919 resultados para Affects
Resumo:
The plant PTR/NRT1 (peptide transporter/nitrate transporter 1) gene family comprises di/tripeptide and low-affinity nitrate transporters; some members also recognize other substrates such as carboxylates, phytohormones (auxin and abscisic acid), or defence compounds (glucosinolates). Little is known about the members of this gene family in rice (Oryza sativa L.). Here, we report the influence of altered OsPTR9 expression on nitrogen utilization efficiency, growth, and grain yield. OsPTR9 expression is regulated by exogenous nitrogen and by the day-night cycle. Elevated expression of OsPTR9 in transgenic rice plants resulted in enhanced ammonium uptake, promotion of lateral root formation and increased grain yield. On the other hand, down-regulation of OsPTR9 in a T-DNA insertion line (osptr9) and in OsPTR9-RNAi rice plants had the opposite effect. These results suggest that OsPTR9 might hold potential for improving nitrogen utilization efficiency and grain yield in rice breeding.
Resumo:
Global complexity of spontaneous brain electric activity was studied before and after chewing gum without flavor and with 2 different flavors. One-minute, 19-channel, eyes-closed electroencephalograms (EEG) were recorded from 20 healthy males before and after using 3 types of chewing gum: regular gum containing sugar and aromatic additives, gum containing 200 mg theanine (a constituent of Japanese green tea), and gum base (no sugar, no aromatic additives); each was chewed for 5 min in randomized sequence. Brain electric activity was assessed through Global Omega (Ω)-Complexity and Global Dimensional Complexity (GDC), quantitative measures of complexity of the trajectory of EEG map series in state space; their differences from pre-chewing data were compared across gum-chewing conditions. Friedman Anova (p < 0.043) showed that effects on Ω-Complexity differed significantly between conditions and differences were maximal between gum base and theanine gum. No differences were found using GDC. Global Omega-Complexity appears to be a sensitive measure for subtle, central effects of chewing gum with and without flavor.
Resumo:
BACKGROUND Although periacetabular osteotomy (PAO) for developmental dysplasia of the hip (DDH) provides conceptual advantages compared with other osteotomies and reportedly is associated with joint survivorship of 60% at 20 years, the beneficial effect of proper acetabular reorientation with concomitant arthrotomy and creation of femoral head-neck offset on 10-year hip survivorship remains unclear. QUESTIONS/PURPOSES We asked the following questions: (1) Does the 10-year survivorship of the hip after PAO improve with proper acetabular reorientation and a spherical femoral head; (2) does the Merle d'Aubigné-Postel score improve; (3) can the progression of osteoarthritis (OA) be slowed; and (4) what factors predict conversion to THA, progression of OA, or a Merle d'Aubigné-Postel score less than 15 points? METHODS We retrospectively reviewed 147 patients who underwent 165 PAOs for DDH with two matched groups: Group I (proper reorientation and spherical femoral head) and Group II (improper reorientation and aspherical femoral head). We compared the Kaplan-Meier survivorship, Merle d'Aubigné-Postel scores, and progression of OA in both groups. A Cox regression analysis (end points: THA, OA progression, or Merle d'Aubigné-Postel score less than 15) was performed to detect factors predicting failure. The minimum followup was 10 years (median, 11 years; range, 10-14 years). RESULTS An increased survivorship was found in Group I. The Merle d'Aubigné-Postel score did not differ. Progression of OA in Group I was slower than in Group II. Factors predicting failure included greater age, lower preoperative Merle d'Aubigné-Postel score, and the presence of a Trendelenburg sign, aspherical head, OA, subluxation, postoperative acetabular retroversion, excessive acetabular anteversion, and undercoverage. CONCLUSIONS Proper acetabular reorientation and the creation of a spherical femoral head improve long-term survivorship and decelerate OA progression in patients with DDH.
Subordinate removal affects parental investment, but not offspring survival in a cooperative cichlid
Resumo:
Summary Subordinates in cooperative breeding systems may provide help to dominant pairs, who can benefit by either an increased total investment in their current brood or a reduced personal contribution to this investment. In the social cichlid Julidochromis ornatus, one large male subordinate generally spends 90% of his time in close proximity to the breeding shelter, whereas the dominants only spend 50% of their time close to the shelter. We experimentally removed the large subordinate for 30 days (approximating one breeding cycle) to study the investment strategies of dominants and the effects on offspring survival, while accounting for subordinate immigration. Experimental groups were compared with control groups, from which subordinates were also caught but not removed. On day one following removal, we tested whether dominants overcompensated, fully compensated or undercompensated for absence of the subordinate on several parental behaviours. Moreover, we tested whether the pairs' potential compensatory behaviour remained high seven days following large subordinate removal. One day following removal, dominants increased their time spent in the territory and their frequency of breeding shelter visits and defence, compared with the pre-removal phase and control groups. The dominant pair overcompensated for the loss of subordinate help in their breeding shelter visits, fully compensated in defence and undercompensated their time spent in the territory. Seven days after large subordinate removal, behavioural differences between treatments had disappeared. However, when distinguishing between groups with or without a new immigrant subordinate, dominant pairs only diminished investment in the presence of an immigrant, suggesting a compensatory role of the large subordinate. Finally, survival of juvenile group members was not affected by the treatment. Our experiments indicate that the presence of a large subordinate does not increase the dominant pairs' current reproductive success, but instead allows them to reduce their personal contribution to investment in the current brood. In addition, we illustrate that dominants may show strikingly different compensatory responses depending on the type of behaviour and emphasize the importance of immigrant subordinates to relieve dominants from costly compensatory responses in cooperative breeding systems.
Age affects the adjustment of cognitive control after a conflict: evidence from the bivalency effect
Resumo:
Age affects cognitive control. When facing a conflict, older adults are less able to activate goal-relevant information and inhibit irrelevant information. However, cognitive control also affects the events after a conflict. The purpose of this study was to determine whether age affects the adjustment of cognitive control following a conflict. To this end, we investigated the bivalency effect, that is, the performance slowing occurring after the conflict induced by bivalent stimuli (i.e., stimuli with features for two tasks). In two experiments, we tested young adults (aged 20-30) and older adults (aged 65-85) in a paradigm requiring alternations between three tasks, with bivalent stimuli occasionally occurring on one task. The young adults showed a slowing for all trials following bivalent stimuli. This indicates a widespread and long-lasting bivalency effect, replicating previous findings. In contrast, the older adults showed a more specific and shorter-lived slowing. Thus, age affects the adjustment of cognitive control following a conflict.
Resumo:
INTRODUCTION Transplacental feto-maternal lipid exchange through the ATP-binding cassette transporters ABCA1 and ABCG1 is important for normal fetal development. However, only scarce and conflicting data exist on the involvement of these transporters in gestational disease. METHODS Placenta samples (n = 72) derived from common gestational diseases, including pre-eclampsia (PE), HELLP, intrauterine growth restriction (IUGR), intrahepatic cholestasis of pregnancy and gestational diabetes, were assessed for their ABCA1 and ABCG1 expression levels and compared to age-matched control placentas with qRT-PCR and immunohistochemistry. ABCA1 expression was additionally investigated with immunoblot in placental membrane vesicles. Furthermore, placental cholesterol and phospholipid contents were assessed. RESULTS ABCA1 mRNA levels differed significantly between preterm and term control placentas (p = 0.0013). They were down-regulated in isolated PE and PE with IUGR (p = 0.0006 and p = 0.0012, respectively), but unchanged in isolated IUGR, isolated HELLP and other gestational diseases compared to gestational age-matched controls. Correspondingly, in PE, ABCA1 protein expression was significantly reduced in the apical membrane of the villous syncytiotrophoblast (p = 0.011) and in villous fetal endothelial cells (p = 0.036). Furthermore, in PE there was a significant increase in the placental content of total and individual classes of phospholipids which were partially correlated with diminished ABCA1 expression. Conversely, ABCG1 mRNA and protein levels were stable in the investigated conditions. CONCLUSIONS In gestational disease, there is a specific down-regulation of placental ABCA1 expression at sites of feto-maternal lipid exchange in PE. At a functional level, the increase in placental lipid concentrations provides indirect evidence of an impaired transport capacity of ABCA1 in this disease.
Resumo:
Fat mobilization to meet energy requirements during early lactation is inevitable because of insufficient feed intake, but differs greatly among high-yielding dairy cows. Therefore, we studied milk production, feed intake, and body condition as well as metabolic and endocrine changes in high-yielding dairy cows to identify variable strategies in metabolic and endocrine adaptation to overcome postpartum metabolic load attributable to milk production. Cows used in this study varied in fat mobilization around calving, as classified by mean total liver fat concentrations (LFC) postpartum. German Holstein cows (n=27) were studied from dry off until d 63 postpartum in their third lactation. All cows were fed the same total mixed rations ad libitum during the dry period and lactation. Plasma concentrations of metabolites and hormones were measured in blood samples taken at d 56, 28, 15, and 5 before expected calving and at d 1 and once weekly up to d 63 postpartum. Liver biopsies were taken on d 56 and 15 before calving, and on d 1, 14, 28, and 49 postpartum to measure LFC and glycogen concentrations. Cows were grouped accordingly to mean total LFC on d 1, 14, and 28 in high, medium, and low fat-mobilizing cows. Mean LFC (±SEM) differed among groups and were 351±14, 250±10, and 159±9 mg/g of dry matter for high, medium, and low fat-mobilizing cows, respectively, whereas hepatic glycogen concentrations postpartum were the highest in low fat-mobilizing cows. Cows in the low group showed the highest dry matter intake and the least negative energy balance postpartum, but energy-corrected milk yield was similar among groups. The decrease in body weight postpartum was greatest in high fat-mobilizing cows, but the decrease in backfat thickness was greatest in medium fat-mobilizing cows. Plasma concentrations of nonesterified fatty acids and β-hydroxybutyrate were highest around calving in high fat-mobilizing cows. Plasma triglycerides were highest in the medium group and plasma cholesterol concentrations were lowest in the high group at calving. During early lactation, the decrease in plasma glucose concentrations was greatest in the high group, and plasma insulin concentrations postpartum were highest in the low group. The revised quantitative insulin sensitivity check index values decreased during the transition period and postpartum, and were highest in the medium group. Plasma cortisol concentrations during the transition period and postpartum period and plasma leptin concentrations were highest in the medium group. In conclusion, cows adapted differently to the metabolic load and used variable strategies for homeorhetic regulation of milk production. Differences in fat mobilization were part of these strategies and contributed to the individual adaptation of energy metabolism to milk production.
Resumo:
BACKGROUND: Excessive and abnormal accumulation of alpha-synuclein (α-synuclein) is a factor contributing to pathogenic cell death in Parkinson's disease. The purpose of this study, based on earlier observations of Parkinson's disease cerebrospinal fluid (PD-CSF) initiated cell death, was to determine the effects of CSF from PD patients on the functionally different microglia and astrocyte glial cell lines. Microglia cells from human glioblastoma and astrocytes from fetal brain tissue were cultured, grown to confluence, treated with fixed concentrations of PD-CSF, non-PD disease control CSF, or control no-CSF medium, then photographed and fluorescently probed for α-synuclein content by deconvolution fluorescence microscopy. Outcome measures included manually counted cell growth patterns from day 1-8; α-synuclein density and distribution by antibody tagged 3D model stacked deconvoluted fluorescent imaging. RESULTS: After PD-CSF treatment, microglia growth was reduced extensively, and a non-confluent pattern with morphological changes developed, that was not evident in disease control CSF and no-CSF treated cultures. Astrocyte growth rates were similarly reduced by exposure to PD-CSF, but morphological changes were not consistently noted. PD-CSF treated microglia showed a significant increase in α-synuclein content by day 4 compared to other treatments (p ≤ 0.02). In microglia only, α-synuclein aggregated and redistributed to peri-nuclear locations. CONCLUSIONS: Cultured microglia and astrocytes are differentially affected by PD-CSF exposure compared to non-PD-CSF controls. PD-CSF dramatically impacts microglia cell growth, morphology, and α-synuclein deposition compared to astrocytes, supporting the hypothesis of cell specific susceptibility to PD-CSF toxicity.
Resumo:
OBJECTIVE Neuro-imaging studies have suggested that the ability to imitate meaningless and meaningful gestures may differentially depend on superior (SPL) and inferior (IPL) parietal lobule. Therefore, we hypothesized that imaging-guided neuro-navigated continuous theta burst stimulation (cTBS) over left SPL mainly affects meaningless and over left IPL predominantly meaningful gestures. METHODS Twelve healthy subjects participated in this study. High resolution structural MRI was used for imaging guided neuro-navigation cTBS. Participants were targeted with one train of cTBS in three experimental sessions: sham stimulation over vertex and real cTBS over left SPL and IPL, respectively. An imitation task, including 24 meaningless and 24 meaningful gestures, was performed 'offline'. RESULTS cTBS over both left IPL and SPL significantly interfered with gestural imitation. There was no differential effect of SPL and IPL cTBS on gesture type (meaningless versus meaningful). CONCLUSIONS Our findings confirm that left posterior parietal cortex plays a predominant role in gestural imitation. However, the hypothesis based on the dual route model suggesting a differential role of SPL and IPL in the processing of meaningless and meaningful gestures could not be confirmed. SIGNIFICANCE Left SPL and IPL play a common role within the posterior-parietal network in gestural imitation regardless of semantic content.