222 research outputs found
Options for Supply Management in Canada with Trade Liberalization
Following the Uruguay Round of trade negotiations Canada replaced its import quotas on sensitive products with tariff rate quotas. The over-quota tariffs on those products operating under domestic supply management schemes (dairy and poultry products) ranged from a low of 155 percent on turkey to a high of 299 percent on butter. These tariffs have effectively blocked over quota imports and are likely to continue to prevent imports, under most market conditions, given the likely range of tariff cuts proposed for sensitive products following a successful completion of the Doha Round. However, it’s argued that tariff cuts in the post-Doha Round will severely limit Canada’s ability to restrict imports and it is important to use the next 15 years to better position the supply managed industries to compete at that time. The paper reviews a number of reform options that could be pursued ranging from a full buy-out of current marketing quotas, the introduction of two types of marketing quota, to providing partial compensation of short-term income losses. The advantages and disadvantages of each option are discussed with respect to their costs and impacts on income and asset values.Canada, trade liberalization, supply management, Demand and Price Analysis, International Relations/Trade,
Performance of Long Modules of Silicon Microstrip Detectors
This note describes the performance of modules assembled with up to twelve silicon microstrip detectors. These modules were built for the instrumented Silicon Target (STAR) that has been installed in the NOMAD spectrometer. Laboratory and test beam results are compared with model predictions. For a module of nine detectors, test beam results indicate a signal--to--noise ratio of 19, a hit finding efficiency of 99.8\% and a spatial resolution of 6.0 m. Laboratory measurements indicate that modules of twelve detectors exhibit a signal--to--noise ratio of the order of 16
Mitochondria dysfunction is associated with long-term cognitive impairment in an animal sepsis mode
Background: Several different mechanisms have been proposed to explain long-term cognitive impairment in sepsis survivors. The role of persisting mitochondrial dysfunction is not known. We thus sought to determine whether stimulation of mitochondrial dynamics improves mitochondrial function and long-term cognitive impairment in an experimental model of sepsis.
Methods: Sepsis was induced in adult Wistar rats by cecal ligation and perforation (CLP). Animals received intracerebroventricular injections of either rosiglitazone (biogenesis activator), rilmenidine, rapamycin (autophagy activators), or n-saline (sham control) once a day on days 7–9 after the septic insult. Cognitive impairment was assessed by inhibitory avoidance and object recognition tests. Animals were killed 24 h, 3 and 10 days after sepsis with the hippocampus and prefrontal cortex removed to determine mitochondrial function.
Results: Sepsis was associated with both acute (24 h) and late (10 days) brain mitochondrial dysfunction. Markers of mitochondrial biogenesis, autophagy and mitophagy were not up-regulated during these time points. Activation of biogenesis (rosiglitazone) or autophagy (rapamycin and rilmenidine) improved brain ATP levels and ex vivo oxygen consumption and the long-term cognitive impairment observed in sepsis survivors.
Conclusion: Long-term impairment of brain function is temporally related to mitochondrial dysfunction. Activators of autophagy and mitochondrial biogenesis could rescue animals from cognitive impairment
A study of backward going and in interactions with the NOMAD detector
Backward proton and production has been studied in
interactions with carbon nuclei. Detailed analyses of the momentum
distributions, of the production rates, and of the general features of events
with a backward going particle, have been carried out in order to understand
the mechanism producing these particles. The backward proton data have been
compared with the predictions of the reinteraction and the short range
correlation models.Comment: 29 pages, 14 figures, submitted to Nucl. Phys.
Stress Levels, Psychological Symptoms, and C-Reactive Protein Levels in COVID-19: A Cross-Sectional Study
BACKGROUND: Although many studies have pointed out a possible relationship between COVID-19 and the presence of psychiatric disorders, the majority of the studies have significant limitations. This study investigates the influence of COVID-19 infection on mental health.
METHODS: This cross-sectional study included an age- and sex-matched sample of adult individuals positive (cases) or negative (controls) for COVID-19. We evaluated the presence of psychiatric conditions and C-reactive protein (CRP).
RESULTS: Findings showed greater severity of depressive symptoms, higher levels of stress, and greater CRP in cases. The severity of depressive and insomnia symptoms, as well as the CRP were more remarkable in individuals with moderate/severe COVID-19. We found a positive correlation between stress and severity of anxiety, depression, and insomnia in individuals with or without COVID-19. There was a positive correlation between CRP levels and severity of depressive symptoms in cases and controls, and a positive correlation between CRP levels and the severity of anxiety symptoms and stress levels only in individuals with COVID-19. Individuals with COVID-19 and depression had greater CRP than those with COVID-19 without current major depressive disorder.
LIMITATIONS: We cannot infer causality because this is a cross-sectional study, and the majority of COVID-19 sample was asymptomatic or had mild symptoms, which may limit the generalizability of our findings for moderate/severe cases.
CONCLUSIONS: Individuals with COVID-19 showed greater severity of psychological symptoms, which may impact on the development of psychiatric disorders in the future. CPR seem to be a promising biomarker for earlier detection of post-COVID depression
Cognitive Dysfunction Is Sustained after Rescue Therapy in Experimental Cerebral Malaria, and Is Reduced by Additive Antioxidant Therapy
Neurological impairments are frequently detected in children surviving cerebral malaria (CM), the most severe neurological complication of infection with Plasmodium falciparum. The pathophysiology and therapy of long lasting cognitive deficits in malaria patients after treatment of the parasitic disease is a critical area of investigation. In the present study we used several models of experimental malaria with differential features to investigate persistent cognitive damage after rescue treatment. Infection of C57BL/6 and Swiss (SW) mice with Plasmodium berghei ANKA (PbA) or a lethal strain of Plasmodium yoelii XL (PyXL), respectively, resulted in documented CM and sustained persistent cognitive damage detected by a battery of behavioral tests after cure of the acute parasitic disease with chloroquine therapy. Strikingly, cognitive impairment was still present 30 days after the initial infection. In contrast, BALB/c mice infected with PbA, C57BL6 infected with Plasmodium chabaudi chabaudi and SW infected with non lethal Plasmodium yoelii NXL (PyNXL) did not develop signs of CM, were cured of the acute parasitic infection by chloroquine, and showed no persistent cognitive impairment. Reactive oxygen species have been reported to mediate neurological injury in CM. Increased production of malondialdehyde (MDA) and conjugated dienes was detected in the brains of PbA-infected C57BL/6 mice with CM, indicating high oxidative stress. Treatment of PbA-infected C57BL/6 mice with additive antioxidants together with chloroquine at the first signs of CM prevented the development of persistent cognitive damage. These studies provide new insights into the natural history of cognitive dysfunction after rescue therapy for CM that may have clinical relevance, and may also be relevant to cerebral sequelae of sepsis and other disorders
Characterization of a pneumococcal meningitis mouse model
<p>Abstract</p> <p>Background</p> <p><it>S. pneumoniae </it>is the most common causative agent of meningitis, and is associated with high morbidity and mortality. We aimed to develop an integrated and representative pneumococcal meningitis mouse model resembling the human situation.</p> <p>Methods</p> <p>Adult mice (C57BL/6) were inoculated in the cisterna magna with increasing doses of <it>S. pneumoniae </it>serotype 3 colony forming units (CFU; n = 24, 10<sup>4</sup>, 10<sup>5</sup>, 10<sup>6 </sup>and 10<sup>7 </sup>CFU) and survival studies were performed. Cerebrospinal fluid (CSF), brain, blood, spleen, and lungs were collected. Subsequently, mice were inoculated with 10<sup>4 </sup>CFU <it>S. pneumoniae </it>serotype 3 and sacrificed at 6 (n = 6) and 30 hours (n = 6). Outcome parameters were bacterial outgrowth, clinical score, and cytokine and chemokine levels (using Luminex<sup>®</sup>) in CSF, blood and brain. Meningeal inflammation, neutrophil infiltration, parenchymal and subarachnoidal hemorrhages, microglial activation and hippocampal apoptosis were assessed in histopathological studies.</p> <p>Results</p> <p>Lower doses of bacteria delayed onset of illness and time of death (median survival CFU 10<sup>4</sup>, 56 hrs; 10<sup>5</sup>, 38 hrs, 10<sup>6</sup>, 28 hrs. 10<sup>7</sup>, 24 hrs). Bacterial titers in brain and CSF were similar in all mice at the end-stage of disease independent of inoculation dose, though bacterial outgrowth in the systemic compartment was less at lower inoculation doses. At 30 hours after inoculation with 10<sup>4 </sup>CFU of <it>S. pneumoniae</it>, blood levels of KC, IL6, MIP-2 and IFN- γ were elevated, as were brain homogenate levels of KC, MIP-2, IL-6, IL-1β and RANTES. Brain histology uniformly showed meningeal inflammation at 6 hours, and, neutrophil infiltration, microglial activation, and hippocampal apoptosis at 30 hours. Parenchymal and subarachnoidal and cortical hemorrhages were seen in 5 of 6 and 3 of 6 mice at 6 and 30 hours, respectively.</p> <p>Conclusion</p> <p>We have developed and validated a murine model of pneumococcal meningitis.</p
Accelerated Blood Clearance (ABC) phenomenon favors the accumulation of tartar emetic in pegylated liposomes in BALB/c mice liver.
Tartar emetic (TE) was the first drug used to treat leishmaniasis.However, its use was discontinued due to high toxicity. Association
of TE with liposomes is a strategy to reduce its side effects. Pegylated liposomes (Lpeg) present lower rates of uptake by macrophages
and prolonged circulation compared to their nonpegylated counterparts. However, repeated administration of Lpeg can cause an
Accelerated Blood Clearance (ABC) phenomenon, whereby recognition of liposomes by antibodies results in faster phagocytosis.
Thiswork evaluated the effect of TE administration on histopathological aspects and the effect of the ABC phenomenon on targeting
and toxicity in mice. Our results show that treatment with free or liposomal TE had no effect on the erythrocyte count, on liver
and spleen weight, and on hepatic, splenic, and cardiac histology in mice. Severe lesions were observed on the kidneys of animals
treated with a single dose of free TE. Treatment with TE in Lpeg after induction of ABC phenomenon caused a significant increase
in Sb level in the liver without toxicity. Furthermore, mice treated with TE in liposomes showed normal renal histopathology. These
results suggest site-specific targeting of Sb to the liver after induction of ABC phenomenon with no toxicity to other organs
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