Oxygen supply and consumption in soilless culture: evaluation of an oxygen simulation model for cucumber

A soil oxygen simulation model (OXSI) was tested and evaluated for evaluating growing media with respect to aeration. In the model, local oxygen concentrations are calculated from coefficients of diffusion and consumption (respiration), assuming equilibrium conditions. Apparent oxygen diffusion coefficients (D) were determined under laboratory conditions in 5 cm high samples at different water contents (-3.2, -10 and -20 cm pressure heads). D values were positively related to air-filled porosity (AFP). For fine-graded perlite D ranged from 9.10-7 at AFP of 34 percent to 5.10-9 m2s-1 at AFP of 19 percent. Possibly due to absence of closed pores in rockwool, the AFP vs. D relation was different for rockwool compared to perlite: D for rockwool ranged from 2.10-6 at AFP of 56 percent to 3.10-9 m2s-1 at AFP of 3 percent. A greenhouse experiment with cucumber was carried out to determine respiration and realised oxygen concentrations. The cucumbers were grown in 20 cm high, 3.5 litre containers filled with fine-graded perlite and supplied with high-frequency irrigation. AFP varied between 25 and 45 percent. At three heights and on four occasions during growth, oxygen concentration ( f volume) in the medium varied between 16.6 and 20 n the perlite. Root respiration of the cucumbers as determined by two independent methods (in vivo and in vitro) ranged from 1.4 to 5.4 10-6 ml.ml-1.s-1. Using these respiration rates, OXSI calculated that no oxygen depletion may occur at D > 1 to 5 10-7 m2s-1, corresponding with an AFP of 30 percent for both perlite and rockwool. Anoxic condtions were calculated for D values of 10-8 m2s-1, corresponding with AFP below 10 percent for rockwool and 20 percent for perlite

Prevalence of Escherichia coli O157:H7 in beef cattle at slaughter and beef carcasses at retail shops in Ethiopia

Background: There is paucity of information regarding the epidemiology of Escherichia coli O157: H7 in developing countries. In this study, we investigated the occurrence of E. coli O157: H7 associated with beef cattle at processing plants and at retail shops in Ethiopia. Methods: Various samples were collected from beef cattle at slaughter/processing plants, carcass at retail shops and humans at health centers. E. coli O157: H7 was isolated, identified and characterized for antimicrobial resistance, using standard microbiological methods. Results: At the processing plants E. coli O157: H7 was detected in 1.89% of fecal, 0.81% of intestinal mucosal swab, 0.54% of skin swab and 0.54% of carcass internal swab samples. At retail shops it was detected in 0.8% of carcass and 0.8% of cutting board swab samples, while all samples from utensils, hands from workers, and fecal and stool samples were negative. All isolates were resistant to Amoxicillin, moderately resistant to Cefoxitine and Nitrofurantoins but susceptible to other antimicrobials tested. Conclusions: E. coli O157: H7 occurs at low prevalence in beef cattle, and the current sanitary dressing procedures in the processing plants and storage conditions in the retail shops are effective against E. coli O157: H7

Indoor Air Quality Design and Control in Low-Energy Residential Buildings, International Energy Agency, EBC Annex 68, Subtask 5 Final Report: Field measurements and case studies

IEA-EBC Annex 68: Indoor Air Quality Design and Control in Low Energy Residential Buildings investigates how to ensure that future low energy buildings are able to improve their energy performance while still providing comfortable and healthy indoor environments. More specifically, Subtask 5 of Annex 68 has dealt with generation of data for the verification of the models and strategies developed in the other Annex 68 Subtasks through controlled field tests and case study presentations

Epilation for minor trachomatous trichiasis: four-year results of a randomised controlled trial.

BACKGROUND: Trachomatous trichiasis (TT) needs to be managed to reduce the risk of vision loss. The long-term impact of epilation (a common traditional practice of repeated plucking of lashes touching the eye) in preventing visual impairment and corneal opacity from TT is unknown. We conducted a randomized controlled trial of epilation versus surgery for the management of minor TT (fewer than six lashes touching the eye) in Ethiopia. Here we report the four-year outcome and the effect on vision and corneal opacity. METHODOLOGY/ PRINCIPAL FINDINGS: 1300 individuals with minor TT were recruited and randomly assigned to quality trichiasis surgery or repeated epilation using high quality epilation forceps by a trained person with good near vision. Participants were examined six-monthly for two-years, and then at four-years after randomisation. At two-years all epilation arm participants were offered free surgery. At four-years 1151 (88.5%) were re-examined: 572 (88%) and 579 (89%) from epilation and surgery arms, respectively. At that time, 21.1% of the surgery arm participants had recurrent TT; 189/572 (33%) of the epilation arm had received surgery, while 383 (67%) declined surgery and had continued epilating ("epilation-only"). Among the epilation-only group, 207 (54.1%) fully controlled their TT, 166 (43.3%) had minor TT and 10 (2.6%) had major TT (>5 lashes). There were no differences between participants in the epilation-only, epilation-to-surgery and surgery arm participants in changes in visual acuity and corneal opacity between baseline and four-years. CONCLUSIONS/ SIGNIFICANCE: Most minor TT participants randomised to the epilation arm continued epilating and controlled their TT. Change in vision and corneal opacity was comparable between surgery and epilation-only participants. This suggests that good quality epilation with regular follow-up is a reasonable second-line alternative to surgery for minor TT for individuals who either decline surgery or do not have immediate access to surgical treatment

Oral doxycycline for the prevention of postoperative trachomatous trichiasis in Ethiopia: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Trachomatous trichiasis is treated surgically to prevent sight loss. Unfavourable surgical outcomes remain a major challenge. We investigated the hypothesis that doxycycline might reduce the risk of postoperative trichiasis following surgery in patients with trachomatous trichiasis through anti-matrix metalloproteinase and anti-inflammatory activity. METHODS: In this randomised, double-blind, placebo-controlled trial, adults (aged >18 years) with upper lid trachomatous trichiasis in association with tarsal conjunctive scarring were recruited through community-based screening and surgical outreach campaigns in Ethiopia. Individuals who had previously had eyelid surgery were excluded. Participants were randomly assigned (1:1), with random block sizes of four or six, to receive oral doxycycline (100 mg once a day) or placebo for 28 days immediately after trichiasis surgery. Randomisation was stratified by surgeon. Patients, investigators, surgeons, and all other study team members were masked to study group allocation and treatment. Participants were examined at 10 days, and 1, 6, and 12 months after surgery. The primary outcome was the cumulative proportion of individuals who developed postoperative trichiasis by 12 months. Primary analyses were done in all participants who attended at least one of the four follow-up assessments. Safety analyses were done in all participants who attended either the 10 day or 1 month follow-up assessments. This trial is registered with the Pan African Clinical Trials Registry, number PACTR201512001370307. FINDINGS: Between Dec 21, 2015, and April 6, 2016, 1000 patients with trichiasis were enrolled and randomly assigned to treatment (499 patients to doxycycline, 501 patients to placebo). All but one participant attended at least one follow-up assessment. Thus, 999 participants were assessed for the primary outcome: 498 in the doxycycline group and 501 in the placebo group. By month 12, 58 (12%) of 498 patients in the doxycycline group and 62 (12%) of 501 patients in the placebo group had developed postoperative trichiasis (adjusted odds ratio 0·91, 95% CI 0·61 to 1·34, p=0·63), with a risk difference of -0·5% (-4·5% to 3·5%). Significantly more patients in the doxycycline group had an adverse event than in the placebo group (18 [4%] of 498 vs six [1%] of 501; odds ratio 3·09, 95% CI 1·21-7·84; p=0·02). The most frequent adverse events in the doxycycline group were gastritis symptoms (n=9), constipation (n=4), and diarrhoea (n=4). INTERPRETATION: Doxycycline did not reduce the risk of postoperative trichiasis and is therefore not indicated for the improvement of outcomes following trachomatous trichiasis surgery. Surgical programmes should continue to make efforts to strengthen surgical training and supervision to improve outcomes. FUNDING: The Wellcome Trust

Posterior lamellar versus bilamellar tarsal rotation surgery for trachomatous trichiasis: Long-term outcomes from a randomised controlled trial.

BACKGROUND: We re-examined the participants of a clinical trial four years after enrolment to identify which of the two most commonly used eyelid surgery procedures to treat the blinding stage of trachoma (trachomatous trichiasis, TT), the posterior Lamellar Tarsal Rotation (PLTR) and Billamelar Tarsal Rotation (BLTR), gives better results in the long-term. METHODS: A randomised, controlled, single masked clinical trial was done in Ethiopia. At baseline, adults (aged >18 years with upper lid unoperated TT were recruited from a community-based screening. Participants were randomly assigned (1:1), to either BLTR or PLTR surgery, stratified by surgeon. At 4 years an independent assessor masked to allocation examined the trial participants' eyes using the same procedures as for the baseline and earlier follow-ups. The primary outcome was the proportion of individuals who had recurrence (postoperative TT, PTT) at the 4-year examination, or a history of repeat surgery in the 4-year period. The intervention effect was estimated by logistic regression, controlled for surgeon as a fixed effect in the model. The trial is registered with the Pan African Clinical Trials Registry (number PACTR201401000743135). FINDINGS: 1000 participants with TT were enrolled, randomly assigned, and treated (501 in the BLTR group and 499 in the PLTR group) between Feb 13, 2014, and May 31, 2014. At year 4, 943 (94.3%) participants were re-examined (471, PLTR; 472, BLTR) and included in the primary outcome analysis. PTT had developed in 169/943 (17•9%) study eyes, among which 129 (76•3%) had minor trichiasis (≤5 lashes touching the eye). PTT was significantly more frequent at 4-year in the BLTR arm (105/472 [22•2%]) than the PLTR arm (64/471 [13•6%]), adjusted OR 1•82 (95% CI, 1•29-2•56); p = 0•0006, with 8•6% (95%CI 3•8-13•5) risk difference. INTERPRETATION: The PLTR surgical procedure had superior long-term outcomes to the BLTR with significantly lower risk of PTT supporting the current WHO guideline that the PLTR should be the procedure of choice for training new surgeons in the programmatic management of TT

Characterising the discharge cycle of CaCl 2 and LiNO 3 hydrated salts within a vermiculite composite scaffold for thermochemical storage

Transpired solar collectors (TSC) are an efficient means of building heating but due to the demand/use mismatch their capabilities are maximised when paired with a suitable storage technology. The Hydration and/dehydration of inorganic salts provides an appropriate energy storage medium which is compatible with the air temperature provided by a conventional TSC (<70 °C). The study reports on technical appraisal of materials which are compatible with building scale energy storage installations. Two salts (CaCl2, and LiNO3) were impregnated into porous vermiculite to form a salt in matrix (SIM). Their performance during the discharge portion of the cycle at high packing density was examined using a laboratory scale reactor. Reactor and exit temperature increases were considerably lower than those predicted from first principles. Peak reactor temperature rises of only 14 °C were observed with a reduction in temperature output from this initial peak over 60 hours. Poor salt utilization resulting from deliquescence near the reactor inlet was identified as being the source of the reduced performance. Changes in reactor size, orientation and cycling between input periods of moist and dry air did not improve reactor performance. The investigation has identified that moist air transit through the packed SIM reactor column is limited to approximately 100 mm from the air inlet. This has implications for reactor design and the operation of any practical building scale installation. Predictions of building scale energy storage capabilities based on simple scaling of laboratory test considerably under estimate the volume and complexity of equipment required

Effect of repeated epilation for minor trachomatous trichiasis on lash burden, phenotype and surgical management willingness: A cohort study.

BACKGROUND: WHO endorsed the use of epilation as an alternative treatment to surgery for the management of both minor unoperated TT (UTT) and postoperative TT (PTT). However, some trachoma control programmes hesitated to implement epilation citing concerns that it would hamper TT surgical acceptance and result in larger numbers of and stiffer trichiatic eyelashes than the original TT lashes. We investigated the burden and phenotypes of post-epilation trichiatic eyelashes, and willingness to accept surgical management separately in unoperated and postoperative TT cases. METHODOLOGY/PRINCIPAL FINDINGS: We recruited cases with minor (≤5 eyelashes from the upper eyelid touching the eye or evidence of epilation in <1/3rd of the upper eyelid) UTT (170) and PTT (169) from community-based screenings in Amhara Region, Ethiopia. Participants eyes were examined and data on present and future willingness to accept surgical management collected at baseline and every month for 6-months. Eyelashes touching the eye were counted and their phenotypes documented. Participants were trained on how to epilate. Epilation was done by the participants at home and by the examiner during follow-ups when requested by the participant. Follow-up rates were ≥97%. There was evidence of a significant reduction in the burden of trichiatic eyelashes in unoperated (mean difference = -0.90 [-1.11- -0.69]; RR = 0.50 [95% CI, 0.40-0.62]; p<0.0001), and postoperative (mean difference = -1.16 [-1.36- -0.95]; RR = 0.38 [95% CI, 0.31-0.48]; p<0.0001) cases 6-month after frequent epilation. Post-epilation trichiatic eyelashes at 6-months had higher odds of being thin (40.2% vs 55.8%, OR = 1.88 [95% CI, 1.21-2.93]; p = 0.0048), weak (39.8% vs 70.8%, OR = 3.68 [95%CI,2.30-5.88]; p<0.0001), and half-length (30.9% vs 43.3%, OR = 1.71 [1.09-2.68]; p = 0.020) than the pre-epilation trichiatic eyelashes in unoperated cases. There was a significant increase in the proportion of weak trichiatic eyelashes (OR = 1.99 [95% CI, 1.03-3.83; p = 0.039) in postoperative cases. In all 6 follow-up time points, 120/164 (73.2%) of unoperated and 134/163 (82.2%) of postoperative cases indicated that they would accept surgery if their trichiasis progressed. CONCLUSIONS/SIGNIFICANCE: In this study setting, frequent epilation neither hampers surgical acceptance nor results in more damaging trichiatic eyelashes than the pre-epilation lashes; and can be used as an alternative to the programmatic management of minor unoperated and postoperative TT cases

3D images as a field grader training tool for trachomatous trichiasis: A diagnostic accuracy study in Ethiopia.

BACKGROUND: Trachomatous trichiasis (TT) will continue to develop among those people who have had repeated infections after active trachoma is controlled. Detecting and treating affected individuals will remain necessary for years; a long "tail" of incident cases is anticipated. As the prevalence of TT declines, there will be fewer cases available for training trachoma graders (TG), necessitating alternative methods. METHODOLOGY/PRINCIPAL FINDINGS: Prospective, diagnostic accuracy study assessing sensitivity and specificity of 3D and 2D photography as a tool for training TG to detect TT. Individuals with TT in Ethiopia were examined, and 2D and 3D clinical images taken. Images were independently graded by four graders for presence or absence of trichiasis and compared to field grading. We recruited 153 participants. Clinical assessments and images were available for 306 eyes. Trichiasis was identified in 204 eyes by field grading. Image grading was performed on a selection of 262 eyes (131 with trichiasis). Most eyes with trichiasis had minor trichiasis (94/131). Pooled sensitivity was 88.3% (3D) and 98.0% (2D); pooled specificity was 59.8% (3D) and 26.8% (2D). 3D photo grading was 33.0% more specific than the 2D photo grading (p = 0.0002). The overall Kappa scores were 0.48 (3D) and 0.25 (2D). We trained 26 novice TG in Ethiopia using 3D images. They were tested on a 3D images set and had 71.4% agreement (kappa 0.46), relative to an expert. They were then tested examining 50 people, and had 86.8% agreement (kappa 0.75). We also tested 27 experienced TG on the same cases (86.4% agreement, kappa 0.75). There was no difference in performance between groups (p = 0.76). All participants preferred 3D over 2D images for training. CONCLUSIONS/SIGNIFICANCE: The slightly higher sensitivity of 2D photos comes at considerable cost in specificity. Training with 3D images enabled novice TG to identify cases as well as experienced TG. 3D were preferred to conventional 2D photos for training. Standardized 3D images of TT could be a useful tool for training TG, in settings where there are now few TT cases

Capacity of health facilities for diagnosis and treatment of HIV/AIDS in Ethiopia

Background: There are dearth of literature on the capacity of the health system to diagnose and treat HIV/AIDS in Ethiopia. In this study we evaluated the capacity of health facilities for HIV/AIDS care, its spatial distribution and variations by regions and zones in Ethiopia. Methods: We analyzed the Service Provision Assessment plus (SPA+) survey data that were collected in 2014 in all regions of Ethiopia. We assessed structural, process and overall capacity of the health system based on the Donabedian quality of care model. We included 5 structural and 8 process indicators and overall capacity score was constructed by taking the average of all indicators. Multiple linear regression was done using STATA 14 to assess the association of the location and types of health facilities with overall capacity score. Maps displaying the average capacity score at Zonal level were produced using ArcGIS Desktop v10.3 (Environmental Systems Research Institute Inc., Redlands CA, USA). Results: A total of 873 health facilities were included in the analysis. Less than 5% of the private facilities provided antiretroviral therapy (ART); had national ART guideline, baseline CD4 count or viral load and tuberculosis screening mechanisms. Nearly one-third of the health centers (34.9%) provided ART. Public hospitals have better capacity score (77.1%) than health centers (45.9%) and private health facilities (24.8%). The overall capacity score for urban facilities (57.1%) was higher than that of the rural (38.2%) health facilities (β = 15.4, 95% CI: 11.7, 19.2). Health centers (β = − 21.4, 95% CI: -25.4, − 17.4) and private health facilities (β = − 50.9, 95% CI: -54.8, − 47.1) had lower overall capacity score than hospitals. Facilities in Somali (β = − 13.8, 95% CI: -20.6, − 7.0) and SNNPR (β = − 5.0, 95% CI: -9.8, − 0.1) regions had lower overall capacity score than facilities in the Oromia region. Zones located in emerging regions such as Gambella and Benishangul Gumz and in remote areas of Oromia and SNNPR had lower capacity score in terms of process indicators. Conclusions: There is a significant geographical heterogeneity on the capacity of health facilities for HIV/AIDS care and treatment in Ethiopia. Targeted capacity improvement initiatives are recommended with focus on health centers and private health facilities, and emerging Regions and the rural and remote areas