The Experts below are selected from a list of 80139 Experts worldwide ranked by ideXlab platform
David A. Weaver - One of the best experts on this subject based on the ideXlab platform.
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Widows and Social Security
Social security bulletin, 2010Co-Authors: David A. WeaverAbstract:This article provides policymakers with context for understanding past and future policy discussions regarding Social Security widow benefits. Using data from surveys, projections from a microsimulation model, and recent research, it examines three types of benefits - those for aged Widows, Widows caring for children, and disabled Widows. The economic well-being of aged Widows has shifted from one of widespread hardship to one in which above-poverty, but still modest, income typically prevails. Many aged Widows experience a decline in their standard of living upon widowhood, a pattern which is pronounced among those with limited education. Widows caring for children have been a sizeable beneficiary group historically, but policy changes and demographic trends have sharply reduced the size of this group. Family Social Security benefits ensure a modest level of household income for Widows caring for children. Disabled Widows differ from the other groups because they are at higher risk for poverty.
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Widows Waiting to Wed?: (Re)Marriage and Economic Incentives in Social Security Widow Benefits
Journal of Human Resources, 2004Co-Authors: Michael J. Brien, Stacy Dickert-conlin, David A. WeaverAbstract:In this paper we focus on an age restriction for remarriage in the Social Security system to determine if individuals respond to economic incentives for marriage. Aged widow(er) benefits are paid by the Federal government to persons whose deceased spouses worked in Social Security covered employment. A widow(er) is eligible to receive benefits if she or he is at least age 60. If a widow(er) remarries before age 60, he or she forfeits the benefit and, therefore, faces a marriage penalty. Under current law, there is no penalty if the remarriage occurs at 60 years of age or later. We investigate whether this rule affects the marriage behavior of Widows. Specifically, we examine the rates of remarriage of women around age 60 under current as well as past Social Security eligibility rules using data from the Vital Statistics. Our results provide compelling evidence that this group of women respond to economic incentives when considering the decision to remarry. First, the 1979 law change that eliminated the marriage penalty for those at least age 60 resulted in a large increase in the marriage rate for Widows at least age 60, suggesting that the marriage penalty discouraged marriage. The data for the most current period show a significant drop in marriage rates immediately prior to age 60 and an increase after that point. We do not observe this pattern in years when the relative marriage penalty was smaller or for divorced women who generally are not subject to the age-60 remarriage rule.
Michael K. Rust - One of the best experts on this subject based on the ideXlab platform.
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The Prevalence of Brown Widow and Black Widow Spiders (Araneae: Theridiidae) in Urban Southern California
Journal of Medical Entomology, 2012Co-Authors: Richard S. Vetter, Leonard S. Vincent, Douglas W. R. Danielsen, Kathryn I. Reinker, Daniel E. Clarke, Amelia A. Itnyre, John N. Kabashima, Michael K. RustAbstract:The brown widow spider, Latrodectus geometricus C. L. Koch, has become newly established in southern California during the first decade of the 21st century. Brown Widows and egg sacs were collected within the urban Los Angeles Basin using timed searches. We also collected and compared the abundance and distribution of the native western black widow spider, Latrodectus hesperus Chamberlin & Ivie, to brown Widows. Brown Widows were very common around urban structures especially outside homes, in parks, under playground equipment, in plant nurseries and landscaping areas, greatly outnumbering native western black Widows, and were very rare or nonexistent in garages, agricultural crops, and natural areas. Western black Widows predominated in xeric habitats and were less prevalent around homes. Neither species was found in the living space of homes. In southern California, envenomation risk exists because brown Widows are now common in urban areas and the spiders hide where people place their fingers and exert pressure to move objects (e.g., under the curled lip of potted plants, in the recessed handle of plastic trash bins). Nonetheless, brown widow spider bites are less toxic than those of native western black widow spiders and, hence, if they are displacing black Widows, overall widow envenomation risk may actually be lower than before brown widow establishment.
Howard M Iams - One of the best experts on this subject based on the ideXlab platform.
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reducing women s poverty by shifting social security benefits from retired couples to Widows
Journal of Policy Analysis and Management, 1997Co-Authors: Steven H Sandell, Howard M IamsAbstract:This article examines proposals to transfer Social Security benefits from married couples to surviving Widows in terms of effects on poverty rates, trust fund expenditures, and Supplemental Security Income (SSI) expenditures. Because Widows are much more likely to be living in poverty than older married women, it makes sense to consider Social Security benefits in a lifetime framework and transfer some benefits from the time both the husband and wife are alive to the time when there is only one survivor, usually the wife. Because of expected life span and age differences of marital partners, a $1 reduction of the couple's benefit can finance a $1.45 increase in the widow's benefit. The 1990 Survey of Income and Program Participation (SIPP) matched to the Social Security Administration's benefit records are the basis for the estimates.
Quinton Loïc - One of the best experts on this subject based on the ideXlab platform.
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Venomics Approach Reveals a High Proportion of Lactrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis.
'MDPI AG', 2020Co-Authors: Dunbar, John P., Fort Antoine, Redureau Damien, Sulpice Ronan, Dugon, Michel M., Quinton LoïcAbstract:peer reviewedaudience: researcher, professional, studentThe noble false widow spider Steatoda nobilis originates from the Macaronesian archipelago and has expanded its range globally. Outside of its natural range, it may have a negative impact on native wildlife, and in temperate regions it lives in synanthropic environments where it frequently encounters humans, subsequently leading to envenomations. S. nobilis is the only medically significant spider in Ireland and the UK, and envenomations have resulted in local and systemic neurotoxic symptoms similar to true black Widows (genus Latrodectus). S. nobilis is a sister group to Latrodectus which possesses the highly potent neurotoxins called α-latrotoxins that can induce neuromuscular paralysis and is responsible for human fatalities. However, and despite this close relationship, the venom composition of S. nobilis has never been investigated. In this context, a combination of transcriptomic and proteomic cutting-edge approaches has been used to deeply characterise S. nobilis venom. Mining of transcriptome data for the peptides identified by proteomics revealed 240 annotated sequences, of which 118 are related to toxins, 37 as enzymes, 43 as proteins involved in various biological functions, and 42 proteins without any identified function to date. Among the toxins, the most represented in numbers are α-latrotoxins (61), δ-latroinsectotoxins (44) and latrodectins (6), all of which were first characterised from black widow venoms. Transcriptomics alone provided a similar representation to proteomics, thus demonstrating that our approach is highly sensitive and accurate. More precisely, a relative quantification approach revealed that latrodectins are the most concentrated toxin (28%), followed by α-latrotoxins (11%), δ-latroinsectotoxins (11%) and α-latrocrustotoxins (11%). Approximately two-thirds of the venom is composed of Latrodectus-like toxins. Such toxins are highly potent towards the nervous system of vertebrates and likely responsible for the array of symptoms occurring after envenomation by black Widows and false Widows. Thus, caution should be taken in dismissing S. nobilis as harmless. This work paves the way towards a better understanding of the competitiveness of S. nobilis and its potential medical importance
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Venomics Approach Reveals a High Proportion of Lactrodectus-Like Toxins in the Venom of the Noble False Widow Spider Steatoda nobilis.
2020Co-Authors: Dunbar, John P., Fort Antoine, Redureau Damien, Sulpice Ronan, Dugon, Michel M., Quinton LoïcAbstract:The noble false widow spider Steatoda nobilis originates from the Macaronesian archipelago and has expanded its range globally. Outside of its natural range, it may have a negative impact on native wildlife, and in temperate regions it lives in synanthropic environments where it frequently encounters humans, subsequently leading to envenomations. S. nobilis is the only medically significant spider in Ireland and the UK, and envenomations have resulted in local and systemic neurotoxic symptoms similar to true black Widows (genus Latrodectus). S. nobilis is a sister group to Latrodectus which possesses the highly potent neurotoxins called α-latrotoxins that can induce neuromuscular paralysis and is responsible for human fatalities. However, and despite this close relationship, the venom composition of S. nobilis has never been investigated. In this context, a combination of transcriptomic and proteomic cutting-edge approaches has been used to deeply characterise S. nobilis venom. Mining of transcriptome data for the peptides identified by proteomics revealed 240 annotated sequences, of which 118 are related to toxins, 37 as enzymes, 43 as proteins involved in various biological functions, and 42 proteins without any identified function to date. Among the toxins, the most represented in numbers are α-latrotoxins (61), δ-latroinsectotoxins (44) and latrodectins (6), all of which were first characterised from black widow venoms. Transcriptomics alone provided a similar representation to proteomics, thus demonstrating that our approach is highly sensitive and accurate. More precisely, a relative quantification approach revealed that latrodectins are the most concentrated toxin (28%), followed by α-latrotoxins (11%), δ-latroinsectotoxins (11%) and α-latrocrustotoxins (11%). Approximately two-thirds of the venom is composed of Latrodectus-like toxins. Such toxins are highly potent towards the nervous system of vertebrates and likely responsible for the array of symptoms occurring after envenomation by black Widows and false Widows. Thus, caution should be taken in dismissing S. nobilis as harmless. This work paves the way towards a better understanding of the competitiveness of S. nobilis and its potential medical importance.Peer reviewe
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Venomics approach reveals a high proportion of Lactrodectus-like toxins in Steatoda nobilis venom - First link to post-bite symptomology
2020Co-Authors: Dunbar John, Fort Antoine, Redureau Damien, Sulpice Ronan, Vitkauskaite Aiste, Dugon Michel, Quinton LoïcAbstract:peer reviewedThe Noble false widow spider Steatoda nobilis has expanded its range globally and may represent a potential threat to native ecosystems and public health. Envenomations can result in local and systemic neurotoxic symptoms, similar to true black Widows (genus Latrodectus). We used transcriptomic and proteomic cutting-edge approaches to deeply characterise S. nobilis venom. Among the toxins, the most represented in numbers are α-latrotoxins, -latroinsectotoxins and latrodectins, which were first characterised from black widow venoms. Approximately two-thirds of the venom is composed of Latrodectus-like toxins. We present symptomology from 23 cases (15 unpublished) of S.nobilis envenomations confirming necrosis and Latrodectus-like symptoms such as debilitating pain, tremors, fatigue, nausea and hypotension. The continued rising numbers of S. nobilis will undoubtedly result in further bites and this study will help provide the medical community with a better understanding of the potential medical outcomes from bites by this species and alert them to the possibility of medically important outcomes
J. Chadwick Johnson - One of the best experts on this subject based on the ideXlab platform.
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A Continuum of Behavioral Plasticity in Urban and Desert Black Widows
Ethology, 2014Co-Authors: Rebecca Halpin, J. Chadwick JohnsonAbstract:Behavioral plasticity marks an individual's ability to modulate behavior across functional contexts. Behavioral syndromes, on the other hand, appear as consistent individual variation in behavior that is both repeatable for individuals within a functional context (e.g., consistent voracity toward prey) and correlated across contexts (e.g., high voracity toward prey and high levels of boldness toward enemies). Thus, adaptive plasticity and syndromes represent two extremes of a behavioral plasticity continuum upon which most behavioral phenotypes fall. We tested for both adaptive plasticity and behavioral syndromes in the western black widow spider, Latrodectus hesperus. We measured behavior in three contexts: startle, startle + prey, and startle + mate, and found (1) classic behaviorally plastic responses to predation risk, (2) high repeatability of behavior within contexts, and (3) evidence of a correlation between startle + prey and startle + mate contexts, indicative of a behavioral syndrome. As relative behavioral plasticity may vary across populations, we also compared urban and desert populations to test whether spiders from these habitats exhibit different behaviors and/or behavioral syndromes. While we found that urban males used in mating trials courted urban females significantly more than desert females, we found no other differences in the behavior of urban and desert black Widows. Thus, black Widows, regardless of habitat, are characterized by both context-specific behavioral plasticity and across-context correlations, presenting a phenotypic complexity that is likely exhibited, to varying degrees, by most organisms.
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Black widow spiders in an urban desert: Population variation in an arthropod pest across metropolitan Phoenix, AZ
Urban Ecosystems, 2012Co-Authors: Patricia Trubl, Theresa Gburek, Lindsay Miles, J. Chadwick JohnsonAbstract:The effects of urban disturbance are critical to understand, as the majority of the world’s population now resides in urban centers. For example, urbanization often leads to reduced species diversity at the expense of a few urban-adapted taxa. However, it remains unclear why some taxa thrive following human disturbance whereas others do poorly. The western black widow spider, Latrodectus hesperus, thrives in disturbed, urban habitat—often forming dense aggregations (i.e., infestations) relative to typical low-density, desert populations. We examined the population dynamics of ten black widow aggregations spread across metropolitan Phoenix, AZ, during the peak of the breeding season (June–August). Here we show that prey abundance, female mass, web volume and population density exhibit minimal temporal variation across the breeding season, but that prey abundance, female mass and population density show significant spatial variation across the ten urban aggregations. Our measure of prey abundance and foraging success, the number of prey carcasses found in black widow webs, shared a strong positive relationship with female mass and population density, but not with web volume. Surprisingly, female mass, web volume and population density were not correlated with each other. The abiotic variables we measured at each site did a poor job of explaining black widow population parameters, although we did find a marginal trend for more recent developments to harbor denser black widow aggregations. Our findings support the generalization that urbanization heightens spatial variation, and we suggest that local urban prey abundance is influential in promoting urban infestations full of heavy, fecund female black Widows. Studies of the population ecology of urban pests are necessary to identify the mechanisms allowing some species to thrive following human disturbance while much native biodiversity is lost following urbanization.
