Miracle-dz/UniFAR-FTUs huggingface dataset:
Friend Effects and Racial Disparities in Academic Achievement

Racial disparities in achievement are a persistent fact of the US educational system. An often cited but rarely directly studied explanation for these disparities is that adolescents from different racial and ethnic backgrounds are exposed to different peers and have different friends. In this article I identify the impact of friends on racial and ethnic achievement disparities. Using data from Add Health and an instrumental variable approach, I show that the achievement characteristics of youths’ friends drive friend effects; adolescents with friends with higher grades are more likely to increase their grades compared to those with lower-achieving friends. Although these effects do not differ across race/ethnicity, given differences in friendship patterns, if black and Latino adolescents had friends with the achievement characteristics of white students, the GPA gap would be 17 to 19 percent smaller. Although modest, this effect represents an important and often overlooked source of difference among black and Latino youth.
UV-C Light Induces Raft-associated Acid Sphingomyelinase and JNK Activation and Translocation Independently on a Nuclear Signal*

The initiation of UV light-induced signaling in mammalian cells is largely considered to be subsequent to DNA damage. Several studies have also described ceramide (CER), a lipid second messenger, as a major contributor in mediating UV light-induced c-Jun N-terminal kinase (JNK) activation and cell death. It is demonstrated here that UV-C light irradiation of U937 cells results in the activation and translocation of a Zn2+-independent acid sphingomyelinase, leading to CER accumulation in raft microdomains. These CER-enriched rafts aggregate and play a functional role in JNK activation. The observation that UV-C light also induced CER generation and the externalization of acid sphingomyelinase and JNK in human platelets conclusively rules out the involvement of a nuclear signal generated by DNA damage in the initiation of a UV light response, which is generated at the plasma membrane.
Locating essential Escherichia coli genes by using mini-Tn10 transposons: the pdxJ operon

The mini-Tn10 transposon (delta 16 delta 17Tn10) confers tetracycline resistance. When inserted between a gene and its promoter, it blocks transcription and prevents expression of that gene. Tetracycline in the medium induces divergent transcription of the tetA and tetR genes within the transposon, and this transcription extends beyond the transposon in both directions into the bacterial genes. If the mini-Tn10 inserts between an essential bacterial gene and its promoter, the insertion mutation can cause conditional growth which is dependent on the presence of tetracycline. Two essential genes in adjacent operons of Escherichia coli have been detected by screening for tetracycline dependence among tetracycline-resistant insertion mutants. These essential genes are the era gene in the rnc operon and the dpj gene in the adjacent pdxJ operon. The pdxJ operon has not been described previously. It consists of two genes, pdxJ and dpj. Whereas the dpj gene is essential for E. coli growth in all media tested, pdxJ is not essential. The pdxJ gene encodes a protein required in the biosynthesis of pyridoxine (vitamin B6).
The costs of suppressing stressful memories

We investigated the costs of suppressing emotional and nonemotional memories, as evidenced in response times on a concurrent sentence verification task with three levels of syntactic complexity. Participants suppressing memories of personal negative experiences (n=26) had slower response times compared to the control group (n=23) and to participants suppressing nonemotional memories (n=25) particularly on the most complex sentences. Participants suppressing nonpersonal negative experiences (n=26) did not differ from either of the other two suppression groups. Suppression failures did not differ between conditions, but failures during the sentence task were related to the intrusiveness of the memory being suppressed. The findings indicate that different kinds of memories have different suppression costs and that even successful thought suppression can impair performance on concurrent tasks, supporting Wegner's ironic processing model in which suppression attempts must compete with other ongoing tasks for scarce mental resources.
Light-to-moderate ethanol feeding augments AMPK-α phosphorylation and attenuates SREBP-1 expression in the liver of rats.

PURPOSE Fatty liver disease, a hepatic manifestation of metabolic syndrome, is one of the major causes of chronic liver diseases. Epidemiological studies suggest that regular light-to-moderate ethanol consumption lowers the risk of developing metabolic disorders including dislipidemia, insulin resistance, type 2 diabetes and fatty liver disease. However, the mechanism(s) of the protective effect of light-to-moderate ethanol consumption on the liver remains unknown. METHODS In the present study, we investigated the effects of light (6%, 0.94 g/kg/day) and moderate (12%, 1.88 g/kg/day) ethanol feeding in rats for 3 weeks on the circulating and hepatic biochemical profiles and on the hepatic protein expression and phosphorylation status of adenosine monophosphate-activated protein kinase-α (AMPK-α) and other down-stream targets of this enzyme including sterol regulatory element-binding protein-1 (SREBP-1), SREBP cleavage-activating protein (SCAP) and 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-CoA reductase). RESULTS Despite no significant difference in food-intake among the groups, light ethanol treatment significantly increased the body weight compared to control rats. Serum glucose, insulin, total cholesterol, triglycerides, phospholipids and hepatic cholesterol and triglycerides were not significantly different among the groups. However, serum free fatty acids were significantly reduced with light ethanol treatment. Both light and moderate ethanol treatment significantly increased the hepatic levels of phosphorylated AMPK-α protein and this was associated with significant reduction of SREBP-1 protein expression, suggesting an enhanced fatty acid oxidation. In addition, light ethanol treatment significantly decreased the SCAP protein expression in the liver. However, liver HMG-CoA protein expression was not significantly different with ethanol consumption. CONCLUSION Chronic light-to-moderate ethanol consumption increased AMPK activation which was associated with decreased expression of SREBP-1 and SCAP in the liver. Thus, our studies provide mechanistic evidence for the earlier epidemiological studies that indicate light-to-moderate ethanol intake lowers the risk of development of fatty liver disease and other metabolic disorders. Our studies demonstrate that the protective effects of light-to-moderate ethanol arise at least in part by increased phosphorylation of AMPK-α and decreased SREBP-1 expression in the liver. Further studies are warranted to determine the effects of light-to-moderate ethanol on intracellular up-stream and down-stream targets of AMPK and also on the implications of light-to-moderate ethanol in protecting non-alcoholic fatty liver disease.
Felonious Arrests of Former Foster Care and TANF-Involved Youth

Income assistance programs (e.g., Temporary Assistance to Needy Families; TANF) and child welfare service (CWS) programs have implicit intentions to prepare children for an adulthood that is free from serious criminal activity. This cross-sectional study compares the felonious arrests as adults of youth who were involved with TANF (n = 6,596) with those who were involved with CWS (n = 1316). In the CWS population, we compare youth who emancipated from foster care (n = 841), those who reunified (n =278), and those with other exits (n = 197). Outcomes of interest include the severity of the felony an individual was charged with as an adult as well as the hazard of being arrested after age 16 years. Findings show that as adults, TANF-involved youth are less likely than former foster youth to be charged with a felony; moreover, when former TANF youth are charged with felonies as adults, the felonies are less severe than felony charges incurred by former foster youth. Overall, as young adults, males and African American youth are not only more likely to be charged with felonies than other race youth or females but also are more likely to be charged with felonies of higher severity ratings than other race youth or females. Entering foster care as an adolescent and having multiple placements in care are associated with poorer outcomes in adulthood. However, youth who remain in foster care longer are less likely to be charged with a felony. The study confirms earlier work on adverse criminal justice-related outcomes for former foster youth and clarifies the need for specific interventions to reduce subsequent criminal involvement.
Performing culture in the classroom: An instructional (auto) ethnography

The notion of performing culture in the classroom is both a paradigmatic description of a phenomenon as well as a theoretical position. This research is poised at the productive intersection of critical pedagogy and the increasing focus on autobiography and autoethnography in Performance Studies. The essay seeks to contribute to the development of education as well as performance theory.
Symptoms are a poor indicator of reflux status after fundoplication for gastroesophageal reflux disease: role of esophageal functions tests.

BACKGROUND If a patient develops foregut symptoms after a fundoplication, it is assumed that the operation has failed, and acid-reducing medications are often prescribed. Esophageal function tests (manometry and pH monitoring) are seldom performed early in the management of these patients. HYPOTHESIS In patients who are symptomatic after fundoplication for gastroesophageal reflux disease, a symptom-based diagnosis is not accurate, and esophageal function tests should be performed routinely before starting acid-reducing medications. DESIGN Prospective study. SETTING University hospital. PATIENTS AND METHODS One hundred twenty-four patients who developed foregut symptoms after laparoscopic fundoplication (average, 17 months postoperatively) underwent esophageal manometry and pH monitoring. Sixty-two patients (50%) were taking acid-reducing medications. MAIN OUTCOME MEASURES Postoperative symptoms, use of antireflux medications, grade of esophagitis, esophageal motility, and DeMeester scores. RESULTS Seventy-six (61%) of the 124 patients had normal esophageal acid exposure, while the acid exposure was abnormal in 48 patients (39%). Only 20 (32%) of the 62 patients who were taking acid-reducing medications had reflux postoperatively. Regurgitation was the only symptom that predicted abnormal reflux. CONCLUSIONS These results show that (1) symptoms were due to reflux in 39% of patients only; (2) with the exception of regurgitation, symptoms were an unreliable index of the presence of reflux; and (3) 68% of patients who were taking acid-reducing medications postoperatively had a normal reflux status. Esophageal function tests should be performed early in the evaluation of patients after fundoplication to avoid improper and costly medical therapy.
Allelic Variation in the Serotonin Transporter Gene-Linked Polymorphic Region (5-HTTLPR) and Cardiovascular Reactivity in Young Adult Male and Female Twins of European-American Descent

Objective To examine the effect of length variation in the serotonin transporter gene-linked polymorphic region (5-HTTLPR) on individual differences in cardiovascular response to psychological challenge. Methods Heart rate (HR) and systolic and diastolic blood pressure (SBP, DBP) responses to computerized versions of two psychological challenges, the Stroop Color-Word Interference Test and mental arithmetic, were measured among 131 monozygotic (MZ) and 60 dizygotic (DZ) male or female (same-sex) European-American twin pairs. Among the 382 participants, 140 were homozygous for the “long” allele (l/l) at 5-HTTLPR, 61 were homozygous for the “short” allele (s/s), and 181 participants had one long and one short allele (l/s). Association and sib-pair analyses were performed to characterize genetic associations. Results In the full sample, 5-HTTLPR was associated with HR reactivity to psychological challenge, albeit in interaction with sex. Task-elicited HR responses of women homozygous for the short allele were significantly greater than among: a) men of the same genotype; and b) women having either one (l/s) or two (l/l) long alleles at 5-HTTLPR. SBP and DBP responsivity was unrelated to genotype. These results were corroborated on reanalysis in two genetically independent subsamples. Variability at 5-HTTLPR also predicted HR reactivity in sib-pair analyses among DZ twins. Conclusions These results suggest that the commonly observed sex difference in HR reactivity may be, in part, genetically mediated and perhaps occur only among individuals homozygous for the short allele at 5-HTTLPR.
Transcranial magnetic stimulation of posterior parietal cortex affects decisions of hand choice

Deciding which hand to use for an action is one of the most frequent decisions people make in everyday behavior. Using a speeded reaching task, we provide evidence that hand choice entails a competitive decision process between simultaneously activated action plans for each hand. We then show that single-pulse transcranial magnetic stimulation to the left posterior parietal cortex biases this competitive process, leading to an increase in ipsilateral, left hand reaches. Stimulation of the right posterior parietal cortex did not alter hand choice, suggesting a hemispheric asymmetry in the representations of reach plans. These results are unique in providing causal evidence that the posterior parietal cortex is involved in decisions of hand choice.
A review of the scientific evidence for biofilms in wounds

Both chronic and acute dermal wounds are susceptible to infection due to sterile loss of the innate barrier function of the skin and dermal appendages, facilitating the development of microbial communities, referred to as biofilms, within the wound environment. Microbial biofilms are implicated in both the infection of wounds and failure of those wounds to heal. The aim of this review is to provide a summary of published papers detailing biofilms in wounds, the effect they have on infection and wound healing, and detailing methods employed for their detection. The studies highlighted within this paper provide evidence that biofilms reside within the chronic wound and represent an important mechanism underlying the observed, delayed healing and infection. The reasons for this include both protease activity and immunological suppression. Furthermore, a lack of responsiveness to an array of antimicrobial agents has been due to the biofilms’ ability to inherently resist antimicrobial agents. It is imperative that effective strategies are developed, tested prospectively, and employed in chronic wounds to support the healing process and to reduce infection rates. It is increasingly apparent that adoption of a biofilm‐based management approach to wound care, utilizing the “antibiofilm tool box” of therapies, to kill and prevent reattachment of microorganisms in the biofilm is producing the most positive clinical outcomes and prevention of infection.
Empirics on global stock market integration : A valuation perspective

The objective of this paper is to study the extent of integration among developed and emerging stock markets in the onset of globalization. It examines market integration that manifests in the convergence of stock valuation ratios of different markets in the long run within a conceptual framework where valuation ratios reflect common global growth opportunities of stocks across markets. The spectrum of transition dynamics of earnings-price, dividend-price and book-price ratios among markets is explored with different notions of convergence, at both the total market and disaggregated industrial sector levels, in three overlapping time periods. Overall test results reveal the time-varying nature of the global stock market integration process. Developed and emerging markets have achieved different degrees of integration, and that integration at the total market level comes with different degrees of integration at the industry level, as evidenced by the asymmetric conclusions drawn from the valuation ratios employed. JEL classification: F36, G12, G15
Structural Basis for Universal Corrinoid Recognition by the Cobalamin Transport Protein Haptocorrin*

Background: Haptocorrin (HC) is a cobalamin (Cbl) transport protein known to recognize a wide range of corrinoids. Results: We solved the crystal structure of human HC in complex with Cbl and cobinamide. Conclusion: HC recognizes corrinoids by establishing distinct contacts with the corrin ring. Significance: Our findings complete the molecular details for corrinoid recognition by human Cbl transport proteins. Cobalamin (Cbl; vitamin B12) is an essential micronutrient synthesized only by bacteria. Mammals have developed a sophisticated uptake system to capture the vitamin from the diet. Cbl transport is mediated by three transport proteins: transcobalamin, intrinsic factor, and haptocorrin (HC). All three proteins have a similar overall structure but a different selectivity for corrinoids. Here, we present the crystal structures of human HC in complex with cyanocobalamin and cobinamide at 2.35 and 3.0 Å resolution, respectively. The structures reveal that many of the interactions with the corrin ring are conserved among the human Cbl transporters. However, the non-conserved residues Asn-120, Arg-357, and Asn-373 form distinct interactions allowing for stabilization of corrinoids other than Cbl. A central binding motif forms interactions with the e- and f-side chains of the corrin ring and is conserved in corrinoid-binding proteins of other species. In addition, the α- and β-domains of HC form several unique interdomain contacts and have a higher shape complementarity than those of intrinsic factor and transcobalamin. The stabilization of ligands by all of these interactions is reflected in higher melting temperatures of the protein-ligand complexes. Our structural analysis offers fundamental insights into the unique binding behavior of HC and completes the picture of Cbl interaction with its three transport proteins.
Same App, Different App Stores: A Comparative Study

To attract more users, implementing the same mobile app for different platforms has become a common industry practice. App stores provide a unique channel for users to share feedback on the acquired apps through ratings and textual reviews. However, each mobile platform has its own online store for distributing apps to users. To understand the characteristics of and discrepancies in how users perceive the same app implemented for and distributed through different platforms, we present a large-scale comparative study of cross-platform apps. We mine the characteristics of 80,000 app-pairs (160K apps in total) from a corpus of 2.4 million apps collected from the Apple and Google Play app stores. We quantitatively compare their app-store attributes, such as stars, versions, and prices. We measure the aggregated user-perceived ratings and find many discrepancies across the platforms. Further, we employ machine learning to classify 1.7 million textual user reviews obtained from 2,000 of the mined app-pairs. We analyze discrepancies and root causes of user complaints to understand cross-platform development challenges that impact cross-platform user-perceived ratings. We also follow up with the developers to understand the reasons behind identified discrepancies.
A focussed single-view hand-held echocardiography protocol for the detection of rheumatic heart disease

Abstract Background Echocardiographic screening represents an opportunity for reduction in the global burden of rheumatic heart disease. A focussed single-view screening protocol could allow for the rapid training of healthcare providers and screening of patients. Objective The aim of this study was to determine the sensitivity and specificity of a focussed single-view hand-held echocardiographic protocol for the diagnosis of rheumatic heart disease in children. Methods A total of nine readers were divided into three reading groups; each interpreted 200 hand-held echocardiography studies retrospectively as screen-positive, if mitral regurgitation ⩾1.5 cm and/or any aortic insufficiency were observed, or screen-negative from a pooled study library. The performance of experts receiving focussed hand-held protocols, non-experts receiving focussed hand-held protocols, and experts receiving complete hand-held protocols were determined in comparison with consensus interpretations on fully functional echocardiography machines. Results In all, 587 studies including 76 on definite rheumatic heart disease, 122 on borderline rheumatic heart disease, and 389 on normal cases were available for analysis. The focussed single-view protocol had a sensitivity of 81.1%, specificity of 75.5%, negative predictive value of 88.5%, and a positive predictive value of 63.2%; expert readers had higher specificity (86.1 versus 64.8%, p<0.01) but equal sensitivity. Sensitivity – experts, 96% and non-experts, 95% – and negative predictive value – experts, 99% and non-experts, 98% – were better for definite rheumatic heart disease. False-positive screening studies resulting from erroneous identification of mitral regurgitation and aortic insufficiency colour jets increased with shortened protocols and less experience (p<0.01). Conclusion Our data support a focussed screening protocol limited to parasternal long-axis images. This holds promise in making echocardiographic screening more practical in regions where rheumatic heart disease remains endemic.
Agrin Isoforms with Distinct Amino Termini

The proteoglycan agrin is required for postsynaptic differentiation at the skeletal neuromuscular junction, but is also associated with basal laminae in numerous other tissues, and with the surfaces of some neurons. Little is known about its roles at sites other than the neuromuscular junction, or about how its expression and subcellular localization are regulated in any tissue. Here we demonstrate that the murine agrin gene generates two proteins with different NH2 termini, and present evidence that these isoforms differ in subcellular localization, tissue distribution, and function. The two isoforms share ∼1,900 amino acids (aa) of common sequence following unique NH2 termini of 49 or 150 aa; we therefore call them short NH2-terminal (SN) and long NH2-terminal (LN) isoforms. In the mouse genome, LN-specific exons are upstream of an SN-specific exon, which is in turn upstream of common exons. LN-agrin is expressed in both neural and nonneural tissues. In spinal cord it is expressed in discrete subsets of cells, including motoneurons. In contrast, SN-agrin is selectively expressed in the nervous system but is widely distributed in many neuronal cell types. Both isoforms are externalized from cells but LN-agrin assembles into basal laminae whereas SN-agrin remains cell associated. Differential expression of the two isoforms appears to be transcriptionally regulated, whereas the unique SN and LN sequences direct their distinct subcellular localizations. Insertion of a “gene trap” construct into the mouse genome between the LN and SN exons abolished expression of LN-agrin with no detectable effect on expression levels of SN-agrin or on SN-agrin bioactivity in vitro. Agrin protein was absent from all basal laminae in mice lacking LN-agrin transcripts. The formation of the neuromuscular junctions was as drastically impaired in these mutants as in mice lacking all forms of agrin. Thus, basal lamina–associated LN-agrin is required for neuromuscular synaptogenesis, whereas cell-associated SN-agrin may play distinct roles in the central nervous system.