217 research outputs found
High Food Prices and Developing Countries: Policy Responses at Home and Abroad
food aid, trade, policy, Agricultural and Food Policy, Food Security and Poverty, International Relations/Trade,
A Compact Solid State Detector for Small Angle Particle Tracking
MIDAS (MIcrostrip Detector Array System) is a compact silicon tracking
telescope for charged particles emitted at small angles in intermediate energy
photonuclear reactions. It was realized to increase the angular acceptance of
the DAPHNE detector and used in an experimental program to check the
Gerasimov-Drell-Hearn sum rule at the Mainz electron microtron, MAMI. MIDAS
provides a trigger for charged hadrons, p/pi identification and particle
tracking in the region 7 deg < theta < 16 deg. In this paper we present the
main characteristics of MIDAS and its measured performances.Comment: 13 pages (9 figures). Submitted to NIM
Desempenho de bezerros cruzados do nascimento à desmama.
O objetivo foi avaliar o peso ao nascimento e o peso e a altura à desmama de bezerros filhos de remeas cruzadas Angus X Nelore (AN) e Simental X Nelore (SN) inseminadas com sêmen de touros das raças Angus, Bonsmara e Canchim. Os dados foram analisados pelo método dos quadrados mínimos cujo modelo estatístico incluiu os efeitos de mês e ano de nascimento, sexo, idade da vaca ao parto, idade à desmama, raça do touro (RT), touro dentro de RT, grupo genético da mãe (GM) e RT x GM. Não foi encontrada diferença entre os grupos genéticos para o peso ao nascimento. Para o peso à desmama, os animais filhos de touros Angus e Bonsmara foram mais pesados que os filhos de touros Canchim. O peso e a altura à desmama dos filhos de vacas SN foram maiores que os dos filhos de vacas AN
Produção de Brachiaria brizantha cv. Marandu quando consorciada com Sorghum bicolor sob períodos de estresse hídrico.
Verificar o desenvolvimento da Brachiaria brizantha cv. Marandu quando em cultivo consorciado com o sorgo, submetida a períodos de déficit hídrico
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.
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
A mouse model reproducing the pathophysiology of neonatal group B streptococcal infection
Group B streptococcal (GBS) meningitis remains a devastating disease. The absence of an animal model reproducing the natural infectious process has limited our understanding of the disease and, consequently, delayed the development of effective treatments. We describe here a mouse model in which bacteria are transmitted to the offspring from vaginally colonised pregnant females, the natural route of infection. We show that GBS strain BM110, belonging to the CC17 clonal complex, is more virulent in this vertical transmission model than the isogenic mutant BM110∆cylE, which is deprived of hemolysin/cytolysin. Pups exposed to the more virulent strain exhibit higher mortality rates and lung inflammation than those exposed to the attenuated strain. Moreover, pups that survive to BM110 infection present neurological developmental disability, revealed by impaired learning performance and memory in adulthood. The use of this new mouse model, that reproduces key steps of GBS infection in newborns, will promote a better understanding of the physiopathology of GBS-induced meningitis.The authors gratefully acknowledge the help of Encarnaca̧ ̃o Ribeiro for excellent technical assistance, Joana Tavares for assisting with IVIS Lumina LT, Susana Roque for the
luminex instrument experiments, the Molecular Microbiology group at i3S for microscope use, and the Portuguese architect and artist Gil Ferreira da Silva for the artworks
included in the last figure. This work was supported by funds from Foundation for
Science and Technology (FCT), European Regional Development Fund (FEDER) and
Compete under project POCI-01-0145-FEDER-016607 (PTDC/IMI-MIC/1049/2014)
and from the project NORTE-01-0145-FEDER-000012, supported by Norte Portugal
Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). T.S.
and A.M. were supported by Investigador FCT (IF/00875/2012 and IF/00753/2014),
POPH and Fundo Social Europeu. E.B.A. and C.C.P. hold postdoctoral fellowships from
FCT (PTDC/IMI-MIC/1049/2014 and SFRH/BPD/91962/2012). Ar.F. and P.T.C. were
supported by Laboratoire d’Excellence (LABEX) Integrative Biology of Emerging Infectious Diseases (grant ANR-10-LABX-62-IBEID).info:eu-repo/semantics/publishedVersio
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