Recently, the log-structured merge-tree (LSM-tree) has been widely adopted for use in the storage layer of modern NoSQL systems. Because of this, there have been a large number of research efforts, ...from both the database community and the operating systems community, that try to improve various aspects of LSM-trees. In this paper, we provide a survey of recent research efforts on LSM-trees so that readers can learn the state of the art in LSM-based storage techniques. We provide a general taxonomy to classify the literature of LSM-trees, survey the efforts in detail, and discuss their strengths and trade-offs. We further survey several representative LSM-based open-source NoSQL systems and discuss some potential future research directions resulting from the survey.
Abstract Purpose The purpose of this study was to document the point and cumulative prevalence of incapacitated rape (IR) and forcible rape (FR) among first-year college women. Methods Female ...students (N = 483) completed a health questionnaire (1) on arrival on campus; (2) at the end of the fall semester; (3) at the end of the spring semester; and (4) at the end of the summer following their first year of college. Results Before entering college, 18% reported IR (attempted and/or completed), and 15% reported FR (attempted and/or completed). During the first year of college, 15% reported IR (attempted or completed) and 9% reported FR (attempted or completed). By the start of the second year (lifetime prevalence), 26% and 22% had experienced IR and FR (attempted or completed), respectively. Conclusions Both incapacitated and forcible sexual assaults and rape have reached epidemic levels among college women. Interventions to address sexual violence on campus are urgently needed.
Alcohol misuse occurs commonly on college campuses, necessitating prevention programs to help college drinkers reduce consumption and minimize harmful consequences. Computer-delivered interventions ...(CDIs) have been widely used due to their low cost and ease of dissemination but whether CDIs are efficacious and whether they produce benefits equivalent to face-to-face interventions (FTFIs) remain unclear. Therefore, we identified controlled trials of both CDIs and FTFIs and used meta-analysis (a) to determine the relative efficacy of these two approaches and (b) to test predictors of intervention efficacy. We included studies examining FTFIs (N=5237; 56% female; 87% White) and CDIs (N=32,243; 51% female; 81% White). Independent raters coded participant characteristics, design and methodological features, intervention content, and calculated weighted mean effect sizes using fixed and random-effects models. Analyses indicated that, compared to controls, FTFI participants drank less, drank less frequently, and reported fewer problems at short-term follow-up (d+s=0.15–0.19); they continued to consume lower quantities at intermediate (d+=0.23) and long-term (d+=0.14) follow-ups. Compared to controls, CDI participants reported lower quantities, frequency, and peak intoxication at short-term follow-up (d+s=0.13–0.29), but these effects were not maintained. Direct comparisons between FTFI and CDIs were infrequent, but these trials favored the FTFIs on both quantity and problem measures (d+s=0.12–0.20). Moderator analyses identified participant and intervention characteristics that influence intervention efficacy. Overall, we conclude that FTFIs provide the most effective and enduring effects.
► A meta-analysis evaluates the efficacy of face-to-face vs computerized alcohol interventions. ► Both types of interventions are associated with less drinking in the short term. ► Face-to-face interventions produce risk reduction across a wider range of drinking outcomes. ► Effects of face-to-face (vs computerized) alcohol interventions last longer. ► Direct comparisons within studies favor face-to-face interventions.
Knowledge of how Mediator and TFIID cross-talk contributes to promoter-enhancer (P-E) communication is important for elucidating the mechanism of enhancer function. We conducted an shRNA knockdown ...screen in murine embryonic stem cells to identify the functional overlap between Mediator and TFIID subunits on gene expression. Auxin-inducible degrons were constructed for TAF12 and MED4, the subunits eliciting the greatest overlap. Degradation of TAF12 led to a dramatic genome-wide decrease in gene expression accompanied by destruction of TFIID, loss of Pol II preinitiation complex (PIC) at promoters, and significantly decreased Mediator binding to promoters and enhancers. Interestingly, loss of the PIC elicited only a mild effect on P-E looping by promoter capture Hi-C (PCHi-C). Degradation of MED4 had a minor effect on Mediator integrity but led to a consistent twofold loss in gene expression, decreased binding of Pol II to Mediator, and decreased recruitment of Pol II to the promoters, but had no effect on the other PIC components. PCHi-C revealed no consistent effect of MED4 degradation on P-E looping. Collectively, our data show that TAF12 and MED4 contribute mechanistically in different ways to P-E communication but neither factor appears to directly control P-E looping, thereby dissociating P-E communication from physical looping.
Abstract Better understanding of the temporal sequence of hookah, cigarette, and marijuana use will help to inform smoking prevention efforts. To address this gap in the literature, we assessed all ...three of these smoking behaviors in a sample of 424 first-year college women. Using a longitudinal design, we investigated whether hookah use predicts initiating/resuming cigarette and/or initiating marijuana use, and whether cigarette and/or marijuana use predicts initiating hookah use. Participants (67% White, M age = 18.1 years) completed nine monthly surveys. The initial (i.e., baseline) survey assessed demographics, sensation-seeking, impulsivity, and pre-college substance use. Follow-up surveys assessed past-month substance use; outcomes were initiating/resuming cigarette use, initiating marijuana use, and initiating hookah use during the first year of college. We controlled for sensation-seeking, impulsivity, binge drinking, and other smoking behaviors in our multivariate logistic regression models. The results showed that (a) pre-college hookah use predicted initiating/resuming cigarette use; (b) pre-college marijuana use predicted initiation of hookah tobacco smoking; and (c) pre-college cigarette use predicted neither hookah nor marijuana initiation. The findings highlight the co-occurrence of smoking behaviors as well as the need for bundling preventive interventions so that they address hookah, cigarette, and marijuana use.
This study reviews diffusion of video and video advertising on the Web sites of 400 community news outlets in the United States. Results suggest that while a significant number of community news ...outlets publish editorial videos online, video advertising lags behind larger publications. The study argues that elements such as circulation and size of a media corporation have little influence on the development and use of video and video advertising on community media Web sites in the U.S.
Metazoan chromosomes are sequentially partitioned into topologically associating domains (TADs) and then into smaller sub-domains. One class of sub-domains, insulated neighborhoods, are proposed to ...spatially sequester and insulate the enclosed genes through self-association and chromatin looping. However, it has not been determined functionally whether promoter-enhancer interactions and gene regulation are broadly restricted to within these loops. Here, we employed published datasets from murine embryonic stem cells (mESCs) to identify insulated neighborhoods that confine promoter-enhancer interactions and demarcate gene regulatory regions. To directly address the functionality of these regions, we depleted estrogen-related receptor β (Esrrb), which binds the Mediator co-activator complex, to impair enhancers of genes within 222 insulated neighborhoods without causing mESC differentiation. Esrrb depletion reduces Mediator binding, promoter-enhancer looping, and expression of both nascent RNA and mRNA within the insulated neighborhoods without significantly affecting the flanking genes. Our data indicate that insulated neighborhoods represent functional regulons in mammalian genomes.
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•Promoters interact with loci within CTCF-cohesin-demarcated insulated neighborhoods•Esrrb knockdown inactivates enhancers by removing mediator from them in mESCs•Enhancer inactivation disrupts promoter-enhancer looping•Enhancer inactivation downregulates genes only within insulated neighborhoods
Sun et al. report that a class of chromosomal sub-domains, “insulated neighborhoods,” broadly constrains communication between a promoter and its enhancers or other elements. Enhancer inactivation by depleting the transcription factor Esrrb downregulates genes within insulated neighborhoods without affecting flanking genes, indicating that these sub-domains constrain enhancer action and represent functional regulons.
Objective: Alcohol use established during the first-year of college can result in adverse consequences during the college years and beyond. In this meta-analysis, we evaluated the efficacy of ...interventions to prevent alcohol misuse by first-year college students. Method: Studies were included if the study reported an individual- or group-level intervention using a randomized controlled trial, targeted 1st-year college students, and assessed alcohol use. Forty-one studies with 62 separate interventions (N = 24,294; 57% women; 77% White) were included. Independent raters coded sample, design, methodological features, and intervention content. Weighted mean effect sizes, using fixed- and random-effects models, were calculated. Potential moderators, determined a priori, were examined to explain variability in effect sizes. Results: Relative to controls, students receiving an intervention reported lower quantity and frequency of drinking and fewer problems (d+s = 0.07-0.14). These results were more pronounced when the interventions were compared with an assessment-only control group (d+s = 0.11-0.19). Intervention content (e.g., personalized feedback) moderated the efficacy of the intervention. Conclusions: Behavioral interventions for 1st-year college students reduce alcohol consumption and alcohol-related problems. Interventions that include personalized feedback, moderation strategies, expectancy challenge, identification of risky situations, and goal-setting optimize efficacy. Strategies to prevent alcohol misuse among first-year students are recommended.
Histone modifications play important roles in regulating DNA-based biological processes. Of the modified sites, histone H3 lysine 56 (H3K56) is unique in that it lies within the globular core domain ...near the entry-exit sites of the nucleosomal DNA superhelix and its acetylation state in yeast is a marker for newly synthesized histones in transcription, DNA repair, and DNA replication. We now report the presence of H3K56 monomethylation (H3K56me1) in mammalian cells and find that the histone lysine methytransferase G9a/KMT1C is required for H3K56me1 both in vivo and in vitro. We also find that disruption of G9a or H3K56 impairs DNA replication. Furthermore, H3K56me1 associates with the replication processivity factor PCNA primarily in G1 phase of the cell cycle and, directly, in vitro. These results find H3K56me1 in mammals and indicate a role for H3K56me1 as a chromatin docking site for PCNA prior to its function in DNA replication.
► H3K56me1 is detected in mammals ► G9a/KMT1C is required for H3K56me1 in vivo and in vitro ► H3K56me1 facilitates DNA replication ► Replication factor PCNA binds preferentially to H3K56me1 in G1 phase
This controlled experimental study investigated the interaction of variables associated with rating the pronunciation component of high-stakes English-language-speaking tests such as IELTS and TOEFL ...iBT. One hundred experienced raters who were all either familiar or unfamiliar with Brazilian-accented English or Papua New Guinean Tok Pisin-accented English, respectively, were presented with speech samples in audio-only or audio-visual mode. Two-way ordinal regression with post hoc pairwise comparisons found that the presentation mode interacted significantly with accent familiarity to increase comprehensibility ratings (χ² = 88.005, df = 3, p < .0001), with presentation mode having a stronger effect in the interaction than accent familiarity (χ² = 59.328, df = 1, p < .0001). Based on odds ratios, raters were significantly more likely to score comprehensibility higher when the presentation mode was audio-visual (compared to audio-only) for both the unfamiliar (91% more likely) and familiar speakers (92.3% more likely). The results suggest that semi-direct speaking tests using audio-only or audio-visual modes of presentation should be evaluated through research to ascertain how accent familiarity and presentation mode interact to variably affect comprehensibility ratings. Such research may be beneficial to investigate the virtual modes of speaking test delivery that have emerged post-COVID-19.
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