171 research outputs found
Mineral content of three several muscles from six cattle genotypes
The aim of this study was to determine the effect of genotype and type of muscle on the mineral content of beef. Altogether 62 young bulls from Angus, Charolais, Holstein, Hungarian Simmental, Hungarian Grey, and Charolais×Hungarian Grey were used. The calcium content varied between 26–46 mg kg−1, in longissimus muscle of Hungarian Simmental it was significantly higher than for other genotypes except for Angus. Psoas major of Holstein had the highest phosphorus content, it significantly differed from the longissimus of Angus. Longissimus muscle of Angus was the poorest for magnesium, and the richest was the psoas major of Holstein and Hungarian Grey. Charolais had higher level of potassium in psoas major than Angus and Charolais×Hungarian Grey. Sodium content of semitendinosus in Charolais×Hungarian Grey was lower than in Holstein. Present data showed that levels were detected in the longissimus of Angus and semitendinosus of Holstein. Concerning zinc, a higher level was found in longissimus, especially for Holstein. The results confirmed that beef mineral content depends on genotype, and is related to muscle type, too
From resonance to chaos by modulating spatiotemporal patterns through a synthetic optogenetic oscillator.
Oscillations are a recurrent phenomenon in biological systems across scales, but deciphering their fundamental principles is very challenging. Here, we tackle this challenge by redesigning the wellcharacterised synthetic oscillator known as "repressilator" in Escherichia coli and controlling it using optogenetics, creating the "optoscillator". Bacterial colonies manifest oscillations as spatial ring patterns. When we apply periodic light pulses, the optoscillator behaves as a forced oscillator and we systematically investigate the properties of the rings under various light conditions. Combining experiments with mathematical modeling, we demonstrate that this simple oscillatory circuit can generate complex dynamics that are transformed into distinct spatial patterns. We report the observation of synchronisation, resonance, subharmonic resonance and period doubling. Furthermore, we present evidence of a chaotic regime. This work highlights the intricate spatiotemporal patterns accessible by synthetic oscillators and underscores the potential of our approach in revealing fundamental principles of biological oscillations
Relationship between optical coherence tomography sector peripapillary angioflow-density and Octopus visual field cluster mean defect values
PURPOSE: To compare the relationship of Octopus perimeter cluster mean-defect (cluster MD) values with the spatially corresponding optical coherence tomography (OCT) sector peripapillary angioflow vessel-density (PAFD) and sector retinal nerve fiber layer thickness (RNFLT) values. METHODS: High quality PAFD and RNFLT images acquired on the same day with the Angiovue/RTVue-XR Avanti OCT (Optovue Inc., Fremont, USA) on 1 eye of 27 stable early-to-moderate glaucoma, 22 medically controlled ocular hypertensive and 13 healthy participants were analyzed. Octopus G2 normal visual field test was made within 3 months from the imaging. RESULTS: Total peripapillary PAFD and RNFLT showed similar strong positive correlation with global mean sensitivity (r-values: 0.6710 and 0.6088, P<0.0001), and similar (P = 0.9614) strong negative correlation (r-values: -0.4462 and -0.4412, P</=0.004) with global MD. Both inferotemporal and superotemporal sector PAFD were significantly (</=0.039) lower in glaucoma than in the other groups. No significant difference between the corresponding inferotemporal and superotemporal parameters was seen. The coefficient of determination (R2) calculated for the relationship between inferotemporal sector PAFD and superotemporal cluster MD (0.5141, P<0.0001) was significantly greater than that between inferotemporal sector RNFLT and superotemporal cluster MD (0.2546, P = 0.0001). The R2 values calculated for the relationships between superotemporal sector PAFD and RNFLT, and inferotemporal cluster MD were similar (0.3747 and 0.4037, respectively, P<0.0001). CONCLUSION: In the current population the relationship between inferotemporal sector PAFD and superotemporal cluster MD was strong. It was stronger than that between inferotemporal sector RNFLT and superotemporal cluster MD. Further investigations are necessary to clarify if our results are valid for other populations and can be usefully applied for glaucoma research
X-Ray computed tomography evaluation of intramuscular fat content in Hungarian simmental cattle
Intramuscular fat content (marbling) is an economically important factor in many beef carcass classification systems. The aim of this study was to evaluate marbling of longissimus muscle with different methods (USDA marbling score, image analysis of X-ray computed tomography scans, and conventional method), moreover it was aimed to establish the relationship between marbling traits and SEUROP conformation and fat score. Bulls (n=46) were slaughtered at an average weight of 536±126 kg and an average age of 646±437 days. The average growth rate of bulls was 955 g day–1, the average chemical fat content of longissimus varied between 2.3 to 5.0% in fat classes. The intramuscular fat content on CT-scans closely correlated with chemical fat content (r=0.9). The highest frequency of USDA marbling score was “small” (55.2%), followed by “slight” (25.5%), “modest” (17%), and “moderate” (2.1%). Bulls with higher growth rate had lower CT-measured marbling traits in longissimus muscle (r = –0.4 – –0.5). The CT scans of longissimus muscle can be used for the evaluation of marbling in Hungarian Simmental cattle. The SEUROP conformation and fat score have no relationship with marbling traits
Does glaucoma medication influence the diameter of the retinal arteriole in the human eye? (A pilot study using the Retinal Vessel Analyser)
Purpose:To investigate the potential in vivoinfluence of different topical glaucoma medications on the diameter of the retinal arterioles of healthy volunteers and glaucoma patients. Methods:The diameter of one pre-selected retinal arteriole per eye was measured using the Retinal Vessel Analyser (RVA), an instrument developed for non-invasive clinical measurement of the diameter of the main retinal vessels. The instrument contains a video system, and the integrated software recognises the boundaries of the retinal vessels by detecting their light-transmission profile. The vessel diameter (in arbitrary units) is plotted against time (seconds) on a separate display screen. In Study Ithe vessel diameter was measured in 12 eyes of six healthy volunteers (age 21–26 years, mean age 24.0 years) on six occasions each separated by 14 days. In a double-masked fashion, each subject's right eye was treated with one of 5 glaucoma medications (brinzolamide 1%, timolol 0.5%, betaxolol 0.5%, brimonidine 0.2% or latanoprost 0.005%) and the left eye always received balanced salt solution. In Study II, one randomly selected eye of 16patients (age 50–79 years, mean age 65.2 years) suffering from primary open-angle glaucoma controlled with topical monotherapy was investigated, in an unmasked fashion. Four patients were on betaxolol 0.5% treatment, sixsubjects were receiving non-selective topical beta receptor blockers and six subjects were being treated with once daily latanoprost 0.005%. Results: The coefficient of variation for the arteriole diameter in the healthy volunteers was less than 12% in each case. No significant post-treatment change of the diameter of the pre-selected arteriole was found for any topical medication investigated, either in the healthy volunteers (Study I)or in the patients suffering from glaucoma (Study II)(p?0.05, paired t-test). In addition, in Study Ino difference was observed in the alteration of the arteriole diameter between the baseline and the hour 2 measurements when the values from the drug-treated and placebo treated eyes were compared (p?0.05, two-way ANOVA). Conclusion:In the present investigations it was not possible to detect any statistically meaningful change of the arteriole diameter at two hours after the instillation of any of several topical antiglaucoma drugs widely used in clinical practice. Further investigations are necessary to clarify whether the lack of observed change is due to the lack of retinal vascular effects of the drugs investigated, or is due to an inability of the RVA instrument in practice to detect alterations between time-points separated by several hours
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