296 research outputs found
Os aspectos psicológicos da ergonomia
Com as mesmas dificuldades técnicas,
com o mesmo material herdwore, é possível
conceber diversos logiciels, diferentes software;
isto significa que é possível organizar
o trabalho, não apenas de uma forma, mas
de várias forma diferentes. Algumas destas
organizações do trabalho serão adoptadas ao
homem; outras, não. O contexto, a longo
termo, é o da saúde e da higiéne pública.
Sentimo-nos no direito de afirmar que actualmente,
um bom conhecimento dos processos
cognitivos, conjuntamente com um acesso
activo à constituição dos logiciels, reunirá a
preocupação já estabelecida da perservação
da saúde e da salubridade dentro e fora da
empresa
Novas tecnologias e trabalho feminino : Efeitos físicos e psicológicos na saúde : A higiene e a segurança dos trabalhadores
Aparentemente a introdução de novas tecnologias pode ser vantajoso para profissões
acessíveis às mulheres, dado que as
actividades mentais que se tornarem predominantes,
não são já apanágio de um dos
dois sexos.
Por outro lado, as novas tecnologias serão
positivas ou negativas em matéria de organização
do trabalho em função daquilo que
irá ser proposto aos indivíduos em substituição
do tempo ganho.
Nesta fase põe-se a seguinte questão: quais
os indivíduos, quais as instâncias, que no
mundo do trabalho profissional e extra-profissional,
serão os agentes de uma análise
crítica da mudança, e oferecerão também,
graça a um maior saber e a escolher políticas
afirmadas, garantias para um melhoramento
real das condições de vida dos trabalhadores e trabalhadoras
Bmp2 and Bmp4 genetically interact to support multiple aspects of mouse development including functional heart development
Bone morphogenetic proteins (BMPs) have multiple roles during embryogenesis. Current data indicate that the dosage of BMPs is tightly regulated for normal development in mice. Since Bmp2 or Bmp4 homozygous mutant mice show early embryonic lethality, we generated compound heterozygous mice for Bmp2 and Bmp4 to explore the impact of lowered dosage of these BMP ligands. Genotyping pups bred between Bmp2 and Bmp4 heterozygous mice revealed that the ratio of adult compound heterozygous mice for Bmp2 and Bmp4 is much lower than expected. During embryogenesis, the compound heterozygous embryos showed several abnormalities, including defects in eye formation, body wall closure defects, and ventricular septal defects (VSD) in the heart. However, the ratio of the compound heterozygous embryos was the same as expected. Caesarean sections at E18.5 revealed that half of the compound heterozygotes died soon after birth, and the majority of the dead individuals exhibited VSD. Survivors were able to grow to adults, but their body weight was significantly lower than control littermates. They demonstrated progressive abnormalities in the heart, eventually showing a branched leaflet in atrioventricular valves. These results suggest that the dosage of both BMP2 and 4 is critical for functional heart formation during embryogenesis and after birth. genesis 47:374–384, 2009. © 2009 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63084/1/20511_ftp.pd
Early Myocardial Function Affects Endocardial Cushion Development in Zebrafish
Function of the heart begins long before its formation is complete. Analyses in mouse and zebrafish have shown that myocardial function is not required for early steps of organogenesis, such as formation of the heart tube or chamber specification. However, whether myocardial function is required for later steps of cardiac development, such as endocardial cushion (EC) formation, has not been established. Recent technical advances and approaches have provided novel inroads toward the study of organogenesis, allowing us to examine the effects of both genetic and pharmacological perturbations of myocardial function on EC formation in zebrafish. To address whether myocardial function is required for EC formation, we examined silent heart (sih(−/−)) embryos, which lack a heartbeat due to mutation of cardiac troponin T (tnnt2), and observed that atrioventricular (AV) ECs do not form. Likewise, we determined that cushion formation is blocked in cardiofunk (cfk(−/−)) embryos, which exhibit cardiac dilation and no early blood flow. In order to further analyze the heart defects in cfk(−/−) embryos, we positionally cloned cfk and show that it encodes a novel sarcomeric actin expressed in the embryonic myocardium. The Cfk(s11) variant exhibits a change in a universally conserved residue (R177H). We show that in yeast this mutation negatively affects actin polymerization. Because the lack of cushion formation in sih- and cfk-mutant embryos could be due to reduced myocardial function and/or lack of blood flow, we approached this question pharmacologically and provide evidence that reduction in myocardial function is primarily responsible for the defect in cushion development. Our data demonstrate that early myocardial function is required for later steps of organogenesis and suggest that myocardial function, not endothelial shear stress, is the major epigenetic factor controlling late heart development. Based on these observations, we postulate that defects in cardiac morphogenesis may be secondary to mutations affecting early myocardial function, and that, in humans, mutations affecting embryonic myocardial function may be responsible for structural congenital heart disease
Myostatin Is Elevated in Congenital Heart Disease and After Mechanical Unloading
Myostatin is a negative regulator of skeletal muscle mass whose activity is upregulated in adult heart failure (HF); however, its role in congenital heart disease (CHD) is unknown.We studied myostatin and IGF-1 expression via Western blot in cardiac tissue at varying degrees of myocardial dysfunction and after biventricular support in CHD by collecting myocardial biopsies from four patient cohorts: A) adult subjects with no known cardiopulmonary disease (left ventricle, LV), (Adult Normal), (n = 5); B) pediatric subjects undergoing congenital cardiac surgery with normal RV size and function (right ventricular outflow tract, RVOT), (n = 3); C) pediatric subjects with worsening but hemodynamically stable LV failure [LV and right ventricle (LV, RV,)] with biopsy collected at the time of orthotopic heart transplant (OHT), (n = 7); and D) pediatric subjects with decompensated bi-ventricular failure on BiVAD support with biopsy collected at OHT (LV, RV, BiVAD), (n = 3).The duration of HF was longest in OHT patients compared to BIVAD. The duration of BiVAD support was 4.3±1.9 days. Myostatin expression was significantly increased in LV-OHT compared to RV-OHT and RVOT, and was increased more than double in decompensated biventricular HF (BiVAD) compared to both OHT and RVOT. An increased myostatin/IGF-1 ratio was associated with ventricular dysfunction.Myostatin expression in increased in CHD, and the myostatin/IGF-1 ratio increases as ventricular function deteriorates. Future investigation is necessary to determine if restoration of the physiologic myostatin/IGF-1 ratio has therapeutic potential in HF
An explorative study to enable environmentally conscious manufacturing for an industrial gearbox manufacturing organization
In recent years, environmentally conscious manufacturing (ECM) has become an important aspect and proactive approach for majority of the manufacturing organizations in India. The reason is that ECM not only helps to produce environment friendly, but also helps to make money by reducing cost or achieving competitive advantage. Industrial gearbox manufacturing organizations have significant environmental impacts as industrial gearbox manufacturing involves several steps which use valuable resources and pollute the environment. Hence, this paper presents an explorative environmental study of an Indian industrial gearbox manufacturing organization. The objective of the current paper is (i) to identify the environmental problems and environmentally conscious manufacturing indicators (ECMI), (ii) to find out the root causes of these problems and (iii) to solve the root causes based on the available state-of-the-art literature. This research work not only reviews the efficient environment friendly manufacturing techniques, but also helps the organization to become eco-efficient by producing environment friendly while making money. First ECMIs selected from literature review, are validated through process mapping. Then these indicators are prioritized using analytic hierarchy process (AHP) to find out the critical environmentally conscious manufacturing indicators (CECMI). The sources of CECMIs are identified using either data envelopment analysis (DEA) or direct observation of the available database. Finally, some possible solutions are also addressed in this paper
Cardiovascular development: towards biomedical applicability: Regulation of cardiomyocyte differentiation of embryonic stem cells by extracellular signalling
Investigating the signalling pathways that regulate heart development is essential if stem cells are to become an effective source of cardiomyocytes that can be used for studying cardiac physiology and pharmacology and eventually developing cell-based therapies for heart repair. Here, we briefly describe current understanding of heart development in vertebrates and review the signalling pathways thought to be involved in cardiomyogenesis in multiple species. We discuss how this might be applied to stem cells currently thought to have cardiomyogenic potential by considering the factors relevant for each differentiation step from the undifferentiated cell to nascent mesoderm, cardiac progenitors and finally a fully determined cardiomyocyte. We focus particularly on how this is being applied to human embryonic stem cells and provide recent examples from both our own work and that of others
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