348 research outputs found

    Nitric oxide as a putative retinal axon pathfinding and target recognition cue in Xenopus laevis

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    Nitric oxide (NO) is an atypical neurotransmitter synthesized by the enzyme nitric oxide synthase (NOS) during many stages of the Xenopus laevis life cycle. This research investigates whether the gas NO is involved in axon guidance, the neurodevelopmental process in which axons travel through the brain to their appropriate target locations to form functional neural circuitry. Through immunocytochemistry and direct labeling of the NO gas with a fluorescent dye, we have found that NOS expression corresponds spatiotemporally with the beginning of retinal axon innervation of the optic tectum in X. laevis. Our function-blocking studies in which NO is chemically inhibited suggest that NO may be necessary for correct pathfinding and targeting, evidenced by qualitative widening of the optic tract and aberrant target innervation

    Models of Inclusion in Child Care: Child Care that Works for Children with Emotional and/or Behavioral Challenges: Family Member Perceptions

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    Although 5-10% of employed parents care for a child with emotional or behavioral challenges (EBCs) (Emlen, 1997), family support resources are notably lacking. A recent focus group study of 41 working parents (Rosenzweig, Brennan, & Ogilvie, 2002) found child care to be particularly difficult to find and maintain for families that included children with EBCs. Participants reported a number of barriers to child care arrangements that could successfully meet their family\u27s needs. First, since few qualified providers had the expertise to meet the needs of children with EBCs, arrangements were difficult to find. A combination of the lack of quality care in general, and few qualified providers for children with emotional or behavioral problems, created a nearly impossible situation for working families looking for child care. The aim of the Models of Inclusion in Child Care study (MICC) was to identify and investigate programs and strategies that improve access for families of children with emotional or behavioral disorders to child care that is inclusive, family-centered, culturally competent, and of high quality

    Mott transition in the π\pi-flux SU(44) Hubbard model on a square lattice

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    We employ the projector quantum Monte Carlo simulations to study the ground-state properties of the square-lattice SU(4) Hubbard model with a π\pi flux per plaquette. In the weak coupling regime, its ground state is in the gapless Dirac semi-metal phase. With increasing repulsive interaction, we show that, a Mott transition occurs from the semimetal to the valence bond solid, accompanied by the Z4Z_4 discrete symmetry breaking. Our simulations demonstrate the existence of a second-order phase transition, which confirms the Ginzburg-Landau analysis. The phase transition point and the critical exponent η\eta are also estimated. To account for the effect of a π\pi flux on the ordering in the strong coupling regime, we analytically derive by the perturbation theory the ring-exchange term which describes the leading-order difference between the π\pi-flux and zero-flux SU(4) Hubbard models.Comment: 8 pages, 9 figure

    Monoclonal Antibodies to the V2 Domain of MN-rgp120: Fine Mapping of Epitopes and Inhibition of α4β7 Binding

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    BACKGROUND: Recombinant gp120 (MN-rgp120) was a major component of the AIDSVAX B/E vaccine used in the RV144 trial. This was the first clinical trial to show that vaccination could prevent HIV infection in humans. A recent RV144 correlates of protection study found that protection correlated with the presence of antibodies to the V2 domain. It has been proposed that antibodies to the α4β7 binding site in the V2 domain might prevent HIV-1 infection by blocking the ability of virions to recognize α4β7 on activated T-cells. In this study we investigated the specificity of monoclonal antibodies (MAbs) to the V2 domain of MN-rgp120 and examined the possibility that these antibodies could inhibit the binding of MN-rgp120 to the α4β7 integrin. METHODOLOGY/PRINCIPAL FINDINGS: Nine MAbs to the V2 domain were isolated from mice immunized with recombinant envelope proteins. The ability of these MAbs to inhibit HIV infection, block the binding of gp120 to CD4, and block the binding of MN-rgp120 to the α4β7 integrin was measured. Mutational analysis showed that eight of the MAbs recognized two immunodominant clusters of amino acids (166-168 and 178-183) located at either end of the C strand within the four-strand anti-parallel sheet structure comprising the V1/V2 domain. CONCLUSIONS/SIGNIFICANCE: These studies showed that the antigenic structure of the V2 domain is exceedingly complex and that MAbs isolated from mice immunized with MN-rgp120 exhibited a high level of strain specificity compared to MAbs to the V2 domain isolated from HIV-infected humans. We found that immunization with MN-rgp120 readily elicits antibodies to the V2 domain and some of these were able to block the binding of MN-rgp120 to the α4β7 integrin

    Comparative Immunogenicity of HIV-1 Clade C Envelope Proteins for Prime/Boost Studies

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    BACKGROUND: Previous clinical efficacy trials failed to support the continued development of recombinant gp120 (rgp120) as a candidate HIV vaccine. However, the recent RV144 HIV vaccine trial in Thailand showed that a prime/boost immunization strategy involving priming with canarypox vCP1521 followed by boosting with rgp120 could provide significant, although modest, protection from HIV infection. Based on these results, there is renewed interest in the development of rgp120 based antigens for follow up vaccine trials, where this immunization approach can be applied to other cohorts at high risk for HIV infection. Of particular interest are cohorts in Africa, India, and China that are infected with clade C viruses. METHODOLOGY/PRINCIPAL FINDINGS: A panel of 10 clade C rgp120 envelope proteins was expressed in 293 cells, purified by immunoaffinity chromatography, and used to immunize guinea pigs. The resulting sera were collected and analyzed in checkerboard experiments for rgp120 binding, V3 peptide binding, and CD4 blocking activity. Virus neutralization studies were carried out with two different assays and two different panels of clade C viruses. A high degree of cross reactivity against clade C and clade B viruses and viral proteins was observed. Most, but not all of the immunogens tested elicited antibodies that neutralized tier 1 clade B viruses, and some sera neutralized multiple clade C viruses. Immunization with rgp120 from the CN97001 strain of HIV appeared to elicit higher cross neutralizing antibody titers than the other antigens tested. CONCLUSIONS/SIGNIFICANCE: While all of the clade C antigens tested were immunogenic, some were more effective than others in eliciting virus neutralizing antibodies. Neutralization titers did not correlate with rgp120 binding, V3 peptide binding, or CD4 blocking activity. CN97001 rgp120 elicited the highest level of neutralizing antibodies, and should be considered for further HIV vaccine development studies

    Cumulative climatic stressors strangles marine aquaculture: Ancillary effects of COVID 19 on Spanish mariculture

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    Marine aquaculture takes advantage of marine ecosystem services to produce goods that can be relevant from a food security point of view. However, this activity is subject to multiple stressors as the ones exerted by global climate change. Local stressed conditions due to environmental drivers may be exacerbated by the COVID19 pandemic crisis. In this paper we analyze the pre-COVID-19 situation in two Spanish regions with the highest aquaculture production, Galicia and the Valencian Community. The incidence of storms, heat waves and mussel farming closure were analyzed, and surveys were used to define the perception of producers in terms of economic problems derived from COVID-19 and synergistic environmental concerns. Also the temporal trend of mussel production was analyzed. Spanish marine aquaculture has been intensively subjected to climatic stressors that made it more vulnerable to COVID-19, showing some weakness in terms of production as can be seen in mussel production and fresh consumption. Anyway, extensive aquaculture and aquaculture developed by Integrated Multi-Trophic Aquaculture (IMTA) was reported as somewhat more resilient to the impact of COVID-19. In order to ensure the environmental and economic sustainability of marine aquaculture - under a future uncertain pandemic scenario – our outcomes underline the need for more resilient adaptation programs and recovery plans taking into account the climate change effects.M.C.M.’s research activity was supported by the European Union’s Horizon 2020 Research and Innovation programme under the Marie Skłodowska-Curie Action (Grant agreement no. 835589, MIRROR Project)

    Diploma Privilege and the Constitution

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    The COVID-19 pandemic and resulting shutdowns are affecting every aspect of society. The legal profession and the justice system have been profoundly disrupted at precisely the time when there is an unprecedented need for legal services to deal with a host of legal issues generated by the pandemic, including disaster relief, health law, insurance, labor law, criminal justice, domestic violence, and civil rights. The need for lawyers to address these issues is great but the prospect of licensing new lawyers is challenging due to the serious health consequences of administering the bar examination during the pandemic. State Supreme Courts are actively considering alternative paths to licensure. One such alternative is the diploma privilege, a path to licensure currently used only in Wisconsin. Wisconsin\u27s privilege, limited to graduates of its two in-state schools, has triggered constitutional challenges never fully resolved by the lower courts. As states consider emergency diploma privileges to address the pandemic, they will face these unresolved constitutional issues. This Article explores those constitutional challenges and concludes that a diploma privilege limited to graduates of in-state schools raises serious Dormant Commerce Clause questions that will require the state to tie the privilege to the particular competencies in-state students develop and avenues they have to demonstrate those competencies to the state\u27s practicing bar over three years. Meeting that standard will be particularly difficult if a state adopts an in-state privilege on an emergency basis. States should consider other options, including privileges that do not prefer in-state schools. The analysis is important both for states considering emergency measures and for those that might restructure their licensing after the pandemic

    The Bar Exam and the COVID-19 Pandemic: The Need for Immediate Action

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    The novel coronavirus COVID-19 has profoundly disrupted life in the United States. Among other challenges, jurisdictions are unlikely to be able to administer the July 2020 bar exam in the usual manner. It is essential, however, to continue licensing new lawyers. Those lawyers are necessary to meet current needs in the legal system. Equally important, the demand for legal services will skyrocket during and after this pandemic. We cannot close doors to the profession at a time when client demand will reach an all-time high.In this brief policy paper, we outline six licensing options for jurisdictions to consider for the Class of 2020. Circumstances will vary from jurisdiction to jurisdiction, but we hope that these options will help courts and regulators make this complex decision. These are unprecedented times: We must work together to ensure we do not leave the talented members of Class of 2020 on the sidelines when we need every qualified professional on the field to keep our justice system moving
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