RESUMO
SIGNIFICANCE: Treatment of myopic children with a dual-focus soft contact lens (DFCL; MiSight 1 day) produced sustained slowing of myopia progression over a 6-year period. Significant slowing was also observed in children switched from a single vision control to treatment lenses (3 years in each lens). PURPOSE: This study aimed to evaluate the effectiveness of DFCLs in sustaining slowed progression of juvenile-onset myopia over a 6-year treatment period and assess myopia progression in children who were switched to a DFCL at the end of year 3. METHODS: Part 1 was a 3-year clinical trial comparing DFCLs with a control contact lens (Proclear 1 day) at four investigational sites. In part 2, subjects completing part 1 were invited to continue for 3 additional years during which all children were treated with MiSight 1 day DFCLs (52 and 56 from the initially treated [T6] and control [T3] groups, respectively). Eighty-five subjects (45 [T3] and 40 [T6]) completed part 2. Cyclopleged spherical equivalent refractive errors (SEREs) and axial lengths (ALs) were monitored, and a linear mixed model was used to compare their adjusted change annually. RESULTS: Average ages at part 2 baseline were 13.2 ± 1.3 and 13.0 ± 1.5 years for the T6 and T3 groups, respectively. Slowed myopia progression in the T6 group observed during part 1 was sustained throughout part 2 (mean ± standard error of the mean: change from baseline SERE [in diopters], -0.52 ± 0.076 vs. -0.51 ± 0.076; change in AL [in millimeters], 0.28 ± 0.033 vs. 0.23 ± 0.033; both P > .05). Comparing progression rates in part 2 for the T6 and T3 groups, respectively, indicates that prior treatment does not influence efficacy (SERE, -0.51 ± 0.076 vs. -0.34 ± 0.077; AL, 0.23 ± 0.03 vs. 0.18 ± 0.03; both P > .05). Within-eye comparisons of AL growth revealed a 71% slowing for the T3 group (3 years older than part 1) and further revealed a small subset of eyes (10%) that did not respond to treatment. CONCLUSIONS: Dual-focus soft contact lenses continue to slow the progression of myopia in children over a 6-year period revealing an accumulation of treatment effect. Eye growth of the initial control cohort with DFCL was slowed by 71% over the subsequent 3-year treatment period.
Assuntos
Lentes de Contato Hidrofílicas , Miopia , Comprimento Axial do Olho , Criança , Progressão da Doença , Humanos , Miopia/diagnóstico , Miopia/terapia , Refração Ocular , Visão OcularRESUMO
PURPOSE: To report on the ocular health and safety of children fit with soft hydrogel daily-disposable contact lenses, and followed for 6-years in a double-masked clinical trial investigating the performance of a dual-focus contact lens designed to control myopia progression. METHODS: Children aged 8-12 years, naïve to contact lens wear, were enrolled across four international sites. During years 1-3, children were randomised to either MiSight® 1 day or Proclear® 1 day (both omafilcon A, CooperVision, Inc.). The lenses were identical in material and geometry except for the front optical zone design. At the end of year-3, all those wearing Proclear 1 day were switched to MiSight 1 day, therefore all wore MiSight 1 day in years 4-6. Subjects agreed to wear the lenses at least 10-hours/day, 6-days/week. After dispensing, study visits were at 1-week, 1-month, 6-months and every 6-months until 6-years. At each visit, ocular measurements and subjective responses were recorded. Biomicroscopy used 0-4 grading scales; grade 0 represented no findings. RESULTS: 144 children were enrolled: 69F:75M; mean age 10.1 years; mean cycloplegic spherical-equivalent refraction -2.11D; ethnicities included 34 East-Asian, 12 West-Asian, and 79 Caucasian. 92 completed the 6-years. Only three subjects discontinued due to an ocular adverse event (AE). No contact lens related AEs were classified as serious. The incidence rate of infiltrative AEs was 0.61% (6.1/1000 wearing-years; 95%CI: 0.24%-1.57%). The most common biomicroscopy findings were limbal, bulbar and tarsal hyperaemia and tarsal roughness. 99% of all biomicroscopy findings were grade-1 or lower. After 6-years of lens wear, ocular health by biomicroscopy was similar to pre-lens wear. CONCLUSIONS: Across the 6-years, there were no contact lens related serious AEs and biomicroscopy showed no significant changes. Results suggest that children this age can successfully wear daily-disposable hydrogel contact lenses with minimal impact on ocular physiology.
Assuntos
Lentes de Contato Hidrofílicas , Miopia , Criança , Equipamentos Descartáveis , Humanos , Miopia/terapia , Satisfação do Paciente , Refração Ocular , Visão OcularRESUMO
Pollen retention on clothes, footwear, hair and body has been used to link people to localities with distinctive vegetation, or soils containing distinctive palynomorphs. Little attention has been given to human skin as a possible medium for carrying a forensically important pollen load and whether this might survive attempts to remove it. We report here the results of experiments testing the retention of pollen of 10 flowering plant species on the human skin through repeated cycles of washing and drying hands, using the WHO protocol to standardize hand-washing and drying. Between 0.36% and 2.74% (mean 0.93%) of the initial pollen load was retained through a single hand-wash. Trace amounts of some species survived multiple hand-wash cycles. It is concluded that forensic analyses can be made of the pollen load of those parts of the skin that may have been in contact with palynologically distinctive vegetation, even in cases where the person involved has washed, or been washed. These observations may also be of relevance in cases where human skin became contaminated with other microscopic particulates.
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Mortuary behavior (activities concerning dead conspecifics) is one of many traits that were previously widely considered to have been uniquely human, but on which perspectives have changed markedly in recent years. Theoretical approaches to hominin mortuary activity and its evolution have undergone major revision, and advances in diverse archeological and paleoanthropological methods have brought new ways of identifying behaviors such as intentional burial. Despite these advances, debates concerning the nature of hominin mortuary activity, particularly among the Neanderthals, rely heavily on the rereading of old excavations as new finds are relatively rare, limiting the extent to which such debates can benefit from advances in the field. The recent discovery of in situ articulated Neanderthal remains at Shanidar Cave offers a rare opportunity to take full advantage of these methodological and theoretical developments to understand Neanderthal mortuary activity, making a review of these advances relevant and timely.
Assuntos
Sepultamento/história , Homem de Neandertal/fisiologia , Paleontologia , Animais , Cavernas , Fósseis , Fraturas Ósseas/patologia , Sedimentos Geológicos/química , História Antiga , IraqueRESUMO
Imaging photoplethysmography (iPPG) is an emerging technology used to assess microcirculation and cardiovascular signs by collecting backscattered light from illuminated tissue using optical imaging sensors. The aim of this study was to study how effective smart garment fabrics could be capturing physiological signs in a non-contact mode. The present work demonstrates a feasible approach of, instead of using conventional high-power illumination sources, integrating a grid of surface-mounted light emitting diodes (LEDs) into cotton fabric to spotlight the region of interest (ROI). The green and the red LEDs (525 and 660 nm) placed on a small cotton substrate were used to locally illuminate palm skin in a dual-wavelength iPPG setup, where the backscattered light is transmitted to a remote image sensor through the garment fabric. The results show that the illuminations from both wavelength LEDs can be used to extract heart rate (HR) reaching an accuracy of 90% compared to a contact PPG probe. Stretching the fabric over the skin surface alters the morphology of iPPG signals, demonstrating a significantly higher pulsatile amplitude in both channels of green and red illuminations. The skin compression by the fabric could be potentially utilised to enhance the penetration of illumination into cutaneous microvascular beds. The outcome could lead a new avenue of non-contact opto-physiological monitoring and assessment with functional garment fabrics.
Assuntos
Vestuário/normas , Processamento de Imagem Assistida por Computador/métodos , Monitorização Fisiológica/métodos , Fenômenos Fisiológicos da Pele/imunologia , HumanosRESUMO
PURPOSE: To determine the retention rate (RR) for neophyte patients fitted with contact lenses (CLs) and to identify factors associated with retention and dropout. METHOD: This multisite, sponsor-masked registry study evaluated the 1-year status of neophyte CL wearers fitted in a representative range of UK practices. A total of 26 UK investigational sites each recruited up to 89 neophyte patients. The participants were requested to complete surveys at 1 month (±1 week from date of fitting), 3 months (±2 weeks), and 12 months (±3 weeks) online or through phone. Participants were contacted by email (or phone) and invited to complete an online survey that asked a range of questions regarding their CL wearing experience. RESULTS: Of the 531 participants recruited, 65.3% (347/531) responded to at least one follow-up survey and 42.3% (225/531) responded to all three surveys. One in four patients showed discontinued CL wear by 12 months. Based on evaluable subjects at 12 months, the RR was 77.6% (194/250, 95% confidence interval: 72.0-82.3). The most common reason for discontinuation was problems with vision (41%), followed by discomfort (36%) and handling problems (25%). The factors affecting first-year RRs: sex, spherical refraction, lens usage (full time or part time), and supply method (collected or posted). CONCLUSIONS: In this prospective study, the first-year RR for neophyte CL wearers was 77.6%. This was consistent with that noted in a retrospective study: 74.0%. As with the previous study, the commonly cited reason for discontinuation was visual problems.
Assuntos
Lentes de Contato/estatística & dados numéricos , Cooperação do Paciente/estatística & dados numéricos , Satisfação do Paciente , Ajuste de Prótese/estatística & dados numéricos , Acuidade Visual , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Inquéritos e Questionários , Adulto JovemRESUMO
The Neanderthal remains from Shanidar Cave, excavated between 1951 and 1960, have played a central role in debates concerning diverse aspects of Neanderthal morphology and behavior. In 2015 and 2016, renewed excavations at the site uncovered hominin remains from the immediate area where the partial skeleton of Shanidar 5 was found in 1960. Shanidar 5 was a robust adult male estimated to have been aged over 40 years at the time of death. Comparisons of photographs from the previous and recent excavations indicate that the old and new remains were directly adjacent to one another, while the disturbed arrangement and partial crushing of the new fossils is consistent with descriptions and photographs of the older discoveries. The newly discovered bones include fragments of several vertebrae, a left hamate, part of the proximal left femur, a heavily crushed partial pelvis, and the distal half of the right tibia and fibula and associated talus and navicular. All these elements were previously missing from Shanidar 5, and morphological and metric data are consistent with the new elements belonging to this individual. A newly discovered partial left pubic symphysis indicates an age at death of 40-50 years, also consistent with the age of Shanidar 5 estimated previously. Thus, the combined evidence strongly suggests that the new finds can be attributed to Shanidar 5. Ongoing analyses of associated samples, including for sediment morphology, palynology, and dating, will therefore offer new evidence as to how this individual was deposited in the cave and permit new analyses of the skeleton itself and broader discussion of Neanderthal morphology and variation.
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Cavernas , Fíbula , Fósseis , Homem de Neandertal , Ossos Pélvicos , Animais , Hominidae , Humanos , Iraque , MasculinoRESUMO
Significant human impacts on tropical forests have been considered the preserve of recent societies, linked to large-scale deforestation, extensive and intensive agriculture, resource mining, livestock grazing and urban settlement. Cumulative archaeological evidence now demonstrates, however, that Homo sapiens has actively manipulated tropical forest ecologies for at least 45,000 years. It is clear that these millennia of impacts need to be taken into account when studying and conserving tropical forest ecosystems today. Nevertheless, archaeology has so far provided only limited practical insight into contemporary human-tropical forest interactions. Here, we review significant archaeological evidence for the impacts of past hunter-gatherers, agriculturalists and urban settlements on global tropical forests. We compare the challenges faced, as well as the solutions adopted, by these groups with those confronting present-day societies, which also rely on tropical forests for a variety of ecosystem services. We emphasize archaeology's importance not only in promoting natural and cultural heritage in tropical forests, but also in taking an active role to inform modern conservation and policy-making.
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Conservação dos Recursos Naturais/história , Florestas , Agricultura/história , Agricultura Florestal/história , História do Século XXI , História Antiga , Humanos , Floresta Úmida , Urbanização/históriaRESUMO
Significant human impacts on tropical forests have been considered the preserve of recent societies, linked to large-scale deforestation, extensive and intensive agriculture, resource mining, livestock grazing and urban settlement. Cumulative archaeological evidence now demonstrates, however, that Homo sapiens has actively manipulated tropical forest ecologies for at least 45,000 years. It is clear that these millennia of impacts need to be taken into account when studying and conserving tropical forest ecosystems today. Nevertheless, archaeology has so far provided only limited practical insight into contemporary human-tropical forest interactions. Here, we review significant archaeological evidence for the impacts of past hunter-gatherers, agriculturalists and urban settlements on global tropical forests. We compare the challenges faced, as well as the solutions adopted, by these groups with those confronting present-day societies, which also rely on tropical forests for a variety of ecosystem services. We emphasize archaeology's importance not only in promoting natural and cultural heritage in tropical forests, but also in taking an active role to inform modern conservation and policy-making.
Assuntos
Conservação dos Recursos Naturais , Agricultura Florestal/história , Floresta Úmida , História Antiga , HumanosRESUMO
The paper presents the results of optical dating of potassium-rich feldspar grains obtained from the Haua Fteah cave in Cyrenaica, northeast Libya, focussing on the chronology of the Deep Sounding excavated by Charles McBurney in the 1950s and re-excavated recently. Samples were also collected from a 1.25 m-deep trench (Trench S) excavated during the present project below the basal level of the Deep Sounding. Optically stimulated luminescence (OSL) data sets for multi-grain, single aliquots of quartz for samples from the Middle Trench were previously published. Re-analyses of these OSL data confirm significant variation in the dose saturation levels of the quartz signal, but allow the most robust OSL ages to be determined for comparison with previous age estimates and with those obtained in this study for potassium-rich feldspars from the Deep Sounding. The latter indicate that humans may have started to visit the cave as early as â¼150 ka ago, but that major use of the cave occurred during MIS 5, with the accumulation of the Deep Sounding sediments. Correlations between optical ages and episodes of "Pre-Aurignacian" artefact discard indicate that human use of the cave during MIS 5 was highly intermittent. The earliest phases of human activity appear to have occurred during interstadial conditions (5e and 5c), with a later phase of lithic discard associated with more stadial conditions, possibly MIS 5b. We argue that the "Pre-Aurignacian" assemblage can probably be linked with modern humans, like the succeeding "Levalloiso-Mousterian" assemblage; two modern human mandibles associated with the latter are associated with a modelled age of 73-65 ka. If this attribution is correct, then the new chronology implies that modern humans using "Pre-Aurignacian" technologies were in Cyrenaica as early as modern humans equipped with "Aterian" technologies were in the Maghreb, raising new questions about variability among lithic technologies during the initial phases of modern human dispersals into North Africa.
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Cavernas , Sedimentos Geológicos/análise , Hominidae , Datação Radiométrica , Animais , Arqueologia , Humanos , Líbia , Medições LuminescentesRESUMO
PURPOSE: To determine the first-year retention rate for patients fitted with contact lenses (CLs) and identify factors associated with retention and dropout. METHODS: This multi-site study was a retrospective chart review of the status of neophyte CL wearers fitted in representative UK eye care practices. RESULTS: Consecutive records for 524 patients at 29 sites were reviewed. Mean age at dispensing was 34 years (range 8-79), 68% were under 45 years and 61% female. Soft CLs were fitted to 98% of patients. After 12 months, 388 were still CL wearers, a retention rate of 74% (95% CI: 70.1-77.6). Of the 136 lapsed, 25% discontinued during the first month and 47% within 60 days. The main reasons cited for discontinuation included poor distance vision (26%; of whom, 37% were toric and 51% multifocal), poor near vision (16%), discomfort (14%) and handling problems (15%). In 32% of cases, the reasons for discontinuation were unknown. For 71% of dropouts, no alternative lens or management strategy had been tried. Significant factors associated with retention in univariate analysis were: age (younger), sphere power (higher), lens type (sphere vs multifocal) and purchase frequency (regular). Multivariate analysis showed lens sphere power, purchase frequency and lens material to be significant factors. There was a wide variation in retention rates between sites (40-100%). CONCLUSIONS: During the first year of CL wear, the overall retention rate for neophyte CL wearers was 74% (spherical CLs 79%, torics 73%, multifocals 57%), with many lapsing during the first 2 months. Factors associated with retention and dropout in these patients include: lens power, material and type, and purchase frequency. While handling and comfort are the most commonly cited performance-related reasons for discontinuing in new spherical lens wearers, visual problems are the most common among new wearers of toric and, in particular, multifocal CLs.
Assuntos
Lentes de Contato/estatística & dados numéricos , Cooperação do Paciente/estatística & dados numéricos , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Erros de Refração/epidemiologia , Erros de Refração/reabilitação , Recusa do Paciente ao Tratamento/estatística & dados numéricos , Adolescente , Adulto , Distribuição por Idade , Idoso , Criança , Lentes de Contato/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Prevalência , Ajuste de Prótese/estatística & dados numéricos , Estudos Retrospectivos , Distribuição por Sexo , Resultado do Tratamento , Reino Unido/epidemiologia , Revisão da Utilização de Recursos de Saúde , Adulto JovemRESUMO
PURPOSE: To characterize and compare the prevalence of soft contact lens-related (SCL) dryness symptoms in large populations of SCL wearers in North America (NAm) and the United Kingdom (UK). METHODS: SCL wearers from NAm (n = 1443) and UK (n = 932) sites completed self-administered questionnaires on SCL symptoms and wearing experiences. A categorization for contact lens-related dry eye (CL-DE) was applied that combined Contact Lens Dry Eye Questionnaire (CLDEQ) items on dryness frequency and intensity at the end of the day (CL-DE+ = constantly/frequently/sometimes plus intensity = 3-5, and CL-DE- = never/rarely plus intensity = 0-1, Marginal = all other ratings). Data were analyzed across regions and categories, with p-values <0.05 significant. RESULTS: Compared to UK wearers, those in NAm wore fewer toric and multifocal designs, and reported significantly longer average and comfortable wearing times (p < 0.001) but similar levels of general and end-of-day comfort. The prevalence of CL-DE+ differed between the UK and NAm: CL-DE+: 31 vs. 39%, Marginal CL-DE: 13 vs. 14%, and CL-DE-: 56 vs. 47%, p = 0.0001. Although daily disposable (DD) lenses were worn more commonly in the UK than NAm (33 vs. 10%, p < 0.0001), their use did not impact the overall prevalence of dryness symptoms. Between regions, NAm wearers reported significantly more frequent and intense end-of-day discomfort and dryness (p < 0.0001) and were significantly more likely to use treatments for CL-related symptoms yet experienced a lower degree of relief. CONCLUSIONS: SCL wearers in NAm reported longer hours of wear with significantly more symptoms of dryness and discomfort. NAm wearers used dryness treatments more often, but experienced less relief than UK wearers. In both regions, the CL-DE categorization was useful to predict poorer comfort, shorter comfortable wearing time, and increased use of treatments. These results highlight the need to benchmark SCL performance locally or regionally to understand and focus on the challenges to the lens wearing experience.
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Lentes de Contato Hidrofílicas/efeitos adversos , Síndromes do Olho Seco/etiologia , Adulto , Lentes de Contato Hidrofílicas/estatística & dados numéricos , Equipamentos Descartáveis , Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/epidemiologia , Feminino , Humanos , Masculino , América do Norte/epidemiologia , Conforto do Paciente , Prevalência , Fatores de Risco , Inquéritos e Questionários , Reino Unido/epidemiologiaRESUMO
BACKGROUND: The aim was to evaluate the effect of ocular topography on soft contact lens fit in Chinese and Caucasians. METHOD: This study evaluated 547 subjects from two ethnic groups, Caucasian (n = 250) and Chinese (n = 297), at investigational sites in three locations: Wenzhou, China, Melbourne, Australia and Jacksonville, USA. Subjects underwent measurement of a range of ocular topographic variables using identical equipment and protocols, including: apical corneal radius (CR), corneal shape factor (CSF) in the two principal meridians, horizontal visible iris diameter (HVID), vertical palpebral aperture (PA), upper lid angle (ULA) and inter-canthal angle (ICA). Subjects were fitted with a spherical lens in two base curves (BCs) (1·Day ACUVUE, 8.50, 9.00 mm) and a toric soft lens (Accelerated Stabilization Design). RESULTS: The steeper base curve (8.50 mm) spherical lenses gave an acceptable overall lens fit with 98 per cent or more of subjects in both groups, while the flatter lens (9.00 mm) was acceptable in a significantly higher proportion of the Chinese compared to Caucasian group (96 versus 82 per cent, p < 0.0001) . The main difference in fit between groups was for centration; there was significantly less decentration with the Chinese group (8.50 BC: 39 versus 72 per cent, p < 0.0001; 9.0 BC: 63 versus. 85 per cent, p = 0.02). The 8.5 mm base curve showed good centration (none or slight decentration) for 97 per cent of Caucasian eyes and 96 per cent of Chinese eyes. With both groups, there were some significant correlations between lens fit and ocular topographic variables, most notable between upper lid angle and toric lens orientation with the Chinese subjects. Regression analysis also showed key predictive values relating to lens fit. CONCLUSIONS: Detailed ocular measurements suggest anatomical differences between Chinese and Caucasian populations that should be considered in soft lens design. The spherical and toric lenses tested in this study fitted a large proportion of both Chinese and Caucasian eyes and are robust to the ocular differences noted.
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Povo Asiático/etnologia , Lentes de Contato Hidrofílicas , Olho/anatomia & histologia , Ajuste de Prótese , População Branca/etnologia , Adolescente , Adulto , Austrália/epidemiologia , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia , Estados Unidos/epidemiologia , Adulto JovemRESUMO
PURPOSE: Replacing soft contact lenses (CLs) on a daily basis brings a number of advantages, most notably, reduced exposure to deposits, disinfectants, allergens, and other contaminants. This retrospective study estimated the prevalence of problems in current wearers of reusable soft CLs and tested the effect of refitting "problem" patients with daily disposable (DD) hydrogel lenses. METHODS: Prevalence was estimated from 398 current reusable CL wearers for: frequent/constant discomfort or dryness, ≥2 h of uncomfortable wear, ≥grade 2 conjunctival hyperaemia (0-4), or ≥grade 3 corneal staining (0-15). In the second part of the study, 217 reusable CL wearers classified as problem patients were randomly refitted with DD lenses manufactured from one of two materials: etafilcon A (n=96) or nelfilcon A (n=121) and reassessed 1 week later. RESULTS: Thirty-nine percent (154/398) had some qualifying criterion: reduced comfortable wearing time (CWT), 20%; dryness, 20%; irritation, 5%; corneal staining, 8%; and hyperaemia, 7%. After refitting with DDs, the prevalence of reduced CWT was decreased from 65% to 51% (P=0.0039), dryness from 60% to 41% (P < 0.0001) and corneal staining from 28% to 21% (P=0.04). There was no significant change in the prevalence of irritation, or hyperaemia. Some differences were noted between the two lens materials. CONCLUSIONS: A high proportion of reusable soft lens wearers encounter clinically relevant signs or symptoms with their current CLs. This study provides evidence that refitting with DD lenses is a useful strategy for alleviating some of the common problems of CL wear.
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Lentes de Contato/estatística & dados numéricos , Doenças da Córnea/epidemiologia , Equipamentos Descartáveis/estatística & dados numéricos , Síndromes do Olho Seco/epidemiologia , Dor Ocular/epidemiologia , Erros de Refração/epidemiologia , Erros de Refração/reabilitação , Adulto , Idoso , Causalidade , Comorbidade , Lentes de Contato Hidrofílicas , Reutilização de Equipamento/estatística & dados numéricos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Ajuste de Prótese/estatística & dados numéricos , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Reino Unido/epidemiologia , Adulto JovemRESUMO
Our limited understanding of terrestrial ecosystem responses to elevated CO2 is a major constraint on predicting the impacts of climate change. A change in botanical composition has been identified as a key factor in the CO2 response with profound implications for ecosystem services such as plant production and soil carbon storage. In temperate grasslands, there is a strong consensus that elevated CO2 will result in a greater physiological stimulus to growth in legumes and to a lesser extent forbs, compared with C3 grasses, and the presumption this will lead in turn to a greater proportion of these functional groups in the plant community. However, this view is based on data mainly collected in experiments of three or less years in duration and not in experiments where defoliation has been by grazing animals. Grazing is, however, the most common management of grasslands and known in itself to influence botanical composition. In a long-term Free Air Carbon Dioxide Enrichment (FACE) experiment in a temperate grassland managed with grazing animals (sheep), we found the response to elevated CO2 in plant community composition in the first 5 years was consistent with the expectation of increased proportions of legumes and forbs. However, in the longer term, these differences diminished so that the proportions of grasses, legumes and forbs were the same under both ambient and elevated CO2 . Analysis of vegetation before and after each grazing event showed there was a sustained disproportionately greater removal ('apparent selection') of legumes and forbs by the grazing animals. This bias in removal was greater under elevated CO2 than ambient CO2 . This is consistent with sustained faster growth rates of legumes and forbs under elevated CO2 being countered by selective defoliation, and so leading to little difference in community composition.
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Dióxido de Carbono , Fabaceae/crescimento & desenvolvimento , Poaceae/crescimento & desenvolvimento , Ovinos/fisiologia , Animais , Ecossistema , Herbivoria , Nova ZelândiaRESUMO
The 1950s excavations by Charles McBurney in the Haua Fteah, a large karstic cave on the coast of northeast Libya, revealed a deep sequence of human occupation. Most subsequent research on North African prehistory refers to his discoveries and interpretations, but the chronology of its archaeological and geological sequences has been based on very early age determinations. This paper reports on the initial results of a comprehensive multi-method dating program undertaken as part of new work at the site, involving radiocarbon dating of charcoal, land snails and marine shell, cryptotephra investigations, optically stimulated luminescence (OSL) dating of sediments, and electron spin resonance (ESR) dating of tooth enamel. The dating samples were collected from the newly exposed and cleaned faces of the upper 7.5 m of the â¼14.0 m-deep McBurney trench, which contain six of the seven major cultural phases that he identified. Despite problems of sediment transport and reworking, using a Bayesian statistical model the new dating program establishes a robust framework for the five major lithostratigraphic units identified in the stratigraphic succession, and for the major cultural units. The age of two anatomically modern human mandibles found by McBurney in Layer XXXIII near the base of his Levalloiso-Mousterian phase can now be estimated to between 73 and 65 ka (thousands of years ago) at the 95.4% confidence level, within Marine Isotope Stage (MIS) 4. McBurney's Layer XXV, associated with Upper Palaeolithic Dabban blade industries, has a clear stratigraphic relationship with Campanian Ignimbrite tephra. Microlithic Oranian technologies developed following the climax of the Last Glacial Maximum and the more microlithic Capsian in the Younger Dryas. Neolithic pottery and perhaps domestic livestock were used in the cave from the mid Holocene but there is no certain evidence for plant cultivation until the Graeco-Roman period.
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Arqueologia , Cavernas , Cronologia como Assunto , Teorema de Bayes , Espectroscopia de Ressonância de Spin Eletrônica , Fósseis , Sedimentos Geológicos/análise , Humanos , Medições Luminescentes , Datação RadiométricaRESUMO
PURPOSE: To evaluate factors affecting corneoscleral profile (CSP) using anterior segment optical coherence tomography (AS-OCT) in combination with conventional videokeratoscopy. METHODS: OCT DATA WERE COLLECTED FROM 204 SUBJECTS OF MEAN AGE 34.9 YEARS (SD: ±15.2 years, range 18-65) using the Zeiss Visante AS-OCT and Medmont M300 corneal topographer. Measurements of corneal diameter (CD), corneal sagittal height (CS), iris diameter (ID), corneoscleral junction angle (CSJ), and scleral radius (SR) were extracted from multiple OCT images. Horizontal visible iris diameter (HVID) and vertical palpebral aperture (PA) were measured using a slit lamp graticule. Subject body height was also measured. Associations were then sought between CSP variables and age, height, ethnicity, sex, and refractive error. RESULTS: Significant correlations were found between age and ocular topography variables of HVID, PA, CSJ, SR, and ID (P < 0.0001), while height correlated with HVID, CD, and ID, and power vector terms with vertical plane keratometry, CD, and CS. Significant differences were noted between ethnicities with respect to CD (P = 0.0046), horizontal and vertical CS (P = 0.0068 and P = 0.0095), and horizontal ID (P = 0.0010). The same variables, with the exception of vertical CS, also varied with sex; horizontal CD (P = 0.0018), horizontal CS (P = 0.0018), and ID (P = 0.0012). Age accounted for the greatest variance in topography variables (36%). CONCLUSIONS: Age is the main factor influencing CSP; this should be taken into consideration in contact lens design, IOL selection, and in the optimization of surgical procedures. Ocular topography also varied with height, sex, ethnicity, and refractive error.
Assuntos
Córnea/anatomia & histologia , Topografia da Córnea/métodos , Topografia da Córnea/normas , Esclera/anatomia & histologia , Tomografia de Coerência Óptica/métodos , Tomografia de Coerência Óptica/normas , Adolescente , Adulto , Fatores Etários , Idoso , Segmento Anterior do Olho/anatomia & histologia , Estudos Transversais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Erros de Refração/patologia , Reprodutibilidade dos Testes , Fatores Sexuais , Adulto JovemRESUMO
PURPOSE: To evaluate the ease with which astigmats from three groups of current non-wearers of toric contact lenses can be fitted with current toric soft lenses, and to determine toric lens-wearing success. METHODS: This was a 1-month, randomized, bilateral, open-label, daily wear study involving 200 subjects and 16 investigational sites in the UK. Three groups of astigmatic subjects aged from 16 to 60 and with a mean age of 36 years (67 spherical soft contact lens users, SW; 72 contact lens drop-outs, DO; and 61 neophytes, Neo) were fitted with one of two toric soft lens types: a daily disposable toric soft lens (1 Day Acuvue Moist for Astigmatism, Johnson & Johnson Vision Care) or a 2-weekly replacement, re-usable toric soft lens (Acuvue Oasys for Astigmatism, Johnson & Johnson Vision Care). Subjects were evaluated after 1 month of wear and success rates calculated according to pre-set criteria for acceptable fit, orientation stability, visual acuity, quality of vision, and overall comfort. RESULTS: Eighty-eight percent of lenses were fitted at the first attempt. Of 198 subjects dispensed with lenses, 182 (92%) completed the study. When analysed by subject group, the success rates according to the pre-set criteria were 80% (53/66), 74% (52/70), and 70% (39/56) for the SW, DO and Neo groups respectively. Comfort was the most common reason for failure with all three groups; however, visual problems were more common in the DO and Neo groups (13% vs 6%). VA with the study lenses was significantly better in the SW group compared to their habitual lenses. For the DO and Neo groups combined (i.e. spectacle wearers), visual acuity was comparable to their habitual spectacles. CONCLUSIONS: A high proportion of astigmats who are not using toric soft contact lenses can be fitted with current lenses. Previous contact lens drop-outs and neophyte wearers achieve visual acuity comparable to spectacles when fitted with toric soft lenses. Spherical contact lens wearing astigmats achieve superior visual acuity when refitted with toric soft lenses. These findings suggest that many astigmats who are not currently using toric soft contact lenses could do so successfully.
Assuntos
Astigmatismo/reabilitação , Lentes de Contato Hidrofílicas , Adolescente , Adulto , Análise de Variância , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Reino Unido , Acuidade Visual , Adulto JovemRESUMO
PURPOSE: To estimate the prevalence of self-reported "sensitive eyes" (SEs) in soft contact lens (CL) wearers, evaluate the clinical characteristics of patients with SEs, and examine the effect of refitting them with silicone hydrogel lenses. METHODS: After self-assessment, 2154 CL wearers were separated into SE and non-SE patients. Demographics, biometric data, wearing time, symptoms, and signs were compared between the two populations. Sixty-three SE patients were randomized into senofilcon A (senA) lenses and 65 into a non-senA arm (lotrafilcon B, omafilcon A, and balafilcon A lenses). The performance of senA lenses was compared against habitual and non-senA lenses 2 weeks later. RESULTS: A total of 12.2% of CL wearers reported SEs with their habitual CLs. No significant differences were noticed between SE and non-SE patients in sex, age, or refraction. The prevalence of dryness (43 vs 19%, p < 0.0001), irritation (25 vs 11%, p < 0.0001), redness (20 vs 6%, p < 0.0001), and stinging (6 vs 1%, p < 0.0001) was higher in SE patients. Average wearing time (13.0 vs 14.1 hours, p < 0.0001) was lower in this group. Limbal/bulbar hyperemia and corneal/conjunctival staining were not significantly different between the two populations. Senofilcon A increased the number of patients reporting no dryness (habitual vs senA, 20 vs 44%, p < 0.0003), irritation (22 vs 37%, p = 0.015), redness (52 vs 76%, p =0.009) and stinging (58 vs 77%, p = 0.012) but did not significantly affect clinical signs. Senofilcon A was significantly more efficient than non-senA lenses in improving dryness (scale of 0 to 3: senA vs non-senA, 0.64 vs 1.02, p = 0.0056), irritation (0.72 vs 1.16, p = 0.0015), and stinging (0.18 vs 0.53, p = 0.0049). CONCLUSIONS: A substantial proportion of CL wearers report SEs with their habitual lenses. These patients are characterized by a high prevalence of additional symptoms, which are not reflected in clinical signs. Senofilcon A, or lenses with similar properties, may help reduce these symptoms in SE patients.
Assuntos
Doenças da Túnica Conjuntiva/epidemiologia , Lentes de Contato Hidrofílicas/efeitos adversos , Doenças da Córnea/epidemiologia , Hiperemia/epidemiologia , Limbo da Córnea/irrigação sanguínea , Adolescente , Adulto , Túnica Conjuntiva/irrigação sanguínea , Doenças da Túnica Conjuntiva/diagnóstico , Doenças da Túnica Conjuntiva/etiologia , Doenças da Córnea/diagnóstico , Doenças da Córnea/etiologia , Feminino , Seguimentos , Humanos , Hiperemia/diagnóstico , Hiperemia/etiologia , Masculino , Prevalência , Ajuste de Prótese , Erros de Refração/terapia , Inquéritos e Questionários , Adulto JovemRESUMO
PURPOSE: To evaluate predisposing factors in subjects susceptible to solution-induced corneal staining (SICS). METHODS: Four hundred forty-six existing soft contact lens wearers were randomly fitted with one of two study lenses (lotrafilcon B, CIBA Vision, or omafilcon A, CooperVision) and used a hydrogen peroxide care system (Clear Care, CIBAVision) for a 1-month period. Each subject was then challenged with the same lenses presoaked in a multipurpose solution (ReNu MultiPlus, Bausch & Lomb) and assessed after approximately 2 h to be categorized as either "stainers" or "non-stainers" based on whether they showed a classic SICS pattern (diffuse punctate corneal staining in three or more peripheral quadrants). RESULTS: Overall, 36% (155 of 425) of eligible subjects were classified as stainers and included a higher proportion of omafilcon wearers: 44% (91 of 205) vs. 29% (64 of 220). After using the peroxide system, the stainers were more likely to show poorer wetting (odds ratio [OR] = 1.76, p = 0.02) compared with the non-stainers. Lens wetting showed a significant negative correlation with film deposits (r = -0.63, p < 0.0001, n = 425). Furthermore, on slit lamp examination, the stainers were more likely to show higher levels of upper- and lower-palpebral hyperemia (OR = 2.18, p = 0.02; OR = 1.93, p = 0.04), tarsal roughness (OR = 1.71, p = 0.01), corneal staining (OR = 17.1, p < 0.0001), and conjunctival staining (OR = 1.94, p = 0.004). Although not exposed to preservatives, twice as many eyes in the stainers group had some level of corneal staining: 51% vs. 25%. There were no significant differences between the stainers and non-stainers with respect to age, sex, refraction, or keratometry (p > 0.05). CONCLUSIONS: This study highlighted some notable trends in patients susceptible to SICS. The findings point toward poor tear quality as a predisposing factor for SICS.