and greater increases were observed in Group 4 during the 8-week culture period. Enhanced cartilage-like matrix deposition of glycosaminoglycan (GAG) and type II collagen were confirmed by Safranin O and immunohistochemistry staining, respectively, in Groups 2 and 4. The GAG and collagen contents also gradually increased over time in Groups 2 and 4; the increase was greater in Group 4. In addition, real-time-polymerase chain reaction demonstrated that the expression of chondrogenic genes, such as COL2, ACAN, and SOX9, was gradually upregulated in Groups 2 and 4. However, greater increases in the expression of these cartilage-like genes were observed in Group 4 from week 4 onward. Our results suggest that the BMSC

  14. Utilization of salt whey from Egyptian Ras (Cephalotyre cheese in microbial milk clotting enzymes production

    Directory of Open Access Journals (Sweden)

    El-Sayed El-Tanboly

    2013-03-01

    Full Text Available Background. Microbial milk-clotting enzymes are valued as calf rennet substitutes in the cheese industry. The worldwide increase of cheese production coupled with a reduced supply of calf rennet has prompted a search for calf rennet substitutes, including microbial and plant rennets. However, most plant rennets have proved unsuitable because they impart a bitter taste to the cheese. Microbial rennet appears to be more promising because its production is cheaper, biochemical diversity is greater, and genetic modifi cation is easier. Most cheese manufacturing facilities in Egypt perform land spreading of salt whey. However, this practice increases the chloride levels of soil, and elevates the risk of crop damage. One possible application for salt whey is to use it as a whole medium for growth and production of milk clotting enzyme from fungi. Material and methods. Mucor pusillus QM 436 was identifi ed to produce the highest milk-clotting activity during screening of 19 fungal strains. Salted whey results from Ras (Cephalotyre cheese manufacture as a whole medium for growth of Mucor pusillus QM 436 and production of the enzyme. Results. The milk-clotting enzyme from Mucor pusillus QM 436 was purifi ed to 7.14-fold with 54.4% recovery by precipitation in ammonium sulfate, ethanol and fractionated by gel fi ltration on Sephadex G-100. The enzyme was active in the pH range 5.5-7.5 and was inactivated completely by heating 5 min at 70°C and 30 min at 65°C. The highest level of enzyme activity was obtained at 60°C, pH 5.5. A positive and proportional relationship occurred in the presence of CaCl2 in milk, with inhibition which occurred in the presence of NaCl. Conclusions. The high level of milk-clotting activity coupled with a low level of thermal stability suggested that the milk-clotting enzyme from Mucor pusillus QM 436 should be considered as a potential substitute for calf rennet.

  15. Founder Control,Ownership Structure and Firm Value:Evidence from Entrepreneurial Listed Firms in China

    Institute of Scientific and Technical Information of China (English)

    Lijun Xia

    2008-01-01

    In emerging markets, the deviation between the ultimate controlling shareholders’ voting rights and their cash flow rights(hereafter "DVC") in the listed firms is quite prevalent. DVC could be introduced due to the ultimate controlling shareholders’ opportunistic incentives, as well as by their incentives to improve firm efficiency. This study uses 229 listed firms ultimately controlled by individuals or families(hereafter "entrepreneurial firms") for 2004 in China, to investigate the effect of DVC on firm value and to determine whether it is different between founder and non-founder controlled firms. We find that DVC has a positive effect on firm value for founder controlled firms. This result implies that investors believe that their interests are better protected by founder controlled firms than by non-founder controlled firms.

  16. Large Bladder Clot-An Unusual Presentation of Neonatal Bilateral Renal Vein Thrombosis-Case Report and Review of Literature.

    Science.gov (United States)

    Bandari, Jathin; Dangle, Pankaj P; Tennyson, Lauren E; Correa, Andres F; Cannon, Glenn M

    2015-10-01

    A 1-day-old boy born at 37 weeks gestation presented with hematuria, thrombocytopenia, and palpable irregular right flank mass. Renal ultrasound demonstrated large clot within the bladder, bilateral kidney masses with loss of corticomedullary differentiation, and reversal of diastolic flow. The patient was diagnosed with bilateral renal vein thrombosis and was managed conservatively. There was complete resolution of the bladder clot with restoration of corticomedullary differentiation bilaterally. We report the first case of renal vein thrombosis associated with a large bladder clot in a neonate.

  17. Essays on Firm Behavior in Developing Economies

    Science.gov (United States)

    Abeberese, Ama Baafra

    The performance of firms is central to growth in developing economies. A burgeoning literature within development economics seeks to understand the behavior of firms in developing countries and the constraints to their performance. This dissertation explores two types of constraints---infrastructure-related constraints and trade-related constraints---faced by manufacturing firms in developing countries. Despite the widely acknowledged importance of infrastructure for economic growth, there has been relatively little research on how infrastructure affects the decisions of firms. Electricity, in particular, is commonly cited by firms in developing countries as a major obstacle to their performance. In the first two chapters, I analyze the responses of firms to two types of electricity constraints, namely electricity prices and electricity shortages. Chapter 1 provides evidence on how electricity prices affect a firm's industry choice and productivity growth using data on Indian manufacturing firms. I construct an instrument for electricity price as the interaction between the price of coal paid by power utilities, which is arguably exogenous to firm characteristics, and the initial share of thermal generation in a state's total electricity generation capacity. I find that, in response to an exogenous increase in electricity price, firms reduce their electricity consumption and switch to industries with less electricity-intensive production processes. I also find that firm output, machine intensity and labor productivity decline with an increase in electricity price. In addition to these level effects, I show that firm output and productivity growth rates are negatively affected by high electricity prices. These results suggest that electricity constraints faced by firms may limit a country's growth by leading firms to operate in industries with fewer productivity-enhancing opportunities. Chapter 2 examines the impact of electricity shortages on firm investment. I

  18. Firm Leverage and the Financial Crisis

    OpenAIRE

    Altunok, Fatih; Oduncu, Arif

    2013-01-01

    The firm growth dynamics is an important topic since the growth performance of firms is the main source of the economic growth in countries. Generally, crises produce a sharp decline in firms’ growth and this leads to a decline in both the level of employment and the income of households. This paper focuses on the role of firm leverage on the growth performance of the firm during the global financial crisis. We investigate whether the firms that experienced a large leverage increase before th...

  19. Earnings Benchmarks in International hotel firms

    Directory of Open Access Journals (Sweden)

    Laura Parte Esteban

    2011-11-01

    Full Text Available This paper focuses on earnings management around earnings benchmarks (avoiding losses and earnings decreases hypothesis in international firms and non international firms belonging to the Spanish hotel industry. First, frequency histograms are used to determine the existence of a discontinuity in earnings in both segments. Second, the use of discretionary accruals as a tool to meet earnings benchmarks is analysed in international and non international firms. Empirical evidence shows that international and non international firms meet earnings benchmarks. It is also noted different behaviour between international and non international firms.

  20. Human Capital and Wages in Exporting Firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    . Using a very rich matched worker-firm longitudinal dataset we find that firms with high export intensities pay higher wages. However, an interaction term between export intensity and skill intensity has a positive impact on wages and it absorbs the direct effect of the export intensity. That is, we find......This paper studies the link between a firms education level, export performance and wages of its workers. We argue that firms may escape intense competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results...... an export wage premium, but it accrues to workers in firms with high skill intensities...

  1. Toward an Integrative Theory of the Firm

    DEFF Research Database (Denmark)

    Li, Xin

    This paper argues that the existing four major theories of the firm, i.e., the transaction cost theory, resource-based view, the entrepreneurial theory, and the stakeholder theory, are all insightful yet partial because each of them has a particular focus on the phenomenon of the firm. To better...... understand the nature and behaviors of the firm, we need a comprehensive yet integrative theory. Toward this end, this paper proposes a relationship-based theory of the firm (R’BT) which claims that it is the relationships between the entrepreneur and other individuals or firms that determine the existence...

  2. Do Treasure Islands Create Firm Value?

    DEFF Research Database (Denmark)

    Lai, Tat-kei; Ng, Travis

    They do! Otherwise, their use would not have been so prevalent among firms. How much firm value they create, however, is still an open question. Exploiting a political event in the U.K. that suddenly raised the cost of using tax havens, we find that there was a 0.87% reduction in cumulative...... abnormal return (CAR) among the sampled firms, corresponding to about £532 million in market capitalization. The firms of stronger corporate governance registered a stronger reduction in CAR. A simple linear extrapolation suggests that the firm value contributed by tax havens can be as much as £31 billion....

  3. The Relationship between Offshoring Strategies and Firm Performance: Impact of innovation, absorptive capacity and firm size

    OpenAIRE

    Roza-van Vuren, Marja

    2011-01-01

    textabstractHow do offshoring strategies impact firm performance? And how are innovation, absorptive capacity and firm size influencing this relationship? This research investigates how firms of varying size, well-established firms and growing firms may profit from relocating business activities to foreign locations. Offshoring strategies are conceptualized as consisting of both organizational attributes – i.e. function offshored, governance mode and location – and strategic attributes – i.e....

  4. Quality Employment and Firm Performance Evidence from Indian Firm-Level Data

    OpenAIRE

    Amoranto, Glenita; Chun, Natalie

    2011-01-01

    We investigate the characteristics of manufacturing firms in India that generate better quality employment and the relationship between quality employment and firm performance using multiple measures of employment quality. Larger firms tend to generally provide better quality employment opportunities even after controlling for aspects related to employee skills. The organizational structure of firms matters, with government, private, and cooperative firms generally in terms of providing highe...

  5. An Aspirational Community Theory of the Firm

    DEFF Research Database (Denmark)

    Li, Xin

    of the firm. In addition, they are all partial due to their particular focus on the multifaceted phenomenon of the firm. We argue that it is necessary and sufficient to develop a comprehensive yet integrative theory of the firm that combines the three competing yet complementary logics. Toward this end, we...... propose an aspirational community theory of the firm (ACT) as a candidate theory by conceptualizing the firm as an aspirational community, the core of which is a group of like-minded people sharing similar or same aspiration/vision. To explain the existence of the firm, we make a distinction between...... contractual labor and aspirational labor, the former being defined as services provided by a laborer in fulfillment of a contract while the latter as services provided by a laborer in pursuit of an aspiration; and argue that firms exist because while the market may be effective and efficient for allocating...

  6. The theory of the firm. Vol. 2

    DEFF Research Database (Denmark)

    Firms have for a long time been part of the explanatory set-up of economics. However, it is only recently that economists have felt the need for an economic theory addressing: why firms are different; why firms exist; what determines their boundaries relative to "the market"; and what determines...... their internal organization. This collection documents the rise of the modern theory of the firm during the last two to three decades. It reprints classic writings from a diversity of perspectives, including not only contractual theories of the firm, but also knowledge-based theories and theories of the firm...... as an information processor. In addition, the collection features perspectives from business strategy and business history as well as methodological and doctrinal historical perspectives. Including over 60 classic papers, these volumes collect together contributions on the theory of the firm, beginning with Ronald...

  7. Hepatic veins as a site of clot formation following liver resection

    Institute of Scientific and Technical Information of China (English)

    Emmanuel Buc; Safi Dokmak; Magaly Zappa; Marie Helene Denninger; Dominique Charles Valla; Jacques Belghiti; Olivier Farges

    2011-01-01

    Pulmonary embolism occurs more frequently after hepatectomy than previously thought but is infrequently associated with peripheral deep vein thrombosis. In thispaper, we report 2 cases of postoperative hepatic vein thrombosis after liver resection. Both patients had undergone major hepatectomy of a non-cirrhotic liver largely exposing the middle hepatic vein. Clots were incidentally found in the middle hepatic vein 4 and 17 d after surgery despite routine systemic thrombo-prophylaxis with low molecular weight heparin. Coagulation of the transitionplan in a context of mutation of the prothrombin gene and inflammation induced biloma were the likely predisposing conditions. Clots disappeared following curative anticoagulation. We conclude that thrombosis of hepatic veins may occur after liver resection and is a potential source of pulmonary embolism.

  8. Rotary blood pump

    Science.gov (United States)

    Benkowski, Robert J. (Inventor); Kiris, Cetin (Inventor); Kwak, Dochan (Inventor); Rosenbaum, Bernard J. (Inventor); Bacak, James W. (Inventor); DeBakey, Michael E. (Inventor)

    1999-01-01

    A blood pump that comprises a pump housing having a blood flow path therethrough, a blood inlet, and a blood outlet; a stator mounted to the pump housing, the stator having a stator field winding for producing a stator magnetic field; a flow straightener located within the pump housing, and comprising a flow straightener hub and at least one flow straightener blade attached to the flow straightener hub; a rotor mounted within the pump housing for rotation in response to the stator magnetic field, the rotor comprising an inducer and an impeller; the inducer being located downstream of the flow straightener, and comprising an inducer hub and at least one inducer blade attached to the inducer hub; the impeller being located downstream of the inducer, and comprising an impeller hub and at least one impeller blade attached to the impeller hub; and preferably also comprising a diffuser downstream of the impeller, the diffuser comprising a diffuser hub and at least one diffuser blade. Blood flow stagnation and clot formation within the pump are minimized by, among other things, providing the inducer hub with a diameter greater than the diameter of the flow straightener hub; by optimizing the axial spacing between the flow straightener hub and the inducer hub, and between the impeller hub and the diffuser hub; by optimizing the inlet angle of the diffuser blades; and by providing fillets or curved transitions between the upstream end of the inducer hub and the shaft mounted therein, and between the impeller hub and the shaft mounted therein.

  9. Relationship between Acquired Deficiency of Vitamin K-dependent Clotting Factors And Hemorrhage

    Institute of Scientific and Technical Information of China (English)

    杨锐; 张小平; 魏文宁; 洪梅; 杨焰; 胡豫

    2010-01-01

    This study examined the changes of activities of vitamin K-dependent clotting factors(VKDCF) under various pathological conditions and explored the relationship between acquired deficiency of VKDCFs and hemorrhage.Clinical data of 35 patients who were diagnosed as having acquired deficiency of VKDCF were retrospectively analyzed.Coagulation factors involved in the intrinsic and extrinsic pathways were detected in these patients and 41 control subjects.The results showed that the average activities of VKDCFs...

  10. Large Right Ventricular Clot in Pulmonary Atresia With Intact Ventricular Septum: In Defense of Biventricular Approach.

    Science.gov (United States)

    Dutta, Nilanjan; Ghosh, Rajarshi; Awasthy, Neeraj; Iyer, Parvathi U; Girotra, Sumir; Iyer, Krishna S

    2016-09-01

    Thrombus formation within the right ventricle (RV) in the setting of pulmonary atresia with intact ventricular septum (PAIVS) is not a very common occurrence and can be catastrophic. We present the case of a seven-month-old child with PAIVS and RV clot who successfully underwent biventricular repair. We discuss the interesting case and the rationale for management by means of biventricular repair over single ventricle repair when feasible in such a setting.

  11. Single amino acid substitutions dissociate fibrinogen-clotting and thrombomodulin-binding activities of human thrombin.

    OpenAIRE

    Wu, Q Y; Sheehan, J P; Tsiang, M; Lentz, S R; Birktoft, J J; Sadler, J E

    1991-01-01

    Thrombin is a serine protease that acts as a procoagulant by clotting fibrinogen and activating platelets and as an anticoagulant by activating protein C in a thrombomodulin-dependent reaction. Fibrinogen and thrombomodulin bind competitively to an anion-binding exosite on thrombin. We prepared recombinant normal human thrombin and mutant thrombins with single amino acid substitutions in order to localize and distinguish the fibrinogen- and thrombomodulin-binding sites. Normal and mutant thro...

  12. Utilization of salt whey from Egyptian Ras (Cephalotyre) cheese in microbial milk clotting enzymes production

    OpenAIRE

    El-Sayed El-Tanboly; Mahmoud El-Hofi; Youssef Bahr Youssef; Wahed El-Desoki; Azza Ismail

    2013-01-01

    Background. Microbial milk-clotting enzymes are valued as calf rennet substitutes in the cheese industry. The worldwide increase of cheese production coupled with a reduced supply of calf rennet has prompted a search for calf rennet substitutes, including microbial and plant rennets. However, most plant rennets have proved unsuitable because they impart a bitter taste to the cheese. Microbial rennet appears to be more promising because its production is cheaper, biochemical diversity is great...

  13. Technology Licensing and Firm Innovation

    DEFF Research Database (Denmark)

    Moreira, Solon

    acquisition. The findings indicate that technology licensing is positively related to the number of inventions produced by the licensee in the years subsequent to the licensing deal. Subsequently, I investigate the moderating effect that organizational slack and myopia have on this main relationship....... The findings also suggest that high levels of Organizational Slack (available financial resources) strengthen the positive effect of licensing on innovation. However, higher levels of Organizational Myopia (the extent to which a firm draws on its own knowledge) can decrease the main effect of licensing....

  14. The firm-nature relationship

    DEFF Research Database (Denmark)

    Ulhøi, John Parm; Madsen, Henning

    2005-01-01

    Taking the stakeholder concept of the firm as a starting point, the paper presents data and analyses from a longitudinal study initiated in 1995 and repeated every four years. In discussing state-of-the-art insights and experiences, the paper identifies challenges which, if adequately addressed......, may help bring the discipline out of its theoretical and epistemological deadlock. The paper concludes that, unless academia proactively brings the environmental management discipline within its domain, reductionists are likely to dominate the agenda-setting in the ongoing environmental debate......, reducing it to a question of self-regulated eco-modernist actions. In closing, the paper addresses implications for academia and industry....

  15. Kinetics of Formations of Ag Clots on AgBr Microcrystals at The Normal Laser Hershel Effect

    Directory of Open Access Journals (Sweden)

    A.B. Piven

    2011-01-01

    Full Text Available It is established that clots of silver have the amorphous structure at the normal laser Hershel effect after exposure of the photographic layer SP–1 (photosensitivity 6 standart units with low time texpos = 10 – 5 sec, and at high exposure times (texpos = 0.5 sec they have the crystal structure. The energy of the crystallization of Ag clots equals Wmin = 10 – 8 J.

  16. Topographic Cues Reveal Two Distinct Spreading Mechanisms in Blood Platelets

    OpenAIRE

    Rabea Sandmann; Sarah Köster

    2016-01-01

    Blood platelets are instrumental in blood clotting and are thus heavily involved in early wound closure. After adhering to a substrate they spread by forming protrusions like lamellipodia and filopodia. However, the interaction of these protrusions with the physical environment of platelets while spreading is not fully understood. Here we dynamically image platelets during this spreading process and compare their behavior on smooth and on structured substrates. In particular we analyze the te...

  17. Firm Projects, NPV and Risk

    CERN Document Server

    Hudakova, J

    2005-01-01

    An investor is estimating net present value of a firm project and performs risk analysis. Usually it is created portfolio hierarchies and make comparison of variants of project based on these hierarchies. Then one finds that portfolio which corresponds to the particular needs of individual groups within the firm. We have formulated a new type of NPV analysis based on the fact that normal distribution of NPV is observed for some projects in some industries. The expected risk of the project is given by variance, in which there is the standard deviation of the year n cash flow, the standard deviation of the investment I in the time zero, the correlation coefficient of the year n cash flow deviation from the average and of the investment I at time zero deviation from the mean investment at time zero, the correlation coefficient of the year n cash flow deviation from the average and of the year n' cash flow deviation from the average. The aim function of the investor into the project was found. The investor is cha...

  18. Human Capital and Wages in Exporting Firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    2006-01-01

    . Osing a very rich matched worker-firm longitudinal dataset we find that firms with high export intensities pay higher wages. However, an interaction term between export intensity and skill intensity has a positive impact on wages and it absorbs the direct effect of the export intensity. That is, we find......This paper studies the link between a firms education level, export performance and wages of its workers. We argue that firms may escape intence competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results...... an export wage premium, but it accrues to workers in firms with high skill intensities.Keywords: Exports, Wages, Human Capital, Rent Sharing, Matched Worker-Firm DataJEL Classification: J30, F10, I20...

  19. Women in Top Management and Firm Performance

    DEFF Research Database (Denmark)

    Smith, Nina; Smith, Valdemar; Verner, Mette

    The purpose of this study is to present new evidence on the relationship between gender diversity in management and firm performance. According to corporate governance literature, board diversity is expected to affect firm performance. Using a large data set with more than 10000 time-observations......The purpose of this study is to present new evidence on the relationship between gender diversity in management and firm performance. According to corporate governance literature, board diversity is expected to affect firm performance. Using a large data set with more than 10000 time......-observations for all Danish firms with more than 50 employees over the period 1994-2003, the analysis suggests that the proportion of women in top management jobs has from none to positive influence on firm performance. However, the results show that the strength of the effects of women in top management depends...

  20. Decomposing Firm-level Sales Variation

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Nguyen, Daniel Xuyen

    , and that for the median product it drives 31% of the sales variation. When we remove first-time exports from our sample, the median value increases to 40%, implying that firm-destination-specific effects are most important the first year. We conclude that while firm-specific productivity can account for some......We measure the contribution of firm-specific effects to overall sales variation within a destination and find it remarkably low. Our empirical decomposition is structurally motivated by a heterogeneity model of exporting involving destination-specific, firm-specific, and firm......-destination-specific latent effects with incidental truncation. We use a highly detailed dataset with exports by products and destinations for all Danish manufacturing fi…rms. We fi…nd the contribution of firm-specific heterogeneity to within-destination sales variation varies greatly across HS6 products...

  1. Contact activation of blood coagulation on a defined kaolin/collagen surface in a microfluidic assay

    OpenAIRE

    Zhu, Shu; Diamond, Scott L.

    2014-01-01

    Generation of active Factor XII (FXIIa) triggers blood clotting on artificial surfaces and may also enhance intravascular thrombosis. We developed a patterned kaolin (0 to 0.3 pg/μm2)/type 1 collagen fibril surface for controlled microfluidic clotting assays. Perfusion of whole blood (treated only with a low level of 4 μg/mL of the XIIa inhibitor, corn trypsin inhibitor) drove platelet deposition followed by fibrin formation. At venous wall shear rate (100 s−1), kaolin accelerated onset of fi...

  2. Intracorneal blood removal six weeks after canaloplasty

    Directory of Open Access Journals (Sweden)

    Alberto Rossetti

    2013-01-01

    Full Text Available In a 71-year-old patient with bilateral open-angle glaucoma, intracorneal blood was found after a canaloplasty procedure in the right eye. Six weeks after surgery on ultrasound biomicroscopy examination, liquified blood and blood clots could be observed nasally in the deep corneal stroma close to the Descemet′s membrane. The intracorneal blood was washed out with balanced saline solution following deep corneal incision and lamellar dissection. Descemet′s membrane was reattached with air injection into the anterior chamber. Two months later, visual acuity improved to 20/50, intraocular pressure was 16 mm Hg without medication and confocal microscopy showed deep stromal folds and limited endothelial cell loss. Viscoelastic entering the cornea at Schwalbe′s line and reflux of blood from the collector channels to Schlemm′s canal can account for corneal hematoma. Even six weeks after canaloplasty, successful blood removal could be fulfilled without rupturing the Descemet′s membrane.

  3. Firms' age, process innovation and productivity growth

    OpenAIRE

    Huergo, Elena; Jaumandreu, Jordi

    2004-01-01

    This paper looks directly at the impact of firms' age and (process) innovations on productivity growth. A model that specifies productivity growth as an unknown function of these variables is devised and estimated using semiparametric methods. Results show that firms enter the market experiencing high productivity growth and that above-average growth rates tend to last for many years, but also that productivity growth of surviving firms converges. Process innovations at some point then lead t...

  4. International working capital practices of Ghanaian firms

    OpenAIRE

    J. Abor

    2005-01-01

    International working capital management is important to firms frequently operating in the international market. This article investigates the international working capital practices of top Ghanaian firms involved in international trade. The objective of the study is to ascertain the extent to which Ghanaian firms use international working capital management vehicles. The article focuses on two main areas of international working capital management; international cash management and int...

  5. Working Capital Management and Firm Listing Status

    OpenAIRE

    Seraina Anagnostopoulou

    2012-01-01

    This study comparatively examines the determinants of working capital management for listed vs. unlisted firms, and assesses the impact of this policy on profitability by focusing on the cash conversion cycle, a commonly used measure of working capital management. By using a large UK public and private firm sample, it is found that private firms have significantly lower cash conversion cycles than their public counterparts, and that traditional determinants of the cycle significantly differ b...

  6. Nearly Optimal Pricing for Multiproduct Firms

    OpenAIRE

    Chenghuan Sean Chu; Phillip Leslie; Alan Sorensen

    2008-01-01

    In principle, a multiproduct firm can set separate prices for all possible bundled combinations of its products (i.e., "mixed bundling"). However, this is impractical for firms with more than a few products, because the number of prices increases exponentially with the number of products. In this study we show that simple pricing strategies are often nearly optimal -- i.e., with surprisingly few prices a firm can obtain 99% of the profit that would be earned by mixed bundling. Specifically, w...

  7. Corporate Governance, Firm Risk and Shareholder Value

    OpenAIRE

    Wolfswinkel, Michiel

    2013-01-01

    textabstractThis dissertation consists of three studies in the field of corporate governance. The research examines the impact of the way Dutch firms are managed and controlled on risk characteristics and the implications for shareholder value. The first study examines the relation between board interlocks and firm risk. In particular, we measure the effect of supervisory directors’ connectivity on firm risk. We find yet unknown aspects of connectivity and based on our findings the validity o...

  8. Knowledge production and firm growth in Brazil

    OpenAIRE

    João Alberto De Negri; Luiz Esteves; Fernando Freitas

    2007-01-01

    The aim of this study is to gauge the impact of the production of knowledge on the accumulation of fixed capital in Brazil. The hypothesis is that investment in R&D causes investment in fixed capital in Brazilian industrial firms. The empirical estimates rest on an IPEA database for information on firms and the workers linked to these firms during the period 1996-2003 and on the National Innovation Survey (PINTEC) for information on technological development. In the article, various estimates...

  9. Entrepreneurship and the Economics of the Firm

    OpenAIRE

    Foss, Nicolai J.; Klein, Peter G.; Bylund, Per L.

    2011-01-01

    The study of entrepreneurship and the study of economic organizing lack contact. In fact, the modern theory of the firm virtually ignores entrepreneurship, while the literature on entrepreneurship often sees little value in the economic theory of the firm. In contrast, we argue in this chapter that entrepreneurship theory and the theory of the firm can be usefully integrated, and that doing so would improve both bodies of theory. Adding the entrepreneur to the theory of the fir...

  10. Busyness and advising at Borsa Istanbul firms

    OpenAIRE

    Emrah Arioğlu; Pinar Arioğlu Kaya

    2015-01-01

    In this study, we investigate director busyness and advising for firms quoted at Borsa Istanbul. We show that firms prefer not to appoint directors with multiple directorships and superior advising skills to monitoring positions, potentially as a result of a trade-off between the monitoring and advising functions of directors. In addition, we find that busy boards have higher advising capacity compared to non-busy boards. Also, we show that firms that have busy boards or higher advising quali...

  11. Tax Compliance by Firms and Audit Policy

    OpenAIRE

    Ralph-C. Bayer; Frank Cowell

    2010-01-01

    Firms are usually better informed than tax authorities about market conditions and the potential profits of competitors. They may try to exploit this situation by underreporting their own taxable profits. The tax authority could offset firms' informational advantage by adopting "smarter" audit policies .that take into account the relationship between a firm's reported profits and reports for the industry as a whole. Such an audit policy will create an externality for the decision makers in th...

  12. Does Labor Diversity Affect Firm Productivity?

    OpenAIRE

    Parrotta, Pierpaolo; Pozzoli, Dario; Pytlikova, Mariola

    2010-01-01

    Using an employer-employee dataset, we analyze how diversity in cultural background, skills and demographic characteristics affects total factor productivity (TFP) of firms in Denmark. Implementing structural estimation of firms’ production function, we find evidence that labor diversity in skills/education significantly enhances firm performance as measured by firm TFP. Conversely, diversity in demographics and ethnicity brings mixed results – both dimensions of workforce diversity have eith...

  13. Negotiating access into firms: obstacles and strategies

    OpenAIRE

    Laryea, Sam; Hughes, Will

    2011-01-01

    Researchers often experience difficulties with the negotiation of access into firms for the purpose of data collection. The question we explore is: What are the main obstacles associated with access negotiation into firms; and what strategies do researchers employ to increase their chances of success? Our research work on the tendering process of contractors took place between 2006 and 2008. We successfully negotiated access into four firms (two each in Ghana and the UK) to observe live ex...

  14. BOARD INFLUENCE ON A FIRM'S INTERNATIONALIZATION

    OpenAIRE

    Barroso, Carmen; Villegas, Mª Mar; Pérez-Calero, Leticia

    2011-01-01

    Abstract Manuscript Type: Empirical Research Question/Issues: The resource-based view of the firm may provide the theoretical explanation as to how boards can be a source of firm competitive advantage. Directors? experience, knowledge, expertise are valuable, rare, inimitable and non-substitutable resources that making up the board potential. These resources must be integrated with others firm resources in strategic processes through dynamics of relations. Research Findings/...

  15. Female directors, key committees, and firm performance

    OpenAIRE

    Green, Colin; Homroy, Swarnodeep

    2015-01-01

    There is pressure to increase female representation on corporate boards. A number of studies have found no, or in some cases a negative, effect of female representation on boards and firm performance. We demonstrate robust positive and economically meaningful effects on firm performance of female representation on European boards. Moreover, while previous work has considered female representation broadly, we focus on membership of committees involved explicitly in firm governance. We demonstr...

  16. The Organization of Knowledge in Multinational Firms

    OpenAIRE

    Gumpert, Anna

    2015-01-01

    This paper provides the first in-depth study of the organization of knowledge in multinational firms. The paper develops a theoretical model that studies how firms optimally split knowledge between their headquarters and their production plants if communication costs impede the access of production plants to headquarter knowledge. The paper assumes that the foreign plants of multinational firms face higher communication costs with headquarters than their domestic plants, and shows that multin...

  17. Effects of innovation types on firm performance

    OpenAIRE

    Günday, Gürhan; Gunday, Gurhan; Ulusoy, Gündüz; Ulusoy, Gunduz; Kılıç, Kemal; Kilic, Kemal; Lütfihak ALPKAN; Alpkan, Lutfihak

    2011-01-01

    Innovation is broadly seen as an essential component of competitiveness, embedded in the organizational structures, processes, products, and services within a firm. The objective of this paper is to explore the effects of the organizational, process, product, and marketing innovations on the different aspects of firm performance, including innovative, production, market, and financial performances, based on an empirical study covering 184 manufacturing firms in Turkey. A theoretical framework...

  18. Firm Performance and Board Committee Structure.

    OpenAIRE

    Klein, April

    1998-01-01

    This article demonstrates a linkage between firm performance and board composition by examining the committee structure of boards and the directors' roles within these committees. Consistent with previous studies, I find little association between firm performance and overall board composition. However, by going into the inner workings of the board via board committee composition, I am able to find significant ties between firm performance and how boards are structured. First, a positive rela...

  19. Accounting Firms: Global Spread with Limited Transnationalization

    OpenAIRE

    Jochen Zimmermann; Jan-Christoph Volckmer

    2012-01-01

    As financial markets have increasingly globalised, the regulatory framework is still nationally fragmented. One core regulatory element is the provision of assurance services by accounting firms. The Big 4 - the leading international providers of audit services Ð are not as international as are accounting standards or their clients. The paper traces three facets of the transnationalization of accounting firms: explanations for internationalization rooted in the theory of the firm, their modes...

  20. Does Wage Dispersion Make All Firms Productive?

    OpenAIRE

    Mahy, Benoît; Rycx, Francois; Volral, Mélanie

    2011-01-01

    This article puts the relationship between wage dispersion and firm productivity to an updated test, taking advantage of access to detailed Belgian linked employer-employee panel data. Controlling for simultaneity issues, time-invariant workplace characteristics and dynamics in the adjustment process of productivity, empirical results reveal the existence of a positive impact from conditional intra-firm wage dispersion to firm productivity (measured by the average value added per hour worked)...

  1. Coevolution of Firm Capabilities and Industry Competition

    OpenAIRE

    Huygens, Marc; Baden-Fuller, Charles; Bosch, Frans; Volberda, Henk

    2001-01-01

    textabstractThis paper proposes that rival firms not only search for new capabilities within their organization, but also for those that rest in their competitive environment. An integrated analysis of these search processes at both firm and industry levels of analysis shows how their interaction makes industries and firms coevolve over time. To contribute to an enhanced understanding of the concept of coevolution, a dynamic and integrative framework crossing meso and micro levels of analysis...

  2. Industrial environmental practices in Polish Firms

    DEFF Research Database (Denmark)

    Kræmer, Trine Pipi

    , and environment. The five case firms all had a Communist past. The firms represent three different industrial sectors; i.e. textile, energy, and publishing and printing industries. Furthermore, the firms are both private and state owned as well as in the process of privatisation.......The study investigates how discursive developments in Poland interact with industrial environmental practices in five production firms. The analysis of the discursive development covers the period from the end of World War I to the turn of the century. The areas in focus are identity, industry...

  3. International working capital practices of Ghanaian firms

    Directory of Open Access Journals (Sweden)

    J. Abor

    2005-12-01

    Full Text Available International working capital management is important to firms frequently operating in the international market. This article investigates the international working capital practices of top Ghanaian firms involved in international trade. The objective of the study is to ascertain the extent to which Ghanaian firms use international working capital management vehicles. The article focuses on two main areas of international working capital management; international cash management and international sales and accounts receivables management. The results of this study reveal low level of use of international working capital vehicles among Ghanaian firms. Recommendations are made in this regard.

  4. Shared Vision promotes family firm performance

    Directory of Open Access Journals (Sweden)

    John Edward Neff

    2015-05-01

    Full Text Available A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS, Role Clarity (RCL, Confidence in Management (CON, and Professional Networking (OLN that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR, the functional integrity of the family itself exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance.

  5. Shared vision promotes family firm performance.

    Science.gov (United States)

    Neff, John E

    2015-01-01

    A clear picture of the influential drivers of private family firm performance has proven to be an elusive target. The unique characteristics of private family owned firms necessitate a broader, non-financial approach to reveal firm performance drivers. This research study sought to specify and evaluate the themes that distinguish successful family firms from less successful family firms. In addition, this study explored the possibility that these themes collectively form an effective organizational culture that improves longer-term firm performance. At an organizational level of analysis, research findings identified four significant variables: Shared Vision (PNS), Role Clarity (RCL), Confidence in Management (CON), and Professional Networking (OLN) that positively impacted family firm financial performance. Shared Vision exhibited the strongest positive influence among the significant factors. In addition, Family Functionality (APGAR), the functional integrity of the family itself, exhibited a significant supporting role. Taken together, the variables collectively represent an effective family business culture (EFBC) that positively impacted the long-term financial sustainability of family owned firms. The index of effective family business culture also exhibited potential as a predictive non-financial model of family firm performance.

  6. Managing Firm Competitiveness in Global Markets

    OpenAIRE

    Gehlhar, M.; Regmi, A.; Stefanou, S.E.; Zoumas, B.

    2006-01-01

    The globalization profile of US food firms is mixed. US sales from foreign direct investment is now over six times the level of exports, while US processed food trade balance has moved from +$9 billion in 1995 to - $7 billion in 2004. Competitive forces drive firms to seek new areas of growth, with either portfolio expansion or penetration and expansion in new markets. Although the forces that weigh heavily on a firm are recognized, their influence in determining a firm¿s action in choosing a...

  7. Small firm subsistence and market dimensionality

    Science.gov (United States)

    Bruggeman, Jeroen; Péli, Gábor

    2014-04-01

    In many markets, large and small firms coexist. As large firms can in principle out-compete small ones, the actual presence of the latter asks for an explanation. In ours, we focus on the dimensionality of markets, which can change as a consequence of product innovations, preference elaboration or institutions. We show that increasing market dimensionality substantially enlarges the market periphery relative to the market center, which creates new potential niches for small firms. We thereby provide a parsimonious explanation for small firm subsistence.

  8. Dynamic and quantitative assessment of blood coagulation using optical coherence elastography

    Science.gov (United States)

    Xu, Xiangqun; Zhu, Jiang; Chen, Zhongping

    2016-04-01

    Reliable clot diagnostic systems are needed for directing treatment in a broad spectrum of cardiovascular diseases and coagulopathy. Here, we report on non-contact measurement of elastic modulus for dynamic and quantitative assessment of whole blood coagulation using acoustic radiation force orthogonal excitation optical coherence elastography (ARFOE-OCE). In this system, acoustic radiation force (ARF) is produced by a remote ultrasonic transducer, and a shear wave induced by ARF excitation is detected by the optical coherence tomography (OCT) system. During porcine whole blood coagulation, changes in the elastic property of the clots increase the shear modulus of the sample, altering the propagating velocity of the shear wave. Consequently, dynamic blood coagulation status can be measured quantitatively by relating the velocity of the shear wave with clinically relevant coagulation metrics, including reaction time, clot formation kinetics and maximum shear modulus. The results show that the ARFOE-OCE is sensitive to the clot formation kinetics and can differentiate the elastic properties of the recalcified porcine whole blood, blood added with kaolin as an activator, and blood spiked with fibrinogen.

  9. Airworthiness Approval of Design Firms

    Directory of Open Access Journals (Sweden)

    Kanchan Biswas

    2006-01-01

    Full Text Available Aviation as a mode of transportation requires that the aircraft designed, developed, andoperated must be maintained under airworthy condition. The basic tenet of airworthiness is thatthe aircraft designed and developed are certified by the independent airworthiness regulatoryorganisations. This requires strict vigil during the development stages. With quantum jump inthe design and development activities, it has been extremely difficult for the regulatory bodiesto cope up with the demand of certification. Delegating this responsibility to a few approvedfirms prove very effective in maintaining the design control through approved agencies andpersonnel. Airworthiness approval of design firms taken up by the Centre for MilitaryAirworthiness & Certification, Bangalore, which is the airworthiness approval authority for militaryaircraft in India, is one such step. This paper discusses the scope and extent of such approvals.

  10. Cultural diversity, cities and innovation: firm effects or city effects?

    OpenAIRE

    Lee, Neil

    2013-01-01

    Growing cultural diversity is seen as important for innovation. Research has focused on two potential mechanisms: a firm effect, with diversity at the firm level improving knowledge sourcing or ideas generation, and a city effect, where diverse cities helping firms innovate. This paper uses a dataset of over 2,000 UK SMEs to test between these two. Controlling for firm characteristics, city characteristics and firm and city diversity, there is strong evidence for the firm effect. Firms with a...

  11. Sources of economic renewal: from the traditional firm to the knowledge firm

    OpenAIRE

    Rodriguez-Palenzuela, Diego

    2001-01-01

    We build on the imperfection of intellectual property rights as the central motivation for the organization of firms. There are several characteristics specific to a theory of the firm grounded on the absence of intellectual property rights: monetary incentive schemes arise naturally as a element of the organization and strategy of the firm, since profits are verifiable; firm's boundaries and the degree of centralization respond to the same economic principle; the sunk cost of physical assets...

  12. Board Structure, Ownership Structure and Firm Performance: A Study of New Zealand Listed-Firms

    OpenAIRE

    Fitriya Fauzi; Stuart Locke

    2012-01-01

    This paper investigates the role of board structure and the effect of ownership structures on firm performance in New Zealand's listed firms. Several studies, the majority from the U.S., U.K. and Japan, have examined the relationship between corporate governance mechanisms, ownership structure and firm performance. Those studies yielded different results, affected by the nature of the prevailing governance system for each country. Investigating New Zealand's listed firms could enhance the div...

  13. A firm-specific exposure analyis of the exchange-rate exposure of Dutch firms

    NARCIS (Netherlands)

    A. de Jong; J. Ligterink; V. Macrae

    2006-01-01

    We examine the relationship between exchange-rate changes and stock returns for a sample of Dutch firms over 1994-1998. We find that over 50 per cent of the firms are significantly exposed to exchange-rate risk. Furthermore, all firms with significant exchange-rate exposure benefit from a depreciati

  14. A Firm-Specific Analysis of the Exchange-Rate Exposure of Dutch Firms

    NARCIS (Netherlands)

    A. de Jong (Abe); J. Ligterink; V. Macrae

    2002-01-01

    textabstractWe examine the relationship between exchange-rate changes and stock returns for a sample of Dutch firms over 1994-1998. We find that over 50% of the firms are significantly exposed to exchange-rate risk. Furthermore, all firms with significant exchange-rate exposure benefit from a deprec

  15. The Quality of the Legal System, Firm Ownership, and Firm Size

    OpenAIRE

    Laeven, Luc; Woodruff, Christopher

    2004-01-01

    Employment in developing countries is disproportionately concentrated in very small firms. The authors examine the extent to which the distribution of firm size is related to the quality of the legal system using data from Mexico. They combine Lucas' (1978) model of firm size with Himmelberg, Hubbard, and Love's (2001) consideration of idiosyncratic risk in a framework in which the distrib...

  16. Prediction of recurrent venous thromboembolism by clot lysis time: a prospective cohort study.

    Directory of Open Access Journals (Sweden)

    Ludwig Traby

    Full Text Available Venous thromboembolism (VTE is a chronic disease, which tends to recur. Whether an abnormal fibrinolytic system is associated with an increased risk of VTE is unclear. We assessed the relationship between fibrinolytic capacity (reflected by clot lysis time [CLT] and risk of recurrent VTE. We followed 704 patients (378 women; mean age 48 yrs with a first unprovoked VTE for an average of 46 months after anticoagulation withdrawal. Patients with natural coagulation inhibitor deficiency, lupus anticoagulant, cancer, homozygosity for factor V Leiden or prothrombin mutation, or requirement for indefinite anticoagulation were excluded. Study endpoint was symptomatic recurrent VTE. For measurement of CLT, a tissue factor-induced clot was lysed by adding tissue-type plasminogen activator. Time between clot formation and lysis was determined by measuring the turbidity. 135 (19% patients had recurrent VTE. For each increase in CLT of 10 minutes, the crude relative risk (RR of recurrence was 1.13 (95% CI 1.02-1.25; p = 0.02 and was 1.08 (95% CI 0.98-1.20; p = 0.13 after adjustment for age and sex. For women only, the adjusted RR was 1.14 (95% CI, 0.91-1.42, p = 0.22 for each increase in CLT of 10 minutes. CLT values in the 4(th quartile of the female patient population, as compared to values in the 1(st quartile, conferred a risk of recurrence of 3.28 (95% CI, 1.07-10.05; p = 0.04. No association between CLT and recurrence risk was found in men. Hypofibrinolysis as assessed by CLT confers a moderate increase in the risk of recurrent VTE. A weak association between CLT and risk of recurrence was found in women only.

  17. Molecular basis of the clotting defect in a bleeding patient missing the Asp-185 codon in the factor X gene.

    Science.gov (United States)

    Lu, Qiuya; Yang, Likui; Manithody, Chandrashekhara; Wang, Xuefeng; Rezaie, Alireza R

    2014-11-01

    Factor X (FX) is a vitamin K-dependent plasma zymogen, which following activation to factor Xa (FXa), converts prothrombin to thrombin in the blood clotting cascade. It was recently demonstrated that a natural variant of FX carrying the Asp-185 deletion (FX-D185del, chymotrypsinogen numbering) was associated with mild bleeding in a patient with severe FX deficiency. In this study, we expressed FX-D185del in mammalian cells and characterized its properties in appropriate kinetic assays in purified systems. We discovered that while the FX variant can be normally activated by physiological activators; both amidolytic and proteolytic activities of the mutant are dramatically impaired. Interestingly, factor Va (FVa) significantly improved the proteolytic defect when the mutant protease was assembled into the prothrombinase complex. Thus, in contrast to >50-fold catalytic defect in the absence of FVa, the variant activated prothrombin with only ~2.5-fold decreased catalytic efficiency in the presence of the cofactor. The FXa variant dramatically lost its susceptibility to inhibition by antithrombin and tissue factor pathway inhibitor, thus exhibiting ~2-3 orders of magnitude lower reactivity with the plasma inhibitors. Further studies revealed that Na(+) no longer activates the variant protease, suggesting that the functionally important allosteric linkage between the Na(+)-binding and the P1-binding sites of the protease has been eliminated. These results suggest that the lower catalytic efficiency of FXa-D185del in the bleeding patient may be partially compensated by the loss of its reactivity with plasma inhibitors, possibly explaining the basis for the paradoxical severe FX deficiency with only mild bleeding tendency for this mutation. PMID:25179519

  18. Use of proteomics for validation of the isolation process of clotting factor IX from human plasma

    OpenAIRE

    Clifton, James; Huang, Feilei; Gaso-Sokac, Dajana; Brilliant, Kate; Hixson, Douglas; Josic, Djuro

    2009-01-01

    The use of proteomic techniques in the monitoring of different production steps of plasma-derived clotting factor IX (pd F IX) was demonstrated. The first step, solid-phase extraction with a weak anion-exchange resin, fractionates the bulk of human serum albumin (HSA), immunoglobulin G, and other non-binding proteins from F IX. The proteins that strongly bind to the anion-exchange resin are eluted by higher salt concentrations. In the second step, anion-exchange chromatography, residual HSA, ...

  19. Comparative evaluation of Bacillus licheniformis 5A5 and Aloe variegata milk-clotting enzymes

    Directory of Open Access Journals (Sweden)

    S. A. Ahmed

    2012-03-01

    Full Text Available The properties of a milk clotting enzyme (MCE produced by bacteria (Bacillus licheniformis 5A5 were investigated and compared to those of rennet extracted from a plant (Aloe variegata. Production of MCE by B. licheniformis 5A5 was better in static than in shaken cultures. Maximum activity (98.3 and 160.3 U/ml of clotting was obtained at 75ºC and 80ºC with bacterial and plant rennet, respectively. In the absence of substrate, the clotting activity of Aloe MCE was found to be less sensitive to heat inactivation up to 80ºC for 75 min, retaining 63.8% of its activity, while bacterial MCE was completely inhibited. CaCl2 stimulated milk clotting activity (MCA up to 2% and 1.5% for bacterial and plant enzymes. NaCl inhibited MCA for both enzymes, even at low concentration (1%. Plant MCE was more sensitive to NaCl at 3% concentration it retained 30.2% of its activity, whereas bacterial MCE retained 64.1%. Increasing skim milk concentration caused a significant increase in MCA up to 6% for both enzymes. Mn2+ stimulated the activity of bacterial and plant enzymes to 158.6 and 177.9%, respectively. EDTA and PMSF increased the activity of plant MCE by 34.4 and 41.1%, respectively, which is higher than those for the bacterial MCE (19.1 and 20.9%. Some natural materials activated MCE, the highest activation of bacterial MCE (128.1% was obtained in the presence of Fenugreek (with acid extraction. However Lupine Giza 1 (with neutral extraction gave the highest activation of plant MCE (137.9%. All extracts from Neem plant increased MCA at range from 105.6% to 136.4%. Plant MCE exhibited much better stability when stored at room temperature (25-30ºC for 30 days, retaining 51.2% of its activity. Bacterial MCE was highly stabile when stored under freezing (-18ºC, retaining 100% of its activity after 30 days. Moreover, bacterial MCE was highly tolerant to repeated freezing and thawing without loss of activity for 8 months.

  20. Agency Costs, Firm Value, and Corporate Investment

    NARCIS (Netherlands)

    M. Teixeira de Vasconcelos (Manuel)

    2012-01-01

    textabstractOften firms lack the necessary internal resources to pursue all profitable investment opportunities at their disposal. One of the most important roles of financial markets is to allocate resources from different economic agents to the firms that will better employ them, thereby enabling

  1. Managing firm competitiveness in global markets

    NARCIS (Netherlands)

    Gehlhar, M.; Regmi, A.; Stefanou, S.E.; Zoumas, B.

    2006-01-01

    The globalization profile of US food firms is mixed. US sales from foreign direct investment is now over six times the level of exports, while US processed food trade balance has moved from +$9 billion in 1995 to - $7 billion in 2004. Competitive forces drive firms to seek new areas of growth, with

  2. Trade credit: Elusive insurance of firm growth

    NARCIS (Netherlands)

    Bams, Dennis; Bos, Jaap; Pisa, Magdalena

    2016-01-01

    Firms depend heavily on trade credit. This paper introduces a trade credit network into a structural model of the economy. In an empirical analysis of the model, we find that trade credit is an elusive insurance: as long as a firm is financially unconstrained and times are good, more trade credit en

  3. Impacts of IST on firms and organisations

    DEFF Research Database (Denmark)

    Jørgensen, Ulrik

    2003-01-01

    A review of socio-economic research on the impact and role of IST in firms and organisations. The study is carried out in ESTO for IPTS.......A review of socio-economic research on the impact and role of IST in firms and organisations. The study is carried out in ESTO for IPTS....

  4. Small firms' formalization: The stick treatment

    OpenAIRE

    De Giorgi, Giacomo; Ploenzke, Matthew; Rahman, Aminur

    2015-01-01

    Firm informality is pervasive throughout the developing world, Bangladesh being no exception. The informal status of many firms substantially reduces the tax basis and therefore impacts the provision of public goods. The literature on encouraging formalization has predominantly focused on reducing the direct costs of formalization and has found negligible impacts of such policies. This pap...

  5. Theoretical Perspectives on the Internationalization of Firms

    Science.gov (United States)

    Rask, Morten; Strandskov, Jesper; Hakonsson, Dorthe Dojbak

    2008-01-01

    The purpose of this article is to build a coherent framework of the four main theories relating to the internationalization of firms, in order to facilitate better business teaching and research. Yet, theories of the internationalization of firms are broad and rest on different underlying assumptions. With the purpose of clarifying the potential…

  6. Performance of Patenting Firms in Danish Manufacturing

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar; Nielsen, Anders Østergaard

    2000-01-01

    -patenting firms within the manufacturing sector in Denmark. Performance is measured both by growth in employment as well as in the return on equity and profit share in turnover. The results suggest that differences in performance of patenting and non-patenting firms are very small, which questions the political...

  7. Psychic Distance, Innovation, and Firm Performance

    NARCIS (Netherlands)

    Azar, Goudarz; Drogendijk, Rian

    2014-01-01

    Previous research suggests that internationalization improves a firm's ability to innovate, but the effect of internationalizing into specific target markets or destinations on the innovation ability of firms has not been fully investigated. This study examined whether the psychic distance between t

  8. New workplace practices and firm performance:

    DEFF Research Database (Denmark)

    Cristini, Annalisa; Pozzoli, Dario

    Using data from the 2004 Workplace Employee Relations Survey on British establishments and two surveys on manufacturing firms located in the North of Italy, we look at the diffusion of new workplace practices in the two countries and at their impact on the firm's value added. We find that the ado...

  9. Objectives of the Airline Firm: Theory

    Science.gov (United States)

    Kneafsey, J. T.

    1972-01-01

    Theoretical models are formulated for airline firm operations that revolve around alternative formulations of managerial goals which these firms are persuing in practice. Consideration is given to the different objective functions which the companies are following in lieu of profit maximization.

  10. Architectural firms: workforce, business strategy and performance

    Directory of Open Access Journals (Sweden)

    Adedapo Adewunmi Oluwatayo

    2011-12-01

    Full Text Available The intent of this research was to investigate the relationship between the workforce, business strategy and performance of architectural firms. Data was collected from 92 firms randomly selected from the cities where architectural firms were most concentrated in Nigeria using questionnaires. Hierarchical regression analysis was carried out to investigate the direct and indirect impacts of the workforce of architectural firms on their performance. The findings confirm the significant positive impact. With business strategy controlled, the specific characteristics of the workforce and its management which influenced performance were the number of architects, the work structure, and the age and experience of the principal partners. The impact of the number of non- architecture professionals and staff participation in decision-making on performance was moderated by the business strategy adopted by the firms. The results suggest that workforce characteristics are more important than the management of the workforce in determining performance of architectural firms. This is contrary to the results of previous studies which suggest higher importance of the management. This probably indicates the peculiarity of architectural firm as a professional service firm in the construction industry.

  11. New Environmental Practices in Polish Production Firms

    DEFF Research Database (Denmark)

    Kræmer, Trine Pipi

    2002-01-01

    Based on five case studies in Poland, the paper discusses, how a specific environmental policy influences the firms? industrial environmental practices. The study illustrates, how the Polish environmental policy, dominated by environmental charges on emissions, is extremely effective in improving...... the environmental state, but at the same time seems to direct the firms towards end-of-pipe solutions and a retrospective environmental strategy....

  12. Paradoxes and Innovation in Family Firms

    DEFF Research Database (Denmark)

    Ingram, Amy E.; Lewis, Marianne W.; Barton, Sid;

    2016-01-01

    Scholars stress that family firms are inherently paradoxical, and that tensions, such as tradition versus change, family liquidity versus business growth, and founder control versus successor autonomy, can both inhibit and foster innovation. Further, theorists propose that firms led by paradoxica...

  13. Identifying High Growth Firms in India

    DEFF Research Database (Denmark)

    Aggarwal, Aradhna; Sato, Takahiro

    Over the past two decades, considerable interest has grown in high growth firms (HGFs). However, the concept of HGFs still remains controversial. One of the most controversial issues is size and age of these firms. The present study argues that the current literature on HGFs may offer little help...

  14. 78 FR 70987 - Proxy Advisory Firm Roundtable

    Science.gov (United States)

    2013-11-27

    ...The Securities and Exchange Commission will host a roundtable about proxy advisory firms. The panel will be asked to discuss topics including the current state of proxy advisory firm use by investment advisers and institutional investors and potential changes that have been suggested by market participants. Panelists will also be invited to discuss any new ideas. The roundtable discussion will......

  15. Electronic Commerce, Digital Information, and the Firm.

    Science.gov (United States)

    Rosenbaum, Howard

    2000-01-01

    Discussion of the social context of electronic commerce (ecommerce) focuses on information imperatives, or rules that are critical for ecommerce firms. Concludes with a discussion of the organizational changes that can be expected to accompany the incorporation of these imperatives into the mission and core business processes of ecommerce firms.…

  16. When do German Firms Change their Dividends?

    NARCIS (Netherlands)

    Correia Da Silva, L.; Goergen, M.; Renneboog, L.D.R.

    2002-01-01

    Anecdotal evidence suggests that the dividend policy of German firms is more flexible than the one of their Anglo-American counterparts.This paper analyses the decision to change the dividend for a panel of 221 German firms from 1984 to 1994.The choice of the period of study is motivated by the fact

  17. Internationalization of Emerging Economies and Firms

    DEFF Research Database (Denmark)

    countries and firms. The impact of country and firm specific factors, the role of institutions and governments, the strive for compensation of initial disadvantages, the struggle for finding ways to counterbalance for late coming into the international arena in the process of internationalization...... are brought under scrutiny in this volume. The chapters provide insights from diverse contexts ranging from Brazil to Malaysia....

  18. Market Imperfections and Firm-Sponsored Training

    NARCIS (Netherlands)

    Picchio, M.; van Ours, J.C.

    2010-01-01

    Recent human capital theories predict that labor market frictions and product market competition influence firm-sponsored training. Using matched worker-firm data from Dutch manufacturing, our paper empirically assesses the validity of these predictions. We find that a decrease in labor market frict

  19. Foreign Entry and Heterogeneous Growth of Firms

    DEFF Research Database (Denmark)

    Deng, Paul Duo; Jefferson, Gary H.

    We adopt the framework of Schumpeterian creative destruction formalized by Aghion et al. (2009) to analyze the impact of foreign entry on the productivity growth of domestic firms. In the face of foreign entry, domestic firms exhibit heterogeneous patterns of growth depending on their technologic...

  20. How does firm performance influence market orientation?

    DEFF Research Database (Denmark)

    Sørensen, Hans Eibe; Stieglitz, Nils

    This paper contributes by investigating how firm performance influences its market orientation. We draw on the aspiration-level model from the behavioral theory of the firm to develop testable propositions that substantiate and extend prior market orientation research. Specifically, we address ho...... performance influences firms' market-oriented search behavior (responsive or proactive) and the allocation of attention (customer and competitor orientation) as well as the formation of aspiration levels. Research and managerial implications are discussed.......This paper contributes by investigating how firm performance influences its market orientation. We draw on the aspiration-level model from the behavioral theory of the firm to develop testable propositions that substantiate and extend prior market orientation research. Specifically, we address how...

  1. Choice of Ownership Structure and Firm Performance

    DEFF Research Database (Denmark)

    Jones, Derek C; Kalmi, Panu; Mygind, Niels

    2003-01-01

    In this paper we use rich panel data for a representative sample of Estonian enterprises to analysediverse issues related to the determinants of ownership structures and ownership changes afterprivatisation. A key focus is to determine whether ownership changes are related to economicefficiency....... While employee owned firms are found to be much more prone than other firms toswitch ownership categories, often `employee owned' firms remain `insider-owned' as ownershippasses from current employees to managers and former employees. Logit analyses of thedeterminants of ownership structures...... and ownership changes provides mixed support for severalhypotheses. As predicted: (i) wealth and resource constraints play a crucial role in thedetermination of ownership, with foreigners buying firms with the highest equity levels andinsiders buying firms with the lowest equity valuations; (ii) risk aversion...

  2. The innovative behaviour of tourism firms

    DEFF Research Database (Denmark)

    Sundbo, Jon; Orfila-Sintes, Francina; Sørensen, Flemming

    2007-01-01

    Tourism firms operate in a competitive sector where innovating is often a condition for survival. This article presents a theoretical framework for understanding tourist firms’ innovative behaviour and innovation systems in tourism. The innovativeness of tourism firms and its determinants...... are investigated by analysing quantitative as well as qualitative data comparing Spain and Denmark. A taxonomy of tourism firms is suggested and the firms’ characteristics which influence their innovativeness are presented. Additionally, the role of innovation networks is discussed, as is the role of innovation...... systems. The article suggests that large size, professionalism, but also entrepreneurship among small tourism firms are important determinants of innovation. Varied innovation networks are another determinant as are supportive innovation systems. These determinants favour Spanish firms, which are more...

  3. Commercialization of Innovations and Firm Performance

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar

    of Danish firms holding information on their R&D investment as well as their expenses on marketing which gives knowledge of the commercialization of their innovations. The results suggest a highly significant commercialization of innovation, which means that firms' follows a strategy of investment both...... in innovation and marketing making R&D and marketing complements in their investment decision. However, there is only week evidence for the hypothesis that commercialization of innovations also creates more value for the firms in the short run.......The decision on investment in R&D is very important and highly risky for firms' performance and survival in their business. This paper focuses on the commercialization of firms' investment in innovation and how these decisions affect their performance. The study uses a large innovation survey...

  4. Commercialization of Innovations and Firm Performance

    DEFF Research Database (Denmark)

    Madsen, Erik Strøjer; Smith, Valdemar

    of Danish firms holding information on their R&D investment as well as their expenses on marketing which gives knowledge of the commercialization of their innovations. The results suggest a highly significant commercialization of innovation, which means that firms' follows a strategy of investment both...... in innovation and marketing making R&D and marketing complements in their investment decision. However, there is only week evidence for the hypothesis that commercialization of innovations also creates more value for the firms in the short run.  ......The decision on investment in R&D is very important and highly risky for firms' performance and survival in their business. This paper focuses on the commercialization of firms' investment in innovation and how these decisions affect their performance. The study uses a large innovation survey...

  5. How Does Family Management Affect Firm Performance : Evidence from Taiwanese Firms

    OpenAIRE

    Shyu, Jonchi; Shen, Yu-Hung

    2011-01-01

    This study used the panel data of 465 Taiwanese listed companies by applying both accounting and market-value indicators to an examination of family management’s influence on firm performances. The empirical results show that family firms in Tai-wan have performed better than non-family firms. The combination of equity owner-ship and management right has helped family firms reduce agency cost and enhance firm value in the long run. As for family management, the empirical results suggest that ...

  6. MASP-1 Induced Clotting--The First Model of Prothrombin Activation by MASP-1.

    Science.gov (United States)

    Jenny, Lorenz; Dobó, József; Gál, Péter; Schroeder, Verena

    2015-01-01

    Mannan-binding lectin-associated serine protease-1 (MASP-1), a protein of the complement lectin pathway, resembles thrombin in terms of structural features and substrate specificity. Due to its interplay with several coagulation factors, it has the ability to induce fibrin clot formation independent of the usual coagulation activation pathways. We have recently shown that MASP-1 activates prothrombin and identified arginine (R) 155, R271, and R393 as potential cleavage sites. FXa cleaves R320 instead of R393, and thrombin cleaves R155 and R284 in prothrombin. Here we have used three arginine-to-glutamine mutants of prothrombin, R271Q, R320Q, R393Q and the serine-to-alanine active site mutant S525A to investigate in detail the mechanism of MASP-1 mediated prothrombin activation. Prothrombin wildtype and mutants were digested with MASP-1 and the cleavage products were analysed by SDS-PAGE and N-terminal sequencing. A functional clotting assay was performed by thrombelastography. We have found that MASP-1 activates prothrombin via two simultaneous pathways, either cleaving at R271 or R393 first. Both pathways result in the formation of several active alternative thrombin species. Functional studies confirmed that both R393 and R320 are required for prothrombin activation by MASP-1, whereas R155 is not considered to be an important cleavage site in this process. In conclusion, we have described for the first time a detailed model of prothrombin activation by MASP-1. PMID:26645987

  7. "Blood" in D.H. Lawrence and O. Wilde

    OpenAIRE

    中山, 本文; Motofumi, NAKAYAMA

    2015-01-01

    Lawrence and Wilde found something special in "blood." Lawrence had a firm belief in "blood" symbolizing primitive "daemonic" energy. Lawrence's blood operates as energy to encourage one to transcend individuality and acquire "a greater life." With profound insight, he asserts that an invisible world of "blood-consciousness" underlies the visible world. Wilde too stresses "blood" as seen in "The Nightingale and the Rose," "The Happy Prince." or "The Selfish Giant." The "blood," which is insep...

  8. Job Creation by Firms in Denmark

    DEFF Research Database (Denmark)

    Ibsen, Rikke Falkner; Westergård-Nielsen, Niels

    (firm) is the legal entity. A company can have many sites, and one of the ways companies can grow is by expanding with multiple sites. This can happen by mergers and acquisitions but can also happen by creating "daughter workplaces". It is therefore essential to look at workplaces and firms at the same...... time. A complication here is that firms switch ID over time because of change of ownership, mergers and divisions. Data must be corrected so that these administrative issues will not affect the survival of firms. The data are used in a way where we can cover firm birth and firm death, spin......-offs and mergers. The analysis will make it possible to differentiate between net and gross creation of jobs because we can follow each single individual in and out of jobs. We have for Denmark found that size on its own does not have a big impact, but young firms are much more likely to contribute to a positive...

  9. Views of CEOs on Firm Performance

    Directory of Open Access Journals (Sweden)

    Dario Berginc

    2014-11-01

    Full Text Available Researching the managerial perspective of performance can contribute to a better understanding of firm performance, and offer a valuable contribution to research on objective performance measurement. The aim of this article is to examine how managers evaluate firm performance and which factors, in their opinion, have the biggest influence on performance. We particularly wanted to investigate the influence of top management and owners on firm performance. We conducted a qualitative study among the CEOs of some of the most successful Slovenian firms. The results show that CEOs connect positive performance with long-term growth and satisfying the needs of key stakeholders (employees, customers and owners, but short-term positive financial performance represents the basic foundation. The second most important factor is a united top management, capable of generating new ideas and acting as a role model to employees. This can lead to a higher degree of engagement by employees and a better understanding of the firm's goals. Owners can contribute to a positive firm performance with their active, strategic and long-term orientation, and with their ability to set clear goals and to trust top management in the long run. Another important factor that influences firm performance is the ownership structure. In the opinion of CEOs, dominant and private ownership has a more positive impact on firm performance than dispersed and state ownership. The present research findings provide several examples of good and bad practice, and highlight opportunities for further research, from an in-depth study of individual factors of firm performance to the search for a more comprehensive model of performance factors, based on a larger sample of CEOs and other managers.

  10. Taxing the Financially Integrated Multinational Firm

    DEFF Research Database (Denmark)

    Johannesen, Niels

    This paper develops a theoretical model of corporate taxation in the presence of financially integrated multinational firms. Under the assumption that multinational firms at least partly use internal loans to finance foreign investment, we find that the optimal corporate tax rate is positive from...... partly fall on investment and thus workers in the former country. This tax exporting mechanism introduces a scope for corporate taxes, which is not present in standard models of international taxation. Accounting for the internal capital markets of multinational firms thus represents a way to resolve...

  11. Human capital and wages in exporting firms

    DEFF Research Database (Denmark)

    Munch, Jakob Roland; Skaksen, Jan Rose

    2008-01-01

    a very rich matched worker-firm longitudinal dataset, we find that there is a weak negative direct effect of exporting on wages, but an interaction term between export intensity and skill intensity has a positive impact on wages. That is, we find an export wage premium, but only in firms where the skill......This paper studies the link between the education level of workers, export performance and wages. We argue that firms may escape intense competition in international markets by using high skilled workers to differentiate their products. This story is consistent with our empirical results. Using...

  12. Internationalisation of Firms in Developing Countries

    DEFF Research Database (Denmark)

    Kuada, John

    The last three decades have witnessed a substantial amount of research into the intrenationalisation process of firms. The focus of most of these studies have, however, been on the downstream aspects of internationalisation with the assumption that all firms initiate their internationalisation...... process with export and proceed in a path-dependent manner towards the location of production activities abroad. The present apper challenges this perspective, arguing that internationalisation of firms may be initiated through either or both upstream and downstream activities. It therefore proposes...

  13. Economic Evaluation of a Chosen Firm

    OpenAIRE

    POSPÍŠILOVÁ, Eva

    2011-01-01

    The aim of my diploma thesis is to evaluate a chosen firm. My evaluated firm is AUDITOR Praha s.r.o. which offers auditing services, audit of bookkeeping and tax, accounting and financial advices. The company has been registered in the official list of auditors of the Czech Republic since 1999. The affiliated company Auditor spol. s r. o. was founded as a 100 percent subsidiary company of an Austrian consulting firm in May 1991 in Prague. Firstly it was needed to elaborate the strategic and f...

  14. Banking Firm, Equity and Value at Risk

    Directory of Open Access Journals (Sweden)

    Udo Broll

    2012-12-01

    Full Text Available The paper focuses on the interaction between the solvency probability of a banking firm and the diversification potential of its asset portfolio when determining optimal equity capital. The purpose of this paper is to incorporate value at risk (VaR into the firm-theoretical model of a banking firm facing the risk of asset return. Given the necessity to achieve a confidence level for solvency, we demonstrate that diversification reduces the amount of equity. Notably, the VaR concept excludes a separation of equity policy and asset-liability management.

  15. Managing the Knowledge-Intensive Firm

    CERN Document Server

    Ejler, Nicolaj; Czerniawska, Fiona

    2011-01-01

    Over the last decade, there has been a substantial rise in the number of knowledge-intensive firms. The core assets of these businesses are the people themselves and so, successful managers of knowledge-intensive firms must inspire their employees and target their individual ambitions, to ensure high performance.This book examines what sets knowledge-intensive firms apart from other types of organizations, and the resultant organizational and strategic differences in business models, talent management, and client-handling approaches. A new model for transforming the management of knowledge-int

  16. Capital and Labor Reallocation Inside Firms

    OpenAIRE

    Giroud, Xavier; Mueller, Holger M.

    2012-01-01

    We document how a plant-specific shock to investment opportunities at one plant of a firm ("treated plant") spills over to other plants of the same firm--but only if the firm is financially constrained. While the shock triggers an increase in investment and employment at the treated plant, this increase is offset by a decrease at other plants of the same magnitude, consistent with headquarters channeling scarce resources away from other plants and toward the treated plant. As a result of the ...

  17. Firm-Specific Foreign Exchange Exposure Identification

    DEFF Research Database (Denmark)

    Aabo, Tom; Brodin, Danielle

    2014-01-01

    Previous studies have used the stock market approach to find the aggregate number of (firms with) foreign exchange exposures in a given country, region, or industry. Methodologies have differed in many aspects but two of the most basic differences relate to observation frequency and the choice......-financial firms and find limited consistency in the detected exchange rate exposures when altering methodology in terms of observation frequency and choice of market index. The results put a question mark to the validity of the stock market approach for exchange rate exposure identification at the firm...

  18. Endogenous Markups, Firm Productivity and International Trade:

    DEFF Research Database (Denmark)

    Bellone, Flora; Musso, Patrick; Nesta, Lionel;

    ) markups are positively related to firm productivity; 3) markups are negatively related to import penetration; 4) markups are positively related to firm export intensity and markups are higher on the export market than on the domestic ones in the presence of trade barriers and/or if competitors...... on the export market are less efficient than competitors on the domestic market. We estimate micro-level price cost margins (PCMs) using firm-level data extending the techniques developed by Hall (1986, 1988) and extended by Domowitz et al. (1988) and Roeger (1995) for the French manufacturing industry from...

  19. AUDITOR ROTATION AT BORSA ISTANBUL FIRMS: AN EVENT STUDY

    OpenAIRE

    Arioglu, Emrah; Tuan, Koray

    2015-01-01

    This study investigates the market reaction surrounding the announcements of audit firm rotation by public firms quoted at BIST. In addition, it investigates how the market reaction to audit firm rotation changes based on the reputation of the previous and the new audit firms. After conducting an event study, we are unable to provide evidence suggesting that investors in Turkish capital markets value audit firm rotation. The market reaction surrounding the announcements of public firms to swi...

  20. Attract and Retain : The importance of employees in small firms

    OpenAIRE

    Tholén, Mattias; Hamberg, Guz

    2010-01-01

    This thesis investigates how a knowledge-intensive, small, young firm, in a highly competitive environment, deal with difficulties in their recruitment process.. Given their assumed disadvantages, how does the firm attract and retain key personnel? A case study was conducted of a small young firm in Silicon Valley. The findings suggest that small firms do not directly compete with larger firms for personnel, and that the company should emphasize small firms´ work characteristics in their recr...

  1. Use of blood and blood products.

    Science.gov (United States)

    Hunt, E; Wood, B

    1999-11-01

    It is sometimes necessary for the practitioner to transfuse the ruminant with whole blood or plasma. These techniques are often difficult to perform in practice, are time-consuming, expensive, and stressful to the animal. Acute loss of 20% to 25% of the blood volume will result in marked clinical signs of anemia, including tachycardia and maniacal behavior. The PCV is only a useful tool with which to monitor acute blood loss after intravascular equilibration with other fluid compartments has occurred. An acutely developing PCV of 15% or less may require transfusion. Chronic anemia with PCV of 7% to 12% can be tolerated without transfusion if the animal is not stressed and no further decline in erythrocyte mass occurs. Seventy-five percent of transfused bovine erythrocytes are destroyed within 48 hours of transfusion. A transfusion rate of 10 to 20 mL/kg recipient weight is necessary to result in any appreciable increase in PCV. A nonpregnant donor can contribute 10 to 15 mL of blood/kg body weight at 2- to 4-week intervals. Sodium citrate is an effective anticoagulant, but acid citrate dextrose should be used if blood is to be stored for more than a few hours. Blood should not be stored more than 2 weeks prior to administration. Heparin is an unsuitable anticoagulant because the quantity of heparin required for clot-free blood collection will lead to coagulation defects in the recipient. Blood cross-matching is only rarely performed in the ruminant. In field situations, it is advisable to inject 200 mL of donor blood into the adult recipient and wait 10 minutes. If no reaction occurs, the rest of the blood can probably be safely administered as long as volume overload problems do not develop. Adverse reactions are most commonly seen in very young animals or pregnant cattle. Signs of blood or plasma transfusion reaction include hiccoughing, tachycardia, tachypnea, sweating, muscle tremors, pruritus, salivation, cough, dyspnea, fever, lacrimation, hematuria

  2. A firm's activity in social media and its relationship with corporate reputation, firm size and firm performance

    OpenAIRE

    Mäkinen, Hanna

    2015-01-01

    The significance of social media has increased greatly in the past few years, leading companies to increase their social media activity and also increase their interest in knowing whether it is genuinely worth being active on social media, including knowing the potential advantages. This study aims to examine the relationship between social media activity and three variables: reputation, firm size and firm performance. The study analyzes the relationships between the constru...

  3. Saliva-Induced Clotting Captures Streptococci: Novel Roles for Coagulation and Fibrinolysis in Host Defense and Immune Evasion.

    Science.gov (United States)

    Wollein Waldetoft, Kristofer; Mohanty, Tirthankar; Karlsson, Christofer; Mörgelin, Matthias; Frick, Inga-Maria; Malmström, Johan; Björck, Lars

    2016-10-01

    Streptococcal pharyngitis is among the most common bacterial infections, but the molecular mechanisms involved remain poorly understood. Here we investigate the interactions among three major players in streptococcal pharyngitis: streptococci, plasma, and saliva. We find that saliva activates the plasma coagulation system through both the extrinsic and the intrinsic pathways, entrapping the bacteria in fibrin clots. The bacteria escape the clots by activating host plasminogen. Our results identify a potential function for the intrinsic pathway of coagulation in host defense and a corresponding role for fibrinolysis in streptococcal immune evasion. PMID:27456827

  4. Analysis of the coagulation of human blood cells on diamond surfaces by atomic force microscopy

    Science.gov (United States)

    Baranauskas, V.; Fontana, M.; Guo, Zhao Jing; Ceragioli, H. J.; Peterlevitz, A. C.

    2004-11-01

    Atomic force microscopy (AFM) was used to study the morphology and coagulation of human blood cells in contact with solid surfaces. Blood was extracted from the veins of healthy adult donors and the samples were used immediately after extraction, deposited either on borosilicate glass or diamond substrates. Some blood samples were anti-coagulated by adding heparin for single cell AFM imaging. No chemicals were used for attaching or immobilizing the cells. The diamond substrates were produced by chemical vapour deposition (CVD diamond) using a hot-filament CVD system fed with ethanol highly diluted in hydrogen. AFM imaging of isolated cells (anti-coagulated by heparin) was only possible on the glass substrates due to the lack of adherence of the cells to the diamond surface. The coagulation results suggest that blood clotting on diamond produces a less rough surface than blood clotting on glass.

  5. Effect of nitrogen on blood compatibility of nickel-free high nitrogen stainless steel for biomaterial

    International Nuclear Information System (INIS)

    The aim of this paper was to study the effect of nitrogen content on blood compatibility including platelet adhesion and kinetic clotting time of nickel-free high nitrogen stainless steel (HNS), also in comparison with a conventional austenitic stainless steel AISI 317L. X-ray photoelectron spectroscopy (XPS) was used to analyze the surface chemical composition. The surface wettability and surface free energy (SFE) of these materials were characterized by water contact angle (WCA) measurement to analysis the relationship between surface properties and blood compatibility. Kinetic clotting time was used to evaluate the blood coagulation for these materials and platelet adhesion was assessed by scanning electron microscopy (SEM). The results showed that more platelets adhered on the surface of 317L stainless steel than that on HNS, and with the increase of nitrogen content, the amount of adherent platelets was further decreased on the surface of HNS. Kinetic clotting time results also showed the increased nitrogen content extended the initial clotting time of HNS. The results of surface properties also explained the effect of nitrogen on blood compatibility by traditional theory of SFE and interfacial energy.

  6. Firm Performance-A Social Networks Perspective

    Directory of Open Access Journals (Sweden)

    Jane Tung

    2012-01-01

    Full Text Available Problem statement: The study aims to offer a discussion on social networks and their effect on firm performance and also to illustrate the ways by which the firms utilize social capital through networks. Approach: The literature review and arguments were conducted to provide a systematic discussion of social networks and their effects. Results: The study had provided with a detailed understanding of the strategies that had been found to be highly significant in successful organizational performance. The results of this discussion suggested that social networks affect firm performance in a positive manner and can contribute to sustainable competitive advantage. Conclusion: It confirms that building up of social networks for big and small firms provides valuable links and solves numerous issues which auger well for the companies and should be treated with great importance.

  7. Diversification patterns and survival as firms mature

    DEFF Research Database (Denmark)

    Coad, Alexander Jean-Luc; Guenther, C.

    2013-01-01

    We focus on the relationship between age and diversification patterns of German machine tool manufacturers in the post-war era. We distinguish between 'minor diversification' (adding a new product variation within a familiar submarket) and 'major diversification' (expanding the product portfolio...... lines). Second, we find that product portfolios of larger firms tend to be more diversified. Third, with respect to consecutive diversification activities, quantile autoregression plots show that firms experiencing diversification in one period are unlikely to repeat this behavior in the following year...... into new submarkets). Our analysis reveals four main insights. First, we observe that firms have lower diversification rates as they grow older, and that eventually diversification rates even turn negative for old firms on average (where negative diversification corresponds to exit from certain product...

  8. Judo Economics in Markets with Multiple Firms

    Directory of Open Access Journals (Sweden)

    Daniel Cracau

    2014-01-01

    Full Text Available We study a sequential Bertrand game with one dominant market incumbent and multiple small entrants selling homogeneous products. Whilst the equilibrium for the case of a single entrant is well known from Gelman and Salop (1983, we derive properties of the N-firm equilibrium and present an algorithm that can be used to calculate this equilibrium. The algorithm is based on a recursive manipulation of polynomials that derive the optimisation problem that each of the market entrants is facing. Using this algorithm we derive the exact equilibrium for the cases of two and three small entrants. For more than three entrants only approximate results are possible. We use numerical results to gain further understanding of the equilibrium for an increasing number of firms and in particular for the case where N diverges to infinity. Similarly to the two-firm Judo equilibrium, we see that a capacity limitation for the small firms is necessary to achieve positive profits.

  9. Cooperative R&D and firm performance

    OpenAIRE

    Belderbos, R.A.; Carree, M.A.; Lokshin, B

    2004-01-01

    We analyse the impact of R&D cooperation on firm performance differentiating between four types of R&D partners (competitors, suppliers, customers, and universities & research institutes), and considering two performance measures: labour productivity and productivity in innovative (new to the market) sales. Using data on a large sample of Dutch innovating firms in two waves of the Community Innovation Survey (1996, 1998), we examine the impact of R&D (collaboration) in 1996 on subsequent prod...

  10. Firms' Rationales for Interaction with Research Universities

    OpenAIRE

    Broström, Anders

    2008-01-01

    R&D managers at 50 firms randomly selected from all firms who have formal relations with two research universities in Stockholm are being interviewed about their rationales for collaboration. Drawing on this material, a distinctive typology of rationales and the therewith associated effects from cooperative relations is presented. As expected, rationales related to innovation, in terms of invented or improved products or processes, are found to be the main drivers for interaction. As regards ...

  11. Service-Oriented Strategies for Manufacturing Firms

    DEFF Research Database (Denmark)

    Tan, Adrian; McAloone, Tim C.; Matzen, Detlef

    2009-01-01

    This chapter establishes PSS (Product/Service-Systems) approaches in the context of manufacturing firms and their existing product-oriented business. PSS can be seen as a strategy for manufacturing firms to gain competitive advantage in the market, but what market conditions and organisational......, customers and partners in business planning and strategy to reap the full benefits. Finally a path to how manufacturers can make the change from product to service-orientation is traced....

  12. Why Small Manufacturing Firms Shun DCF

    OpenAIRE

    Walker, Joe; Burns, Richard; Denson, Chad

    1993-01-01

    Although there is ample literature on the use of capital budgeting techniques by small firms, there is practically no research available on why small firms don’t use discounted cash flow methods. This paper looks at this rationale issue in die light of Brigham's 10 hypodieses (in Fundamentals of Financial Management, sixth edition). Support is found primarily for Brigham’s ignorance hypothesis, but also for his other hypotheses concerning small firms’ short-run cash flow orientation, the comp...

  13. Globalisation, Corporate Governance and Firm Productivity

    OpenAIRE

    Byung S. MIN; Russell Smyth

    2012-01-01

    We examine the relationship between globalisation, corporate governance and firm productivity by breaking down total effects into direct and indirect effects. The estimation results, using longitudinal data from Korea, indicate that the positive effect of liberalising equity ownership on firms’ total factor productivity (TFP) was reinforced by indirect managerial effects when a firm improved its corporate governance. Our findings also confirm that the interaction of the managerial effect with...

  14. Board Reforms and Firm Value: Worldwide Evidence

    OpenAIRE

    Xi Li; Mingyi Hung; Larry Fauver; Alvaro Taboada

    2015-01-01

    We examine the impact of corporate board reforms on firm value in 41 countries. Using a difference-in-differences design, we find that firm value increases after enactment of the reforms. The valuation increase is associated with both the intensity and major components of the reform, including board independence, audit committee, and the separation of the roles of chief executive officer and chairman. We also find that the effect of these reforms primarily exists in countries with weak legal ...

  15. Family Firms, Corporate Governance, and Export

    OpenAIRE

    Raoul Minetti; Pierluigi Murro; Susan Chun Zhu

    2013-01-01

    This paper tests the impact of family ownership on firms' export decisions using a rich data set of about 20,000 Italian manufacturers. The results reveal that family ownership increases the probability that firms export, although the effect weakens as ownership concentration rises. The benefit of family owners is especially pronounced when they retain control rights (ownership is aligned with control) and seek the support of external managers (ownership is partially separated from management...

  16. International business competence and the contemporary firm

    OpenAIRE

    Gary A Knight; Daekwan Kim

    2009-01-01

    The trend of increasing internationalization of small and medium enterprises (SMEs) is noteworthy, because such firms typically have far fewer financial and tangible resources than large multinational enterprises. As a result, international business is often more challenging for smaller firms. In this study we investigate the widespread internationalization of SMEs, and specific factors that support their superior performance abroad. We uncover a collection of intangible capabilities that are...

  17. From Global Firms to Global Boards?

    OpenAIRE

    Oxelheim, Lars; Gregorič, Aleksandra; Randøy, Trond; Thomsen, Steen

    2013-01-01

    This study investigates the internationalization of corporate boards, using a sample of 346 non-financial listed Nordic firms during 2001-2008. Given a high level of international activity, these firms have surprisingly few foreign directors. The picture of international expertise changes considerably, however, if we also count the international experience of national directors. The percentage of foreign directors is related primarily to financial internationalization rather than foreign sale...

  18. Innovation strategies of Mexican pharmaceutical firms

    OpenAIRE

    José Luis Solleiro; Roberto E. López Martínez; Gabriela Sánchez; Yissel Inurrueta; Ana L. Sánchez; Antonia Terán; Jorge I. Castillo

    2010-01-01

    Mexican pharmaceutical market is the most important in Latin America and a significant number of global firms have different business activities in this country: production, licensing of patents, alliances with Mexican firms, distribution facilities or partnerships, etc. In terms of innovation, global pharmaceutical industry has passed through structural changes mainly of technological and institutional nature. These changes have been influential along the whole value chain and have triggered...

  19. Firm. An intermediate language for compiler research

    OpenAIRE

    Beck, Michael; Boesler, Boris; Geiß, Rubino; Lindenmaier, Götz

    2005-01-01

    State of the art compiler intermediate representations incorporate SSA data dependencies in a graph based manner. We present the intermediate representation Firm, which extends the functional stores of Steensgard and introduces a novel representation of exceptions. Firm offers a high-level representation of the type hierarchy and object-oriented features, which makes it exceptional suitable for analysing and optimizing of strongly typed languages. The co...

  20. The Firm as an Internal Capital Market

    DEFF Research Database (Denmark)

    Duus, Henrik Johannsen

    1996-01-01

    A review of current strategy literature shows that the portfolio view seems to have become unfashionable. This article argues in favor of a revitalization of the portfolio view, and attempts to show that with a few changes, it can be used together with the modern theories of the firm and its stra...... strategy. At the same time it shows how a heterodox portfolio model may be used to control the competence development of firms situated in turbulent and complex settings....

  1. Facilitated inter-firm collaboration in Ghana

    DEFF Research Database (Denmark)

    Kuada, John Ernest; Sørensen, Olav Jull

    2005-01-01

    Since the mid-1980s, aid agencies have endorsed the need to support private enterprise development in developing countries as an instrument for overall economic development and poverty reduction. Facilitation of collaboration between developed and developing country firms has become one of the mo...... the mechanisms of third-party inter-firm facilitation and assesses how effective the catalyst institutions are in nurturing collaborations between companies in developed and developing countries. The discussions are illustrated with case examples drawn from Ghana....

  2. Adoption of Internet Strategies by Agribusiness Firms

    OpenAIRE

    Henderson, Jason R.; Dooley, Frank J.; Akridge, Jay T.; Carerre, Antonio

    2005-01-01

    This paper explores the factors guiding Internet adoption by agribusiness firms. The relationship between Internet strategies and manager perceptions on the barriers to and catalysts for Internet adoption are analyzed in a supply-chain management framework. Using factor analysis and an ordered Probit model, results indicate that Internet strategies are more likely to be adopted in larger firms with a global scope. Also, manager perceptions regarding the impact of Internet adoption on transact...

  3. Corporate Governance and Firm Valuation in Colombia

    OpenAIRE

    Pombo, Carlos; Luis H. Gutiérrez

    2007-01-01

    This paper studies the separation of ownership and control of 108 listed companies in Colombia from 1996 to 2002, finding that voting rights are greater than cash flow rights because of indirect ownership across firms. The paper also examines the association of various ownership and control measures and separation ratios with a firm’s value and performance for the same sample of companies that traded their stock from 1998 to 2002. Large blockholders were found to exert a positive influence up...

  4. Bohai Prominent for Cooperation with Foreign Firms

    Institute of Scientific and Technical Information of China (English)

    Han Qingbing; Wang Zhan; Du Genqi

    1997-01-01

    @@ Bohai Oilfields started to cooperate with foreign firms earlier than other oil fields. From 1980 up to now, Bohai Oilfields has signed 14 petroleum cooperation contracts with 18 foreign oil firms from Japan, France, the United States and Britain. The total investment for cooperative exploration and development is nearly $1.5 billion. In addition, Bohai Oilfields,taking various forms for cooperation, has formed a number of specialized joint ventures for offshore operation in partnership with foreign technical companies.

  5. Environmental Regulation and Innovation in Firms

    OpenAIRE

    Umali, Celia L.

    1998-01-01

    The Porter hypothesis has advanced the idea that stricter environmental regulation will generate benefits to firms through increased innovation, improved product design and will generally enhance the competitive standing of the firm or industry in adding value to its products. While environmental economists have been critical in receiving the Porter's proposal as being based on too optimistic expectations of the size of the benefits the business community has welcome them. By using selected c...

  6. Share holding Pattern and Firm Performance

    OpenAIRE

    Jayesh Kumar

    2004-01-01

    Corporate Governance deals with the issue of how suppliers of finance to corporations assure themselves of getting a return on their investment. Several Studies have examined the relationship between ownership structure and firm performance. Using di erent data samples most of the studies provide general support for the argument that increase in managerial ownership increases firm performance. However, these results have been questioned recently. This study examines empirically the effects of...

  7. Ownership Structure and Corporate Firm Performance

    OpenAIRE

    Jayesh Kumar

    2003-01-01

    Corporate Governance deals with the issue, how suppliers of finance to corporations assure themselves of getting a return on their investment. Several Studies have examined the relationship between managerial ownership and firm performance. Using different samples most of the studies provide general support for the argument that increase in managerial ownership increases firm performance. However, these results have been questioned recently. This work examines empirically the effects of owner...

  8. Method of establishing firm SWU commitment

    International Nuclear Information System (INIS)

    The procedures used in making the customer's firm separative work requirements are outlined. Information which must be supplied to DOE for firming up the customer's appendices is outlined. The Variable Tails Assay Option (VTAO), available only to AFC customers, is discussed. Planning estimates are needed by DOE to plan the operation of its enrichment complex. The customer notices which are required every year are listed

  9. Neighbourhood Effects on Firm Success and Strategy

    OpenAIRE

    Sleutjes, Bart

    2012-01-01

    The main objective of this dissertation is to provide new insights on the relationship between local firms and their neighbourhoods. As a result of economic transitions and several societal developments over the past 50 years, residential neighbourhoods have developed from being places where people predominantly live into places where people also work. A growing number of small- and medium-sized firms are located in residential neighbourhoods, many of which are home-based. Triggered by relati...

  10. BOARD DIVERSITY, NETWORK AND FIRM VALUE

    OpenAIRE

    Sitthipongpanich, Thitima; Polsiri, Piruna

    2014-01-01

    Using a large sample analysis of Thai listed firms, we address an important question. Do board diversity and network add value to firms? This article extends the debate on the benefits and costs of board diversity and network and their effect on the broader picture of corporate governance. Moreover, this article sheds light on the necessity of applying the resource dependence theory in research about boards of directors, in addition to the agency theory. We find that diversity in ...

  11. Capabilities and The Theory of The Firm

    OpenAIRE

    Nicolai J Foss

    2009-01-01

    The recent decade has witnessed a strong expansion of work on the firm, both from a capabilities perspective and from a contractual perspective. These two bodies of theories are often thought to be fundamentally different, because their domains of applications are different (knowledge-accumulation vs contracts and incentives). However, we need to integrate propositions from capabilities perspectives with ideas about economic organization (markets, hybrids, firms). This is because only a more ...

  12. The process of International Expansion of Firms

    OpenAIRE

    Fazal, Imran

    2009-01-01

    A firm may enter into the foreign market by different modes. Firm could operate in the foreign country by physical appearance in the host country such as establishing factories and joint venture. In contrast, some mode could be expands in the foreign country while operate from home country such as exporting. Exporting mode is very common to expand internationally. It required low investment relative to other modes such as joint venture and establishing factories in the foreign country. By app...

  13. Innovation strategies of Mexican pharmaceutical firms

    Directory of Open Access Journals (Sweden)

    José Luis Solleiro

    2010-01-01

    Full Text Available Mexican pharmaceutical market is the most important in Latin America and a significant number of global firms have different business activities in this country: production, licensing of patents, alliances with Mexican firms, distribution facilities or partnerships, etc. In terms of innovation, global pharmaceutical industry has passed through structural changes mainly of technological and institutional nature. These changes have been influential along the whole value chain and have triggered transformations in firm's organization, market structure and sector's investments. Mexico's industry, in spite of having a very attractive domestic market, has serious limitations for technology development. Very little resources are invested in R&D and lack of articulation between research labs and industry provoke that Mexico has only exceptional innovation achievements and a high technological dependence. At the same time, some Mexican companies have developed new strategies to be competitive in open markets and have shown that a combination of competitive intelligence, rapid adoption of technologies, collaboration with advanced firms and research institutes, permanent training and continuous improvement are key factors for success. This paper deals with the results of a piece of research aimed at developing a model for the effective transfer of technology for Mexican pharmaceutical firms, with a strong component of knowledge and skills to manage the flows of information, people and technologies among firms, research labs, universities and other health organizations.

  14. Effects of International Diversification and Firm Resources on Firm Performance Risk

    OpenAIRE

    Nejat Capar; Ravi Chinta; Fiona Sussan

    2015-01-01

    Researchers in international business and strategic management have long been interested in understanding international diversification as a strategy to manage and control firm performance risk. The general argument in this research stream has been arguing that international diversification or multinationality serves as a portfolio diversification strategy that can reduce firm performance risk. However, a major shortcoming of existing studies has been the failure of incorporating firm resourc...

  15. Motives behind software adoption in Finnish accounting firms: Technology adoption motives in two case firms

    OpenAIRE

    Laitinen, Aki

    2014-01-01

    Objectives of the Study: The objective of this study is to better understand the factors affecting software adoption decision-making in Finnish accounting firms. These firms are, more often than not, smaller organisations and same systems are used for long periods of time. As efforts to improve data transfer standards and processes progress at the regulatory level, it is curious to see how technology adoption decision-making takes place at a firm level. Academic background and method...

  16. Financial health, exports, and firm survival: evidence from UK and French firms

    OpenAIRE

    Görg, Holger; Spaliara, Marina-Eliza

    2014-01-01

    We use firm level data to assess the role of exporting in the link between financial health and firm survival. The data are for the UK and France. We examine whether firms at different stages of export activity (starters, exiters, continuers, switchers) react differently to changes in financial variables. In general, export starters and exiters experience much stronger adverse effects of financial constraints for their survival prospects. By contrast, the exit probability of continuous export...

  17. Firm Internationalization and Demand for Foreign Language Skills: A Firm-level Investigation

    OpenAIRE

    Antonietti Roberto; Loi Massimo

    2014-01-01

    Relying on a rich firm-level dataset, we investigate the factors underlying firm's demand for foreign language skills, with a focus on internationalization activities. Our univariate and multivariate probit estimates show that the probability to demand for foreign language skills increases with firm's size, human capital, engagement in R&D and increasing exposure to foreign trade. When including the demand for other attributes of job applicants, we find that the effect of increased internatio...

  18. Are firms credit constrained? The supply effect of bond market access on firm leverage

    OpenAIRE

    Soini, Aleksi

    2011-01-01

    PURPOSE OF THE STUDY The banking market is hypothesized of having a tendency to ration and constrain lending to firms, while the public debt market (bond market) is hypothesized to afford borrowers with added supply of debt capital thereby having the effect of relaxing credit constraints. This study examines the degree to which bond market access of firms is correlated with the leverage of firms to uncover whether bond market access has a significant effect on leverage. Two-stage least sq...

  19. In black south africans from rural and urban communities, the 4G/5G PAI-1 polymorphism influences PAI-1 activity, but not plasma clot lysis time

    NARCIS (Netherlands)

    Z. de Lange (Zelda); D.C. Rijken (Dingeman); T. Hoekstra (Tiny); K.R. Conradie (Karin); J.C. Jerling (Johann); M. Pieters (Marlien)

    2013-01-01

    textabstractData on genetic and environmental factors influencing PAI-1 levels and their consequent effect on clot lysis in black African populations are limited. We identified polymorphisms in the promoter area of the PAI-1 gene and determined their influence on PAI-1act levels and plasma clot lysi

  20. Leakage of protein into lungs of preterm ventilated rabbits is correlated with activation of clotting, complement, and polymorphonuclear leukocytes in plasma

    NARCIS (Netherlands)

    Brus, F; vanOeveren, W; Heikamp, A; Okken, A; Oetomo, SB

    1996-01-01

    We investigated whether leakage of protein in lungs of pre term ventilated rabbits of 28- and 29-d gestational age is correlated with activation of clotting, complement, and polymorphonuclear leukocytes (PMN) in plasma. We found signs of systemic activation of clotting, complement, and PMN in ventil