13 research outputs found

    Genetic analysis on three South Indian sympatric hipposiderid bats (Chiroptera, Hipposideridae)

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    In mitochondrial DNA, variations in the sequence of 16S rRNA region were analyzed to infer the genetic relationship and population history of three sympatric hipposiderid bats, Hipposideros speoris, H. fulvus and H. ater. Based on the DNA sequence data, we observed relatively lower haplotype and higher nucleotide diversity in H. speoris than in the other two species. The pairwise comparisons of the genetic divergence inferred a genetic relationship between the three hipposiderid bats. We used haplotype sequences to construct a phylogenetic tree. Maximum parsimony and Bayesian inference analysis generated a tree with similar topology. H. fulvus and H. ater formed one cluster and H. speoris formed another cluster. Analysis of the demographic history of populations using Jajima’s D test revealed past changes in populations. Comparison of the observed distribution of pairwise differences in the nucleotides with expected sudden expansion model accepts for H. fulvus and H. ater but not for H. speoris populations

    Genetic diversity and population structure of leaf-nosed bat Hipposideros speoris (Chiroptera: Hipposideridae) in Indian subcontinent

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    Genetic variation and population structure of the leaf-nosed bat Hipposideros speoris were estimated using 16S rRNA sequence and microsatellite analysis. Twenty seven distinct mitochondrial haplotypes were identified from 186 individuals, sampled from eleven populations. FST test revealed significant variations between populations in the overall pairwise estimation (FST = 0.710; p < 0.001). In addition, haplotype network and analysis of molecular variation analysis (AMOVA) consistently suggest the prevalence of genetic structure in the sampled populations. However, the mtDNA data was not significantly different in few closely located urban populations, but significant difference has been observed with the use of microsatellite data. The Bayesian clustering analysis identified eight clusters among the populations; the clustering pattern also corresponded to the haplotype networks. Overall, the present study suggests a "macrogeographic genetic isolation-by-distance" and possibility of gene flow among closely located populations

    Electric Vehicles Charging Stations’ Architectures, Criteria, Power Converters, and Control Strategies in Microgrids

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    Electric Vehicles (EV) usage is increasing over the last few years due to a rise in fossil fuel prices and the rate of increasing carbon dioxide (CO2) emissions. The EV charging stations are powered by the existing utility power grid systems, increasing the stress on the utility grid and the load demand at the distribution side. The DC grid-based EV charging is more efficient than the AC distribution because of its higher reliability, power conversion efficiency, simple interfacing with renewable energy sources (RESs), and integration of energy storage units (ESU). The RES-generated power storage in local ESU is an alternative solution for managing the utility grid demand. In addition, to maintain the EV charging demand at the microgrid levels, energy management and control strategies must carefully power the EV battery charging unit. Also, charging stations require dedicated converter topologies, control strategies and need to follow the levels and standards. Based on the EV, ESU, and RES accessibility, the different types of microgrids architecture and control strategies are used to ensure the optimum operation at the EV charging point. Based on the above said merits, this review paper presents the different RES-connected architecture and control strategies used in EV charging stations. This study highlights the importance of different charging station architectures with the current power converter topologies proposed in the literature. In addition, the comparison of the microgrid-based charging station architecture with its energy management, control strategies, and charging converter controls are also presented. The different levels and types of the charging station used for EV charging, in addition to controls and connectors used in the charging station, are discussed. The experiment-based energy management strategy is developed for controlling the power flow among the available sources and charging terminals for the effective utilization of generated renewable power. The main motive of the EMS and its control is to maximize usage of RES consumption. This review also provides the challenges and opportunities for EV charging, considering selecting charging stations in the conclusion.publishedVersio

    Consequences of late-stage non-small cell lung cancer cachexia on muscle metabolic processes

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    Introduction: Loss of muscle is common in patients with advanced non-small cell lung cancer (NSCLC), and contributes to the high morbidity and mortality of this group. The exact mechanisms behind the loss of muscle are unclear. Patients and methods: To investigate this, 4 patients with stage IV NSCLC meeting the clinical definitions for sarcopenia and cachexia were recruited, along with 4 age-matched healthy volunteers. Following an overnight fast, biopsies were obtained from the vastus lateralis and key components associated with inflammation and the control of muscle protein, carbohydrate and fat metabolism assessed. Results: Compared to healthy volunteers, significant increases in mRNA levels for interleukin-6 and NFκB signalling were observed in NSCLC patients along with lower intramyocellular lipid content in slow-twitch fibres. While a significant decrease in phosphorylation of mTOR signalling protein 4E-BP1 (Ser65) was observed along with a trend towards reduced p70 S6K (Thr389) phosphorylation (P=0.06), there was no difference between groups for mRNA levels of MAFbx and MuRF1, chymotrypsin-like activity of the proteasome, or protein levels of multiple proteasome subunits. Moreover, despite decreases in intramyocellular lipid content, no robust changes in mRNA levels for key proteins involved in insulin signalling, glycolysis, oxidative metabolism or fat metabolism were observed.Conclusions: These findings suggest that an examination of the contribution of suppressed mTOR signalling in the loss of muscle mass in late-stage NSCLC patients is warranted and reinforces our need to understand the potential contribution of impaired fat metabolism and muscle protein synthesis in the aetiology of cancer cachexia

    Obesity appears to be associated with altered muscle protein synthetic and breakdown responses to increased nutrient delivery in older men, but not reduced muscle mass or contractile function.

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    Obesity is increasing, yet despite the necessity to maintain muscle mass and function with age, the effect of obesity on muscle protein turnover in older adults remains unknown. Eleven obese (BMI 31.9 ±1.1) and 15 healthy weight (HW; BMI 23.4 ±0.3) older men (55-75 years old) participated in a study that determined muscle protein synthesis (MPS) and leg protein breakdown (LPB) under post-absorptive (hypoinsulinaemic euglycaemic clamp) and post-prandial (hyperinsulinemic hyperaminoacidaemic euglycaemic clamp) conditions. Obesity was associated with systemic inflammation, greater leg fat mass, and patterns of mRNA expression consistent with muscle deconditioning, whilst leg lean mass, strength and work done during maximal exercise were no different. Under post-absorptive conditions, MPS and LPB were equivalent between groups, while insulin and amino acid administration increased MPS in only HW subjects and was associated with lower leg glucose disposal (LGD, 63%) in obese. Blunting of MPS in the obese was offset by an apparent decline in LPB, which was absent in HW subjects. Lower post-prandial LGD in obese subjects and blunting of MPS responses to amino acids suggests obesity in older adults is associated with diminished muscle metabolic quality. However this doesn’t appear to be associated with lower leg lean mass or strength

    Consequences of late-stage non-small cell lung cancer cachexia on muscle metabolic processes

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    Introduction: Loss of muscle is common in patients with advanced non-small cell lung cancer (NSCLC), and contributes to the high morbidity and mortality of this group. The exact mechanisms behind the loss of muscle are unclear. Patients and methods: To investigate this, 4 patients with stage IV NSCLC meeting the clinical definitions for sarcopenia and cachexia were recruited, along with 4 age-matched healthy volunteers. Following an overnight fast, biopsies were obtained from the vastus lateralis and key components associated with inflammation and the control of muscle protein, carbohydrate and fat metabolism assessed. Results: Compared to healthy volunteers, significant increases in mRNA levels for interleukin-6 and NFκB signalling were observed in NSCLC patients along with lower intramyocellular lipid content in slow-twitch fibres. While a significant decrease in phosphorylation of mTOR signalling protein 4E-BP1 (Ser65) was observed along with a trend towards reduced p70 S6K (Thr389) phosphorylation (P=0.06), there was no difference between groups for mRNA levels of MAFbx and MuRF1, chymotrypsin-like activity of the proteasome, or protein levels of multiple proteasome subunits. Moreover, despite decreases in intramyocellular lipid content, no robust changes in mRNA levels for key proteins involved in insulin signalling, glycolysis, oxidative metabolism or fat metabolism were observed. Conclusions: These findings suggest that an examination of the contribution of suppressed mTOR signalling in the loss of muscle mass in late-stage NSCLC patients is warranted and reinforces our need to understand the potential contribution of impaired fat metabolism and muscle protein synthesis in the aetiology of cancer cachexia

    Skeletal muscle carnitine loading increases energy expenditure, modulates fuel metabolism gene networks and prevents body fat accumulation in humans

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    Twelve weeks of daily L-carnitine and carbohydrate feeding in humans increases skeletal muscle total carnitine content, and prevents body mass accrual associated with carbohydrate feeding alone. Here we determined the influence of L-carnitine and carbohydrate feeding on energy metabolism, body fat mass andmuscle expression of fuel metabolism genes. Twelve males exercised at 50% maximal oxygen consumption for 30 min once before and once after 12 weeks of twice daily feeding of 80 g carbohydrate (Control, n=6) or 1.36 g L-carnitine+80 g carbohydrate (Carnitine, n=6). Maximal carnitine palmitolytransferase 1 (CPT1) activity remained similar in both groups over 12 weeks. However, whereas muscle total carnitine, long-chain acyl-CoA and whole-body energy expenditure did not change over 12 weeks in Control, they increased in Carnitine by 20%, 200% and 6%, respectively (P<0.05). Moreover, body mass and whole-body fat mass (dual-energy X-ray absorptiometry) increased over 12 weeks in Control by 1.9 and 1.8 kg, respectively (P<0.05), but did not change in Carnitine. Seventy-three of 187 genes relating to fuel metabolism were upregulated in Carnitine vs. Control after 12 weeks, with ‘insulin signalling’, ‘peroxisome proliferator-activated receptor signalling’ and ‘fatty acid metabolism’ as the three most enriched pathways in gene functional analysis. In conclusion, increasing muscle total carnitine in healthy humans can modulate muscle metabolism, energy expenditure and body composition over a prolonged period, which is entirely consistent with a carnitine-mediated increase in muscle long-chain acyl-group translocation via CPT1. Implications to health warrant further investigation, particularly in obese individuals who have a reduced reliance on muscle fat oxidation during low-intensity exercise

    Effect of stacking sequence of glass and jute fiber reinforced polymer composites on their low velocity impact properties

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    This paper investigated the effect of stacking sequence on the low velocity impact behavior of glass and jute fiber reinforced hybrid composites. The hand layup method is used to fabricate the composites with various stacking sequences. The low velocity impact analysis was carried out at various impact energies, namely 5 J, 10 J and 15 J. Dye penetrant inspection (liquid penetrate inspection) was performed to analyses the damage area in the composites. Compression after impact (CAI) testing was conducted to study the compression strength of the composites after the impact. The study revealed that the jute fiber composites exhibited better results in terms of energy absorption, but the damage area of the composites was higher, compared to the other specimens fabricated. Meanwhile, hybrid composite S7 presented high energy absorption and the minimum damage area. To conclude, the hybrid composite S7 appeared to have the optimum formulation, showing better results in energy absorption, with lower damage and higher compression strength

    Statin myalgia is not associated with reduced muscle strength, mass or protein turnover in older male volunteers, but is allied with a slowing of time to peak power output, insulin resistance and differential muscle mRNA expression.

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    Statins are associated with muscle myalgia and myopathy, which probably reduce habitual physical activity. This is particularly relevant to older people who are less active, sarcopaenic and at increased risk of statin myalgia. We hypothesised that statin myalgia would be allied to impaired strength and work capacity in older people, and determined whether differences aligned with divergences in lean mass, protein turnover, insulin sensitivity and the molecular regulation of these processes. Knee extensor strength and work output during 30 maximal isokinetic contractions were assessed in healthy male volunteers, nine with no statin use (control 70.4 ± 0.7 years) and nine with statin myalgia (71.5 ± 0.9 years). Whole body and leg glucose disposal, muscle myofibrillar protein synthesis (MPS) and leg protein breakdown (LPB) were measured during fasting (≈5 mU l(-1) insulin) and fed (≈40 mU l(-1) insulin + hyperaminoacidaemia) euglyceamic clamps. Muscle biopsies were taken before and after each clamp. Lean mass, MPS, LPB and strength were not different but work output during the initial three isokinetic contractions was 19% lower (P < 0.05) in statin myalgic subjects due to a delay in time to reach peak power output. Statin myalgic subjects had reduced whole body (P = 0.05) and leg (P < 0.01) glucose disposal, greater abdominal adiposity (P < 0.05) and differential expression of 33 muscle mRNAs (5% false discovery rate (FDR)), six of which, linked to mitochondrial dysfunction and apoptosis, increased at 1% FDR. Statin myalgia was associated with impaired muscle function, increased abdominal adiposity, whole body and leg insulin resistance, and evidence of mitochondrial dysfunction and apoptosis
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