223 research outputs found
Targeted Advertising and Voter Turnout: An Experimental Study of the 2000 Presidential Election
Scholars disagree whether negative advertising demobilizes or stimulates the electorate. We use an experiment with over 10,200 eligible voters to evaluate the two leading hypotheses of negative political advertising. We extend the analysis to examine whether advertising differentially impacts the turnout of voter subpopulations depending on the advertisementçâÂŽ message. In the short term, we find no evidence that exposure to negative advertisements decreases turnout and little that suggests it increases turnout. Any effect appears to depend upon the message of the advertisement and the characteristics of the viewer. In the long term, we find little evidence that the information contained in the treatment groupsĂŁÆ»advertisements is sufficient to systematically alter turnout.
Changing Owners, Changing Content: Does Who Owns the News Matter for the News?
The press is essential for creating an informed citizenry, but its existence depends on attracting and maintaining an audience. It is unclear whether supply-side effects â including those dictated by the owners of the media â influence how the media cover politics, yet this question is essential given their abilities to set the agenda and frame issues that are covered. We examine how ownership influences media behavior by investigating the impact of Rupert Murdochâs purchase of the Wall Street Journal (WSJ) in August 2007. We collect data on every front-page story and editorial for 27 months, and we compare the difference in political coverage between the New York Times (NYT) and WSJ using a difference-in-differences design. We show that the amount of political content in the opinion pages of the two papers were unchanged by the sale, but the WSJâs front-page coverage of politics increased markedly relative to the NYT. Similar patterns emerge when comparing the WSJâs content to the USA Today and the Washington Post. Our finding highlights potential limits to journalistsâ ability to fulfill their supposed watchdog role in democracies without interference from owners in the boardroom
Removing the entropy from the definition of entropy: clarifying the relationship between evolution, entropy, and the second law of thermodynamics
Abstract Misinterpretations of entropy and conflation with additional misunderstandings of the second law of thermodynamics are ubiquitous among scientists and non-scientists alike and have been used by creationists as the basis of unfounded arguments against evolutionary theory. Entropy is not disorder or chaos or complexity or progress towards those states. Entropy is a metric, a measure of the number of different ways that a set of objects can be arranged. Herein, we review the history of the concept of entropy from its conception by Clausius in 1867 to its more recent application to macroevolutionary theory. We provide teachable examples of (correctly defined) entropy that are appropriate for high school or introductory college level courses in biology and evolution. Finally, we discuss the association of these traditionally physics-related concepts to evolution. Clarification of the interactions between entropy, the second law of thermodynamics, and evolution has the potential for immediate benefit to both students and teachers
Genomic characterization of pediatric Bâlymphoblastic lymphoma and Bâlymphoblastic leukemia using formalinâfixed tissues
BackgroundRecurrent genomic changes in Bâlymphoblastic leukemia (BâALL) identified by genomeâwide singleânucleotide polymorphism (SNP) microarray analysis provide important prognostic information, but gene copy number analysis of its rare lymphoma counterpart, Bâlymphoblastic lymphoma (BâLBL), is limited by the low incidence and lack of fresh tissue for genomic testing.ProcedureWe used molecular inversion probe (MIP) technology to analyze and compare copy number alterations (CNAs) in archival formalinâfixed paraffinâembedded pediatric BâLBL (n = 23) and BâALL (n = 55).ResultsSimilar to BâALL, CDKN2A/B deletions were the most common alteration identified in 6/23 (26%) BâLBL cases. Eleven of 23 (48%) BâLBL patients were hyperdiploid, but none showed triple trisomies (chromosomes 4, 10, and 17) characteristic of BâALL. IKZF1 and PAX5 deletions were observed in 13 and 17% of BâLBL, respectively, which was similar to the reported frequency in BâALL. Immunoglobulin light chain lambda (IGL) locus deletions consistent with normal light chain rearrangement were observed in 5/23 (22%) BâLBL cases, compared with only 1% in BâALL samples. None of the BâLBL cases showed abnormal, isolated VPREB1 deletion adjacent to IGL locus, which we identified in 25% of BâALL.ConclusionsOur study demonstrates that the copy number profile of BâLBL is distinct from BâALL, suggesting possible differences in pathogenesis between these closely related diseases.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137353/1/pbc26363.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137353/2/pbc26363_am.pd
Maternal Style Selectively Shapes Amygdalar Development and Social Behavior in Rats Genetically Prone to High Anxiety
The early-life environment critically influences neurodevelopment and later psychological health. To elucidate neural and environmental elements that shape emotional behavior, we developed a rat model of individual differences in temperament and environmental reactivity. We selectively bred rats for high vs. low behavioral response to novelty and found that high reactive (bHR) rats display greater risk-taking, impulsivity, and aggression relative to low reactive (bLR) rats, which show high levels of anxiety/depression-like behavior and certain stress vulnerability. The bHR/bLR traits are heritable but prior work revealed bHR/bLR maternal style differences, with bLR dams showing more maternal attention than bHRs. The present study implemented a cross-fostering paradigm to examine the contribution of maternal behavior on bLR offspringâs brain development and emotional behavior. bLR offspring were reared by biological bLR mothers or fostered to a bLR or bHR mother and then evaluated to determine effects on: 1) developmental gene expression in the hippocampus and amygdala; and 2) adult anxiety/depression-like behavior. Genome-wide expression profiling showed that cross-fostering bLR rats to bHR mothers shifted developmental gene expression in the amygdala (but not hippocampus), reduced adult anxiety and enhanced social interaction. Our findings illustrate how an early-life manipulation such as cross-fostering changes the brainâs developmental trajectory and ultimately impacts adult behavior. Moreover, while earlier studies highlighted hippocampal differences contributing to the bHR/bLR phenotypes, our results point to a role of the amygdala as well. Future work will pursue genetic and cellular mechanisms within the amygdala that contribute to bHR/bLR behavior either at baseline or following environmental manipulations
Association of acute toxic encephalopathy with litchi consumption in an outbreak in Muzaffarpur, India, 2014: a case-control study
Background Outbreaks of unexplained illness frequently remain under-investigated. In India, outbreaks of an acute
neurological illness with high mortality among children occur annually in Muzaffarpur, the countryâs largest litchi
cultivation region. In 2014, we aimed to investigate the cause and risk factors for this illness.
Methods In this hospital-based surveillance and nested age-matched case-control study, we did laboratory
investigations to assess potential infectious and non-infectious causes of this acute neurological illness. Cases were
children aged 15 years or younger who were admitted to two hospitals in Muzaffarpur with new-onset seizures or
altered sensorium. Age-matched controls were residents of Muzaffarpur who were admitted to the same two hospitals
for a non-neurologic illness within seven days of the date of admission of the case. Clinical specimens (blood,
cerebrospinal fluid, and urine) and environmental specimens (litchis) were tested for evidence of infectious
pathogens, pesticides, toxic metals, and other non-infectious causes, including presence of hypoglycin A or
methylenecyclopropylglycine (MCPG), naturally-occurring fruit-based toxins that cause hypoglycaemia and metabolic
derangement. Matched and unmatched (controlling for age) bivariate analyses were done and risk factors for illness
were expressed as matched odds ratios and odds ratios (unmatched analyses).
Findings Between May 26, and July 17, 2014, 390 patients meeting the case definition were admitted to the two referral
hospitals in Muzaffarpur, of whom 122 (31%) died. On admission, 204 (62%) of 327 had blood glucose concentration
of 70 mg/dL or less. 104 cases were compared with 104 age-matched hospital controls. Litchi consumption (matched
odds ratio [mOR] 9·6 [95% CI 3·6 â 24]) and absence of an evening meal (2·2 [1·2â4·3]) in the 24 h preceding illness
onset were associated with illness. The absence of an evening meal significantly modified the effect of eating litchis
on illness (odds ratio [OR] 7·8 [95% CI 3·3â18·8], without evening meal; OR 3·6 [1·1â11·1] with an evening meal).
Tests for infectious agents and pesticides were negative. Metabolites of hypoglycin A, MCPG, or both were detected in
48 [66%] of 73 urine specimens from case-patients and none from 15 controls; 72 (90%) of 80 case-patient specimens
had abnormal plasma acylcarnitine profiles, consistent with severe disruption of fatty acid metabolism. In 36 litchi
arils tested from Muzaffarpur, hypoglycin A concentrations ranged from 12·4 Όg/g to 152·0 Όg/g and MCPG ranged
from 44·9 Όg/g to 220·0 Όg/g.
Interpretation Our investigation suggests an outbreak of acute encephalopathy in Muzaffarpur associated with both
hypoglycin A and MCPG toxicity. To prevent illness and reduce mortality in the region, we recommended minimising
litchi consumption, ensuring receipt of an evening meal and implementing rapid glucose correction for suspected
illness. A comprehensive investigative approach in Muzaffarpur led to timely public health recommendations,
underscoring the importance of using systematic methods in other unexplained illness outbreaks
- âŠ