The critical period for surgical treatment of dense congenital unilateral cataract

-fX Purpose. Early treatment of dense congenital unilateral cataract is associated with better acuity outcomes. It is unclear whether there is a gradual worsening of prognosis with delay of treatment from the time of birth (linear model) or whether there exists an early window of time during which treatment is maximally effective, followed by declining success (bilinear model). The aim of the current study was to determine which model better describes the response to treatment. Methods. A maximum likelihood procedure that permits statistical comparison between linear and bilinear models was applied to acuity outcomes from a group of 45 children 5 to 8 years of age with a history of dense congenital unilateral cataract diagnosed at 1 to 10 days of age. Contrast sensitivity and vernier acuity data from a subset of these children were evaluated with nonparametric statistical methods. Results. The bilinear model provided a significantly better fit to the acuity outcome data. The line fitted to the initial portion of the function had a shallow slope that was not significantly different from 0.0. The intersection of the two linear functions occurred at 5.6 weeks and was followed by a steep decline in visual acuity outcomes. Contrast sensitivity and vernier outcome measures over a range of spatiotemporal conditions showed better outcomes were obtained with early treatment. Conclusions. Intervention before 6 weeks of age may minimize the effects of congenital unilateral deprivation on the developing visual system and provide for optimal rehabilitation of visual acuity. Invest Ophthalmol Vis Sci. 1996;37:1532-153

Full lifetime perspectives on the costs and benefits of lay date variation in tree swallows

Animals must balance various costs and benefits when deciding when to breed. The costs and benefits of breeding at different times have received much attention, but most studies have been limited to investigating short-term season-to-season fitness effects. However, breeding early, versus late, in a season may influence lifetime fitness over many years, trading off in complex ways across the breeder?s lifepan. In this study, we examined the complete life histories of 867 female tree swallows (Tachycineta bicolor) breeding in Ithaca, New York, between 2002 and 2016. Earlier breeders outperformed later breeders in short-term measures of reproductive output and offspring quality. Though there were weak indications that females paid long-term future survival costs for breeding early, lifetime fledgling output was markedly higher overall in early-breeding birds. Importantly, older females breeding later in the season did not experience compensating life-history advantages that suggested an alternative equal-fitness breeding strategy. Rather, most or all of the swallows appear to be breeding as early as they can, and differences in lay dates appear to be determined primarily by differences in individual quality or condition. Lay date had a significant repeatability across breeding attempts by the same female, and the first lay date of females fledged in our population was strongly influenced by the first lay date of their mothers, indicating the potential for ongoing selection on lay date. By examining performance over the entire lifespan of a large number of individuals, we were able to clarify the relationship between timing of breeding and fitness and gain new insight into the sources of variability in this important life history trait.Fil: Winkler, David Ward. Cornell University; Estados UnidosFil: Hallinger, Kelly K.. Cornell University; Estados UnidosFil: Pegan, Teresa M.. University of Michigan; Estados UnidosFil: Taff, Conor C.. Cornell University; Estados UnidosFil: Verhoeven, Mo A.. University of Groningen; Países BajosFil: Van Oordt, David Chang. Cornell University; Estados UnidosFil: Stager, Maria. University of Montana; Estados UnidosFil: Uehling, Jennifer J.. Cornell University; Estados UnidosFil: Vitousek, Maren N.. Cornell University; Estados UnidosFil: Andersen, Michael J.. University of New Mexico; Estados UnidosFil: Ardia, Daniel R.. Franklin & Marshall College; Estados UnidosFil: Belmaker, Amos. Tel Aviv University; IsraelFil: Ferretti, Valentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Ecología, Genética y Evolución de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Ecología, Genética y Evolución de Buenos Aires; ArgentinaFil: Forsman, Anna M.. University Of Central Florida; Estados UnidosFil: Gaul, Jennifer R.. International High School at La Guardia Community College; Estados UnidosFil: Llambias, Paulo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Orzechowski, Sophia C.. Harvard University; Estados UnidosFil: Shipley, Ryan. Max Planck Institute For Animal Behavior; AlemaniaFil: Wilson, Maya. Virginia Polytechnic Institute. Department Of Geological Sciences; Estados UnidosFil: Yoon, Hyun Seok. University of Tennessee; Estados Unido

Late Holocene linkages between decade–century scale climate variability and productivity at Lake Tanganyika, Africa

Microlaminated sediment cores from the Kalya slope region of Lake Tanganyika provide a near-annually resolved paleoclimate record between ~~2,840 and 1,420 cal. yr B.P. demonstrating strong linkages between climate variability and lacustrine productivity. Laminae couplets comprise dark, terrigenous-dominated half couplets, interpreted as low density underflows deposited from riverine sources during the rainy season, alternating with light, planktonic diatomaceous ooze, with little terrigenous component, interpreted as windy/dry season deposits. Laminated portions of the studied cores consist of conspicuous dark and light colored bundles of laminae couplets. Light and dark bundles alternate at decadal time scales. Within dark bundles, both light and dark half couplets are significantly thinner than within light bundles, implying slower sediment accumulation rates during both seasons over those intervals. Time series analyses of laminae thickness patterns demonstrate significant periodicities at interannual¿centennial time scales. Longer time scale periodicities (multidecadal to centennial scale) of light and dark half couplet thicknesses are coherent and in some cases are similar to solar cycle periods on these time scales. Although laminae thickness cycles do not strongly covary with the actual ¿14C record for this same time period, two large ¿14C anomalies are associated with substantial decreases in both light and dark laminae thickness. In contrast to the multidecadal¿ centennial time scale, significant annual to decadal periodicities, which are broadly consistent with ENSO/PDO forcing and their impact on East African climate, are not coherent between light and dark half couplets. The coherency of light¿dark couplets at decadal¿centennial time scales, but not at shorter time scales, is consistent with a model of a long-term relationship between precipitation (recorded in wet season dark laminae thickness) and productivity (light laminae thickness), which is not manifest at shorter time scales. We hypothesize that this coupling results from long-term recharging of internal nutrient loading during wet periods (higher erosion of soil P) and reduced loading during drought intervals. The relationship is not expressed on short time scales during which the dominant control on productivity is wind-driven, dry season upwelling, which is uncorrelated with wet-season precipitation. Our record greatly extends the temporal record of this quasi-periodic behavior throughout the late Holocene and provides the first evidence linking decade- to century-scale episodes of enhanced productivity to enhanced precipitation levels and nutrient recharge in a productive tropical lake

Lakeside View: Sociocultural Responses to Changing Water Levels of Lake Turkana, Kenya

Throughout the Holocene, Lake Turkana has been subject to drastic changes in lake levels and the subsistence strategies people employ to survive in this hot and arid region. In this paper, we reconstruct the position of the lake during the Holocene within a paleoclimatic context. Atmospheric forcing mechanisms are discussed in order to contextualize the broader landscape changes occurring in eastern Africa over the last 12,000 years. The Holocene is divided into five primary phases according to changes in the strand-plain evolution, paleoclimate, and human subsistence strategies practiced within the basin. Early Holocene fishing settlements occurred adjacent to high and relatively stable lake levels. A period of high-magnitude oscillations in lake levels ensued after 9,000 years BP and human settlements appear to have been located close to the margins of the lake. Aridification and a final regression in lake levels ensued after 5,000 years BP and human communities were generalized pastoralists-fishers-foragers. During the Late Holocene, lake levels may have dropped below their present position and subsistence strategies appear to have been flexible and occasionally specialized on animal pastoralism. Modern missionary and government outposts have encouraged the construction of permanent settlements in the region, which are heavily dependent on outside resources for their survival. Changes in the physical and cultural environments of the Lake Turkana region have been closely correlated, and understanding the relationship between the two variables remains a vital component of archaeological research

Onset and Progression of With-the-Rule Astigmatism in Children with Infantile Nystagmus Syndrome

Both our cross-sectional and longitudinal data showed that with-the-rule astigmatism is common among children with infantile nystagmus syndrome and increases in magnitude with age during the first 8 years of life

Binocular iPad treatment for amblyopia in preschool children

Photograph of a scene in a neighborhood affected by toxic waste from a Conoco Refinery Plant