1,228 research outputs found
Seasonal Variation of the Hydro-Environmental Factors and Phytoplankton Community around Waters in Tincan Island, Lagos State, Nigeria
The phytoplankton diversity, pigment, abundance and distribution in
relation to physico-chemical parameters were studied from four stations
for a period of five months (May \u2013 September 2018) and were
analysed using standard procedures. Rainfall was highest (329.5 mm) in
September and lowest (142.7 mm) in July. The total suspended solid
(TSS) had a mean value of 63.10\ub112.81 mg/L and the total dissolved
solids (TDS) had the highest value of 15189 mg/L in May which was not
significantly different around the sampling points {P > 0.05}. The
pH and nitrate level recorded had a mean value of 7.25\ub10.33 and
3.11\ub11.33 mg/L respectively. Microscopic identification revealed a
total of 129 species belonging to 62 genera, 22 families and five
divisions in the following order of specie abundance: Bacillariophyceae
(65 taxa) > Cyanophyceae (27 taxa) > Chlorophyta (20 taxa) >
Dinophyceae (10 taxa) > Euglenophyceae (7 taxa). The high dominance
of Microcystis aeruginosa observed was indicative of organic
pollution. The range of community structure indices were as follows:
Margalef Index (0.1406 \u2013 5.295) and Shannon \u2013 Weiner Index
(0.02644 - 0.4979). The relatively high nutrient status favours the
high abundance of phytoplankton which is understood to be deleterious
to the ecosystem. Municipal wastes must be treated or recycled before
discharge and a continuous environmental surveillance is required to
maintain the biological integrity of this area
Open versus closed view autorefraction in young adults
Purpose:
While there are numerous studies comparing open-view autorefractors to subjective refraction or other open-view autorefractors, most studies between closed and open-view autorefraction tend to focus on children rather than young adults. The aim of this study was to determine the concordance in non-cycloplegic refractive error between two modern objective autorefractors: the closed-view monocular Topcon TRK-2P and the binocular open-view Grand Seiko WR-5500.
Methods:
Fifty young adults aged 20–29 years (mean age 22 ± 1.6 years) underwent non-cycloplegic autorefraction using the Grand Seiko WAM-5500 (open view) and Topcon TRK-2P (closed-view) autorefractors on both eyes. Findings were expressed as the isolated spherical component and were also converted from clinical to vector notation: Mean Spherical Error (MSE) and the astigmatic components J0 and J45.
Results:
Mean MSE ± SD was −1.00 ± 2.40D for the Grand Seiko WAM-5500 compared to −1.23 ± 2.29D for the Topcon TRK-2P. Up to seventy-six percent of the cohort had mean spherical errors from the Topcon TRK-2P which fell within ±0.50D of the Grand Seiko reading and 58% fell within ±0.25D. Mean differences between the two instruments were statistically significant for all components (J0, spherical, and MSE) (p 0.05).
Conclusions:
The differences in non-cycloplegic MSE between these two instruments are small, but statistically significant. From a clinical perspective the Topcon TRK-2P may serve as a useful starting point for subjective refraction, but additional work is needed to help further minimise differences between the instruments
Neuromuscular Electrical Stimulation for Intermittent Claudication (NESIC): multicentre, randomized controlled trial
\ua9 The Author(s) 2023. Published by Oxford University Press on behalf of BJS Society Ltd. METHODS: This was an open, multicentre, randomized controlled trial. Patients with intermittent claudication attending vascular surgery outpatient clinics were randomized (1:1) to receive either neuromuscular electrical stimulation (NMES) or not in addition to local standard care available at study centres (best medical therapy alone or plus supervised exercise therapy (SET)). The objective of this trial was to investigate the clinical efficacy of an NMES device in addition to local standard care in improving walking distances in patients with claudication. The primary outcome was change in absolute walking distance, measured by a standardized treadmill test at 3 months. Secondary outcomes included intermittent claudication (IC) distance, adherence, quality of life, and haemodynamic changes. RESULTS: Of 200 participants randomized, 160 were included in the primary analysis (intention to treat, Tobit regression model). The square root of absolute walking distance was analysed (due to a right-skewed distribution) and, although adjunctive NMES improved it at 3 months, no statistically significant effect was observed. SET as local standard care seemed to improve distance compared to best medical therapy at 3 months (3.29 units; 95 per cent c.i., 1.77 to 4.82; P < 0.001). Adjunctive NMES improved distance in mild claudication (2.88 units; 95 per cent c.i., 0.51 to 5.25; P = 0.02) compared to local standard care at 3 months. No serious adverse events relating to the device were reported. CONCLUSION: Supervised exercise therapy is effective and NMES may provide further benefit in mild IC.This trial was supported by a grant from the Efficacy and Mechanism Evaluation Program, a Medical Research Council and National Institute for Health and Care Research partnership. Trial registration: ISRCTN18242823.Patients with intermittent claudication experience pain in their legs during walking or exercise which ends with rest. This severely impairs physical activity and quality of life. Treatment for such patients typically involves best medical therapy, which includes exercise advice. This study aimed to determine whether a neuromuscular electrical stimulation device improved the walking distance of patients with intermittent claudication compared to local standard care available (which may include supervised exercise therapy) in a trial. Supervised exercise improved walking distances but there was no difference in those that received a device in this patient group
On the similarity of Sturm-Liouville operators with non-Hermitian boundary conditions to self-adjoint and normal operators
We consider one-dimensional Schroedinger-type operators in a bounded interval
with non-self-adjoint Robin-type boundary conditions. It is well known that
such operators are generically conjugate to normal operators via a similarity
transformation. Motivated by recent interests in quasi-Hermitian Hamiltonians
in quantum mechanics, we study properties of the transformations in detail. We
show that they can be expressed as the sum of the identity and an integral
Hilbert-Schmidt operator. In the case of parity and time reversal boundary
conditions, we establish closed integral-type formulae for the similarity
transformations, derive the similar self-adjoint operator and also find the
associated "charge conjugation" operator, which plays the role of fundamental
symmetry in a Krein-space reformulation of the problem.Comment: 27 page
Sex differences in basal hypothalamic anorectic and orexigenic gene expression and the effect of quantitative and qualitative food restriction
Abstract Background Research into energy balance and growth has infrequently considered genetic sex, yet there is sexual dimorphism for growth across the animal kingdom. We test the hypothesis that in the chicken, there is a sex difference in arcuate nucleus neuropeptide gene expression, since previous research indicates hypothalamic AGRP expression is correlated with growth potential and that males grow faster than females. Because growth has been heavily selected in some chicken lines, food restriction is necessary to improve reproductive performance and welfare, but this increases hunger. Dietary dilution has been proposed to ameliorate this undesirable effect. We aimed to distinguish the effects of gut fullness from nutritional feedback on hypothalamic gene expression and its interaction with sex. Methods Twelve-week-old male and female fast-growing chickens were either released from restriction and fed ad libitum or a restricted diet plus 15% w/w ispaghula husk, a non-nutritive bulking agent, for 2 days. A control group remained on quantitative restriction. Hypothalamic arcuate nucleus neuropeptides were measured using real-time PCR. To confirm observed sex differences, the experiment was repeated using only ad libitum and restricted fed fast-growing chickens and in a genetically distinct breed of ad libitum fed male and female chickens. Linear mixed models (Genstat 18) were used for statistical analysis with transformation where appropriate. Results There were pronounced sex differences: expression of the orexigenic genes AGRP (P < 0.001) and NPY (P < 0.002) was higher in males of the fast-growing strain. In genetically distinct chickens, males had higher AGRP mRNA (P = 0.002) expression than females, suggesting sex difference was not restricted to a fast-growing strain. AGRP (P < 0.001) expression was significantly decreased in ad libitum fed birds but was high and indistinguishable between birds on a quantitative versus qualitative restricted diet. Inversely, gene expression of the anorectic genes POMC and CART was significantly higher in ad libitum fed birds but no consistent sex differences were observed. Conclusion Expression of orexigenic peptides in the avian hypothalamus are significantly different between sexes. This could be useful starting point of investigating further if AGRP is an indicator of growth potential. Results also demonstrate that gut fill alone does not reduce orexigenic gene expression
Muscle fiber conduction velocity is more affected after eccentric than concentric exercise
It has been shown that mean muscle fiber conduction velocity (CV) can be acutely impaired after eccentric exercise. However, it is not known whether this applies to other exercise modes. Therefore, the purpose of this experiment was to compare the effects of eccentric and concentric exercises on CV, and amplitude and frequency content of surface electromyography (sEMG) signals up to 24 h post-exercise. Multichannel sEMG signals were recorded from biceps brachii muscle of the exercised arm during isometric maximal voluntary contraction (MVC) and electrically evoked contractions induced by motor-point stimulation before, immediately after and 2 h after maximal eccentric (ECC group, N = 12) and concentric (CON group, N = 12) elbow flexor exercises. Isometric MVC decreased in CON by 21.7 ± 12.0% (± SD, p < 0.01) and by 30.0 ± 17.7% (p < 0.001) in ECC immediately post-exercise when compared to baseline. At 2 h post-exercise, ECC showed a reduction in isometric MVC by 24.7 ± 13.7% (p < 0.01) when compared to baseline, while no significant reduction (by 8.0 ± 17.0%, ns) was observed in CON. Similarly, reduction in CV was observed only in ECC both during the isometric MVC (from baseline of 4.16 ± 0.3 to 3.43 ± 0.4 m/s, p < 0.001) and the electrically evoked contractions (from baseline of 4.33 ± 0.4 to 3.82 ± 0.3 m/s, p < 0.001). In conclusion, eccentric exercise can induce a greater and more prolonged reduction in muscle force production capability and CV than concentric exercis
Study design and baseline characteristics of patients on dialysis in the ASCEND-D trial
BACKGROUND: The Anemia Studies in chronic kidney disease (CKD): Erythropoiesis via a Novel prolyl hydroxylase inhibitor (PHI) Daprodustat-Dialysis (ASCEND-D) trial will test the hypothesis that daprodustat is non-inferior to comparator epoetin alfa or darbepoetin alfa for two co-primary endpoints: haemoglobin efficacy and cardiovascular safety. METHODS: We report the trial design, key demographic, clinical, and laboratory findings, and baseline therapies of 2964 patients randomised in the open-label (sponsor-blinded) active-controlled, parallel-group, randomised ASCEND-D clinical trial. We also compare baseline characteristics of ASCEND-D patients with patients who are on dialysis (CKD G5D) enrolled in other large cardiovascular outcome trials (CVOTs) and in the most relevant registries. RESULTS: The median age of patients was 58 years, 43% were female; 67% were white and 16% were black. The median haemoglobin at baseline was 10.4 g/dL. Among randomised patients, 89% were receiving haemodialysis and 11% peritoneal dialysis. Among key co-morbidities, 42% reported a history of diabetes mellitus, and 45% a history of cardiovascular disease. Median blood pressure was 134/74 mmHg. The median weekly dose of epoetin was 5751 units. Intravenous and oral iron use was noted in 64% and 11% of patients, respectively. Baseline demographics were similar to patients with CKD G5D enrolled in other CVOTs and renal patient registries. CONCLUSION: ASCEND-D will evaluate the efficacy and safety of daprodustat compared with epoetin alfa or darbepoetin alfa in the treatment of patients with anaemia with CKD G5D
Smoking and health-related quality of life in English general population: Implications for economic evaluations
Copyright @ 2012 Vogl et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Little is known as to how health-related quality of life (HRQoL) when measured by generic instruments such as EQ-5D differ across smokers, ex-smokers and never-smokers in the general population; whether the overall pattern of this difference remain consistent in each domain of HRQoL; and what implications this variation, if any, would have for economic evaluations of tobacco control interventions. Methods: Using the 2006 round of Health Survey for England data (n = 13,241), this paper aims to examine the impact of smoking status on health-related quality of life in English population. Depending upon the nature of the EQ-5D data (i.e. tariff or domains), linear or logistic regression models were fitted to control for biology, clinical conditions, socio-economic background and lifestyle factors that an individual may have regardless of their smoking status. Age- and gender-specific predicted values according to smoking status are offered as the potential 'utility' values to be used in future economic evaluation models. Results: The observed difference of 0.1100 in EQ-5D scores between never-smokers (0.8839) and heavy-smokers (0.7739) reduced to 0.0516 after adjusting for biological, clinical, lifestyle and socioeconomic conditions. Heavy-smokers, when compared with never-smokers, were significantly more likely to report some/severe problems in all five domains - mobility (67%), self-care (70%), usual activity (42%), pain/discomfort (46%) and anxiety/depression (86%) -. 'Utility' values by age and gender for each category of smoking are provided to be used in the future economic evaluations. Conclusion: Smoking is significantly and negatively associated with health-related quality of life in English general population and the magnitude of this association is determined by the number of cigarettes smoked. The varying degree of this association, captured through instruments such as EQ-5D, may need to be fed into the design of future economic evaluations where the intervention being evaluated affects (e.g. tobacco control) or is affected (e.g. treatment for lung cancer) by individual's (or patients') smoking status
Quercetin prevents progression of disease in elastase/LPS-exposed mice by negatively regulating MMP expression
Abstract Background Chronic obstructive pulmonary disease (COPD) is characterized by chronic bronchitis, emphysema and irreversible airflow limitation. These changes are thought to be due to oxidative stress and an imbalance of proteases and antiproteases. Quercetin, a plant flavonoid, is a potent antioxidant and anti-inflammatory agent. We hypothesized that quercetin reduces lung inflammation and improves lung function in elastase/lipopolysaccharide (LPS)-exposed mice which show typical features of COPD, including airways inflammation, goblet cell metaplasia, and emphysema. Methods Mice treated with elastase and LPS once a week for 4 weeks were subsequently administered 0.5 mg of quercetin dihydrate or 50% propylene glycol (vehicle) by gavage for 10 days. Lungs were examined for elastance, oxidative stress, inflammation, and matrix metalloproteinase (MMP) activity. Effects of quercetin on MMP transcription and activity were examined in LPS-exposed murine macrophages. Results Quercetin-treated, elastase/LPS-exposed mice showed improved elastic recoil and decreased alveolar chord length compared to vehicle-treated controls. Quercetin-treated mice showed decreased levels of thiobarbituric acid reactive substances, a measure of lipid peroxidation caused by oxidative stress. Quercetin also reduced lung inflammation, goblet cell metaplasia, and mRNA expression of pro-inflammatory cytokines and muc5AC. Quercetin treatment decreased the expression and activity of MMP9 and MMP12 in vivo and in vitro, while increasing expression of the histone deacetylase Sirt-1 and suppressing MMP promoter H4 acetylation. Finally, co-treatment with the Sirt-1 inhibitor sirtinol blocked the effects of quercetin on the lung phenotype. Conclusions Quercetin prevents progression of emphysema in elastase/LPS-treated mice by reducing oxidative stress, lung inflammation and expression of MMP9 and MMP12.http://deepblue.lib.umich.edu/bitstream/2027.42/78260/1/1465-9921-11-131.xmlhttp://deepblue.lib.umich.edu/bitstream/2027.42/78260/2/1465-9921-11-131.pdfPeer Reviewe
The ASCEND-ND trial: Study design and participant characteristics
BACKGROUND: Anaemia is common in chronic kidney disease (CKD), and assessment of the risks and benefits of new therapies is important. METHODS: The Anaemia Study in CKD: Erythropoiesis via a Novel prolyl hydroxylase inhibitor Daprodustat-Non-Dialysis (ASCEND-ND) trial includes adult patients with CKD Stages 3-5, not using erythropoiesis-stimulating agents (ESAs) with screening haemoglobin (Hb) 8-10 g/dL, or receiving ESAs with screening Hb of 8-12 g/dL. Participants were randomised to daprodustat or darbepoetin alfa (1:1) in an open- label trial (steering committee- and sponsor-blinded), with blinded endpoint assessment. The co-primary endpoints are mean change in Hb between baseline and evaluation period (average over Weeks 28 to 52) and time to first adjudicated major adverse cardiovascular (CV) event. Baseline characteristics were compared with those of participants in similar anaemia trials. RESULTS: Overall, 3872 patients were randomised from 39 countries (median age 67 years, 56% female; 56% White, 27% Asian, and 10% Black). Median baseline Hb was 9.9 g/dL, blood pressure was 135/74 mmHg and eGFR was 18 mL/min/1.73 m2. Among randomised patients, 53% were ESA non-users, 57% had diabetes and 37% had a history of CV disease. At baseline, 61% of participants were using renin- angiotensin system blockers, 55% were taking statin and 49% oral iron. Baseline demographics were similar to those in other large non-dialysis anaemia trials. CONCLUSION: ASCEND-ND will define the efficacy and safety of daprodustat compared with darbepoetin alfa in the treatment of patients with anaemia associated with CKD not on dialysis
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