14,156 research outputs found
Attempted DNA extraction from a Rancho La Brea Columbian mammoth (Mammuthus columbi): prospects for ancient DNA from asphalt deposits.
Fossil-bearing asphalt deposits are an understudied and potentially significant source of ancient DNA. Previous attempts to extract DNA from skeletons preserved at the Rancho La Brea tar pits in Los Angeles, California, have proven unsuccessful, but it is unclear whether this is due to a lack of endogenous DNA, or if the problem is caused by asphalt-mediated inhibition. In an attempt to test these hypotheses, a recently recovered Columbian mammoth (Mammuthus columbi) skeleton with an unusual pattern of asphalt impregnation was studied. Ultimately, none of the bone samples tested successfully amplified M.ācolumbi DNA. Our work suggests that reagents typically used to remove asphalt from ancient samples also inhibit DNA extraction. Ultimately, we conclude that the probability of recovering ancient DNA from fossils in asphalt deposits is strongly (perhaps fatally) hindered by the organic compounds that permeate the bones and that at the Rancho La Brea tar pits, environmental conditions might not have been ideal for the general preservation of genetic material
Visualization of the distribution of autophosphorylated calcium/calmodulin-dependent protein kinase II after tetanic stimulation in the CA1 area of the hippocampus
Autophosphorylation of calcium/calmodulin-dependent protein kinase II (CaMKII) at threonine-286 produces Ca2+-independent kinase activity and has been proposed to be involved in induction of long-term potentiation by tetanic stimulation in the hippocampus. We have used an immunocytochemical method to visualize and quantify the pattern of autophosphorylation of CaMKII in hippocampal slices after tetanization of the Schaffer collateral pathway. Thirty minutes after tetanic stimulation, autophosphorylated CaM kinase II (P-CaMKII) is significantly increased in area CA1 both in apical dendrites and in pyramidal cell somas. In apical dendrites, this increase is accompanied by an equally significant increase in staining for nonphosphorylated CaM kinase II. Thus, the increase in P-CaMKII appears to be secondary to an increase in the total amount of CaMKII. In neuronal somas, however, the increase in P-CaMKII is not accompanied by an increase in the total amount of CaMKII. We suggest that tetanic stimulation of the Schaffer collateral pathway may induce new synthesis of CaMKII molecules in the apical dendrites, which contain mRNA encoding its alpha-subunit. In neuronal somas, however, tetanic stimulation appears to result in long-lasting increases in P-CaMKII independent of an increase in the total amount of CaMKII. Our findings are consistent with a role for autophosphorylation of CaMKII in the induction and/or maintenance of long-term potentiation, but they indicate that the effects of tetanus on the kinase and its activity are not confined to synapses and may involve induction of new synthesis of kinase in dendrites as well as increases in the level of autophosphorylated kinase
Structural Evolution and Petroleum Potential of a Cambrian Intracratonic Rift System: Mississippi Valley Graben, Rough Creek Graben, and Rome Trough
Drilling and geophysical data demonstrate that the Mississippi Valley Graben, Rough Creek Graben, and Rome Trough are fault-bounded structures filled with as much as 27,000 ft of Cambrian sediments. Data including stratigraphic tops from 1,764 wells, 106 seismic profiles, aeromagnetic and gravity surveys, and mapped surface geology at a scale of 1:24,000 were used to study seven stratigraphic packages across parts of Kentucky, Ohio, Indiana, Illinois, Missouri, and Tennessee. Detailed analysis of the thickness patterns of these stratigraphic packages was used to interpret the locations and timing of movement along major fault systems in the study area.
Active rifting of the Precambrian crystalline bedrock began by the Early Cambrian and resulted in thick, sand-rich deposits of the Reelfoot Arkose in the Mississippi Valley Graben and Rough Creek Graben, and the Rome Formation in the Rome Trough. Subsidence continued in these grabens during the Middle to Late Cambrian, leading to deposition of an alternating succession of shales and carbonates (Eau Claire Formation of the Illinois Basin and Conasauga Group of the Appalachian Basin) on top of the coarse clastic Reelfoot Arkose and Rome Formation. Although the tectonic extension that formed these features ended by the Late Cambrian, fault-zone reactivation during the Taconic, Acadian, and Alleghenian Orogenies altered fault-block orientations and produced areas of basin inversion, possibly creating numerous deep structural traps for hydrocarbons sourced by the Cambrian shales of the Eau Claire Formation and Conasauga Group
Evaluating Sweat Gland Activity with Imprint Techniques
Starch-iodine and bromphenol blue are standard indicators used to record the distribution and number of actively secreting sweat glands. In this report, techniques employing these indicators were compared with methods utilizing newer plastic and silicone impressions.1. Both the plastic and silicone impressions yielded consistently greater sweat gland droplet counts than either of the indicators (p < 0.01).2. A simple technique applying thin films of a silicone rubber monomer to obtain sharp, permanent and uniformly reproducible sweat droplet impressions with little technical skill was judged superior to all methods evaluated
The Volunteer Fisheries Liaison Officer (VFLO) program: an analysis of recreational fishing data from 1995 - 2007
The aim of this report was to explore the data collected by VFLOs from 1995 - 2007 in each of the stateās four marine bioregions. During this period, volunteers undertook \u3e2,000 days of activities, the majority of which were educational displays at events such as boat shows and patrols in coastal, marine and estuarine environs. Patrols focused on interviews with recreational anglers to provide information about sustainable fishing and collect data on catch and effort
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The Child Tax Credit: How the United States Underinvests in Its Youngest Children in Cash Assistance and How Changes to the Child Tax Credit Could Help
In this dissertation I examine the Child Tax Credit (CTC), who gets it and who doesn't, paying particular attention to children under the age of three, its legislative and political history, and how it could be improved. At 59.5 billion (JCT, 2011). Created in 1997, it has been expanded seven times in just the last decade. Yet in spite of America's federal commitment of dollars and legislative commitment of reform, little has been written about the CTC.
I examine the literature first to see if cash and cash assistance matter, finding on balance that there is strong evidence that it does, particularly for young children; second to show that the U.S. underinvests in this domain in young children relative both to what is needed and to what other advanced industrialized countries do; and third to lay out the case that changes to the refundable CTC offer one opportunity to address this underinvestment. I examine the legislative history of the CTC, as I believe both the policy analysis and history need to be understood to inform the policy responses.
Next, I examine whether the portion of the new safety net that was fashioned as tax policy is working as child policy - specifically, whether it is reaching our youngest children, with initial evidence that it may not be in the case of the CTC (Burman and Wheaton, 2007) yet may be in the case of the EITC (Dowd and Horowitz, 2011). Using the 2011 Current Population March Supplement, I examine empirical evidence of the age distribution of federal tax credits for children, finding that 29% of children under the age of three are in families with too little earnings to get the full CTC, as opposed to 20% of older children. Nearly 13% of children under the age of three are in families with no earnings and as such get no CTC or EITC, as opposed to 8% of older children. While the EITC may disproportionately benefit young children, poor young children are more likely to be left out eligibility of the EITC than their older counterparts. Since infants may or may not be eligible for any CTC or EITC, depending on their birth month, I suggest that as some have found a marriage penalty in parts of the tax code, that there may also be a "baby penalty." I use micro-simulation to examine the costs and benefits of alternative CTC policies. Here I find that while full refundability may be the optimum CTC policy, that there are other possibilities, including those that increase the phase-in of eligibility, that are less costly, and also substantially lower child poverty among young children, including doubling the CTC for young children, increasing the phase in, and using a look back provision to allow families to use their previous year's earnings to calculate their refundable CTC and EITC. Yet, only moving to full refundability would do anything for the 12.67% of young children in families with no earnings.
Finally, I propose policy responses that are rooted both in the science of increased cash investments in young children, and in the politics of working legislatively to get there, suggesting that policy makers consider the question of age equity when examining the distributional effects of tax policies. Implications for research and policy are discussed
The experience of accommodating privacy restrictions during implementation of a large-scale surveillance study of an osteoporosis medication.
PurposeTo explore whether privacy restrictions developed to protect patients have complicated research within a 15-year surveillance study conducted with US cancer registries.MethodsData from enrolling 27 cancer registries over a 10-year period were examined to describe the amount of time needed to obtain study approval. We also analyzed the proportion of patients that completed a research interview out of the total reported by the registries and examined factors thought to influence this measure.ResultsThe average length of the research review process from submission to approval of the research was 7āmonths (range, <1 to 24āmonths), and it took 6āmonths or more to obtain approval of the research at 41% of the cancer registries. Most registries (78%) required additional permission steps to gain access to patients for research. After adjustment for covariates, the interview response proportion was 110% greater (ratio of response proportionā=ā2.1; 95% confidence interval: 1.3, 3.3) when the least restrictive versus the most restrictive permission steps were required. An interview was more often completed for patients (or proxies) if patients were alive, within a year of being diagnosed, or identified earlier in the study.ConclusionsLengthy research review processes increased the time between diagnosis and provision of patient information to the researcher. Requiring physician permission for access to patients was associated with lower subject participation. A single national point of entry for use of cancer registry data in health research is worthy of consideration to make the research approval process efficient. Ā© 2016 The Authors. Pharmacoepidemiology and Drug Safety published by John Wiley & Sons Ltd
The Importance of Importance: Self-Descriptors in Dysphoria
This study examined the relationship between importance ratings of positive and negative personal attributes and depressed mood. Undergraduate psychology students (n = 115) completed the Beck Depression Inventory-II and made self-referential ratings on several adjectives. Participants subsequently indicated how important it was for them to possess or fail to exhibit each of these traits. The results demonstrated that the perceived lack of important positive traits was related to increased depressed mood whereas not exhibiting important negative traits was associated with less depressed mood. Moreover, depressed mood was related to the degree to which respondents were certain about their endorsement of the traits. The implications of these results are discussed
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