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The literature on disability has suggested that an educated individual with a disability is more likely to better cope with her/his disability than those without education. However, few published studies explore whether the relationship between education and ability to cope with a disability is anything more than an association. Using data on disability and accommodation from a large Danish survey from 2012-13 and exploiting a major Danish schooling reform as a natural experiment, we identified a potential causal effect of education on both economic (holding a job) as well as social (cultural activities, visiting clubs/associations, etc.) dimensions of coping among individuals with a disability, controlling for background factors, functioning, and disability characteristics. We found that endogeneity bias was only present in the case of economic participation and more educated individuals with a disability indeed had higher levels of both economic and social coping. To some extent, having more knowledge of public support systems and higher motivation explained the better coping among the group of individuals with disabilities who were educated. Our results indicated, however, that a large part of the effect of education on the ability to cope with a disability among individuals with disabilities was suggestive of a causal relationship.

Hearing loss is one of the most common conditions related to aging, and previous descriptive evidence links it to early exit from the labor market. These studies are usually based on self-reported hearing difficulties, which are potentially endogenous to labor supply. We use unique representative data collected in the spring of 2005 through in-home interviews. The data contains self-reported functional and clinically-measured hearing ability for a representative sample of the Danish population aged 50-64. We estimate the causal effect of hearing loss on early retirement via disability benefits, taking into account the endogeneity of functional hearing. Our identification strategy involves the simultaneous estimation of labor supply, functional hearing, and coping strategies (i.e. accessing assistive devices at work or informing one's employer about the problem). We use hearing aids as an instrument for functional hearing. Our main empirical findings are that endogeneity bias is more severe for men than women and that functional hearing problems significantly increase the likelihood of receiving disability benefits for both men and women. However, relative to the baseline the effect is larger for men (47% vs. 20%, respectively). Availability of assistive devices in the workplace decreases the likelihood of receiving disability benefits, whereas informing an employer about hearing problems increases this likelihood., (Copyright © 2016 Elsevier B.V. All rights reserved.)

In this paper, we use the policy variation of two different types of health insurance in the US and in Denmark - employer-provided and universal insurance combined with substantial differences in expected and actual medical out-of-pocket expenditures - to explore the effect of new severe health shocks on the labor force participation of older workers. Our results not only provide insight into how relative disease risk affects labor force participation at older ages, but also into how different types of health care and health insurance systems affect individual decisions of labor force participation. Although employer-tied health insurance and greater out-of-pocket medical expenditures give US Americans greater incentives to continue to work, we find only small differences in the work response between the two countries. We provide compelling evidence that our somewhat counterintuitive finding is the result of differential mortality and baseline health differences coupled with distinct treatment regimes under the respective health care systems., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Becker's theory of taste-based discrimination predicts that relative employment of the discriminated social group will improve if there is a decrease in the level of prejudice for the marginally discriminating employer. In this paper we experimentally test this prediction offered by Garry Becker in his seminal work on taste based discrimination, in the context of caste in India, with management students (potential employers in the near future) as subjects. First, we measure caste prejudice and show that awareness through a TV social program reduces implicit prejudice against the lower caste and the reduction is sustained over time. Second, we find that the treatment reduces the prejudice levels of those in the left tail of the prejudice distribution--the group which can potentially affect real outcomes as predicted by the theory. And finally, a larger share of the treatment group subjects exhibit favorable opinion about reservation in jobs for the lower caste.

A number of studies have documented negative long term effects of low birth weight. Yet, not much is known about the dynamics of the process leading to adverse health and educational outcomes in the long run. While previous studies focusing mainly on LBW effects on physical growth and cognitive outcomes have found effects of the same size at both school age and young adulthood, others have found a diminishing negative effect over time. The purpose of this paper was to bring new evidence to this issue by analyzing the medium run effects of low birth weight on child behavioral outcomes as well as physical growth at ages 6 months, 3, 7 and 11 years using data from the Danish Longitudinal Survey of Children. Observing the same children at different points in time enabled us to chart the evolution of anthropometric and behavioral deficits among children born with low birth weight and helped understanding the nature and timing of interventions., (Copyright © 2011 Elsevier B.V. All rights reserved.)

We use matched Danish health survey and register data to investigate discrepancies between register-based diagnoses and self-reported morbidity. We hypothesize that false negatives (medical diagnoses existing in the register but not reported in the survey) arise partly because individuals fear career repercussions of being discovered suffering a chronic or severe illness that potentially lowers productivity. We find evidence of substantial underreporting, which is indeed systematically higher for individuals in the labor market., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

We reassess the impact of health on retirement plans of older workers using a unique survey-register match-up which allows comparing the retirement effects of potentially biased survey self-reports of health to those of unbiased register-based diagnostic measures. The aim is to investigate whether even for narrowly defined health measures a divergence exists in the impacts of health on retirement between self-reported health and objective physician-reported health. Our sample consists of older workers and retirees drawn from a Danish panel survey from 1997 and 2002, merged to longitudinal register data. Estimation of measurement error-reduced and selection-corrected pooled OLS and fixed effects models of retirement show that receiving a medical diagnosis is an important determinant of retirement planning for both men and women, in fact more important than economic factors. The type of diagnosis matters, however. For men, the largest reduction in planned retirement age occurs for a diagnosis of lung disease while for women it occurs for musculo-skeletal disease. Except for cardiovascular disease, diagnosed disease is more influential in men's retirement planning than in women's. Our study provides evidence that men's self-report of myalgia and back problems and women's self-report of osteoarthritis possibly yield biased estimates of the impact on planned retirement age, and that this bias ranges between 1.5 and 2 years, suggesting that users of survey data should be wary of applying self-reports of health conditions with diffuse symptoms to the study of labor market outcomes. On the other hand, self-reported cardiovascular disease such as high blood pressure does not appear to bias the estimated impact on planned retirement., (Copyright (c) 2009 John Wiley & Sons, Ltd.)

This paper investigates whether a satisfactory work environment can promote employee health even after controlling for socioeconomic status and life style factors. A dynamic panel model of health is estimated from worker samples from Denmark, France and Spain, employing both self-assessed general health and the presence of a functional limitation. In all three countries and for both types of health measures, a good perceived work environment is found to be a highly significant determinant of worker health even after controlling for unobserved heterogeneity and minimizing reverse causality. The marginal effect is, however, larger in France and Denmark than in Spain. Several potential explanations for this finding are discussed. Further, a satisfactory working environment is found to be at least as important for employee health as socioeconomic status. Thus, investing in giving workers a satisfying work environment could be a low-cost way of improving employee health.

We investigate the effect of an acute health shock on retirement among elderly male workers in Denmark, 1991-1999, and in particular whether various welfare state programs and institutions impinge on the retirement effect. The results show that an acute health event increases the retirement chances of elderly male workers by 8%, and that this increase in the baseline retirement probability is not affected by eligibility to early exit programs and persists even after accounting for selection due to take-up of disability pension. Neither is it affected by the relatively long duration of sickness benefits in Denmark nor by the promotion of corporate social responsibility initiatives since the mid-1990s. In the late 1990s, however, the retirement rate following a health shock is reduced to 3% with the introduction of the subsidized employment program ( fleksjob ) but this effect is on the margin of being significant. For the most part, the retirement effect following a health shock seems to be immune to the availability of a multitude of government programs for older workers in Denmark.

The structure of bacteriorhodopsin (bR) has been probed by a large number of experimental methods. In earlier work distance constraints measured from the 1BRD Brookhaven structure (1, 2) were used to guide site-directed mutagenesis/affinity labeling experiments (3-5). In the present study we report on the use of limited molecular dynamics (MD) investigations of the same bR/affinity label system. We show here that the chiral center introduced when 4-bromo-all-trans retinal is synthesized produces variable impact on potential crosslinking. Our MD analysis suggests the following ranking of binding site mutants in order of reactivity: R118C > S118C >> S121C > R141C >> S141C >>> R121C, R138C, S138C. Chirality appears to have limited effect for the M118C mutants but shows more dramatic impact for the T121C and S141C mutants. These results are in excellent agreement with the experimental observations and offer encouragement that MD can be a useful component of experimental design with considerable predictive power.

The porphyrin photosensitizer, meso-Tetra (4-N-methylpyridyl) porphine tetraperchlorate binds to calf thymus DNA by intercalation and by external electrostatic association. This was concluded from the results of measruements involving Scatchard analysis, viscometry, thermal denaturation, and circular dichroism.

The binding stoichiometry and binding equilibria of human serum albumin with water-soluble four free base porphyrins and six chloroiron (+3) porphyrins have been determined in 0.1M phosphate buffer, pH 7.2, by fluorescence quenching and filtration methods. The binding stoichiometry is observed to be 1:1, porphyrin to protein. The dissociation constants, Kd, between the porphyrins and the protein are found to be 1-4 microM. A binding mechanism between the protein and the porphyrins has been presented.

The binding stoichiometry and equilibria of three polycationic water-soluble porphyrins with human serum albumin (HSA) have been determined by fluorescence quenching and filtration methods in 0.1M phosphate buffer, pH 7.2 at 25 degrees. For one porphyrin the binding equilibrium was also measured by measuring the lifetime of tryptophan and also by measuring the polarization of bound porphyrin. Energy transfer between the porphyrin and the tryptophan residue of HSA has been studied.

The interaction of hematoporphyrin IX and two synthetic porphyrin tumor localizers, meso-tetra (4-carboxyphenyl) porphine (TCPP) and mesotetra (4-sulfonatophenyl) porphine (TPPS4) with fibrinogen was investigated in the presence and absence of light. Both TPPS4 and TCPP were found to bind to fibrinogen in greater than a 1/1 mole ratio in the absence of light. Chromatographic analysis indicated that during illumination TPP4 bound to fibrinogen to a greater extent that did either TCPP or hematoporphyrin. Both TCPP and TPPS4 were found to exhibit a greater inhibitory effect on clotting in the presence of light than did hematoporphyrin. In the absence of light and added Ca2+, both TCPP and TPPS4 were found to stimulate clotting at very specific porphyrin/fibrinogen concentration ratios, with TPPS4 being the more potent stimulator of the two. Hematoporphyrin exhibited little or no effect on clotting times. Fibrinogen, photoirradiated in the presence of the porphyrins was found to inhibit the clotting of unirradiated fibrinogen. A comparison of the stimulatory effects on clotting times by either calcium or TCPP and TPPS4 indicated that the porphyrins were capable of eliciting a greater stimulatory response than did calcium. The magnitude of the stimulatory response caused by the porphyrins alone was substantially reduced in the presence of calcium although the overall stimulatory response was increased but not additive. This suggests some interaction between either the calcium and porphyrin molecules or similarities in the respective stimulatory mechanism(s) involved. A possible correlation between these observations and the porphyrins ability to localize in tumors is also discussed.

The photosensitizing effects of hematoporphyrin derivative, meso-tetra(p-sulfonatophenyl)porphine, meso-tetra(p-carboxyphenyl)porphine, and meso-tetra(4-N-methylpyridyl)-porphine on ColE1 supercoiled DNA were studied using agarose gel electrophoresis. Photoinduced single- and double-strand breaks were observed to form under neutral conditions. Singlet oxygen was shown to predominate in the mechanism of the induction of these lesions in the case of hematoporphyrin derivative, meso-tetra(p-sulfonatophenyl)porphine, and meso-tetra(p-carboxyphenyl)porphine and to play a significant role in the case of meso-tetra(4-N-methylpyridyl)porphine. The results suggest the possibility that the risk of photodynamic carcinogenesis may accompany photochemotherapy and fluorescence endoscopic procedures involving porphyrin photosensitizers.

Six tetraphenylporphyrins have been studied for their binding with human apohemoglobin and methemoglobin. Four showed binding with apohemoglobin, in a way hemin binds, to form analogs of recondtituted hemoglobin. Five porphyrins bound with methemoglobin, perhaps, through random ionic interaction.

The role of the neoplastic cell in both porphyrin localization and the photochemotherapeutic response was investigated with the use of a series of tumor-localizing porphyrins and the L1210 tumor system. In vivo photoirradiation of DBA/2Ha mice bearing L1210 solid tumors and previously given injections of meso-tetra-(4-sulfonatophenyl)-porphine, meso-tetra-(4-carboxyphenyl)-porphine, or hematoporphyrin derivative (Hpd) indicated that all three chemicals elicited a photodynamic response resulting in necrosis of exposed tissue. Isolation of tumor cells from mice given injections of porphyrin with the use of mild mechanical means and physiologic conditions followed by in vitro photoirradiation of the cells under conditions established to optimize rapid cytocidal effects resulted in no appreciable cell death. A similar situation was noted with the use of spleen cells from mice given injections of Hpd, the spleen cells presumably containing substantial amounts of porphyrin. Both fluorescence microscopy and chemical extraction and quantitation of the porphyrins in the cells indicated that the inability to elicit a rapid cytocidal effect upon in vitro photoirradiation resulted from either the absence of or the presence of only very small amounts of porphyrin. These results indicate that in this particular tumor system the neoplastic cell per se plays only a minor role in porphyrin localization and, as a consequence, cannot be readily killed upon photoirradiation, suggesting that rapid cytocidal effects, due solely to porphyrin contained within the cell, probably do not occur among the majority of parenchymal cells during in vivo photoirradiation.

The binding of two tumor localizing porphyrins, meso-tetra (4-carboxyphenyl) porphine (TCPP) and meso-tetra (4-sulfonatophenyl) porphine (TPPS4) to fibrin clots was determined in vitro. Both TCPP and TPPS4 were found to bind extensively, although weakly, to fibrin. No appreciable binding by Hematoporphyrin IX to the fibrin matrix was detectable. Similar results were obtained whether the clot was non-crosslinked or crosslinked with factor XIII. Photoirradiation of a porphyrin-impregnated non-crosslinked clot rendered it urea insoluble. Electrophoretic analysis indicated that the alpha chain of the fibrinogen molecule was most affected by photoirradiation. This was manifested as a loss of the alpha chain intensity and a concomitant increase of high molecular weight components, suggesting the formation of crosslinks. No substantial differences were noted in susceptibility to plasmin lysis between photoirradiated and non-irradiated clots. Photoirradiated clots were, however, significantly more resistant to lysis induced by the plasminogen activators urokinase and streptokinase, suggesting that inactivation of plasminogen within the clot matrix had occurred during photoirradiation. The relevance of porphyrin binding to fibrin with regard to tumor localization and destruction is also discussed.