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The goal of this study was to apply insights from social identity gratifications and ethnic/racial identity development frameworks to better understand how adolescents perceive, select, and avoid media content which has the potential to damage self-and group-concept. We conducted focus groups with 32 Latino adolescents aged 13 to 15. We found mixed evidence that youth prioritized the ethnicity of characters in program selection. Most referenced personality or age as the primary identity-based factors of interest. Although students widely recognized negative stereotypes of Latinos in mainstream English-language media, this did not overwhelmingly dictate media choices, seemingly due to lack of alternative choices. In contrast, Spanish language programming offered a positive alternative to English-language media and may serve identity needs. The theoretical and practical implications are discussed.

Gene targeting is extensively used to generate designer mouse mutants and to study gene function in vivo. Knockout mice that harbor a null allele in their germline provide appropriate genetic models of inherited diseases and often exhibit embryonic or early postnatal lethality. To study gene function in adult mice and in selected cell types, a refined strategy for conditional gene inactivation has been developed that relies on the DNA recombinase Cre and its recognition (loxP) sites. This process has traditionally relied on the complex process involving genome editing in embryonic stem (ES) cells despite its limitations, including incorrect targeting or cassette structure, and difficulties with germline transmission of the allele from chimeric mice. CRISPR-Cas9 gene editing technology has considerably facilitated the generation of mouse knockout alleles, relieving many of the cumbersome and time-consuming steps of traditional mouse ES cell technology. However, the generation of conditional knockout alleles remains an important challenge. An earlier study reported up to 16% efficiency in generating conditional knockout alleles in mice using 2 single guide RNAs (sgRNA) and 2 single-stranded oligonucleotides (ssODN), which has been questioned by another report combining data from multiple transgenic cores. With the advent of CRISPR/Cas9 as a mouse genome modification tool, we assessed the efficiency of using this method in creating conditional targeted alleles in three genes, phosphatase and actin regulator 1 (Phactr1), apolipoprotein A-I (ApoA1), and actin-related protein T2 (Actrt2). Even though overall success rate was low—about 2.5%—we show that it’s possible to reliably generate conditional knockout alleles using CRISPR/Cas9 on a consistent basis.

Long non-coding RNAs (lncRNA) are key regulators of gene expression both at the transcriptional and post-transcriptional levels. The lncRNA metastasis associated lung adenocarcinoma transcript 1 (Malat1) is overexpressed in many types of cancer, including hepatocarcinoma, and induces cell proliferation in several cell lines in vitro. However, the direct causal effects of Malat1 on hepatocyte proliferation and liver carcinogenesis in vivo are not fully understood. To better determine the contribution of Malat1 to hepatocarcinoma oncogenesis, this study was aimed at testing the hypothesis that its absence confers resistance to the development of liver tumors. Male Malat1-/- mice and their wild-type (WT) littermates were studied one year after treatment with the genotoxic agent diethylnitrosamine (DEN), a potent inducer of liver cancer. As expected, in WT mice, Malat1 expression was significantly higher in hepatic tumors than in healthy liver regions. Altered hepatic mRNA levels of Ki67, HDAC3, NFκB and p27 were observed in DEN-treated Malat1-/- mice. Despite this, these mice were characterized by similar liver weight, prevalence of tumors, and histological features compared to those of their WT littermates. In parallel, plasma lipids and glucose homeostasis did not significantly differ between DEN-treated groups. These findings support a role for Malat1 as a marker of liver carcinogenesis, but also suggest that its role in the regulation of hepatocyte hyperproliferation in mice is either minimal or masked by redundant and/or overwhelming mechanisms.

Background CRISPR-Cas9 gene-editing technology has facilitated the generation of knockout mice, providing an alternative to cumbersome and time-consuming traditional embryonic stem cell-based methods. An earlier study reported up to 16% efficiency in generating conditional knockout (cKO or floxed) alleles by microinjection of 2 single guide RNAs (sgRNA) and 2 single-stranded oligonucleotides as donors (referred herein as “two-donor floxing” method). Results We re-evaluate the two-donor method from a consortium of 20 laboratories across the world. The dataset constitutes 56 genetic loci, 17,887 zygotes, and 1718 live-born mice, of which only 15 (0.87%) mice contain cKO alleles. We subject the dataset to statistical analyses and a machine learning algorithm, which reveals that none of the factors analyzed was predictive for the success of this method. We test some of the newer methods that use one-donor DNA on 18 loci for which the two-donor approach failed to produce cKO alleles. We find that the one-donor methods are 10- to 20-fold more efficient than the two-donor approach. Conclusion We propose that the two-donor method lacks efficiency because it relies on two simultaneous recombination events in cis, an outcome that is dwarfed by pervasive accompanying undesired editing events. The methods that use one-donor DNA are fairly efficient as they rely on only one recombination event, and the probability of correct insertion of the donor cassette without unanticipated mutational events is much higher. Therefore, one-donor methods offer higher efficiencies for the routine generation of cKO animal models.

CRISPR-Cas9 gene editing technology has considerably facilitated the generation of mouse knockout alleles, relieving many of the cumbersome and time-consuming steps of traditional mouse embryonic stem cell technology. However, the generation of conditional knockout alleles remains an important challenge. An earlier study reported up to 16% efficiency in generating conditional knockout alleles in mice using 2 single guide RNAs (sgRNA) and 2 single-stranded oligonucleotides (ssODN) (2sgRNA-2ssODN). We re-evaluated this method from a large data set generated from a consortium consisting of 17 transgenic core facilities or laboratories or programs across the world. The dataset constituted 17,887 microinjected or electroporated zygotes and 1,718 live born mice, of which only 15 (0.87%) mice harbored 2 correct LoxP insertions in cis configuration indicating a very low efficiency of the method. To determine the factors required to successfully generate conditional alleles using the 2sgRNA-2ssODN approach, we performed a generalized linear regression model. We show that factors such as the concentration of the sgRNA, Cas9 protein or the distance between the placement of LoxP insertions were not predictive for the success of this technique. The major predictor affecting the method’s success was the probability of simultaneously inserting intact proximal and distal LoxP sequences, without the loss of the DNA segment between the two sgRNA cleavage sites. Our analysis of a large data set indicates that the 2sgRNA–2ssODN method generates a large number of undesired alleles (>99%), and a very small number of desired alleles (

This study tests the effects of feedback from a virtual pet on behavior change. A randomized field experiment with 39 adolescents in the US examined how a mobile phone game influenced their likelihood to eat breakfast. Manipulations included varying positive and negative visual feedback in response to participants' photos of breakfast meals. Results indicate that participants with a virtual pet that provided both positive and negative feedback were twice as likely to eat breakfast than those with a pet that provided only positive feedback or participants in the control condition.

Copper is a microelement routinely added to facilitate the normal growth of pigs. Copper fed at 30 to 250 mg/kg is recognized for its growth enhancement effect, particularly in weaned pigs. Past studies have proved its effect in improving the growth performance of pigs due to its antibacterial properties. However, studies also showed that the addition of high levels of copper results in low digestibility and absorption, which causes increased excretion of this mineral in feces and poses an environmental problem. This study aimed to enhance the copper digestibility in pigs when it is used as a growth promotant by modifying the copper size into nanometer. It is hoped that by improving the absorption of copper in pigs, the fecal excretion levels could be reduced and minimize environmental pollution. Two experiments were performed to explore the effects of nanocopper supplementation on the serum traits of weanling pigs. Using crossover design, eight LYD growing pigs were randomly assigned to three treatment groups, which are control, nanoCu and CuSO4, to investigate the effect of nanoCu supplementation on the availability of copper and digestibility of nutrients in pigs. Each treatment was replicated thrice. Another trial was conducted on thirty-six LYD weanling pigs to determine the effect of supplementing nanoCu on their growth performance and serum traits. For both trials, copper levels in nanoCu and CuSO4 groups were supplemented at a ratio of 50 mg/kg. Experimental results indicated statistically significant improvements in growth performance of the piglets when copper was supplemented at nanosize. Copper availability was significantly improved and feces copper level was reduced in the nanoCu supplemented group, as compared to the CuSO4 group. Significant differences were observed in the improvement of the digestibility of crude fat and energy in pigs under nanoCu diet. The serum copper level and serum cholesterol concentrations, as well as hematology traits— RBC, WBC, MCV, HGB, HCT, PLT and RDW, were not affected by nanoCu supplementation. However, statistically significant improvements were observed in the IgG, γ-globulin and total globulin protein levels, and in the SOD activity of the nanoCu group. In conclusion, nanosize copper supplementation was proven to reduce copper excretion level in piglets, improve the digestible energy and absorption of fat, and enhance the SOD activity in blood serum and the immunity level of piglets.

Background. There is a need to prevent or minimize bone loss associated with antiretroviral treatment (ART) initiation. We compared maraviroc (MVC)- to tenofovir disoproxil fumarate (TDF)–containing ART. Methods. This was a double-blind, placebo-controlled trial. ART-naive subjects with human immunodeficiency virus type 1 RNA load (viral load [VL]) >1000 copies/mL and R5 tropism were randomized to MVC 150 mg or TDF 300 mg once daily (1:1), stratified by VL

We report a case of upper limb phocomelia in a monochorionic, diamniotic twin pregnancy associated with increased nuchal translucency at 12 weeks' gestation. No other major structural defects were identified on ultrasound examination at 16 weeks' gestation or on postmortem examination at approximately 18 weeks' gestation. The differential diagnoses were reviewed and included thrombocytopenia-absent radius (TAR) syndrome and Robert syndrome. Chromosomal analysis of amniocytes revealed normal female karyotypes and no evidence of premature centromere separation. This is one of an increasing number of skeletal conditions that have been reported in association with increased nuchal translucency in chromosomally normal fetuses. The pathophysiologic mechanisms underlying this association are unclear.