Buoyant surface jets discharged into a strong crossflow

Analytical and experimental investigations were carried out for three-dimensional buoyant surface jets with strong ambient flow but without boundary attachment. A numerical model in curvilinear coordinates was developed from an integral jet analysis modified for buoyancy effects and included asymmetry of the jet. Detailed temperature distributions were measured in the laboratory with densimetric Froude numbers (F̥) of 5, 10 and 15 and 0 velocity ratios (R) from 2 to 13. Experimental results showed that ambient crossflows can cause significant distortion of the jet, even for R = 13. Near the exit, the lower portion of the jet is swept toward the lee side of the jet. The resulting L-shaped cross section and the associated density instability may enhance spreading on the lee side and may contribute to the subsequent formation of bimodal temperature distributions. The jet bending increases as R decreases and as F̥ increases. Dilution increases with increasing F̥ and decreasing R. The model was calibrated against the entire set of measured temperatures for each run and is capable of predicting temperature 0 distributions to an accuracy of 0.63C˚. The agreement could probably be improved by using similarity profiles better suited to the actual jet cross sectional shape which was not known at the beginning of the research.U.S. Department of the InteriorU.S. Geological SurveyOpe

OPAAS: a web server for optimal, permuted, and other alternative alignments of protein structures

The large number of experimentally determined protein 3D structures is a rich resource for studying protein function and evolution, and protein structure comparison (PSC) is a key method for such studies. When comparing two protein structures, almost all currently available PSC servers report a single and sequential (i.e. topological) alignment, whereas the existence of good alternative alignments, including those involving permutations (i.e. non-sequential or non-topological alignments), is well known. We have recently developed a novel PSC method that can detect alternative alignments of statistical significance (alignment similarity P-value <10(−5)), including structural permutations at all levels of complexity. OPAAS, the server of this PSC method freely accessible at our website (), provides an easy-to-read hierarchical layout of output to display detailed information on all of the significant alternative alignments detected. Because these alternative alignments can offer a more complete picture on the structural, evolutionary and functional relationship between two proteins, OPAAS can be used in structural bioinformatics research to gain additional insight that is not readily provided by existing PSC servers

Study of stratified overflows and underflows

The study presents a general analysis of two-layered stratified flows taking into account effects of sidewall friction and variation of density with horizontal distance. The analysis is applied to the study of arrested thermal wedges and arrested cold water intrusions. Laboratory data were collected and analyzed and it was determined that bed roughness has a significant effect on the interfacial friction factor for arrested thermal wedges but not for arrested cold water intrusions. Friction factors were found to vary significantly along the wedges indicating that use of average values is perhaps undesirable. Local values of friction factor were found to increase with values of a local interfacial Reynolds number.U.S. Department of the InteriorU.S. Geological SurveyOpe

Association between duration of gonadotrophin-releasing hormone agonist use and cardiovascular risks: A population-based competing-risk analysis

Background Although androgen deprivation therapy has known cardiovascular risks, it is unclear if its duration is related to cardiovascular risks. This study thus aimed to investigate the associations between gonadotrophin-releasing hormone (GnRH) agonist use duration and cardiovascular risks. Methods This retrospective cohort study included adult patients with prostate cancer receiving GnRH agonists in Hong Kong during 1999–2021. Patients who switched to GnRH antagonists, underwent bilateral orchidectomy, had <6 months of GnRH agonist, prior myocardial infarction (MI), or prior stroke was excluded. All patients were followed up until September 2021 for a composite endpoint of MI and stroke. Multivariable competing-risk regression using the Fine-Gray subdistribution model was used, with mortality from any cause as the competing event. Results In total, 4038 patients were analyzed (median age 74.9 years old, interquartile range (IQR) 68.7–80.8 years old). Over a median follow-up of 4.1 years (IQR 2.1–7.5 years), longer GnRH agonists use was associated with higher risk of the endpoint (sub-hazard ratio per year 1.04 [1.01–1.06], p = 0.001), with those using GnRH agonists for ≥2 years having an estimated 23% increase in the sub-hazard of the endpoint (sub-hazard ratio 1.23 [1.04–1.46], p = 0.017). Conclusion Longer GnRH agonist use may be associated with greater cardiovascular risks

The Case for Dynamic Models of Learners' Ontologies in Physics

In a series of well-known papers, Chi and Slotta (Chi, 1992; Chi & Slotta, 1993; Chi, Slotta & de Leeuw, 1994; Slotta, Chi & Joram, 1995; Chi, 2005; Slotta & Chi, 2006) have contended that a reason for students' difficulties in learning physics is that they think about concepts as things rather than as processes, and that there is a significant barrier between these two ontological categories. We contest this view, arguing that expert and novice reasoning often and productively traverses ontological categories. We cite examples from everyday, classroom, and professional contexts to illustrate this. We agree with Chi and Slotta that instruction should attend to learners' ontologies; but we find these ontologies are better understood as dynamic and context-dependent, rather than as static constraints. To promote one ontological description in physics instruction, as suggested by Slotta and Chi, could undermine novices' access to productive cognitive resources they bring to their studies and inhibit their transition to the dynamic ontological flexibility required of experts.Comment: The Journal of the Learning Sciences (In Press

Pre-vaccination prevalence of anogenital and oral human papillomavirus in young HIV-infected men who have sex with men.

The aims of this study were to: 1) determine prevalence of anogenital and oral HPV, 2) determine concordance between HPV at anal, perianal, scrotal/penile, and oral sites; and 3) describe factors associated with anogenital HPV types targeted by the 9-valent vaccine. Data were collected from 2012 to 2015 among men who have sex with men 18-26 years of age enrolled in a vaccine trial (N = 145). Penile/scrotal, perianal, anal, and oral samples were tested for 61 HPV types. Logistic regression was used to identify factors associated with types in the 9-valent vaccine. Participants' mean age was 23.0 years, 55.2% were African-American, and 26.2% were Hispanic; 93% had anal, 40% penile, and 6% oral HPV. Among those with anogenital infection, 18% had HPV16. Concordance was low between anogenital and oral sites. Factors independently associated with a 9-valent vaccine-type HPV were: race (African-American vs. White, OR=2.67, 95% CI=1.11-6.42), current smoking (yes vs. no, OR=2.37, 95% CI=1.03-5.48), and number of recent receptive anal sex partners (2+ vs. 0, OR=3.47, 95% CI=1.16-10.4). Most MSM were not infected with HPV16 or HPV18, suggesting that they may still benefit from HPV vaccination, but anogenital HPV was very common, highlighting the importance of vaccinating men before sexual initiation. CLINICAL TRIAL NUMBER: NCT01209325

Expansion microscopy of C. elegans.

Funder: John DoerrFunder: The Open Philanthropy ProjectFunder: Lisa YangWe recently developed expansion microscopy (ExM), which achieves nanoscale-precise imaging of specimens at ~70 nm resolution (with ~4.5x linear expansion) by isotropic swelling of chemically processed, hydrogel-embedded tissue. ExM of C. elegans is challenged by its cuticle, which is stiff and impermeable to antibodies. Here we present a strategy, expansion of C. elegans (ExCel), to expand fixed, intact C. elegans. ExCel enables simultaneous readout of fluorescent proteins, RNA, DNA location, and anatomical structures at resolutions of ~65-75 nm (3.3-3.8x linear expansion). We also developed epitope-preserving ExCel, which enables imaging of endogenous proteins stained by antibodies, and iterative ExCel, which enables imaging of fluorescent proteins after 20x linear expansion. We demonstrate the utility of the ExCel toolbox for mapping synaptic proteins, for identifying previously unreported proteins at cell junctions, and for gene expression analysis in multiple individual neurons of the same animal

An early years toolbox for assessing early executive function, language, self-Regulation, and social development validity, reliability, and preliminary norms

Several methods of assessing executive function (EF), self-regulation, language development, and social development in young children have been developed over previous decades. Yet new technologies make available methods of assessment not previously considered. In resolving conceptual and pragmatic limitations of existing tools, the Early Years Toolbox (EYT) offers substantial advantages for early assessment of language, EF, self-regulation, and social development. In the current study, results of our large-scale administration of this toolbox to 1,764 preschool and early primary school students indicated very good reliability, convergent validity with existing measures, and developmental sensitivity. Results were also suggestive of better capture of children’s emerging abilities relative to comparison measures. Preliminary norms are presented, showing a clear developmental trajectory across half-year age groups. The accessibility of the EYT, as well as its advantages over existing measures, offers considerably enhanced opportunities for objective measurement of young children’s abilities to enable research and educational applications

Disruption of Murine mp29/Syf2/Ntc31 Gene Results in Embryonic Lethality with Aberrant Checkpoint Response

Human p29 is a putative component of spliceosomes, but its role in pre-mRNA is elusive. By siRNA knockdown and stable overexpression, we demonstrated that human p29 is involved in DNA damage response and Fanconi anemia pathway in cultured cells. In this study, we generated p29 knockout mice (mp29GT/GT) using the mp29 gene trap embryonic stem cells to study the role of mp29 in DNA damage response in vivo. Interruption of mp29 at both alleles resulted in embryonic lethality. Embryonic abnormality occurred as early as E6.5 in mp29GT/GT mice accompanied with decreased mRNA levels of α-tubulin and Chk1. The reduction of α-tubulin and Chk1 mRNAs is likely due to an impaired post-transcriptional event. An aberrant G2/M checkpoint was found in mp29 gene trap embryos when exposed to aphidicolin and UV light. This embryonic lethality was rescued by crossing with mp29 transgenic mice. Additionally, the knockdown of zfp29 in zebrafish resulted in embryonic death at 72 hours of development postfertilization (hpf). A lower level of acetylated α-tubulin was also observed in zfp29 morphants. Together, these results illustrate an indispensable role of mp29 in DNA checkpoint response during embryonic development