RESUMO
AIMS: The influence of soil edaphic factors on recruitment and composition of bacteria in the legume nodule is unknown. Typically, low (acidic) pH soils have a negative effect on the plant-rhizobia symbiosis and thereby reduce clover growth. However, the specific relationship between soil pH and the ecology of rhizobia is unknown, in either their free-living or nodule-inhabiting states. We used New Zealand pasture systems with soils of different pH, and white (WC) and subterranean (SC) clovers, to examine the relationship between soil pH and the diversity of bacteria that inhabit the nodules. METHODS AND RESULTS: Amplicon sequencing (16S rRNA) assessed the bacterial community in 5299 nodules recovered from both legume species grown in 47 soils of different edaphic (including pH) properties. Fewer nodules were formed on both clovers at low soil pH. As expected, rhizobia comprised â¼ 92% of the total reads in both clovers, however 28 non-rhizobia genera were also present. Soil pH influenced the community structure of bacteria within the nodule, and this was more evident in non-Rhizobium taxa than Rhizobium. Host strongly influenced the diversity of bacteria in the nodules. The alpha diversity of nodule microbiome in SC nodules was higher than in WC nodules and SC nodules also harbored a higher relative abundance of non-Rhizobium bacteria than WC. Beta diversity of Rhizobium and non-Rhizobium bacteria was influenced more by clover species rather than edaphic factors. CONCLUSIONS: The results indicate that these clover species modified their nodule biomes in response to pH-stress. SIGNIFICANCE AND IMPACT OF THE STUDY: The non-Rhizobium bacteria may have some functional significance (such as improved clover persistence in low pH soils) in legume nodules.
Assuntos
Microbiota , Rhizobium , Trifolium , Concentração de Íons de Hidrogênio , Filogenia , RNA Ribossômico 16S/genética , Nódulos Radiculares de Plantas , Solo , SimbioseRESUMO
1 High affinity binding of [3H]-dopamine and [3H]-5-hydroxytryptamine ([3H]-5-HT) was measured in membrane fractions prepared from cerebral cortex, amygdala, hypothalamus, thalamus and brain stem of rats of either sex and of rats which had been either neonatally castrated or androgenized. 2 Binding was measured in rats of 8, 20 and 30 days old as well as in adults. 3 [3H]-dopamine bound with approximately 30 nM affinity ahd [3H]-5-HT with approximately 10 nM affinity to all areas of the brain tested. The relative inhibitory effects of haloperidol, apomorphine, cis-flupenthixol, unlabelled dopamine, noradrenaline, spiroperone, (+)-butaclamol, fluphenazine, pimozide and 5-HT on [3H]-dopamine binding in the cerebral cortex was consistent with receptor status for the binding components there as were the relative inhibitory effects of methysergide, dopamine, fluoxetine and ouabain on [3H]-5-HT binding in the fore brain. 4 Neither [3H]-dopamine nor [3H]-5-HT binding varied with the state of the sexual cycle in females. 5 There were no sexual differences in [3H]-5-HT binding in any of the brain areas tested nor was it affected by neonatal androgenization or neonatal castration. 6 [3H]-dopamine binding was greater in the cerebral cortex and amygdala of male than of female rats. These differences could be mimicked artificially by neonatal castration of males (female type development) or neonatal androgenization of females (male type development). Sexual dimorphism did not become overt until 20 days of age and did not extend to hypothalamus, thalamus or brain stem. 7 It is concluded that neonatal sex differences in exposure to steroid hormones has permanent effects on the number of dopamine binding sites in the cerebral cortex and is suggested that this sexual dimorphism extends to the amygdala.
Assuntos
Androgênios/farmacologia , Encéfalo/metabolismo , Dopamina/metabolismo , Serotonina/metabolismo , Diferenciação Sexual/efeitos dos fármacos , Envelhecimento , Animais , Sítios de Ligação/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Castração , Feminino , Masculino , Ratos , Ratos Endogâmicos , Fatores Sexuais , Testosterona/farmacologiaRESUMO
Synapses develop at similar rates in the suprachiasmatic nucleus of rats of both sexes, but values are higher in male than in female animals from birth to maturity. Male-type development cannot be mimicked by neonatal androgenization but results suggest that female-type development can be induced by neonatal castration of males. The results suggested that both prenatal and postnatal androgens are essential to normal male development.
Assuntos
Diferenciação Sexual , Núcleo Supraquiasmático/fisiologia , Animais , Castração , Feminino , Masculino , Ratos , Ratos Endogâmicos , Núcleo Supraquiasmático/efeitos dos fármacos , Sinapses/fisiologia , Testosterona/farmacologiaRESUMO
OBJECTIVES: This paper considers the specific administrative procedures set up by managers of public healthcare establishments and those responsible for health and welfare policies to care for low-income pregnant women for whom 100% of the "price per act" (T2A) is refunded. What are the limitations and what improvements can be suggested? PATIENTS AND METHOD: The results are based on an analysis of data from semi-structured interviews, legislation and documents. RESULTS: The State, health insurance systems, public health establishments, local authorities, charities and outpatient services are involved in handling low-income parturients in different services and different establishments, both locally and regionally. A health and welfare policy comprising specific, coordinated actions and measures has been developed. The T2A "price per act" system may threaten its survival: the limited number of front-line facilities is often saturated and demand is increasing, treatment is often reduced to reactive management leading to unwanted readmissions, ethics are sometimes called into question and there is a risk of patient selection. DISCUSSION AND CONCLUSION: This pilot study provided some encouraging information but also indicated the limitations of the approach adopted. However, it was still of interest to see whether it was possible to use this approach, which did not require considerable resources, to reveal useful markers. This appeared to be the case. Regional Health Agencies (ARS) and local authorities could support the system. Additional funding is needed.