Clean Face Research Articles

A cross-sectional survey of water and clean faces in trachoma endemic communities in Tanzania

BackgroundFace washing is important to interrupt the transmission of trachoma, the leading infectious cause of blindness worldwide. We aimed to assess the household and personal factors that affected water use and face washing practices in Kongwa, Tanzania.MethodsWe conducted a household water use survey in 173 households (329 children) in January, 2010. Self reported data on water use practices, observed water in the household, and observed clean faces in children were collected. Contingency table analyses and logistic regression analyses were used to measure associations between unclean faces and risk factors.ResultsWe found that women are recognized as primary decision makers on water use in a household, and respondents who reported laziness as a reason that others do not wash children's faces were significantly more likely to have children with clean faces. Washing was reported as a priority for water use in most households. Sixty four percent (95% Confidence Interval = 59%-70%) of children had clean faces.ConclusionsAttitudes toward face washing and household water use appear to have changed dramatically from 20 years ago when clean faces were rare and men made decisions on water use in households. The sources of these attitudinal changes are not clear, but are positive changes that will assist the trachoma control program in strengthening its hygiene efforts.

Trachoma in Northern Ghana: A Need for Further Studies

Background: The northern Ghana Upper East Region [UER], Upper West Region [UWR], and Northern Region (NR) lie within the African trachoma belt. The 3 regions share common features of poverty, dryness, dusty environments, and poor environmental hygiene. Trachoma has been identified previously in the NR and the UWR as a disease of public health importance and a control program is underway.Purpose: To establish baseline prevalence and risk factor parameters in the Upper East for possible control of trachoma in the region.Methods: Population-based cross-sectional survey using multi-staged cluster sampling techniques was used. In all 26,323 participants from 4,374 households in 160 communities were examined with a 2.5x magnifying binocular loupe for trachoma; 7,763 were children aged 1–9 years and 15,191 were aged 15 years and over.Results: Only 3 children were identified with active trachoma (trachoma with follicles, TF = 1; trachoma with intense inflammation, TI = 2) giving regional prevalence of 0.01% (Confidence Limits, CL: 0.0–0.1) for TF and 0.03% (CL: 0.0–0.1) for TI. Trachomatous trichiasis was measured at 0.05% (CL: 0.0–0.1) while children with clean faces was measured at 95.5%. Only 3.6% of the examined households in the region had access to a toilet facility.Conclusion: Trachoma is not a disease of public health importance in the UER of Ghana despite being in a trachoma endemic zone and sharing the necessary risk factors for the disease.

Hydrogen released from bulk ZnO single crystals investigated by time-of-flight electron-stimulated desorption

Electron beam (e-beam) irradiation effects on ZnO single crystals have been investigated by using time-of-flight electron-stimulated desorption (TOF-ESD). The samples were irradiated by using a continuous 0.5 or 1.5 keV e-beam, while the TOF-ESD spectra were taken by using a pulsed 0.5 keV e-beam. For both the O-terminated and Zn-terminated surfaces, the major desorption is H+ desorption. The main trend of H+ desorption intensity and evolution as a function of irradiation time is similar for both faces. The H+ peak is much higher after 1.5 keV irradiation than after 0.5 keV irradiation. The intensity of the H+ peak decreases exponentially as a function of irradiation time and partially recovers after the irradiation is stopped. These observations suggest that the main contribution of the H+ desorption is hydrogen released from the dissociation of H-related defects and complexes in the bulk region of the ZnO by e-beam irradiation. This finding can be used to explain the reported ultraviolet degradation of ZnO single crystals under electron irradiation observed by cathodoluminescence. The surfaces play a lesser role for the H+ desorption, as there are differences of the decreasing rate between the two faces and additionally the intensity of the H+ peak for both the unclean O-face and Zn-facesis smaller than that for clean faces. While the H+ desorption is mainly dominated by the bulk region, O+ desorption is more influenced by the surfaces. There are two kinds of O+ desorbed from ZnO having 13.0 μs TOF and 14.2 μs TOF. The O+ desorption depends on the surface polarity, the surface conditions and the energy used for irradiation.

Randomised trial of face-washing to develop a standard definition of a clean face for monitoring trachoma control programmes

Surgery, antibiotics, facial cleanliness and environmental improvements (SAFE) are recommended for trachoma control. Programmes assess clean faces in children, but no standard definition of a clean face exists. We conducted a randomised controlled trial of face-washing to develop a valid and repeatable definition of a clean face. A total of 424 children were randomised to washed and unwashed groups after a first observation. Three additional observations were made throughout the day. Photographs were taken at each observation. No difference was observed in wet nasal discharge, dust, food or flies on the face between the face washed and unwashed groups at baseline or after washing. A difference was observed in the presence of ocular discharge (P < 0.001) and dry nasal discharge (P < 0.001) after washing. Agreement among observers was highest for flies (Kappa = 0.89, 95% CI = 0.87-0.91), followed by nasal (Kappa = 0.64, 0.62-0.66) and ocular (Kappa = 0.48, 0.46-0.50) discharge. The ability of any definition to identify whether a face had been washed decreased at each observation. This study suggests that the absence of ocular and dry nasal discharge can be used as an indicator of 'clean face', although it is not a good predictor of whether a face has been washed and is difficult to recommend.

Effects of intervention with the SAFE strategy on trachoma across Ethiopia

Background/AimsThe impact of the SAFE strategy (surgery, antibiotics, face washing, environmental hygiene), recommended to eliminate blinding trachoma, is not well explored. We determined the operational effectiveness of the whole SAFE...

“We Cubans Are Obligated Like Cats to Have a Clean Face”: Malaria, Quarantine, and Race in Neocolonial Cuba, 1898-1940

In a paper presented to the Academy of Medical, Physical and Natural Sciences of Havana on December 14, 1923, Dr. Jorge LeRoy y Cassá identified the “unsanitary immigration” to Cuba of Haitians and British West Indians as his country's most pressing health problem. “Those undesirable elements,” he contended, had introduced malaria, smallpox, typhoid fever, and intestinal parasites into eastern Cuba, maladies which then spread to the rest of the island. Through their “vices,” “violent crimes,” and “nefarious practices of brujerí;a [witchcraft],” in fact, Afro-Caribbean immigrants constituted a “double threat”—moral as well as physical—to the health of the Cuban nation. Somewhat surprisingly, the man who was later hailed as the “Father of Cuban Sanitary Statistics” mustered no direct evidence to support his condemnation of West Indian immigration on medical grounds. But such proof was hardly necessary for his esteemed audience. Although the medical doctors and public health officials assembled before LeRoy y Cassa at the Academy of Sciences may have differed on the issue of prohibiting.

“We Cubans Are Obligated Like Cats to Have a Clean Face”: Malaria, Quarantine, and Race in Neocolonial Cuba, 1898-1940

In a paper presented to the Academy of Medical, Physical and Natural Sciences of Havana on December 14, 1923, Dr. Jorge LeRoy y Cassá identified the “unsanitary immigration” to Cuba of Haitians and British West Indians as his country's most pressing health problem. “Those undesirable elements,” he contended, had introduced malaria, smallpox, typhoid fever, and intestinal parasites into eastern Cuba, maladies which then spread to the rest of the island. Through their “vices,” “violent crimes,” and “nefarious practices of brujerí;a [witchcraft],” in fact, Afro-Caribbean immigrants constituted a “double threat”—moral as well as physical—to the health of the Cuban nation. Somewhat surprisingly, the man who was later hailed as the “Father of Cuban Sanitary Statistics” mustered no direct evidence to support his condemnation of West Indian immigration on medical grounds. But such proof was hardly necessary for his esteemed audience. Although the medical doctors and public health officials assembled before LeRoy y Cassa at the Academy of Sciences may have differed on the issue of prohibiting.

Estimation of effects of community intervention with Antibiotics, Facial cleanliness, and Environmental improvement (A,F,E) in five districts of Ethiopia hyperendemic for trachoma

AimsThe WHO recommends the SAFE (surgery, antibiotics, facial cleanliness and environmental improvement) strategy for trachoma control. We aimed to investigate the association between active trachoma and community intervention with antibiotics,...

Princess

Eva Baltasar Eva Baltasar was born inBarcelona in 1978 and now lives inGirona. She studied educational theory at the Universit?t de Barcelona and the Freie Universit?t in Berlin. Her publications include two books of poetry: Laia (2008), fromwhich the present translations are drawn, and At?viques feres (2009; Atavistic beasts). Glebe I stack up ears of corn all over your body without hurting even a single poppy. Span by span, I traceyour trails with thegentle, browned hands of amower who loves your fields and knows theirborders. Desire is a scatteringof soil filledwith ancient seeds thatgerminate without expecting the least sign of rain. Iperfect a precisely formed shadow with every part ofme andmaintain it flush with you, likea faint mist that littleby littlegrows thicker and seems to rub against theearth, as if wanting to cut a broad enough path to reach theother sidewith a clean face. I traverse all your places: beyond you the land bears no name. Kiss As amouth newly come into the world opens and usurps theentire face with a single cry,piercing and constant such is the claim of every living thing when forced to liveuncared foras a mouth arrives at the instant, unperceived yet precise, when thevoice is reconciled toallmanner of silence provided itsupports and retains a rhythm, so my mouth plunges into yours, greedily, utterly relentless, with the newborn's unseeing annoyance at seeking thebreast in the wrong place but perceiving the sweet tasteofmilk inevery pore of skin, incited to lickevery bit and to focus on it. Thus my mouth invades you. Princess Let's consider the poem an excuse, once again. I'll spell a rabble ofwords already scrawled, intendingdiscreetly tomove closer to the true word. Fd be a littlegirl, and at thebeach, firstthing in the morning, you'd have a trailof shells and other things thatare reallyvery important, like the imprintofmy fingers,a border on the wet sand that takes you straight to thedoors of our house. You getmy drift: we'd be girls and spell house with the six lettersof the tallest castle. The excuse, between battlement and tower,would justifythepoem. And you would be theprincess. Translationsfrom the Catalan By LawrenceVenuti 56 i World Literature Today ...

Kiss

Eva Baltasar Eva Baltasar was born inBarcelona in 1978 and now lives inGirona. She studied educational theory at the Universit?t de Barcelona and the Freie Universit?t in Berlin. Her publications include two books of poetry: Laia (2008), fromwhich the present translations are drawn, and At?viques feres (2009; Atavistic beasts). Glebe I stack up ears of corn all over your body without hurting even a single poppy. Span by span, I traceyour trails with thegentle, browned hands of amower who loves your fields and knows theirborders. Desire is a scatteringof soil filledwith ancient seeds thatgerminate without expecting the least sign of rain. Iperfect a precisely formed shadow with every part ofme andmaintain it flush with you, likea faint mist that littleby littlegrows thicker and seems to rub against theearth, as if wanting to cut a broad enough path to reach theother sidewith a clean face. I traverse all your places: beyond you the land bears no name. Kiss As amouth newly come into the world opens and usurps theentire face with a single cry,piercing and constant such is the claim of every living thing when forced to liveuncared foras a mouth arrives at the instant, unperceived yet precise, when thevoice is reconciled toallmanner of silence provided itsupports and retains a rhythm, so my mouth plunges into yours, greedily, utterly relentless, with the newborn's unseeing annoyance at seeking thebreast in the wrong place but perceiving the sweet tasteofmilk inevery pore of skin, incited to lickevery bit and to focus on it. Thus my mouth invades you. Princess Let's consider the poem an excuse, once again. I'll spell a rabble ofwords already scrawled, intendingdiscreetly tomove closer to the true word. Fd be a littlegirl, and at thebeach, firstthing in the morning, you'd have a trailof shells and other things thatare reallyvery important, like the imprintofmy fingers,a border on the wet sand that takes you straight to thedoors of our house. You getmy drift: we'd be girls and spell house with the six lettersof the tallest castle. The excuse, between battlement and tower,would justifythepoem. And you would be theprincess. Translationsfrom the Catalan By LawrenceVenuti 56 i World Literature Today ...

Associations between Active Trachoma and Community Intervention with Antibiotics, Facial Cleanliness, and Environmental Improvement (A,F,E)

BackgroundSurgery, Antibiotics, Facial cleanliness and Environmental improvement (SAFE) are advocated by the World Health Organization (WHO) for trachoma control. However, few studies have evaluated the complete SAFE strategy, and of these, none have investigated the associations of Antibiotics, Facial cleanliness, and Environmental improvement (A,F,E) interventions and active trachoma. We aimed to investigate associations between active trachoma and A,F,E interventions in communities in Southern Sudan.Methods and FindingsSurveys were undertaken in four districts after 3 years of implementation of the SAFE strategy. Children aged 1–9 years were examined for trachoma and uptake of SAFE assessed through interviews and observations. Using ordinal logistic regression, associations between signs of active trachoma and A,F,E interventions were explored. Trachomatous inflammation-intense (TI) was considered more severe than trachomatous inflammation-follicular (TF). A total of 1,712 children from 25 clusters (villages) were included in the analysis. Overall uptake of A,F,E interventions was: 53.0% of the eligible children had received at least one treatment with azithromycin; 62.4% children had a clean face on examination; 72.5% households reported washing faces of children two or more times a day; 73.1% households had received health education; 44.4% of households had water accessible within 30 minutes; and 6.3% households had pit latrines. Adjusting for age, sex, and district baseline prevalence of active trachoma, factors independently associated with reduced odds of a more severe active trachoma sign were: receiving three treatments with azithromycin (odds ratio [OR] = 0.1; 95% confidence interval [CI] 0.0–0.4); clean face (OR = 0.3; 95% CI 0.2–0.4); washing faces of children three or more times daily (OR = 0.4; 95% CI 0.3–0.7); and presence and use of a pit latrine in the household (OR = 0.4; 95% CI 0.2–0.9).ConclusionAnalysis of associations between the A,F,E components of the SAFE strategy and active trachoma showed independent protective effects against active trachoma of mass systemic azithromycin treatment, facial cleanliness, face washing, and use of pit latrines in the household. This strongly argues for continued use of all the components of the SAFE strategy together.

Trachoma control using the WHO adopted \"SAFE with azithromycin\"

To report on and share the experiences, accomplishments and lessons learnt by African Medical and Research Foundation (AMREF), Sight Savers International (SSI), University of Nairobi (UON) and the Ministry of Health (MOH) during implementation of a three year Shompole trachoma control pilot study using azithromycin. The target of the project was to reduce the prevalence of active and potentially blinding trachoma by 50% by the year 2005. Community based survey. Shompole location, Magadi division, Kajiado district of the Rift Valley Province of Kenya. Five hundred and twenty six randomly selected households from 166 manyattas (bomas/ homesteads) proportionately distributed in all the 13 villages of the four sub-locations of Shompole location were visited. Nine hundred and ninety eight children (1-9 years) and 898 adults (215 years) were examined for active trachoma (TF) and potentially blinding trachoma (TT) respectively. The prevalence of active trachoma (TF) in children has dropped from 46.4% in 2002 to 16.0% in 2006 and that of potentially blinding trachoma (TT) from 4.5% to 1.7% in the same period. Women have more TT than men. Out of the 15 cases of TT reported in the survey, only two were recurrences. The prevalence of active trachoma (TF) is higher in boys than girls, p=0.044. The proportion of children with clean faces has not changed but the proportion of children with many (>5) flies has drastically reduced from 48.0% in 2002 to 6.0% in 2006. The community holds strong negative believes about pit latrines. The project is sustainable. This project has positively influenced eye care policy locally and globally. The targets for "SA" components of SAFE were achieved while "FE" components were partially achieved. The ongoing scale up of the project to cover the whole of Kajiado district is justified. Formative study and review of the project's health promotion strategy is necessary. Collaboration and joint planning with neighbouring endemic districts of Kenya and Tanzania should be encouraged because of the nomadic nature of the Maasai who are the project beneficiaries.

Issues in defining and measuring facial cleanliness for national trachoma control programs

The WHO trachoma control strategy includes promotion of facial cleanliness to interrupt transmission. However, scant data exist on measuring a clean face. Our goals were to determine reliable indicators of a clean face in a child, and disparities between the assessments of faces at a clinic versus at home. Five hallmarks of a clean face were assessed on 50 children in Tanzania. In five districts, 973 children (age 1-5 years) were evaluated for facial cleanliness at home, and again 2 days later at a central location for a trachoma examination. Data on environmental risk factors were collected. Only three signs, ocular and nasal discharge, and flies on the face, were reliable indicators of facial cleanliness (kappa>0.6); dust and food were less reliable. Unclean faces were more prevalent when measured at home (62%) than at the clinic (51%), although both were related to trachoma. The environmental markers of absence of latrines and tin roofs were consistent markers across all districts of households at risk of poor facial cleanliness. We conclude that for accurate estimates of clean faces, some assessment strategy outside the clinical environment is necessary. Additionally, behavior change programs in these districts in Tanzania should especially target families without tin roofs or latrines.

Evaluating a school-based trachoma curriculum in Tanzania

Trachoma remains a public health problem in a number of sub-Saharan Africa countries; behavioral change and environmental improvements are cornerstones of prevention efforts. Evidence of successful health education are few in Africa. Health education efforts through primary schools have recently been developed and adopted in Tanzania. We evaluated changes from 2004 to 2005 in knowledge and reported behavioral change as well as nasal and ocular discharge and clean faces in selected schools in central Tanzania. This was a mixed-methods study involving both schoolchildren and school teachers. We found a significant reduction in nasal discharge (from 4.5% to 0.5%) and dirty faces (from 3.6% to 0.9%) and improvements in some knowledge- and behavior-related indices by primary schoolchildren in the intervention villages. The teachers viewed the trachoma curriculum positively but reported that the lack of water at the schools limited application of the health education messages. The disparity between health education messages and environmental capacities for implementing these messages (no wells at the schools and minimal latrine facilities at the schools and homes) limited usefulness of the curriculum.

Oxidation of the Nb(1 1 0) surface by ab initio calculations

We report ab initio (FPLAPW) results referring to the early stages of oxygen deposition on the Nb(1 1 0) surface. We considered the cases of half and full monolayer depostion and we evaluated the structural and electronic properties of the resulting overlayers. From the calculated electronic strctures, it came out that the oxygen atoms form stronger bonds with the Nb surface atoms in the [0 0 1] than in the [ 1 1 ¯ 0 ] direction, a fact that implies also shorter bond lengths in the former direction and different structural relaxations in the neighbouring Nb atoms. In addition, we found that the Nb–O bonding, which is attributed to d–p hybridization of double bond-like character, results in the introduction of new electronic states that lay well below the lowest states of the clean Nb face, while it also contributes into the increase of states around the Fermi level. Interestingly, the Nb–O bonding type along the preponderated direction yields free oxygen p z orbitals that can be regarded as dangling-like bonds. These results elucidate the early stages of Nb oxidation and can be used to enlighten the mechanisms of surface reactions, catalytic activity and oxides growth mechanisms.

The importance of a clean face: the effect of different washing procedures on the association of Tamm–Horsfall glycoprotein and other urinary proteins with calcium oxalate crystals

This study was undertaken to determine whether the use of different washing procedures could explain dissident findings in published studies examining the role of urinary macromolecules in urolithiasis. Calcium oxalate monohydrate (COM) crystals were deposited from or added to the same sieved urine, washed with copious or limited amounts of distilled water, or with methanol, and examined by field emission scanning electron microscopy (FESEM). Demineralized extracts were analysed by SDS-PAGE and Western blotting for Tamm-Horsfall glycoprotein (THG), human serum albumin (HSA), osteopontin (OPN) and prothrombin fragment 1 (PTF1). Synchrotron X-ray diffraction (SXRD) with Rietveld whole-pattern peak fitting and profile analysis was used to determine non-uniform crystal strain and crystallite size in crystals generated from inorganic solutions in the presence of increasing concentrations of THG and prothrombin (PT). HSA and PTF1 were present in all demineralized crystal extracts, confirming their inclusion within COM. OPN was present in all extracts except those derived from pure inorganic COM crystals, because of its occlusion within small numbers of calcium oxalate dihydrate (COD) crystals contaminating the COM population. THG was absent from the demineralized extracts of all crystals washed copiously with water, but present in those washed with methanol or limited amounts of water. FESEM showed extraneous organic material associated only with crystals whose extracts contained THG, confirming that the protein does not bind permanently to the COM crystal surface and is not occluded within the mineral bulk. This was confirmed by SXRD, which showed that non-uniform strain and crystallite size remained unaltered in crystals grown in the presence of increasing THG concentrations. However, non-uniform strain increased and crystallite size decreased with increasing PT concentrations, demonstrating unambiguously that PT is included in COM crystals. It was concluded that scrupulous care must be taken to ensure the complete removal of extraneous THG adventitiously associated with CaOx crystals in order to avoid inaccurate analysis of crystal matrix protein content and possible misinterpretation of experimental data.

Market Structure and Technology Diffusion Incentives under Emission Taxes and Emission Reduction Subsidies

This paper compares emission taxes with emission reduction subsidies regarding the incentives they create to enhance technology diffusion under imperfect competition. Finns can adopt a technology or a abatement technology. If the clean and dirty products are perfect substitutes, and clean firms face a net absolute advantage over dirty firms, taxes provide the strongest incentive. This ranking is reversed if there is a distortion on output. Subsidies can neutralize this distortion because output supply is stimulated, which would normally be lower than optimal under perfect competition.

Effective interventions with chlorhexidine gluconate (CHG) to decrease hemodialysis (HD) tunneled catheter‐related infections

Purpose: Identify practices to reduce HD catheter access related bacteremias (ARB). Methods: Data was collected per the CDC Dialysis Surveillance Network protocol. ARB was defined as a patient with a positive blood culture with no apparent source other than the vascular access catheter. ARB's were calculated in events per 100 patient months with 3 cohorts. Cohort 1 was observed for 12 months, Cohort 2 for the subsequent 10 months, and Cohort 3 for the final 10 months. Cohort 1 had weekly transparent dressing changes, cleansing of the skin and 5 minute soaking of the connection lines with 10% povidone‐iodine (PI) solution, and HCW use of clean gloves and face shield without a mask. Cohort 2 changes consisted of thrice weekly gauze dressing changes, skin cleansing with ChloraPrep, a 2% CHG/70% isopropyl alcohol applicator, masks on the patients, adding a face mask to the shield, and application of 10% PI ointment to the exit site. Cohort 3 changes included weekly application of BioPatch (BioP), an antimicrobial dressing with CHG, sterile glove use, and replacing the PI line soaks with 4% CHG. Results: The catheter‐associated ARB rate per 100 patient months was 7.9 (17ARB/216 patient months) in Cohort 1, 8.6 (13/151) in Cohort 2, and 4.7 (5/107) in Cohort 3(p = 0.31 compared with Cohorts 1 and 2 combined). During the last 2 months, in Cohort 3, 9 catheter lumen cracks occurred, with one of the patients having a bacteremia. Conclusions: Addition of CHG line soaks and BioP reduced tunneled catheter infections, although this is not statistically significant. The increased number of catheter lumen cracks raises concern with the use of CHG line soaks. Further investigation with use of CHG line soaks and the BioP for decreasing ARB is needed.

Face washing promotion for preventing active trachoma.

Trachoma remains a major cause of avoidable blindness among underprivileged populations in many developing countries. It is estimated that about 146 million people have active trachoma and nearly six million people are blind due to complications associated with repeat infections. The objective of this review is to assess the effects of face washing on the prevalence of active trachoma in endemic communities. We searched the Cochrane Central Register of Controlled Trials - CENTRAL (which contains the Cochrane Eyes and Vision Group trials register) on The Cochrane Library (Issue 2, 2004), MEDLINE (1966 to February 2004), EMBASE (1980 to February 2004), the reference lists of identified trials and the Science Citation Index. We also contacted investigators and experts in the field to identify additional trials. We included randomised or quasi-randomised controlled trials, comparing face washing with no treatment or face washing combined with antibiotics against antibiotics alone. Participants in the trials were people normally resident in endemic trachoma communities. Two reviewers independently extracted data and assessed trial quality. Study authors were contacted for additional information. Two clinically heterogeneous trials are included, therefore a meta-analysis was considered inappropriate. This review includes two trials with data from a total of 2560 participants. Face washing combined with topical tetracycline was compared to topical tetracycline alone in three pairs of villages in one trial. The trial found a statistically significant effect for face washing combined with topical tetracycline in reducing 'severe' active trachoma compared to topical tetracycline alone. No statistically significant difference was observed between the intervention and control villages in reducing ('non-severe') active trachoma. The prevalence of clean faces was higher in the intervention villages than the control villages and this was statistically significant. Another trial compared eye washing to no treatment or to topical tetracycline alone or to a combination of eye washing and tetracycline drops in children with follicular trachoma. The trial found no statistically significant benefit of eye washing alone or in combination with tetracycline eye drops in reducing follicular trachoma amongst children with follicular trachoma. There is some evidence that face washing combined with topical tetracycline can be effective in reducing severe trachoma and in increasing the prevalence of clean faces. Current evidence does not however support a beneficial effect of face washing alone or in combination with topical tetracycline in reducing active trachoma.

Market Structure and Technology Diffusion Incentives under Alternative Environmental Policy Schemes

The paper compares emission taxes, subsidies, permits and credits with respect to the incentives they create to enhance technology diffusion under imperfect competition. Forms can adopt a dirty technology or a clean abatement technology. When the clean and dirty products are perfect substitutes, and clean firms face a net absolute advantage over dirty firms, permits and taxes provide the strongest incentive, followed by credits and subsidies respectively. This ranking order is reversed if there is a distortion on output. Subsidies can neutralize this distortion; subsidies stimulate output supply, which would normally be lower than optimal under perfect competition.