Search

Your search keyword '"Holmes, Jonathan"' showing total 1,694 results
Start Over Author "Holmes, Jonathan"
1,694 results on '"Holmes, Jonathan"'

4. Complications, Visual Acuity, and Refractive Error 3 Years after Secondary Intraocular Lens Implantation for Pediatric Aphakia

Author

Freedman, Sharon F., Wallace, David K., Enyedi, Laura B., Prakalapakorn, Sasapin, Jones, Sarah K., Hug, Denise, Stahl, Erin D., Dent, Rebecca J., Kong, Lingkun, Wang, Serena, Gallerson, Bryan K., Hutchinson, Amy K., Lenhart, Phoebe, Brower, Judy, Morrison, David G., Ruark, Scott T., Mets-Halgrimson, Rebecca, Yoon, Hawke, Ralay-Ranaivo, Hantamalala, Hamidullah, Aaliyah, Areaux, Raymond, Anderson, Jill S., Holleschau, Ann M., Superstein, Rosanne, Belanger, Caroline, Fallaha, Nicole, Hamel, Patrick, Thibeault, Maryse, Tamkins, Susanna M., Chang, Ta, Park, Hee-Jung S., Trumler, Anya A., Liu, Xiaonong, Astle, William F., Sanders, Emi N., Traboulsi, Elias, Ghasia, Fatema, McOwen, Diana C., Gray, Michael E., Yang, Michael B., Bowman, Corey S., Galvin, Jennifer, Therriault, Margaret, Smith, Heather, Whitaker, Michele E., Orge, Faruk, Grigorian, Adriana P., Baird, Alicia M., Strominger, Mitchell B., Chen, Vicki, Klein, Shelley, Kemmer, Jacquelyn D., Neiman, Alexandra E., Mendoza, Myra N., Frohwein, Jill J., Bremer, Don, Cassady, Cybil, Golden, Richard, Jordan, Catherine, Rogers, David, Oravec, Sara A., Yanovitch, Tammy L., Lunsford, Keven, Nye, Christina, Shea, Caroline, Stillman, SueAnn M., LaRoche, G. Robert, Van Iderstine, Stephen C., Robertson, Elisa, Cruz, Oscar A., Ghadban, Rafif, Govreau, Dawn, Larson, Scott A., Longmuir, Susannah, Shan, Xiaoyan, Clarke, Michael P., Taylor, Kate, Powell, Christine, Hammond, Benjamin P., Gearinger, Matthew D., Czubinski, Andrea, Hendricks, Dorothy H., Jin, Jing, Salvin, Jonathan H., Fisher, Alicia, Lee, Katherine A., Brooks, Daniel, Schweinler, Bonita R., Sala, Nicholas A., Sala, Allyson M., Summers, Allison I., Karr, Daniel J., Wilson, Lorri B., Rauch, Paula K., O'Hara, Mary, Gandhi, Nandini, Hashmi, Tania, Colburn, Jeffrey, Dittman, Eileen, Whitfill, Charles R., Wheeler, Amy M., McCourt, Emily A., Singh, Jasleen, Welnick, Nanastasia, Azar, Nathalie F., Baker, Joseph, Droste, Patrick J., Peters, Robert J., Hilbrands, Jan, Pineles, Stacy L., Bernardo, Marianne J., Peterson, Edward, Peterson, Charla H., Kumar, Kartik, Melese, Ephrem, Lingua, Robert, Grijalva, Jeff, Crouch, Earl R., jr., Crouch, Earl R., III, Ventura, Gaylord, Anninger, William, Benson, Shawn L., Karp, Karen A., Smith, Jordana M., Brickman-Kelleher, Jill, Ticho, Benjamin H., Khammar, Alexander J., Clausius, Deborah A., Guo, Suquin, Suh, Donny, Chamberlain, Carolyn, Schloff, Susan, Madigan, William P., Burkman, Donna, Christiansen, Stephen P., Ramsey, Jean E., McConnell, Kate H., Friedman, Ilana, Rosado, Jose, Sauberan, Donald P., Hemberger, Jody C., Davis, Patricia L., Rudaitis, Indre, Lowery, Robert S., Cupit, Shawn, Bothun, Erick D., Mohney, Brian G., Wernimont, Suzanne M., Neilsen, Rebecca A., Herlihy, Erin P., Baran, Francine, Gladstone, Amy, Smith, Justin, Mellott, Mei, Kieser, Troy, Erzurum, S. Ayse, Colon, Beth, Shah, Birva, Quebbemann, Micaela, Beck, Roy W., Austin, Darrell S., Boyle, Nicole M., Conner, Courtney L., Chandler, Danielle L., Donahue, Quayleen, Fimbel, Brooke P., Robinson, Julianne L., Hercinovic, Amra, Hoepner, James E., Kaplon, Joseph D., Henderson, Robert J., Melia, B. Michele, Ortiz, Gillaine, Woodard, Victoria C., Stutz, Kathleen M., Sutherland, Desirae R., Wu, Rui, Everett, Donald F., Diener-West, Marie, Baker, John D., Davis, Barry, Phelps, Dale L., Poff, Stephen W., Saunders, Richard A., Tychsen, Lawrence, Bradfield, Yasmin S., Foster, Nicole C., Plager, David A., Salchow, Daniel J., Birch, Eileen E., Manny, Ruth E., Silver, Jayne L., Weise, Katherine K., Verderber, Lisa C., Repka, Michael X., Dean, Trevano W., Kraker, Raymond T., Li, Zhuokai, Yen, Kimberly G., de Alba Campomanes, Alejandra G., Young, Marielle P., Rahmani, Bahram, Haider, Kathryn M., Whitehead, George F., Lambert, Scott R., Kurup, Sudhi P., Kraus, Courtney L., Cotter, Susan A., Holmes, Jonathan M., Hatt, Sarah R., and Traboulsi, Elias I.

Published
2024
Full Text
View/download PDF

5. The Pediatric Optic Neuritis Prospective Outcomes Study: Two-Year Results.

Author

Pineles, Stacy, Henderson, Robert, Repka, Michael, Heidary, Gena, Liu, Grant, Waldman, Amy, Borchert, Mark, Khanna, Sangeeta, Graves, Jennifer, Collinge, Janine, Conley, Julie, Davis, Patricia, Kraker, Raymond, Cotter, Susan, and Holmes, Jonathan

Subjects
Neuro-ophthalmology, Pediatric ophthalmology, Pediatric optic neuritis, Adolescent, Child, Child, Preschool, Female, Humans, Male, Multiple Sclerosis, Myelin-Oligodendrocyte Glycoprotein, Neoplasm Recurrence, Local, Neuromyelitis Optica, Optic Neuritis, Prospective Studies, Retrospective Studies, Vision Disorders
Abstract

PURPOSE: Pediatric optic neuritis (ON) is a rare disease that has not been well characterized. The Pediatric ON Prospective Outcomes Study (PON1) was the first prospective study to our knowledge aiming to evaluate visual acuity (VA) outcomes, including VA, recurrence risk, and final diagnosis 2 years after enrollment. DESIGN: Nonrandomized observational study at 23 pediatric ophthalmology or neuro-ophthalmology clinics in the United States and Canada. PARTICIPANTS: A total of 28 (64%) of 44 children initially enrolled in PON1 (age 3-

Published
2022

6. Adult Strabismus Preferred Practice Pattern®

Author

Dagi, Linda R., Velez, Federico G., Holmes, Jonathan M., Archer, Steven M., Strominger, Mitchell B., Pineles, Stacy L., Paysse, Evelyn A., Pihlblad, Matthew Simon, Atalay, Hatice Tuba, Campolattaro, Brian N., and Chang, Yoon-Hee

Published
2024
Full Text
View/download PDF

9. Eight-Year Outcomes of Bilateral Lateral Rectus Recessions versus Unilateral Recession-Resection in Childhood Basic-Type Intermittent Exotropia

Author

Miller, Aaron M., Olvera, Maria N., Alexander, Monsey L., Curtin, Kathleen Mary, Dillon, Angela C., Gray, Carole L., Jackson, Jorie L., Qadir, Ximena V., Ramos, Cynthia R., Paysse, Evelyn A., Coats, David K., Yen, Kimberly G., Romany, Gihan, Homann, Melynda J., Kong, Lingkun, Law, Christine, Churchill, Sarah, MacSween, Lesley E., Hoover, Darren L., Huston, Pamela A., Racan, Pamela M., Soros, Kari E., Sala, Nicholas A., Sala, Nicholas Anthony, Johnson, Catherine, Sala, Allyson, Zeto, V. Lori, Donahue, Sean P., Wilkins, Carsyn Saige, Biernacki, Ronald J., Campbell, Megan K., Fraine, Lisa A., Ruark, Scott T., Crouch, Eric, Crouch, Earl R., Jr., Ventura, Gaylord G., Fritz, Carolina Andrea, Anderson, Jill S., Areaux, Raymond G., Jr, Holleschau, Ann M., Harder, Jessica Ann, May, Laura M., Merrill, Kim S., Schweigert, Anna I., Petersen, David B., Pickens, Tori S., McMurtrey, J. Ryan, Morrell, Beth A., Repka, Michael X., Liu, Xiaonong, Christoff, Alex, Silbert, David I., Modjesky, Heather, Woodall, Hayley L., Summers, Allison I., Kuo, Annie F., Wilson, Lorri B., Rauch, Paula, Lee, Jessy, Casey, Grant A., Narain, Srianna, Woodruff, Kevin, Ticho, Benjamin H., Clausius, Deborah A., Allen, Megan, Quebbemann, Micaela N., Shah, Birva K., Bothun, Erick D., Holmes, Jonathan M., Mohney, Brian G., Wernimont, Suzanne M., Czaplewski, Lindsay L., Eastman, Stacy L., Huisman, Jordan Joseph, Klaehn, Lindsay D., Kramer, Andrea M., Kroening, Rose M., Priebe, Debbie M., Wohlers, Moriah A., Jensen, Allison A., Flanagan, Maureen A., Tolbert, Tiffany Talia, Traboulsi, Elias, Ghasia, Fatema F., Meador, Angela M., McOwen, Diana Christine, Enyedi, Laura B., Jones, Sarah K., Kashyap, Namita, Loud, Rachel N., Waters, Amy L., Marsh, Justin D., Bond, Lezlie L., Ariss, Michelle M., Dent, Rebecca J., Phillips, Paul H., Lowery, Robert Scott, Haley, Wendy Jean, Brown, Shaina, Colon, Beth, Cupit, Shawn L., Holtorf, Hannah L., Sanders, Hayley Elizabeth, Bowsher, James D., Cheeseman, Edward W., Weas, Nikki M., Bradham, Carol U., Rahmani, Bahram, Ranaivo, Hantamalala Ralay, Cruz, Karla G., De Leon, Erika A., Klauer, Anthony Jeffrey, Tzanetakos, Vivian, McCoy Vrablec, Laura, Orge, Faruk H., Richards, Leslie, Baird, Alicia Marie, Glaser, Stephen R., Yost, Kasey L., Flores, Odalis R., Herlihy, Erin P., Taira, Alyssa, Alexander, Jessica, Gladstone, Amy, Kiens, Bridget Ann, Tews, Lyndsey A., Whitehead, George F., Shea, Caroline J., Stillman, SueAnn Marie, Nye, Christina N., Bartiss, Michael John, McGaw, Tennille F., Davis, Patricia L., Hulett, Katie R., Twite, Jacqueline, Bradfield, Yasmin S., Adler, Angela M., Anderson, Kristin A., Kraker, Raymond T., Beck, Roy W., Austin, Darrell S., Boyle, Nicole M., Chandler, Danielle L., Connelly, Patricia L., Conner, Courtney L., Donahue, Quayle, Fimbel, Brooke P., Henderson, Robert J., Hoepner, James E., Kaplon, Joseph D., Melia, B. Michele, Ortiz, Gillaine, Robinson, Julianne L., Stutz, Kathleen M., Sutherland, Desirae R., Toro, David O., Woodard, Victoria C., Wu, Rui, Cotter, Susan A., Birch, Eileen E., Christiansen, Stephen P., Hatt, Sarah R., Leske, David A., Melia, Michele, O’Hara, Mary, Pang, Yi, Romanchuck, Kenneth, Tamkins, Susanna M., Wallace, David K., Wheeler, David T., Bhatt, Amit, Chen, Angela M., Cheung, Nathan L., Cobb, Patricia, Colon, Beth J., Crouch, Eric R., Dean, Trevano W., Erzurum, S. Ayse, Esposito, Christina A., Fang, Caroline C., Gray, Michael E., Gunton, Kammi B., Hopkins, Kristine B., Jastrzembski, Benjamin G., Jenewein, Erin C., Jordan, Catherine O., Kraus, Courtney, Kurup, Sudhi P., Lazar, Elizabeth L., Li, Zhuokai, Lorenzana, Ingryd, McDowell, Paula S., Morrison, Ann M., Morrison, David G., Nylin, Elyse, Parker, Sue M., Patel, Reena, Plaumann, Maureen D., Pollack, Karen, Raghuram, Aparna, Retnasothie, Dashaini V., Roberts, Tawna L., Scheiman, Mitchell M., Shah, Veeral S., Superstein, Rosanne, Titelbaum, Jenna R., Vricella, Marilyn, Yamada, Tomohiko, Astle, William F., Christian, Melanie L., Everett, Donald F., Freedman, Sharon F., Good, William V., Lambert, Scott R., Lee, Katherine A., London, Richard, Manh, Vivian M., Manny, Ruth E., Pineles, Stacy L., Rogers, David L., Schweinler, Bonita R., Silver, Jayne L., Suh, Donny W., Verderber, Lisa C., Weise, Katherine K., Diener-West, Marie, Baker, John D., Davis, Barry, Higgins, Rosemary D., Poff, Stephen W., Saunders, Richard A., and Tychsen, Lawrence

Published
2024
Full Text
View/download PDF

13. A Randomized Clinical Trial of Immediate Versus Delayed Glasses for Moderate Hyperopia in Children 3 to 5 Years of Age.

Author

Holmes, Jonathan, Kulp, Marjean, Dean, Trevano, Suh, Donny, Kraker, Raymond, Wallace, David, Petersen, David, Cotter, Susan, Crouch, Earl, Lorenzana, Ingryd, Ticho, Benjamin, Verderber, Lisa, and Weise, Katherine

Subjects
Child, Preschool, Depth Perception, Eyeglasses, Female, Humans, Hyperopia, Male, Prospective Studies, Strabismus, Time-to-Treatment, Vision, Binocular, Visual Acuity
Abstract

PURPOSE: To compare visual acuity (VA) and binocularity outcomes in moderately hyperopic children with normal VA and binocularity assigned to glasses versus observation. DESIGN: Prospective randomized clinical trial (RCT). METHODS: One hundred nineteen 3- to 5-year-old children with hyperopia between +3.00D and +6.00D spherical equivalent were randomly assigned to glasses versus observation (with glasses prescribed if deteriorated for subnormal distance VA or near stereoacuity, or manifest strabismus). Follow-up occurred every 6 months. At 3 years, the treatment strategy was classified as failed if any of the following were met, both with and without correction: subnormal distance VA or stereoacuity; manifest strabismus; or strabismus surgery during follow-up. RESULTS: Of 84 (71%) children who completed the primary outcome examination, failure occurred in five (12%; 95% confidence interval [CI]: 4%-26%) of 41 assigned to glasses and four (9%; 95% CI: 3%-22%) of 43 assigned to observation (difference = 3%; 95% CI: -12%-18%; P = .72). Deterioration prior to 3 years (requiring glasses per protocol) occurred in 29% (95% CI: 19%-43%) assigned to glasses and 27% (95% CI: 17%-42%) assigned to observation. CONCLUSIONS: In an RCT comparing glasses to observation for moderately hyperopic 3- to 5-year-old children with normal VA and binocularity, failure for VA or binocularity was not common. With insufficient enrollment and retention, our study was unable to determine whether immediate glasses prescription reduces failure rate, but low failure rates suggest that immediate glasses prescription for these children may not be needed to prevent failure for VA and/or binocularity.

Published
2019

15. Design and performance assessment of a low-cost rain collector for stable isotope samples.

Author

DIXIT, YAMA, HOLMES, JONATHAN A., and SINGH, ANUBHAV

Subjects
*ATMOSPHERIC sciences, *STABLE isotope analysis, *ATMOSPHERIC models, *OXYGEN isotopes, *ENVIRONMENTAL research, *RAINFALL, *RAIN gauges
Abstract

The article discusses the design and performance assessment of a low-cost rain collector for stable isotope samples, focusing on the importance of oxygen and hydrogen isotope ratios in precipitation for hydroclimatic studies. The study presents a low-cost rain collector design that minimizes post-collection fractionation, validated through control experiments in Delhi during the 2023 summer monsoon. The rain collector's cost-effective construction and performance make it suitable for establishing dense sampling networks for rainfall isotopes, providing valuable insights into past and present hydroclimate dynamics. The study highlights the significance of appropriate rainwater collection methods to preserve sample integrity and isotopic composition for research purposes. [Extracted from the article]

Published
2024

16. Treatment of amblyopia as a function of age

Author

HOLMES, JONATHAN M and LEVI, DENNIS M

Subjects
Biomedical and Clinical Sciences, Ophthalmology and Optometry, Clinical Research, Pediatric, Brain Disorders, Neurosciences, Eye Disease and Disorders of Vision, Evaluation of treatments and therapeutic interventions, 6.1 Pharmaceuticals, Eye, Age Factors, Aging, Amblyopia, Child, Child, Preschool, Humans, Binocular, Videogames, Perceptual learning, Patching, Pharmacological treatment, Motor activity, Phenotyping, Medical and Health Sciences, Psychology and Cognitive Sciences, Neurology & Neurosurgery, Ophthalmology and optometry
Abstract

Although historically, treatment of amblyopia has been recommended prior to closure of a critical window in visual development, the existence and duration of that critical window is currently unclear. Moreover, there is clear evidence, both from animal and human studies of deprivation amblyopia, that there are different critical windows for different visual functions and that monocular and binocular deprivation have different neural and behavioral consequences. In view of the spectrum of critical windows for different visual functions and for different types of amblyopia, combined with individual variability in these windows, treatment of amblyopia has been increasingly offered to older children and adults. Nevertheless, treatment beyond the age of 7 years tends to be, on average, less effective than in younger children, and the high degree of variability in treatment response suggests that age is only one of many factors determining treatment response. Newly emerging treatment modalities may hold promise for more effective treatment of amblyopia at older ages. Additional studies are needed to characterize amblyopia by using new and existing clinical tests, leading to improved clinical classification and better prediction of treatment response. Attention also needs to be directed toward characterizing and measuring the impact of amblyopia on the patients' functional vision and health-related quality of life.

Published
2018

18. Doses of medial rectus muscle recessions for divergence insufficiency-type esotropia

Author

Miller, Aaron M., primary, Holmes, Jonathan M., additional, Wu, Rui, additional, Kraker, Raymond T., additional, Crouch, Eric R., additional, Lee, Katherine A., additional, Del Monte, Monte A., additional, Marsh, Justin D., additional, Kraus, Courtney L., additional, Wallace, David K., additional, Colburn, Jeffrey D., additional, Kemp, Pavlina S., additional, Cotter, Susan A., additional, Beck, Roy W., additional, Alvarez, Gillaine, additional, Austin, Darrell S., additional, Boyle, Nicole M., additional, Chandler, Danielle L., additional, Connelly, Patricia L., additional, Conner, Courtney L., additional, Dean, Trevano W., additional, Donahue, Quayleen, additional, Fimbel, Brooke P., additional, Henderson, Robert J., additional, Hercinovic, Amra, additional, Hoepner, James E., additional, Kaplon, Joseph D., additional, Li, Zhuokai, additional, Melia, B. Michele, additional, Robinson, Julianne L., additional, Shah, Jennifer A., additional, Toro, David O., additional, Jenewein, Erin C., additional, Felius, Joost, additional, Collins, Megan E., additional, Leske, David A., additional, Astle, William F., additional, Birch, Eileen E., additional, Chen, Angela M., additional, Christian, Melanie L., additional, Christiansen, Stephen P., additional, Crouch, Earl R., additional, Donahue, Sean P., additional, Enyedi, Laura B., additional, Erzurum, S. Ayse, additional, Everett, Donald F., additional, Freedman, Sharon F., additional, Good, William V., additional, Lambert, Scott R., additional, London, Richard, additional, Manh, Vivian M., additional, Manny, Ruth E., additional, Morrison, David G., additional, Pineles, Stacy L., additional, Ranaivo, Hantamalala Ralay, additional, Repka, Michael X., additional, Ruark, Scott T., additional, Schweinler, Bonita R., additional, Silver, Jayne L., additional, Summers, Allison I., additional, Verderber, Lisa C., additional, and Weise, Katherine K., additional

Published
2024
Full Text
View/download PDF

23. Stable-isotope variability in daily precipitation: insights from a low-cost collector in SE England.

Author

Holmes, Jonathan, Jourdan, Anne-Lise, and Darling, W. George

Subjects
*PRECIPITATION variability, *RAINFALL, *DEUTERIUM, *ISOTOPES, *WEATHER
Abstract

Precipitation stable-isotope data are often used in hydroclimatic, hydrological and hydrogeological investigations, with measurements typically undertaken on integrated monthly samples. However, daily sampling reveals overlooked aspects of controls on precipitation isotope values, including synoptic meteorological conditions. We present a one-year record of stable isotopes in daily precipitation during 2021, from a site in SE England close to Greater London. We find marked daily variability over the course of the year (–15.62 to +0.92 ‰ for δ18O, –108.7 to +2.9 ‰ for δ2H and –6.5 to +23.1 ‰ for deuterium excess). Correlations with individual meteorological variables including precipitation amount, temperature and weather type are moderate to weak suggesting complex controls on the daily rainfall isotope values. The daily data are compared with three other daily datasets from England and, by conversion to monthly values, directly with data from three long-term collection stations across Britain and Ireland. The scale of variability in the daily data from our site is consistent with that seen in other English records despite them all coming from different time periods. The monthly data show broad consistency, although there are differences that also highlight geographical variability in precipitation values across the British Isles. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

29. Evaluation of the Intermittent Exotropia Questionnaire using Rasch analysis.

Author

Leske, David, Holmes, Jonathan, and Melia, B

Subjects
Adolescent, Child, Child, Preschool, Cross-Sectional Studies, Exotropia, Female, Health Status, Humans, Infant, Male, Quality of Life, Reproducibility of Results, Sickness Impact Profile, Surveys and Questionnaires
Abstract

IMPORTANCE: The Intermittent Exotropia Questionnaire (IXTQ) is a patient, proxy, and parental report of quality of life specific to children with intermittent exotropia. We refine the IXTQ using Rasch analysis to improve reliability and validity. OBSERVATION: Rasch analysis was performed on responses of 575 patients with intermittent exotropia enrolled from May 15, 2008, through July 24, 2013, and their parents from each of the 4 IXTQ health-related quality-of-life questionnaires (child 5 through 7 years of age and child 8 through 17 years of age, proxy, and parent questionnaires). Questionnaire performance and structure were confirmed in a separate cohort of 379 patients with intermittent exotropia. One item was removed from the 12-item child and proxy questionnaires, and response options in the 8- to 17-year-old child IXTQ and proxy IXTQ were combined into 3 response options for both questionnaires. Targeting was relatively poor for the child and proxy questionnaires. For the parent questionnaire, 3 subscales (psychosocial, function, and surgery) were evident. One item was removed from the psychosocial subscale. Resulting subscales had appropriate targeting. CONCLUSIONS AND RELEVANCE: The Rasch-revised IXTQ may be a useful instrument for determining how intermittent exotropia affects health-related quality of life of children with intermittent exotropia and their parents, particularly for cohort studies.

Published
2015

33. Early Ipswichian (last interglacial) sea level rise in the channel region: Stone Point Site of Special Scientific Interest, Hampshire, England

Author

Briant, Rebecca M., Bates, Martin R., Boreham, Steve, Cameron, Nigel G., Coope, G. Russell, Field, Michael H., Hatch, B. Marcus, Holmes, Jonathan A., Keen, David H., Kilfeather, Aiobhean A., Penkman, Kirsty E.H., Simons, Rianne M.J., Schwenninger, Jean-Luc, Wenban-Smith, Francis F., Whitehouse, Nicola J., and Whittaker, John E.

Published
2019
Full Text
View/download PDF

40. Essays on Health Insurance Policy and Inequality in the United States

Author

Holmes, Jonathan

Subjects
Economics
Abstract

In this dissertation, I study how health insurance products are priced, and how consumers select health insurance products in the United States. The first chapter focuses on selection and choice at the broader level of health care markets, comparing Medicaid, employer sponsored insurance, and insurance exchanges. I study cross-market adverse selection in the context of the Affordable Care Act, which simultaneously expanded Medicaid while creating health insurance exchanges. Using state decisions to expand Medicaid and variation in federal reinsurance payments as identification, I find that Medicaid expansion reduced prices on individual health insurance exchanges by an average of $504 (9.7%) per person, per year. These price reductions on the individual market represent an indirect benefit of Medicaid expansion that is equal to 9% of the total costs of expansion, and increased enrollment of higher income individuals (above 400% of the Federal Poverty Level) on the individual market by 10%. I then estimate a structural demand model with rich individual heterogeneity across consumers using a combination of public and administrative datasets. This model shows that, while the 2014 Medicaid expansion reduced prices in private markets, further expansions to Medicaid would have the opposite effect because they target a healthier population. In the second chapter, we study differentiation across health insurance providers in the market for employer-sponsored health insurers. Using rich administrative data and firm and employer changes between plans we recover the causal contribution of private insurers/brands to health care spending overall, prices and quantities as well as granular measures of health care utilization. We find clear variation in total spending between private health insurers. E.g. moving from United Health Care to Regence causally increases spending by an average of 40%. We find that changes in spending between insurers are largely explained by differences in extensive margin measures of quantity of care consumed. We find much less differentiation across insurers in terms of bargaining over provider prices or utilization of high versus low value care.

Published
2021

46. The response of ostracod faunal assemblages to hydrology, lake level, and carbon cycling in a Jamaican marl lake: a palaeolimnological investigation.

Author

Greenway, Hannah, Holmes, Jonathan, and Burn, Michael

Subjects
BODIES of water, LAKE sediments, HYDROLOGY, CARBON cycle, GROUNDWATER
Abstract

Ostracod taxa from shallow freshwater lakes are sensitive to a range of limnological factors including temperature, hydrological habitat, lake level, and the distribution of aquatic plants. Ostracod assemblages preserved in Quaternary lake sediments can be used to reconstruct limnological change and are therefore potentially valuable palaeoenvironmental proxies. However, lack of autecological information about some taxa may limit the validity of such reconstructions. We use fossil ostracod assemblages recovered from radiocarbon-dated late Holocene sediments from Wallywash Great Pond, a small, shallow freshwater lake in southwestern Jamaica, to reconstruct limnological change over the past ∼ 1800 years. We circumvent ongoing taxonomic and ecological uncertainties associated with the identification of fossil ostracod taxa by drawing on observations of the ecology of ostracods found living in Jamaican water bodies. By combining this information with limnological data from the extant lake, and with sedimentological and isotopic data from the lake sediments, we show that a published interpretation of ostracod assemblages for the late Quaternary of Wallywash Great Pond is simplistic, at least for the late Holocene section of the sediment record. We conclude that changes in ostracod assemblages are linked to variations in the input of undersaturated groundwater to the northern part of the lake from which the core was recovered. These variations, which were driven by changes in the precipitation / evaporation ratio (effective moisture), also controlled sedimentation, with reduced effective moisture and a decline in undersaturated groundwater input favouring marl precipitation, whereas organic sediments are linked to increased effective moisture and enhanced groundwater input. Our findings suggest that the dramatic shifts in ostracod assemblages at this site are a complex response to changes in hydrology, sedimentology, and carbonate saturation rather than being a simple indicator of lake-level change. Combining ostracod assemblage data with the results of other palaeolimnological analyses also allows more detailed reconstructions to be made for this lake, and such a multiproxy approach is recommended for similar lakes elsewhere. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

47. Climate and atmospheric circulation during the Early and Mid-Holocene inferred from lake-carbonate oxygen-isotope records from western Ireland.

Author

HOLMES, JONATHAN A., TINDALL, JULIA, JONES, MATTHEW, HOLLOWAY, MAX, ROBERTS, NEIL, and FEESER, INGO

Subjects
ATMOSPHERIC circulation, ICE sheet thawing, OXYGEN isotopes, HUMIDITY, SEAWATER, LAKE sediments
Abstract

The Early to Mid-Holocene experienced marked climate change over the northern hemisphere midlatitudes in response to changing insolation and declining ice volume. Oxygen isotopes from lake sediments provide a valuable climate proxy, encoding information regarding temperature, hydroclimate and moisture source. We present oxygen-isotope records from two lakes in western Ireland that are strongly influenced by the North Atlantic. Excellent replication between the records suggests they reflect regional, not local, influences. Carbonate oxygenisotope values peaked at the start of the Holocene, between 11.2 and 11.1 cal ka BP, and then decreased markedly until 6 cal ka BP at both sites. Palaeoecological evidence supports only modest change in temperature or hydroclimate during this interval and we therefore explain the decrease primarily by a reduction in the oxygen-isotope composition of precipitation (δ18Oppt). We show a similar decrease in δ18O values in a forward model of carbonate isotopes between 12-11 and 6-5 cal ka BP. However, the inferred reduction in δ18Oppt between the Early and Mid-Holocene in the model is mainly linked to a decrease in the δ18O of the ocean source water from ice sheet melting whereas the lake carbonate isotope records are more consistent with changes in the transport pathway of moisture associated with atmospheric circulation change as the dominant cause. [ABSTRACT FROM AUTHOR]

Published
2024
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results