Flux creep in Bi2Sr2CaCu2O8(sub +x) single crystals

The results of a magnetic study on a Bi2Sr2CaCu2O(8+x) single crystal are reported. Low field susceptibility (dc and ac), magnetization cycles and time dependent measurements were performed. With increasing the temperature the irreversible regime of the magnetization cycles is rapidly restricted to low fields, showing that the critical current J(sub c) becomes strongly field dependent well below T(sub c). At 2.4 K the critical current in zero field, determined from the remanent magnetization by using the Bean formula for the critical state, is J(sub c) = 2 10(exp 5) A/sq cm. The temperature dependence of J(sub c) is satisfactorily described by the phenomenological law J(sub c) = J(sub c) (0) (1 - T/T(sub c) (sup n), with n = 8. The time decay of the zero field cooled magnetization and of the remanent magnetization was studied at different temperatures for different magnetic fields. The time decay was found to be logarithmic in both cases, at least at low temperatures. At T = 4.2 K for a field of 10 kOe applied parallel to the c axis, the average pinning energy, determined by using the flux creep model, is U(sub o) = 0.010 eV

Open ventral hernia repair with a composite ventral patch : final results of a multicenter prospective study

Background: This study assessed clinical outcomes, including safety and recurrence, from the two-year follow-up of patients who underwent open ventral primary hernia repair with the use of the Parietex (TM) Composite Ventral Patch (PCO-VP). Methods: A prospective single-arm, multicenter study of 126 patients undergoing open ventral hernia repair for umbilical and epigastric hernias with the PCO-VP was performed. Results: One hundred twenty-six subjects (110 with umbilical hernia and 16 with epigastric hernia) with a mean hernia diameter of 1.8cm (0.4-4.0) were treated with PCO-VP. One hundred subjects completed the two-year study. Cumulative hernia recurrence was 3.0% (3/101; 95%CI: 0.0-6.3%) within 24months. Median Numeric Rating Scale pain scores improved from 2 [0-10] at baseline to 0 [0-3] at 1 month (P<0.001) and remained low at 24months 0 [0-6] (P<0.001). 99% (102/103) of the patients were satisfied with their repair at 24months postoperative. Conclusions: The use of PCO-VP to repair primary umbilical and epigastric defects yielded a low recurrence rate, low postoperative and chronic pain, and high satisfaction ratings, confirming that PCO-VP is effective for small ventral hernia repair in the two-year term after implantation. Trial registration: The study was registered publically at clinicaltrials.gov (NCT01848184 registered May 7, 2013)

Haspin regulates Ras localization to promote Cdc24-driven mitotic depolarization

Cell polarization is of paramount importance for proliferation, differentiation, development, and it is altered during carcinogenesis. Polarization is a reversible process controlled by positive and negative feedback loops. How polarized factors are redistributed is not fully understood and is the focus of this work. In Saccharomyces cerevisiae, mutants defective in haspin kinase exhibit stably polarized landmarks and are sensitive to mitotic delays. Here, we report a new critical role for haspin in polarisome dispersion; failure to redistribute polarity factors, in turn, leads to nuclear segregation defects and cell lethality. We identified a mitotic role for GTP-Ras in regulating the local activation of the Cdc42 GTPase, resulting in its dispersal from the bud tip to a homogeneous distribution over the plasma membrane. GTP-Ras2 physically interacts with Cdc24 regulateing its mitotic distribution. Haspin is shown to promote a mitotic shift from a bud tip-favored to a homogenous PM fusion of Ras-containing vesicles. In absence of haspin, active Ras is not redistributed from the bud tip; Cdc24 remains hyperpolarized promoting the activity of Cdc42 at the bud tip, and the polarisome fails to disperse leading to erroneously positioned mitotic spindle, defective nuclear segregation, and cell death after mitotic delays. These findings describe new functions for key factors that modulate cell polarization and mitotic events, critical processes involved in development and tumorigenesis

How to improve compliance with protective health measures during the covid-19 outbreak. Testing a moderated mediation model and machine learning algorithms

In the wake of the sudden spread of COVID-19, a large amount of the Italian population practiced incongruous behaviors with the protective health measures. The present study aimed at examining psychological and psychosocial variables that could predict behavioral compliance. An online survey was administered from 18–22 March 2020 to 2766 participants. Paired sample t-tests were run to compare efficacy perception with behavioral compliance. Mediation and moderated mediation models were constructed to explore the association between perceived efficacy and compliance, mediated by self-efficacy and moderated by risk perception and civic attitudes. Machine learning algorithms were trained to predict which individuals would be more likely to comply with protective measures. Results indicated significantly lower scores in behavioral compliance than efficacy perception. Risk perception and civic attitudes as moderators rendered the mediating effect of self-efficacy insignificant. Perceived efficacy on the adoption of recommended behaviors varied in accordance with risk perception and civic engagement. The 14 collected variables, entered as predictors in machine learning models, produced an ROC area in the range of 0.82–0.91 classifying individuals as high versus low compliance. Overall, these findings could be helpful in guiding age-tailored information/advertising campaigns in countries affected by COVID-19 and directing further research on behavioral compliance

Rol de las ciudades intermedias en la copresencia de modelos de producción agropecuarios : Enseñanzas del caso de Rodez (Francia) para las problemáticas identificadas en Francia y Argentina

El objetivo de este trabajo consiste en analizar el rol de las ciudades intermedias localizadas en el corazón de espacios rurales y agropecuarios, tomando el caso de la ciudad de Rodez, en la Región Occitania, en el suroeste de Francia, en tanto caso emblemático para luego generar una reflexión metodológica en un espacio representativo de lo agropecuario a nivel mundial: la región pampeana argentina. Nuestra hipótesis es que estas ciudades intermedias en esos espacios cumplen un papel esencial en la articulación, competencia y dependencia/ complementariedad funcional con la actividad agropecuaria en su área de influencia y aún en otras escalas. Partimos de considerar que no hay espacios rurales dinámicos sin ciudades dinámicas y que este tipo de dupla produce innovaciones sociales, económicas y tecnológicas que hacen a un proyecto territorial. Para lograr este objetivo, en este trabajo se movilizan dos conceptos centrales para aprehender la ciudad y la actividad agropecuaria en una visión geográfica. Por un lado, el concepto de ciudad intermedia y, por otro, el de copresencia. El análisis demuestra la copresencia de modelos agropecuarios que operan por simultaneidad en la ciudad intermedia de Rodez y emerge así un dispositivo para el estudio de estas problemáticas que se están aplicando en otras ciudades de Francia y de la Argentina.Facultad de Ciencias Agrarias y ForestalesConsejo Nacional de Investigaciones Científicas y TécnicasInstituto Nacional de Tecnología Agropecuari

The Incorporation of Ribonucleotides Induces Structural and Conformational Changes in DNA

Ribonucleotide incorporation is the most common error occurring during DNA replication. Cells have hence developed mechanisms to remove ribonucleotides from the genome and restore its integrity. Indeed, the persistence of ribonucleotides into DNA leads to severe consequences, such as genome instability and replication stress. Thus, it becomes important to understand the effects of ribonucleotides incorporation, starting from their impact on DNA structure and conformation. Here we present a systematic study of the effects of ribonucleotide incorporation into DNA molecules. We have developed, to our knowledge, a new method to efficiently synthesize long DNA molecules (hundreds of basepairs) containing ribonucleotides, which is based on a modified protocol for the polymerase chain reaction. By means of atomic force microscopy, we could therefore investigate the changes, upon ribonucleotide incorporation, of the structural and conformational properties of numerous DNA populations at the single-molecule level. Specifically, we characterized the scaling of the contour length with the number of basepairs and the scaling of the end-to-end distance with the curvilinear distance, the bending angle distribution, and the persistence length. Our results revealed that ribonucleotides affect DNA structure and conformation on scales that go well beyond the typical dimension of the single ribonucleotide. In particular, the presence of ribonucleotides induces a systematic shortening of the molecules, together with a decrease of the persistence length. Such structural changes are also likely to occur in vivo, where they could directly affect the downstream DNA transactions, as well as interfere with protein binding and recognition

Generation of three iPSC lines from fibroblasts of a patient with Aicardi Gouti&#232;res Syndrome mutated in TREX1

Fibroblasts from a patient with Aicardi Gouti\ue8res Syndrome (AGS) carrying a compound heterozygous mutation in TREX1, were reprogrammed into induced pluripotent stem cells (iPSCs) to establish isogenic clonal stem cell lines: UNIBSi006-A, UNIBSi006-B, and UNIBSi006-C. Cells were transduced using the episomal Sendai viral vectors, containing human OCT4, SOX2, c-MYC and KLF4 transcription factors. The transgene-free iPSC lines showed normal karyotype, expressed pluripotent markers and displayed in vitro differentiation potential toward cells of the three embryonic germ layers

Sailing for Science: on board experiences for transferring knowledge on Historical Oceanography for Future Innovation

Smart, sustainable and inclusive Blue Growth means also knowing past technology and the paths followed by ancients in order to understand and monitor marine environments. In general, history of Science is a matter that is not enough explored and explained or promoted in high schools or university official programmes, and, usually, scientist do not consider it as an important part of their curricula. However, bad or good ideas, abandoned or forgotten beliefs, concepts, opinions, do still have a great potential for inspiring present and future scientists, no matter in which historical period they may have been formulated: they should be always be taken into consideration, critically examined and observed by a very close point of view, not just as part of the intellectual framework of some obsolete ‘Cabinet of Curiosities’ with limited access except for the chosen few. Moreover, history of Science should be transmitted in a more practical way, with hands-on labs showing the limits and challenges that prior generations of ocean explorers, investigators and seafarers had to face in order to answer to crucial questions as self-orientation in open sea, understanding main currents and waves, predicting meteorological conditions for a safe navigation. Oceanography is a relatively young branch of science, and still needs further approvals and knowledge (National Science Foundation, 2000). The Scientific Dissemination Group (SDG) “La Spezia Gulf of Science” – made up by Research Centres, Schools and Cultural associations located in La Spezia (Liguria, Italy) - has a decadal experience in initiatives aimed at people and groups of people of all ages, who are keen on science or who can be guided in any case to take an interest in scientific matters (Locritani et al., 2015). Amongst the SDG activities, the tight relationship with the Historical Oceanography Society, the Italian Navy and the Naval Technical Museum (that collects a rich heritage of civilization, technology and culture witnesses, related to the naval history of seamanship from the origins up to nowadays), allowed the creation of a special educational format based on Historical Oceanography, for university and high school students as an integration for their curriculum. The Historical Oceanography Society has provided the major knowledges included in the ancient volumes of its archive, thanks to the availability of its members that also held theoretical and practical lessons during the course. The present paper will describe the one-week special course (about 60 hours of theory and practice with technical visits to Research centres and Museums) that has been planned to be carried out on board of the Italian Training Navy Ship (A. Vespucci) and has been organized in order to give the hints about on board life, as well as theoretical lessons on modern and historical oceanography, hands-on labs on oceanographic instruments from public and private collections, physiology of diving techniques and astronomy. The general aim of this course has been, hence, to give to excellent students all those technological but also creative and imaginative features of our past.PublishedVienna1TM. Formazion

PARP-1 modulates amyloid beta peptide-induced neuronal damage.

Amyloid beta peptide (A beta) causes neurodegeneration by several mechanisms including oxidative stress, which is known to induce DNA damage with the consequent activation of poly (ADP-ribose) polymerase (PARP-1). To elucidate the role of PARP-1 in the neurodegenerative process, SH-SY5Y neuroblastoma cells were treated with A beta(25-35) fragment in the presence or absence of MC2050, a new PARP-1 inhibitor. A beta(25-35) induces an enhancement of PARP activity which is prevented by cell pre-treatment with MC2050. These data were confirmed by measuring PARP-1 activity in CHO cells transfected with amylod precursor protein and in vivo in brains specimens of TgCRND8 transgenic mice overproducing the amyloid peptide. Following A beta(25-35) exposure a significant increase in intracellular ROS was observed. These data were supported by the finding that A beta(25-35) induces DNA damage which in turn activates PARP-1. Challenge with A beta(25-35) is also able to activate NF-kB via PARP-1, as demonstrated by NF-kB impairment upon MC2050 treatment. Moreover, A beta(25-35) via PARP-1 induces a significant increase in the p53 protein level and a parallel decrease in the anti-apoptotic Bcl-2 protein. These overall data support the hypothesis of PARP-1 involvment in cellular responses induced by A beta and hence a possible rationale for the implication of PARP-1 in neurodegeneration is discussed

RNase H activities counteract a toxic effect of Polymerase in cells replicating with depleted dNTP pools

RNA:DNA hybrids are transient physiological intermediates that arise during several cellular processes such as DNA replication. In pathological situations, they may stably accumulate and pose a threat to genome integrity. Cellular RNase H activities process these structures to restore the correct DNA:DNA sequence. Yeast cells lacking RNase H are negatively affected by depletion of deoxyribonucleotide pools necessary for DNA replication. Here we show that the translesion synthesis DNA polymerase (Pol ) plays a role in DNA replication under low deoxyribonucleotides condition triggered by hydroxyurea. In particular, the catalytic reaction performed by Pol is detrimental for RNase H deficient cells, causing DNA damage checkpoint activation and G2/M arrest. Moreover, a Pol mutant allele with enhanced ribonucleotide incorporation further exacerbates the sensitivity to hydroxyurea of cells lacking RNase H activities. Our data are compatible with a model in which Pol activity facilitates the formation or stabilization of RNA:DNA hybrids at stalled replication forks. However, in a scenario where RNase H activity fails to restore DNA, these hybrids become highly toxic for cells