Sleeping out-of-home in a kibbutz communal arrangement: It makes a difference for infant-mother attachment

Wetensch. publicatieFaculteit der Sociale Wetenschappe

Epistemic and social scripts in computer-supported collaborative learning

Collaborative learning in computer-supported learning environments typically means that learners work on tasks together, discussing their individual perspectives via text-based media or videoconferencing, and consequently acquire knowledge. Collaborative learning, however, is often sub-optimal with respect to how learners work on the concepts that are supposed to be learned and how learners interact with each other. One possibility to improve collaborative learning environments is to conceptualize epistemic scripts, which specify how learners work on a given task, and social scripts, which structure how learners interact with each other. In this contribution, two studies will be reported that investigated the effects of epistemic and social scripts in a text-based computer-supported learning environment and in a videoconferencing learning environment in order to foster the individual acquisition of knowledge. In each study the factors ‘epistemic script’ and ‘social script’ have been independently varied in a 2×2-factorial design. 182 university students of Educational Science participated in these two studies. Results of both studies show that social scripts can be substantially beneficial with respect to the individual acquisition of knowledge, whereas epistemic scripts apparently do not to lead to the expected effects

Bacterial Vaginosis Associated with Increased Risk of Female-to-Male HIV-1 Transmission: A Prospective Cohort Analysis among African Couples

In a prospective study, Craig Cohen and colleagues investigate the association between bacterial vaginosis and the risk of female-to-male HIV-1 transmission

Single molecule study of a processivity clamp sliding on DNA

Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder

The systemic treatment of recurrent ovarian cancer revisited

Treatment approaches for relapsed ovarian cancer have evolved over the past decade from a calendar-based decision tree to a patient-oriented biologically driven algorithm. Nowadays, platinum-based chemotherapy should be offered to all patients with a reasonable chance of responding to this therapy. The treatment-free interval for platinum is only one of many factors affecting patients' eligibility for platinum re-treatment. Bevacizumab increases the response to chemotherapy irrespective of the cytotoxic regimen and can be valuable in patients with an urgent need for symptom relief (e.g. pleural effusion, ascites). For patients with recurrent high-grade ovarian cancer, which responds to platinum-based treatment, maintenance therapy with a poly(ADP-ribose) polymerase inhibitor can be offered, regardless of the BRCA mutation status. Here we review contemporary decision-making processes in the systemic treatment of relapsed ovarian cancer

Platelets induce free and phospholipid-esterified 12-hydroxyeicosatetraenoic acid generation in colon cancer cells by delivering 12-lipoxygenase

Platelets promote tumor metastasis by inducing promalignant phenotypes in cancer cells and directly contributing to cancer-related throm-botic complications. Platelet-derived extracellular vesicles (EVs) can promote epithelial-mesenchymal transition (EMT) in cancer cells, which confers high-grade malignancy. 12S-hydroxyeicosatetraenoic acid (12-HETE) generated by platelet-type 12-lipoxygenase (12-LOX) is considered a key modulator of cancer metastasis through unknown mechanisms. In plate-lets, 12-HETE can be esterified into plasma membrane phospholipids (PLs), which drive thrombosis. Using cocultures of human platelets and human colon adenocarcinoma cells (line HT29) and LC-MS/MS, we investigated the impact of platelets on cancer cell biosynthesis of 12S-HETE and its esterification into PLs and whether platelet ability to transfer its mo-lecular cargo might play a role. To this aim, we performed coculture experiments with CFSE[5-(and-6)-carboxyfluorescein diacetate, succinimidyl ester]-loaded platelets. HT29 cells did not generate 12S-HETE or express 12-LOX. However, they ac-quired the capacity to produce 12S-HETE mainly esterified in plasmalogen phospholipid forms following the uptake of platelet-derived medium-sized EVs (mEVs) expressing 12-LOX. 12-LOX was detected in plasma mEV of patients with adenomas/ adenocarcinomas, implying their potential to deliver the protein to cancer cells in vivo. In cancer cells exposed to platelets, endogenous but not exogenous 12S-HETE contributed to changes in EMT gene expression, mitigated by three structurally unrelated 12-LOX inhibitors. In conclusion, we showed that platelets induce the generation of primarily esteri-fied 12-HETE in colon cancer cells following mEV-mediated delivery of 12-LOX. The modification of cancer cell phospholipids by 12-HETE may functionally impact cancer cell biology and represent a novel target for anticancer agent development

Acceptability of a cognitive behavior therapy intervention to implantable cardioverter defibrillator recipients

We aimed to assess cardiac patients, acceptance of cognitive behavior therapy (CBT); determine if gender was associated with treatment engagement (session attendance and utilization of intervention strategies); and relate engagement to outcome. Of 193 patients receiving an implantable cardioverter defibrillator (ICD) who agreed to participate in a randomized controlled trial, 96 were randomized to CBT. Measures of treatment acceptance indicated that most participants rated counseling as “very to extremely helpful.” Gender was associated with only one treatment engagement index. Symptoms of depression and post-traumatic stress improved from baseline to 6- and 12-month follow-up. Number of counseling session attendance was not associated with outcome. Reported utilization of two of the six CBT strategies (modifying faulty thinking, correcting cognitive distortions) was associated with a better treatment outcome. In conclusion, a CBT intervention was well received by ICD patients. There was some indication that treatment engagement related to better treatment outcomes.Social Sciences and Humanities Research Council (SHHRC

MLL-rearranged B lymphoblastic leukemias selectively express the immunoregulatory carbohydrate-binding protein galectin-1

Leukemias with 11q23 translocations involving the Mixed Lineage Leukemia (MLL) gene exhibit unique clinical and biological features and have a poor prognosis. In a screen for molecular markers of MLL rearrangement, we identified the specific overexpression of an immunomodulatory lectin Galectin-1 (Gal1) in MLL-rearranged B lymphoblastic leukemias (B-ALL) compared to other MLL-germline ALLs. To assess the diagnostic utility of Gal1 expression in identifying MLL-rearranged B-ALLs, we performed Gal1 immunostaining on a large series of primary ALLs with known MLL status. All 11 MLL-rearranged B-ALLs had abundant Gal1 expression; in marked contrast, only 1 of 42 germline-MLL B-ALLs expressed Gal1. In addition, Gal1 was readily detected in diagnostic samples of MLL-rearranged B-ALLs by intracellular flow cytometry. Since deregulated gene expression in MLL-rearranged leukemias may be related to the altered histone methyltransferase activity of MLL fusion protein complex, we analyzed histone H3 lysine 79 (H3K79) dimethylation in the Gal1 promoter region using chromatin immunoprecipitation. Gal1 promoter H3K79diMe was ≈ 5 fold higher in a MLL-rearranged B-ALL cell line than in a B-ALL line without the MLL translocation. Furthermore, the Gal1 promoter H3K79 was significantly hypermethylated in primary MLL-rearranged B-ALLs compared to MLL-germline B-ALLs and normal pre-B cells, implicating this epigenetic modification as a mechanism for Gal1 overexpression in MLL B-ALL.Fil: Juszczynski, Przemyslaw. Dana Farber Cancer Institute; Estados UnidosFil: Rodig, Scott J.. Brigham & Women; Estados UnidosFil: Ouyang, Jing. Dana Farber Cancer Institute; Estados UnidosFil: O´Donnell, Evan. Dana Farber Cancer Institute; Estados UnidosFil: Takeyama, Kunihiko. Dana Farber Cancer Institute; Estados UnidosFil: Mlynarski, Wojciech. Dana Farber Cancer Institute; Estados UnidosFil: Mycko, Katarzyna. Dana Farber Cancer Institute; Estados UnidosFil: Szczepanski, Tomasz. Dana Farber Cancer Institute; Estados UnidosFil: Gaworczyk, Anna. Medical University of Lodz; PoloniaFil: Krivtsov, Andrei. Medical University of Lodz; PoloniaFil: Faber, Joerg. Medical University of Silesia; PoloniaFil: Sinha, Amit U.. Medical University of Lublin; PoloniaFil: Rabinovich, Gabriel Adrian. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; ArgentinaFil: Armstrong, Scott A.. Children; Estados UnidosFil: Kutok, Jeffery. Children; Estados UnidosFil: Shipp, Margaret A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Biología y Medicina Experimental (i); Argentina; Argentin

Ciudadanía, sociedad civil y participación en políticas públicas: la experiencia de los foros vecinales de seguridad en el municipio de La Plata

The article presents results of a study about citizen participation in public safety policies in the municipality of La Plata, Buenos Aires, Argentina. The work focuses on the analysis of the participation practices observed in Community Safety Forums and on the meaning that the forum members attribute to these forums. The study utilized qualitative data collection and analysis techniques, such as participant observation, interviews with key informants and interviews with Forum members. One important conclusion is that the participation does not take advantage of all the public policy possibilities, and that the forums thus express a form of “limited citizenship”. An example of this is the self-identification of the forum members as ‘neighbors’, a category that can be seen as moral and depoliticized. Finally, it is hoped that the article can support empiric research and the debate about the political meaning of participation of civil society in public policies

QCD Sum Rule Analysis of the Decays B→Kℓ+ℓ−B \to K \ell^+ \ell^- and B→K∗ℓ+ℓ−B \to K^* \ell^+ \ell^-

We use QCD sum rules to calculate the hadronic matrix elements governing the rare decays $B \to K \ell^+ \ell^-$ and $B \to K^* \ell^+ \ell^-$ induced by the flavour changing neutral current $b \to s$ transition. We also study relations among semileptonic and rare $B \to K^{(*)}$ decay form factors. The analysis of the invariant mass distribution of the lepton pair in $B \to K^{(*)} \ell^+ \ell^-$ and of the angular asymmetry in $B \to K^* \ell^+ \ell^-$ provides us with interesting tests of the Standard Model and its extensions.Comment: 26 pages REVTEX + 7 figures. Some typos corrected, figure 5 and 7 modified. This version will appear on Physical Review