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1.
Br Ir Orthopt J ; 18(1): 111-120, 2022.
Article in English | MEDLINE | ID: mdl-36186145

ABSTRACT

Introduction: In response to the need for easily accessible, high-quality information about nystagmus, the Nystagmus Information Pack was created and made freely available online in 2017. This study was undertaken to evaluate the content and accessibility of the Nystagmus Information Pack. Methods: Clinicians, eye clinic liaison officers (ECLOs), teachers, patients, families, and any person with an interest in nystagmus were invited to complete an online questionnaire about the content and accessibility of the Nystagmus Information Pack. Results: One hundred and sixty respondents completed the questionnaire. Respondents who had previously accessed the Nystagmus Information Pack (n = 49, 30.6%) reported the content was appropriate (86%), of sufficient detail (94%), and easy to understand (88%). Minor suggestions were made to improve the content. Respondents who had not accessed the Nystagmus Information Pack (n = 111, 69.4%) reported not being aware of the resource (90%) but had already accessed nystagmus information from a wide range of sources. Poor vision was a barrier to accessing the resource for a small number of respondents (4.5%). Conclusion: Some improvements to the content and accessibility of the Nystagmus Information Pack should be considered, in particular the format options in which it is available, to enable access in preferred formats and with poor vision. The availability of the Nystagmus Information Pack should be promoted and shared more widely, as the majority of respondents were unaware of the resource despite having an association with or interest in nystagmus.

2.
Strabismus ; 29(2): 74-80, 2021 06.
Article in English | MEDLINE | ID: mdl-33890535

ABSTRACT

To evaluate the effect of monocular blur induced by Bangerter filters (BF) on visual acuity (VA) and stereoacuity. Monocular blur was induced by a range of Trusetal BF strengths (0.1, 0.2, 0.4, 0.6) to 23 visually normal adult volunteers (aged 18-25, mean age 20.33 ± 1.79 years). The right monocular and binocular logMAR VA and distance stereoacuity using the FD2 were measured at 6 m with no filter (baseline) and with each filter strength. The order of testing the filters was randomized. Results were analyzed using one factor repeated measures ANOVAs, t-tests using Bonferroni correction and Pearson's product moment correlation. All filters degraded right monocular distance VA from baseline, but less significantly between the 0.4 and 0.6 filters than the other filters (p < .05 and p < .001, respectively). Degradation was in concordance with the labeled filter density, excluding filter strength 0.4. For all filter strengths, binocular VA was significantly but not clinically reduced from baseline (p < .05). Filters statistically and clinically significantly degraded distance stereoacuity from baseline (p < .001). A significant negative correlation existed between the mean degraded right monocular VA and stereoacuity (r = -0.998, p < .02). Trusetal BF significantly reduced monocular VA and stereoacuity but binocular VA remained within normal levels. The impact on VA and stereoacuity in a normal population can be of clinical relevance when applied to the use of BF for management of amblyopia and intractable diplopia. It is advised that clinicians ensure the desired level of degradation has been achieved in clinic before prescribing a particular filter strength.


Subject(s)
Amblyopia , Adolescent , Adult , Ambulatory Care Facilities , Healthy Volunteers , Humans , Vision, Binocular , Visual Acuity , Young Adult
3.
Br Ir Orthopt J ; 16(1): 19-24, 2020 Apr 15.
Article in English | MEDLINE | ID: mdl-32999989

ABSTRACT

AIM: To investigate if the EyeChart app gives accurate visual acuity (VA) measurements that are comparable to those achieved using traditional VA charts. METHOD: Twenty-four participants (aged 18-27 years, mean 20.13 ± 1.78 years) with VA of 6/60 Snellen or better regardless of any strabismus, amblyopia, or ocular pathology volunteered for this prospective study. The best-corrected monocular VA of each participant's right eye was measured on the Snellen chart at 6 m, the ETDRS chart at 3 m, and the EyeChart app presented on an iPhone SE at 1.2 m (4ft). RESULTS: The mean VA scores obtained were: -0.13 ± 0.08 logMAR on the Snellen chart, -0.11 ± 0.08 logMAR on the ETDRS chart, and -0.09 ± 0.07 logMAR on the EyeChart app. After Bonferroni Correction adjustments were applied, a significant difference was found between the EyeChart app and the Snellen chart (t = -3.756, p = 0.003), however the difference between the EyeChart app and the ETDRS chart did not reach statistical significance (t = -2.391, p = 0.076). The EyeChart app had a strong correlation with both the Snellen (r = 0.79, p < 0.01) and ETDRS charts (r = 0.88, p < 0.01). The Coefficients of Agreement revealed a variation of less than one logMAR line between the EyeChart app and the traditional VA charts (Snellen: 0.09 logMAR; ETDRS: 0.08 logMAR). CONCLUSION: This study found that the EyeChart app gives accurate VA scores that are comparable to those achieved using the gold-standard ETDRS chart in a healthy young adult population. However, the accuracy and repeatability of the EyeChart app when testing a patient population must be investigated before it can be integrated into clinical practice.

4.
Curr Eye Res ; 45(12): 1611-1618, 2020 12.
Article in English | MEDLINE | ID: mdl-32546022

ABSTRACT

PURPOSE: Oscillopsia is a debilitating symptom resulting from involuntary eye movement most commonly associated with acquired nystagmus. Investigating and documenting the effects of oscillopsia severity on visual acuity (VA) is challenging. This paper aims to further understanding of the effects of oscillopsia using a virtual reality simulation. METHODS: Fifteen right-beat horizontal nystagmus waveforms, with different amplitude (1°, 3°, 5°, 8° and 11°) and frequency (1.25 Hz, 2.5 Hz and 5 Hz) combinations, were produced and imported into virtual reality to simulate different severities of oscillopsia. Fifty participants without ocular pathology were recruited to read logMAR charts in virtual reality under stationary conditions (no oscillopsia) and subsequently while experiencing simulated oscillopsia. The change in VA (logMAR) was calculated for each oscillopsia simulation (logMAR VA with oscillopsia - logMAR VA with no oscillopsia), removing the influence of different baseline VAs between participants. A one-tailed paired t-test was used to assess statistical significance in the worsening in VA caused by the oscillopsia simulations. RESULTS: VA worsened with each incremental increase in simulated oscillopsia intensity (frequency x amplitude), either by increasing frequency or amplitude, with the exception of statistically insignificant changes at lower intensity simulations. Theoretical understanding predicted a linear relationship between increasing oscillopsia intensity and worsening VA. This was supported by observations at lower intensity simulations but not at higher intensities, with incremental changes in VA gradually levelling off. A potential reason for the difference at higher intensities is the influence of frame rate when using digital simulations in virtual reality. CONCLUSIONS: The frequency and amplitude were found to equally affect VA, as predicted. These results not only consolidate the assumption that VA degrades with oscillopsia but also provide quantitative information that relates these changes to amplitude and frequency of oscillopsia.


Subject(s)
Nystagmus, Pathologic/physiopathology , Perceptual Disorders/physiopathology , Virtual Reality , Vision Disorders/physiopathology , Visual Acuity/physiology , Adult , Female , Humans , Male , Oscillometry
5.
Br Ir Orthopt J ; 15(1): 47-52, 2019 Apr 11.
Article in English | MEDLINE | ID: mdl-32999974

ABSTRACT

AIM: The aim of this study was to determine and compare test-retest variability (TRV) of the computerised visual acuity (VA) COMPlog system on participants with normal vision and non-normal vision induced by bangerter foils (BFs). METHODS: Twenty adult volunteers with VA of 0.100 logMAR or better in each eye and no eye conditions were included. Monocular VA data using the COMPlog system under five conditions-with plain Plano glasses (visually normal condition) and four pairs of Plano glasses with BF strengths of 0.6, 0.3, 0.2 and 0.1 (induced non-normal vision conditions)-were collected on two separate visits. To reduce bias, the eye tested and order of the BFs assessed were randomised. Data comparison was analysed using 2-factor ANOVA and paired t-tests and Bland Altman analysis to assess TRV. RESULTS: Mean VA score from the two visits was -0.072 ± 0.1 logMAR for Plano, 0.106 ± 0.1 logMAR for BF 0.6, 0.428 ± 0.1 logMAR for BF 0.3, 0.662 ± 0.09 logMAR for BF 0.2 and 0.850 ± 0.08 logMAR for BF 0.1. As BF density increased, VA score significantly worsened (p < 0.0001). Overall mean VA score from the first and second visit was 0.410 ± 0.4 logMAR and 0.379 ± 0.4 logMAR, respectively. This improvement was significant (p < 0.009). The 95% limits of agreement of the VA scores between testing conditions had a range of ±0.120 to ±0.220 logMAR. CONCLUSIONS: Increase in BF strength led to a worsened VA score. However, the COMPlog TRV under the visually normal and induced non-normal vision conditions were within a similar range (±0.120 to ±0.220 logMAR). VA significantly improved on the second visit, suggesting a possible learning effect, which could have a clinical impact.

6.
Br Ir Orthopt J ; 15(1): 115-124, 2019 Jul 04.
Article in English | MEDLINE | ID: mdl-32999982

ABSTRACT

BACKGROUND/AIMS: Computer games have been used to stimulate vision in amblyopia with varying degrees of success. The aim of this pilot study was to evaluate the feasibility of conducting a randomised controlled trial to test the effectiveness of computer game play compared to close work during occlusion treatment in children. METHOD: Children aged 2-7 years with amblyopia and no prior amblyopia treatment were invited to participate. Participants were randomised to a computer game group or close work group and asked to complete two hours occlusion per day, incorporating one hour of their allocated activity. LogMAR visual acuity (VA) was assessed before treatment commenced and after 7(±1) weeks. The same examiner, who was unaware of the allocated treatment, assessed the participant using the same VA test. RESULTS: Eighteen participants (mean age of 4.2 ± 1.3 years) completed the study. After seven weeks the mean VA of the amblyopic eye in the computer game group improved by 0.147 ± 0.182 logMAR, and in the close work group improved by 0.181 ± 0.124 logMAR. The difference in VA improvement between the computer game and the close work groups was not statistically significant (F(1,32) = 3.71; p = 0.06). CONCLUSION: No significant difference was found in visual outcomes between the two groups, but a larger sample size would be needed to draw conclusions regarding the amblyopic population. Evaluation of the study design suggests it would be feasible to conduct a randomised controlled trial comparing computer games and close work during occlusion to determine if a significant difference in visual outcome exists.

7.
Br Ir Orthopt J ; 14(1): 25-29, 2018 May 10.
Article in English | MEDLINE | ID: mdl-32999961

ABSTRACT

AIMS: The aims of this study were to evaluate the current provision of patient information about nystagmus in orthoptic clinics in the UK and Ireland and to develop a standardised information pack about nystagmus. METHODS: A questionnaire was circulated to orthoptists in the UK and Ireland asking whether they had information to provide to patients with nystagmus, what was included in this information and how it could be improved. Orthoptists were also asked what should be included in a standardised information pack about nystagmus. RESULTS: Two hundred and thirty three orthoptists completed the questionnaire. One-third of responding orthoptists did not have information to provide to patients with nystagmus. Most reported the information available to them included details of support services and physical symptoms. Including information about living with nystagmus at different ages and long-term prognosis were the most common suggestions to improve information about nystagmus. More than half of orthoptists selected all the suggested topics to be included in a standardised information pack, with support services and long-term prognosis most frequently selected. CONCLUSIONS: Only 67% of responding orthoptists had information about nystagmus to give to patients or their families. Ways to improve the current information and content considered important by orthoptists were taken into account to create a nystagmus information pack, which is now available online.

8.
Br Ir Orthopt J ; 14(1): 45-49, 2018 Jun 19.
Article in English | MEDLINE | ID: mdl-32999964

ABSTRACT

PURPOSE: Nystagmus is characterised by involuntary eye movement. A proportion of those with nystagmus experience the world constantly in motion as their eyes move: a symptom known as oscillopsia. Individuals with oscillopsia can be incapacitated and often feel neglected due to limited treatment options. Effective communication of the condition is challenging and no tools to aid communication exist. This paper describes a virtual reality (VR) application that recreates the effects of oscillopsia, enabling others to appreciate the condition. METHODS: Eye tracking data was incorporated into a VR oscillopsia simulator and released as a smartphone app - "Nystagmus Oscillopsia Sim VR". When a smartphone is used in conjunction with a Google Cardboard headset, it presents an erratic image consistent with oscillopsia. The oscillopsia simulation was appraised by six participants for its representativeness. These individuals have nystagmus and had previously experienced oscillopsia but were not currently symptomatic; they were therefore uniquely placed to judge the app. The participants filled in a questionnaire to record impressions and the usefulness of the app. RESULTS: The published app has been downloaded ~3700 times (28/02/2018) and received positive feedback from the nystagmus community. The validation study questionnaire scored the accuracy of the simulation an average of 7.8/10 while its ability to aid communication received 9.2/10. CONCLUSION: The evidence indicates that the simulation can effectively recreate the sensation of oscillopsia and facilitate effective communication of the symptoms associated with the condition. This has implications for communication of other visual conditions.

9.
Br Ir Orthopt J ; 14(1): 56-63, 2018 Oct 09.
Article in English | MEDLINE | ID: mdl-32999966

ABSTRACT

PURPOSE: Evaluation of the students' experience and academic achievements following the introduction of online learning. METHODS AND MATERIALS: In 2011, online learning activities were introduced in the teaching of the Research in Orthoptics module for final year undergraduate orthoptic students. The online learning activities were created and delivered in Moodle; an open-source online learning platform. Students from the academic year groups of 2012-13, 2013-14 and 2016-17 completed an online questionnaire. The questionnaire was divided into 6 categories (relevance, reflection, interactivity, tutor support, peer support and interpretation) with 4 questions within each category. A 5-point Likert scale was used to score each question. The sum of answers within each category ranged from 4 (negative perception) to 20 (positive perception). Student performance was assessed using the marks retrospectively for 2 years before online learning was introduced and when online learning was included. RESULTS: Forty-two students replied to the questionnaire with a mean age of 23.0 ± 2.3 years (range 21-32). There were 38 females (90.5%) and 4 males (9.5%). Combining the 3 academic cohorts there was a significant difference between the 6 categories of the questionnaire (p < 0.0001). Three categories obtained the same high median score of 16: relevance (range 9-20), reflection (range 11-20) and tutor support (range 12-20). Peer support resulted in the lowest median score of 13. Separation of the three academic year cohorts' revealed significant differences for tutor support (p = 0.03). The score increased from 16 in 2012-13 and 2013-14 to 18 in 2016-17. Significant differences were found between the marks for the cohorts from 2009-10 to 2016-17 (F7,245 = 5.07: p < 0.0001). The mean mark for year group 2009-2010 was significantly less compared to 2012-13 (p < 0.0001), 2014-15 (p = 0.01) and 2015-16 (p = 0.02) and year group 2011-12's mark significantly less than 2012/13 (p = 0.001). CONCLUSIONS: Including online learning in the research module had a positive impact on the student experience, although more work needs to be done to improve peer support. Marks obtained by the orthoptic students have improved since the introduction of online learning suggesting that a mixture of teaching and learning methods is beneficial for students. However, more work needs to be done to provide teacher assistance in the design of online learning and blended learning approach.

10.
J Appl Phycol ; 29(6): 3121-3137, 2017.
Article in English | MEDLINE | ID: mdl-29213185

ABSTRACT

Fucoidans are sulphated fucose-rich polysaccharides predominantly found in the cell walls of brown algae. The bioactive properties of fucoidans attract increasing interest from the medico-pharmaceutical industries and may drive an increase in demand of brown algae biomass. In nature, the biochemical composition of brown algae displays a seasonal fluctuation driven by environmental factors and endogenous rhythms. To cultivate and harvest kelps with high yields of fucoidans, knowledge is needed on seasonal variation and impact of environmental conditions on the fucoidan content of brown algae. The relations between the fucoidan content and key environmental factors (irradiance, nutrient availability, salinity and exposure) were examined by sampling natural populations of the common North Atlantic kelps, Saccharina latissima and Laminaria digitata, over a full year at Hanstholm in the North Sea and Aarhus in the Kattegat. In addition, laboratory experiments were carried out isolating the effects of the single factors. The results demonstrated that (1) seasonal variation alters the fucoidan content by a factor of 2-2.6; (2) interspecific differences exist in the concentrations of crude fucoidan (% of dry matter): L. digitata (11%) > S. latissima (6%); and (3) the effects of single environmental factors were not consistent between species or between different conspecific populations. The ambiguous response to single environmental factors complicates prospective directions for manipulating an increased content of fucoidan in a cultivation scenario and emphasizes the need for knowledge on performance of local kelp ecotypes.

11.
Int J Mol Sci ; 18(10)2017 Sep 30.
Article in English | MEDLINE | ID: mdl-28973963

ABSTRACT

Bio-plastics and bio-materials are composed of natural or biomass derived polymers, offering solutions to solve immediate environmental issues. Polysaccharide-based bio-plastics represent important alternatives to conventional plastic because of their intrinsic biodegradable nature. Amylose-only (AO), an engineered barley starch with 99% amylose, was tested to produce cross-linked all-natural bioplastic using normal barley starch as a control. Glycerol was used as plasticizer and citrate cross-linking was used to improve the mechanical properties of cross-linked AO starch extrudates. Extrusion converted the control starch from A-type to Vh- and B-type crystals, showing a complete melting of the starch crystals in the raw starch granules. The cross-linked AO and control starch specimens displayed an additional wide-angle diffraction reflection. Phospholipids complexed with Vh-type single helices constituted an integrated part of the AO starch specimens. Gas permeability tests of selected starch-based prototypes demonstrated properties comparable to that of commercial Mater-Bi© plastic. The cross-linked AO prototypes had composting characteristics not different from the control, indicating that the modified starch behaves the same as normal starch. The data shows the feasibility of producing all-natural bioplastic using designer starch as raw material.


Subject(s)
Amylose/chemistry , Biodegradable Plastics/chemistry , Citric Acid/chemistry , Cross-Linking Reagents/chemistry , Hordeum/chemistry , Crystallization , Glycerol/chemistry , Permeability , Phase Transition , Plants, Genetically Modified/chemistry , Plasticizers/chemistry , Starch/chemistry
12.
Bioresour Technol ; 238: 16-21, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28432948

ABSTRACT

Seaweed represents an abundant, renewable, and fast-growing biomass resource for 3rd generation biofuel production. This study reports an efficient butanol fermentation process carried out by Clostridium beijerinckii DSM-6422 using enzymatic hydrolysate of the sugar-rich brown seaweed Laminaria digitata harvested from the coast of the Danish North Sea as substrate. The highest butanol yield (0.42g/g-consumed-substrates) compared to literature was achieved, with a significantly higher butanol:acetone-butanol-ethanol (ABE) molar ratio (0.85) than typical (0.6). This demonstrates the possibility of using the seaweed L. digitata as a potential biomass for butanol production. For the first time, consumption of alginate components was observed by C. beijerinckii DSM-6422. The efficient utilization of sugars and lactic acid further highlighted the potential of using this strain for future development of large-scale cost-effective butanol production based on (ensiled) seaweed.


Subject(s)
Clostridium beijerinckii , Fermentation , Laminaria , Seaweed , Acetone , Butanols , Clostridium , Ethanol
13.
Ugeskr Laeger ; 179(15)2017 Apr 10.
Article in Danish | MEDLINE | ID: mdl-28416051

ABSTRACT

We describe a case of mirror syndrome. A 41-year-old woman, para 4, was referred to hospital at 32 weeks of gestational age with excessive oedema. She developed oliguria, mild hypertension and proteinuria. Fetal ultrasound confirmed severe hydrops fetalis. Intrauterine pleural drainage was performed without improvement of the condition. Since maternal symptoms worsened, a caesarean section was performed at 34 weeks with delivery of a live hydropic girl who died after 17 hours. Maternal symptoms decreased four days after delivery with full recovery two weeks post-partum.


Subject(s)
Edema/diagnosis , Hydrops Fetalis/diagnostic imaging , Pregnancy Complications , Adult , Cesarean Section , Female , Humans , Perinatal Death , Pregnancy , Pregnancy Complications/diagnosis , Pregnancy Complications/therapy , Syndrome , Ultrasonography, Prenatal
14.
Acta Radiol ; 58(8): 997-1004, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28273731

ABSTRACT

Background Due to improved ultrasound scanners, new three-dimensional (3D) modalities, and novel Anti-Müllerian hormone (AMH)-assays, the ultrasound criteria for polycystic ovarian morphology are under debate and the appropriate thresholds are often requested. Purpose To quantify the differences in estimates of ovarian volume and antral follicle count (AFC) from two-dimensional (2D) and 3D transvaginal ultrasound (TVUS) and magnetic resonance imaging (MRI). Material and Methods A cross-sectional study on 66 overweight women with polycystic ovary syndrome (PCOS) according to Rotterdam criteria. Ovarian volume and AFC were estimated from MRI, 2D TVUS, and 3D TVUS, and serum AMH levels were assessed. Bland-Altman statistics were used for comparison. Results Participants had a median age of 29 years (age range, 19-44 years) with a mean BMI of 32.7 kg/m2 (SD 4.5). Ovarian volume from 2D TVUS was 1.48 mL (95% confidence interval [CI], 0.94-2.03; P < 0.001) and 1.25 mL (95% CI, 0.62-1.87; P < 0.001) smaller than from 3D TVUS and MRI, respectively. AFC from 2D TVUS was 18% (95% CI, 13-23; P < 0.005) and 16% (95% CI, 6-25; P < 0.005) smaller than estimates from 3D TVUS and MRI, respectively. Correlations between AMH and AFC from 2D TVUS, 3D TVUS, and MRI were 0.67, 0.78, and 0.70, respectively ( P < 0.001 for all). Conclusion In an overweight PCOS population, 2D TVUS underestimated ovarian volume and AFC as compared with 3D TVUS and MRI. Serum AMH correlated best with AFC from 3D TVUS, followed by MRI and 2D TVUS. The advantage of 3D TVUS might be of minor clinical importance when diagnosing PCOS, but useful when the actual AFC are of interest, e.g. in fertility counseling and research.


Subject(s)
Anti-Mullerian Hormone/blood , Magnetic Resonance Imaging/methods , Polycystic Ovary Syndrome/blood , Polycystic Ovary Syndrome/diagnostic imaging , Ultrasonography/methods , Adult , Biomarkers/blood , Cross-Sectional Studies , Female , Humans , Ovarian Follicle/diagnostic imaging , Overweight
15.
AMB Express ; 5(1): 80, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26695947

ABSTRACT

Solid state fermentation of cassava residue with Trichoderma pseudokoningii was conducted for 12 days. The fermentation was carried out at temperature of 24 °C and a pH of 5.0. Urea and ammonium sulphate were used as nutrient sources and moisture content varied at 60 and 70 %. Protein content of the unfermented cassava residue was increased from 8.4 to 12.5 % when urea was used with initial moisture content of 70 % w/v. This study showed that a maximum of 48.1 % protein enrichment was achieved using urea as a source of nutrient for the growth of the fungi, whiles ammonium sulphate achieved 36.9 % protein enrichment under the same condition.

16.
Bioresour Technol ; 197: 310-7, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26342344

ABSTRACT

A wild-growing glucose-rich (i.e. 56.7% glucose content) brown seaweed species Laminaria digitata, collected from the North Coast of Denmark in August 2012, was used as the feedstock for an integrated bioethanol and protein production. Glutamic acid and aspartic acid are the two most abundant amino acids in the algal protein, both with proportional content of 10% in crude protein. Only minor pretreatment of milling was used on the biomass to facilitate the subsequent enzymatic hydrolysis and fermentation. The Separate Hydrolysis and Fermentation (SHF) resulted in obviously higher ethanol yield than the Simultaneous Saccharification and Fermentation (SSF). High conversion rate at maximum of 84.1% glucose recovery by enzymatic hydrolysis and overall ethanol yield at maximum of 77.7% theoretical were achieved. Protein content in the solid residues after fermentation was enriched by 2.7 fold, with similar distributions of amino acids, due to the hydrolysis of polymers in the seaweed cell wall matrix.


Subject(s)
Algal Proteins/metabolism , Ethanol/metabolism , Laminaria/chemistry , Biomass , Denmark , Fermentation , Glucose/metabolism , Hydrolysis , Laminaria/metabolism , Seaweed/chemistry , Seaweed/metabolism
17.
AMB Express ; 5(1): 60, 2015 Dec.
Article in English | MEDLINE | ID: mdl-26384340

ABSTRACT

Enzymatic hydrolysis of cassava peels was evaluated using cellulase and beta-glucanase enzymes and their mixtures at three different enzyme loadings with time. The pH of the medium used for hydrolysis was 5 and the temperature was 50 °C. The efficiency of the hydrolysis using beta-glucanase was better than cellulase and glucose recovery of 69 % was realised when beta-glucanase dosage was increased to 10 % (v/w) at 48 h which rose to 73 % at 120 h, releasing 11.19 g/l and 12.17 g/l of glucose respectively. Less than 20 % of glucose was hydrolysed at 10 % (v/w) cellulase at 120 h releasing 2.6 g/l glucose. The optimum experimental condition for hydrolysis of cassava peel was established at 120 h when glucose recovery increased to 88 % for enzyme mixture of 5 % (v/w) cellulase + 10 % (v/w) beta-glucanase producing 14.67 g/l glucose in the hydrolysate.

18.
Neuroophthalmology ; 38(4): 189-198, 2014.
Article in English | MEDLINE | ID: mdl-27928298

ABSTRACT

Normative visual field area, feasibility and repeatability using (Octopus) semi-automated kinetic perimetry are reported in 221 healthy volunteers aged 5-22 years. I4e and I2e stimuli assessed the visual field at 5°/second (°/s) or 3°/s. Blind spot was assessed with I2e at 2°/s. Reliable visual fields were plotted in 23% of participants <10 years, 64% of 10-12-year-olds, and 98% aged 13-22 years. Visual field areas were unchanged with age using 5°/s, but increased using 3°/s for I2e (p = 0.028). Blind spot area was unchanged with age. Reaction times reduced with age (p < 0.004). There was no learning effect. A test speed of 5°/s is recommended.

19.
Bioresour Technol ; 140: 36-42, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23672937

ABSTRACT

A qualified estimate for pretreatment of the macroalgae Chaetomorpha linum for ethanol production was given, based on the experience of pretreatment of land-based biomass. C. linum was subjected to hydrothermal pretreatment (HTT), wet oxidation (WO), steam explosion (STEX), plasma-assisted pretreatment (PAP) and ball milling (BM), to determine effects of the pretreatment methods on the conversion of C. linum into ethanol by simultaneous saccharification and fermentation (SSF). WO and BM showed the highest ethanol yield of 44 g ethanol/100g glucan, which was close to the theoretical ethanol yield of 57 g ethanol/100g glucan. A 64% higher ethanol yield, based on raw material, was reached after pretreatment with WO and BM compared with unpretreated C. linum, however 50% of the biomass was lost during WO. Results indicated that the right combination of pretreatment and marine macroalgae, containing high amounts of glucan and cleaned from salts, enhanced the ethanol yield significantly.


Subject(s)
Biofuels , Biotechnology/methods , Ethanol/metabolism , Seaweed/metabolism , Biomass , Carbohydrates/analysis , Fermentation/drug effects , Hydrolysis/drug effects , Oxidation-Reduction/drug effects , Plasma Gases/pharmacology , Seaweed/chemistry , Seaweed/drug effects , Steam , Temperature , Water/pharmacology
20.
Appl Biochem Biotechnol ; 166(8): 2051-63, 2012 Apr.
Article in English | MEDLINE | ID: mdl-22415783

ABSTRACT

Plasma-assisted pretreated wheat straw was investigated for cellulase and xylanase production by Trichoderma reesei fermentation. Fermentations were conducted with media containing washed and unwashed plasma-assisted pretreated wheat straw as carbon source which was sterilized by autoclavation. To account for any effects of autoclavation, a comparison was made with unsterilized media containing antibiotics. It was found that unsterilized washed plasma-assisted pretreated wheat straw (which contained antibiotics) was best suited for the production of xylanases (110 IU ml(-1)) and cellulases (0.5 filter paper units (FPU) ml(-1)). Addition of Avicel boosted enzyme titers with the highest cellulase titers (1.5 FPU ml(-1)) found with addition of 50 % w/w Avicel and with the highest xylanase production (350 IU ml(-1)) reached in the presence of 10 % w/w Avicel. Comparison with enzyme titers from other nonrefined feedstocks suggests that plasma pretreated wheat straw is a promising and suitable substrate for cellulase and hemicellulase production.


Subject(s)
Cellulase/biosynthesis , Endo-1,4-beta Xylanases/biosynthesis , Plasma Gases/chemistry , Trichoderma/metabolism , Triticum/chemistry , Acetates/chemistry , Carbohydrates/chemistry , Fermentation
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