274 research outputs found
Executive control in the anterior cingulate cortex
Converging evidence supports the hypothesis that the prefrontal cortex is critical for executive control. One prefrontal subregion, the anterior cingulate cortex has previously been shown to be active in situations involving high conflict, presentation of salient, distracting stimuli, and error processing, i.e. situations that occur when learning new response contingencies, when previously learned response strategies fail, or when a shift in attention or responding is required. These situations all involve goal-oriented monitoring of performance in order to effectively adjust cognitive processes. Several neuropsychological disorders, for instance schizophrenia, attention deficit hyperactivity disorder, and obsessive compulsive disorder, are correlated with morphological changes in the anterior cingulate cortex. Individuals with these disorders show impairments on tasks that require goal-oriented monitoring. The current studies used multiple behavioral paradigms to assess the effects of anterior cingulate cortex excitotoxic lesions in rats on executive control. Animals with anterior cingulate cortex lesions showed greater decline in cognitive capacity as tasks progressed, longer response latencies to conflicting stimuli, impaired reversal learning, impaired error processing, and impaired performance in the presence of previously relevant distractors. These results are consistent with the hypothesis that the anterior cingulate cortex is involved in executive control, specifically monitoring impairments in performance that signal the need to adjust cognitive control
Evaluating the story of the United States as told through the United States History and Government Regents Exam: Omissions, obscurations, and oppressions in a mandatory New York State high school assessment
Doctor of EducationCurriculum and Instruction ProgramsJ. Spencer ClarkThe United States history survey course is a standard high school history class in the state of New York. The academic goal is for students to understand key people and developments that molded the United States into its modern identity as a progressive, democratic nation-state. This research examined one manifestation of this course in New York State, the United States History and Government Regents exam. The United States History and Government Regents exam is a mandatory, standardized assessment usually taken by high school juniors after completing their annual survey U.S. history class. From 2001 to 2020, the exam positioned 50 multiple-choice questions with a chronological permutation of the survey course. I analyzed the exam over a two-decade period with 57 individual exams and 2,850 multiple-choice questions.
The goal of this research was to interrogate an unsuspecting objective history of the United States as conveyed through this exam. Using a combination of critical theories to look for patterns and trends, I considered both hidden content and featured pillars of the survey course through the medium of the Part I multiple-choice. For included content, I asked if questions were phrased in a way that forced conclusions about certain events, such as the internment of thousands of Americans during World War II. I used discourse analysis to better understand the covert intentions of plural pronouns like we and people. The findings in Chapter 4 revealed that these collective pronouns were used to conceal oppressions against certain groups. The implications section of Chapter 5 deconstructed how the exam was tethered to a master narrative of the United States, and to a linear, progressive history that was unwilling to highlight oppressed voices or recognize unresolved, regressive, antidemocratic choices.
For excluded content, I asked whose perspectives were continually missing. Which features were centered on political maps and which features were absent? Whose stories were central and whose stories were sacrificed to bolster a narrative about progress? How were advances for some disguised as advances for all, and at whose expense? What critical historical developments were omitted from the 2,850 questions?
The findings are important for multiple reasons. First is that New York State officially committed its public education system to cultural responsiveness in 2019 with the New York State Culturally Responsive and Sustaining Education framework. How can curriculum meaningfully evolve in the future if educators do not fully understand the ways it was culturally irresponsive in the past?
Second is that the survey U.S. history course is a powerful transmitter of knowledge about the story of the United States. Are we, as culturally responsive educators in New York, willing to extend the curriculum to include traditionally hidden developments, even if those developments interrogate and compromise the master narrative? Can we diversify the evidence, acknowledge regression, and clarify the specific beneficiaries of progress, thereby creating spaces for students to derive their own interpretations about the story and trajectory of the United States?
These are difficult questions, yet educators can confront them more intentionally if we are willing to grapple with the complexities of the survey United States history course and the
interaction between the discipline of history and the goals of nation building
Improving global estimates of syphilis in pregnancy by diagnostic test type: A systematic review and meta-analysis
AbstractBackground“Probable active syphilis,” is defined as seroreactivity in both non-treponemal and treponemal tests. A correction factor of 65%, namely the proportion of pregnant women reactive in one syphilis test type that were likely reactive in the second, was applied to reported syphilis seropositivity data reported to WHO for global estimates of syphilis during pregnancy.ObjectivesTo identify more accurate correction factors based on test type reported.Search StrategyMedline search using: “Syphilis [Mesh] and Pregnancy [Mesh],” “Syphilis [Mesh] and Prenatal Diagnosis [Mesh],” and “Syphilis [Mesh] and Antenatal [Keyword].Selection CriteriaEligible studies must have reported results for pregnant or puerperal women for both non-treponemal and treponemal serology.Data collection and analysisWe manually calculated the crude percent estimates of subjects with both reactive treponemal and reactive non-treponemal tests among subjects with reactive treponemal and among subjects with reactive non-treponemal tests. We summarized the percent estimates using random effects models.Main resultsCountries reporting both reactive non-treponemal and reactive treponemal testing required no correction factor. Countries reporting non-treponemal testing or treponemal testing alone required a correction factor of 52.2% and 53.6%, respectively. Countries not reporting test type required a correction factor of 68.6%.ConclusionsFuture estimates should adjust reported maternal syphilis seropositivity by test type to ensure accuracy
Reaching beyond pregnant women to eliminate mother-to-child transmission of syphilis in Africa
Congenital syphilis is a devastating disease that can be prevented by screening and treatment of infected pregnant women. The WHO is leading a global initiative to eliminate mother-to-child-transmission of syphilis with a goal of 50 congenital syphilis cases per 100,000 live births and targets of 95% antenatal care, 95% syphilis testing, and 95% treatment coverage. We estimated current congenital syphilis rates for 43 African countries, and additional scenarios in a subset of 9 countries. Our analysis suggested that only 4 of 43 countries are likely to currently have a congenital syphilis rate 50 per 100,000 live births, and none of the 9 countries could reach this goal even in 5 different scenarios with improved services. To achieve the eliminate mother-to-child-transmission goal, it appears necessary to intervene beyond services for pregnant women, and decrease prevalence of syphilis in the general population as well
Integrating physiology into correlative models can alter projections of habitat suitability under climate change for a threatened amphibian
Rapid global change has increased interest in developing ways to identify suitable refu-gia for species of conservation concern. Correlative and mechanistic species distribu-tion models (SDMs) represent two approaches to generate spatially-explicit estimates of climate vulnerability. Correlative SDMs generate distributions using statistical associations between environmental variables and species presence data. In contrast, mechanistic SDMs use physiological traits and tolerances to identify areas that meet the conditions required for growth, survival and reproduction. Correlative approaches assume modeled environmental variables influence species distributions directly or indirectly; however, the mechanisms underlying these associations are rarely verified empirically. We compared habitat suitability predictions between a correlative-only SDM, a mechanistic SDM and a correlative framework that incorporated mechanis-tic layers (‘hybrid models’). Our comparison focused on green salamanders Aneides aeneus, a priority amphibian threatened by climate change throughout their disjunct range. We developed mechanistic SDMs using experiments to measure the thermal sensitivity of resistance to water loss (ri) and metabolism. Under current climate con-ditions, correlative-only, hybrid and mechanistic SDMs predicted similar overlap in habitat suitability; however, mechanistic SDMs predicted habitat suitability to extend into regions without green salamanders but known to harbor many lungless salaman-ders. Under future warming scenarios, habitat suitability depended on climate sce-nario and SDM type. Correlative and hybrid models predicted a 42% reduction or 260% increase in area considered to be suitable depending on the climate scenario. In mechanistic SDMs, energetically suitable habitat declined with both climate scenarios and was driven by the thermal sensitivity of ri. Our study indicates that correlative-only and hybrid approaches produce similar predictions of habitat suitability; however, discrepancies can arise for species that do not occupy their entire fundamental niche, which may hold consequences of conservation planning of threatened species
Global Estimates of Prevalent and Incident Herpes Simplex Virus Type 2 Infections in 2012
Herpes simplex virus type 2 (HSV-2) infection causes significant disease globally. Adolescent and adult infection may present as painful genital ulcers. Neonatal infection has high morbidity and mortality. Additionally, HSV-2 likely contributes substantially to the spread of HIV infection. The global burden of HSV-2 infection was last estimated for 2003. Here we present new global estimates for 2012 of the burden of prevalent (existing) and incident (new) HSV-2 infection among females and males aged 15-49 years, using updated methodology to adjust for test performance and estimate by World Health Organization (WHO) region.We conducted a literature review of HSV-2 prevalence studies world-wide since 2000. We then fitted a model with constant HSV-2 incidence by age to pooled HSV-2 prevalence values by age and sex. Prevalence values were adjusted for test sensitivity and specificity. The model estimated prevalence and incidence by sex for each WHO region to obtain global burden estimates. Uncertainty bounds were computed by refitting the model to reflect the variation in the underlying prevalence data. In 2012, we estimate that there were 417 million people aged 15-49 years (range: 274-678 million) living with HSV-2 infection world-wide (11.3% global prevalence), of whom 267 million were women. We also estimate that in 2012, 19.2 million (range: 13.0-28.6 million) individuals aged 15-49 years were newly-infected (0.5% of all individuals globally). The highest burden was in Africa. However, despite lower prevalence, South-East Asia and Western Pacific regions also contributed large numbers to the global totals because of large population sizes.The global burden of HSV-2 infection is large, leaving over 400 million people at increased risk of genital ulcer disease, HIV acquisition, and transmission of HSV-2 to partners or neonates. These estimates highlight the critical need for development of vaccines, microbicides, and other new HSV prevention strategies
A Road Map for the Global Elimination of Congenital Syphilis
Congenital syphilis is the oldest recognized congenital infection, and continues to account for extensive global perinatal morbidity and mortality today. Serious adverse pregnancy outcomes caused by maternal syphilis infection are prevented with screening early in pregnancy and prompt treatment of women testing positive. Intramuscular penicillin, an inexpensive antibiotic on the essential medicine list of nations all over the world, effectively cures infection and prevents congenital syphilis. In fact, at a cost of $11–15 per disability adjusted life year (DALY) averted, maternal syphilis screening and treatment is among the most cost-effective public health interventions in existence. Yet implementation of this basic public health intervention is sporadic in countries with highest congenital syphilis burden. We discuss the global burden of this devastating disease, current progress and ongoing challenges for its elimination in countries with highest prevalence, and next steps in ensuring a world free of preventable perinatal deaths caused by syphilis
Global burden of maternal and congenital syphilis in 2008 and 2012: a health systems modelling study
Background: In 2007, WHO launched a global initiative for the elimination of mother-to-child transmission of syphilis (congenital syphilis). An important aspect of the initiative is strengthening surveillance to monitor progress towards elimination. In 2008, using a health systems model with country data inputs, WHO estimated that 1·4 million maternal syphilis infections caused 520 000 adverse pregnancy outcomes. To assess progress, we updated the 2008 estimates and estimated the 2012 global prevalence and cases of maternal and congenital syphilis.
Methods: We used a health systems model approved by the Child Health Epidemiology Reference Group. WHO and UN databases provided inputs on livebirths, antenatal care coverage, and syphilis testing, seropositivity, and treatment in antenatal care. For 2012 estimates, we used data collected between 2009 and 2012. We updated the 2008 estimates using data collected between 2000 and 2008, compared these with 2012 estimates using data collected between 2009 and 2012, and performed subanalyses to validate results.
Findings: In 2012, an estimated 930 000 maternal syphilis infections caused 350 000 adverse pregnancy outcomes including 143 000 early fetal deaths and stillbirths, 62 000 neonatal deaths, 44 000 preterm or low weight births, and 102 000 infected infants worldwide. Nearly 80% of adverse outcomes (274 000) occurred in women who received antenatal care at least once. Comparing the updated 2008 estimates with the 2012 estimates, maternal syphilis decreased by 38% (from 1 488 394 cases in 2008 to 927 936 cases in 2012) and congenital syphilis decreased by 39% (from 576 784 to 350 915). India represented 65% of the decrease. Analysis excluding India still showed an 18% decrease in maternal and congenital cases of syphilis worldwide.
Interpretation: Maternal and congenital syphilis decreased worldwide from 2008 to 2012, which suggests progress towards the elimination of mother-to-child transmission of syphilis. Nonetheless, maternal syphilis caused substantial adverse pregnancy outcomes, even in women receiving antenatal care. Improved access to quality antenatal care, including syphilis testing and treatment, and robust data are all important for achieving the elimination of mother-to child transmission of syphilis.
Funding: The UNDP-UNFPA-UNICEF-WHO-World Bank Special Programme of Research, Development and Research Training in Human Reproduction in WHO, and the US Centers for Disease Control and Prevention
Prenatal Protein Malnutrition Produces Resistance to Distraction Similar to Noradrenergic Deafferentation of the Prelimbic Cortex in a Sustained Attention Task
Exposure to malnutrition early in development increases likelihood of neuropsychiatric disorders, affective processing disorders, and attentional problems later in life. Many of these impairments are hypothesized to arise from impaired development of the prefrontal cortex. The current experiments examine the impact of prenatal malnutrition on the noradrenergic and cholinergic axons in the prefrontal cortex to determine if these changes contribute to the attentional deficits seen in prenatal protein malnourished rats (6% casein vs. 25% casein). Because prenatally malnourished animals had significant decreases in noradrenergic fibers in the prelimbic cortex with spared innervation in the anterior cingulate cortex and showed no changes in acetylcholine innervation of the prefrontal cortex, we compared deficits produced by malnutrition to those produced in adult rats by noradrenergic lesions of the prelimbic cortex. All animals were able to perform the baseline sustained attention task accurately. However, with the addition of visual distractors to the sustained attention task, animals that were prenatally malnourished and those that were noradrenergically lesioned showed cognitive rigidity, i.e., were less distractible than control animals. All groups showed similar changes in behavior when exposed to withholding reinforcement, suggesting specific attentional impairments rather than global difficulties in understanding response rules, bottom-up perceptual problems, or cognitive impairments secondary to dysfunction in sensitivity to reinforcement contingencies. These data suggest that prenatal protein malnutrition leads to deficits in noradrenergic innervation of the prelimbic cortex associated with cognitive rigidity
Global and Regional Estimates of Prevalent and Incident Herpes Simplex Virus Type 1 Infections in 2012
Herpes simplex virus type 1 (HSV-1) commonly causes orolabial ulcers, while HSV-2 commonly causes genital ulcers. However, HSV-1 is an increasing cause of genital infection. Previously, the World Health Organization estimated the global burden of HSV-2 for 2003 and for 2012. The global burden of HSV-1 has not been estimated.We fitted a constant-incidence model to pooled HSV-1 prevalence data from literature searches for 6 World Health Organization regions and used 2012 population data to derive global numbers of 0-49-year-olds with prevalent and incident HSV-1 infection. To estimate genital HSV-1, we applied values for the proportion of incident infections that are genital.We estimated that 3709 million people (range: 3440-3878 million) aged 0-49 years had prevalent HSV-1 infection in 2012 (67%), with highest prevalence in Africa, South-East Asia and Western Pacific. Assuming 50% of incident infections among 15-49-year-olds are genital, an estimated 140 million (range: 67-212 million) people had prevalent genital HSV-1 infection, most of which occurred in the Americas, Europe and Western Pacific.The global burden of HSV-1 infection is huge. Genital HSV-1 burden can be substantial but varies widely by region. Future control efforts, including development of HSV vaccines, should consider the epidemiology of HSV-1 in addition to HSV-2, and especially the relative contribution of HSV-1 to genital infection
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