Characterization of Recombinant Dengue-2 Virus Derived from a Single Nucleotide Substitution in the 5′ Noncoding Region

Variants of wild-type dengue serotype 2 (DEN-2) virus containing nucleotide substitutions at positions 14, 15, or 57 in the 5′ NCR were constructed by PCR-mediated site-directed mutagenesis. All three viruses containing a single point substitution demonstrated attenuation phenotype as evidenced by decreases replication and plaque size in cell culture assay. All three variants were less neurovirulent in newborn mice compared to the wild type. The mutants were immunogenic in adult mice immunogenicity and maintained stable replication characteristics following passage in mice. The variant viruses were competent for replication in Aedes aegypi mosquito vector, albeit at lower levels of infection and dissemination in the mosquito than the wild-type Den-2 16681 virus. Although all of the viruses, including the wild type, were found transmissible in mosquito life cycles, they were found subsequentially decreased in efficiency of infection, transmission, and dissemination rates along the mosquito generations and all of them remained genetically stable

The Alphavirus 3′-Nontranslated Region: Size Heterogeneity and Arrangement of Repeated Sequence Elements

AbstractThe 3′-nontranslated region (NTR) of representative strains of all known alphavirus species was amplified by reverse transcription–polymerase chain reaction. For 23 of them, the 3′-NTR sequence was determined. Together with previously published data, this allowed an analysis of the 3′-NTR of the viruses in the genus Alphavirus. The length of the 3′-NTRs varied from 77 nt for Pixuna virus to 609 nt for Bebaru virus. The 19-nt conserved sequence element directly adjacent to the poly(A) tract was found in all viruses, supporting the hypothesis that this region is acis-acting sequence element during viral replication and essential for virus growthin vitro. Within the 3′-NTR of all alphaviruses, repeated sequence elements of various numbers and lengths were found. Their composition was very consistent in both the Venezuelan equine encephalitis (VEE) and the Sindbis-like viruses, although their number was constant only within the latter group. For the VEE viruses, our data suggested that insertion events rather than deletions from an ancestor with a long 3′-NTR created the various number of repeated sequence elements. Among the remaining viruses, both the number and the composition of repeated sequence elements varied remarkedly

“An Institution Can Have Good Intentions and Still Be Atrocious : Transgender and Gender Expansive Experiences in Social Work Education

Educational settings have been found to be challenging arenas for transgender and gender expansive (TGE) youth and young adults due to misgendering, lack of affirming bathrooms, systemic exclusion (e.g., legal names and lack of inclusive gender identity demographic options), and frequent silence or avoidance related to TGE issues. Though studies of TGE adult experiences in higher education are emerging, most explore disaffirming experiences. Social work education focuses on diversity, equity, and inclusion, along with how to promote social justice, which suggests more affirming environments for TGE individuals. However, little is known about the experiences of TGE students and even less about faculty in social work education. To help fill this gap, the researchers interviewed 23 TGE social work students and faculty to explore their experiences of gender-related affirmation and challenges in social work educational programs. The findings from a thematic analysis identified examples of affirming and disaffirming experiences and recommendations for improving gender affirmation and inclusion in social work programs. Social work is in a strategic position to serve the needs and impact the social welfare of TGE individuals, starting with educational settings

Does it get better? Exploring “it gets better” videos using visual sociology

In 2010, the It Gets Better (IGB) project website was launched to house videos containing messages of support for youth who identify as sexual and/or gender minorities (SGMs). Despite success as a virtual social movement, scholars have suggested that the imagery portrayed may unintentionally exclude those who are most marginalized and that the videos often implore individuals to endure suffering now to gain happiness later. Using visual sociology methodology, the visual messaging and demographics of IGB video producers were examined and compared against criticisms of the project. Imagery portrayed was consistent with common concerns about exclusions of minorities, those who do not fit social standards of physical attractiveness, and those who challenge heteronormativity and adherence to gender norms. Despite IGB videos’ intentions to promote hope, the tales of struggle and hardship relayed often resulted in the depiction of negative emotions. Expressions of confidence, defiance, and empathy were visible, but the most prevalent emotion was sadness. Negative visual presentations and exclusion of significant demographics within the SGM community suggest IGB videos project more complex visual signals and different messaging than would be expected from videos designed to be supportive. Professionals should be attuned to these concerns when working with SGM youth

Exploring Gender Identity with a Photo Diary

Gender identity is an abstract component of one’s identity, yet a person’s physical appearance can be a significant source of anxiety and dysphoria or acceptance and integration. Distinct from individuals’ sex assigned at birth, gender identities refer to the internal sense of self. The social construct of gender identity, however, has been predominantly understood as a continuum or dichotomy of masculinity and femininity. According to J. Butler, gender is a performative act with a basis that lies in socialization, whereas sex is a biological categorization of male, female, or intersex according to scientific indicators, including external genitalia, gonads, internal reproductive organs, and sex chromosomes. When working with transgender people of color, A. A. Singh and V. S. McKleroy note the importance of understanding their resilience and how it may have helped them navigate challenges related to race and ethnicity in addition to gender identity. For affirming care, practitioners need to integrate understanding of intersectionality into their practice

Fabrication of Ankle-Foot Orthoses using Selective Laser Sintering Technology

Passive dynamic ankle-foot orthoses (AFOs) are often prescribed to improve gait performance for those with various neuromuscular disorders. Designs and materials used for AFOs range from simple polypropylene braces to advanced custom carbon fiber dynamic AFOs that passively store and release mechanical energy during gait. AFO designs vary in the shape and length of the foot component as well as the stiffness and length of the tibial component, depending on the desired functional outcomes. However, the current fabrication technology is not ideally suited for refined customization of AFO characteristics to optimize performance, or for rapid lowcost, high volume manufacturing and global distribution. A promising engineering solution for producing customized dynamic AFOs is the application of Selective Laser Sintering (SLS), which is a versatile manufacturing technology that provides advantages over traditional methods and has already been successfully used to fabricate prosthetic sockets for lower limb amputees (e.g., Faustini et al., 2006). Thus, the primary objective of this study was to explore the feasibility of using an SLSbased design, analysis and manufacturing framework to produce subject-specific passive dynamic AFOs in a cost-effective manner

Boundary Effective Field Theory and Trans-Planckian Perturbations: Astrophysical Implications

We contrast two approaches to calculating trans-Planckian corrections to the inflationary perturbation spectrum: the New Physics Hypersurface [NPH] model, in which modes are normalized when their physical wavelength first exceeds a critical value, and the Boundary Effective Field Theory [BEFT] approach, where the initial conditions for all modes are set at the same time, and modified by higher dimensional operators enumerated via an effective field theory calculation. We show that these two approaches -- as currently implemented -- lead to radically different expectations for the trans-Planckian corrections to the CMB and emphasize that in the BEFT formalism we expect the perturbation spectrum to be dominated by quantum gravity corrections for all scales shorter than some critical value. Conversely, in the NPH case the quantum effects only dominate the longest modes that are typically much larger than the present horizon size. Furthermore, the onset of the breakdown in the standard inflationary perturbation calculation predicted by the BEFT formalism is likely to be associated with a feature in the perturbation spectrum, and we discuss the observational signatures of this feature in both CMB and large scale structure observations. Finally, we discuss possible modifications to both calculational frameworks that would resolve the contradictions identified here.Comment: Reworded commentary, reference added (v2) References added (v3

A generic estimate of trans-Planckian modifications to the primordial power spectrum in inflation

We derive a general expression for the power spectra of scalar and tensor fluctuations generated during inflation given an arbitrary choice of boundary condition for the mode function at a short distance. We assume that the boundary condition is specified at a short-distance cutoff at a scale $M$ which is independent of time. Using a particular prescription for the boundary condition at momentum $p = M$, we find that the modulation to the power spectra of density and gravitational wave fluctuations is of order $(H/M)$, where $H$ is the Hubble parameter during inflation, and we argue that this behavior is generic, although by no means inevitable. With fixed boundary condition, we find that the shape of the modulation to the power spectra is determined entirely by the deviation of the background spacetime from the de Sitter limit.Comment: 15 pages (RevTeX), 2 figure

The Lyth Bound and the End of Inflation

We derive an extended version of the well-known Lyth Bound on the total variation of the inflaton field, incorporating higher order corrections in slow roll. We connect the field variation $\Delta\phi$ to both the spectral index of scalar perturbations and the amplitude of tensor modes. We then investigate the implications of this bound for ``small field'' potentials, where the field rolls off a local maximum of the potential. The total field variation during inflation is {\em generically} of order $m_{\rm Pl}$, even for potentials with a suppressed tensor/scalar ratio. Much of the total field excursion arises in the last e-fold of inflation and in single field models this problem can only be avoided via fine-tuning or the imposition of a symmetry. Finally, we discuss the implications of this result for inflationary model building in string theory and supergravity.Comment: 10 pages, RevTeX, 2 figures (V3: version accepted for publication by JCAP

Constraining Inflation

Slow roll reconstruction is derived from the Hamilton-Jacobi formulation of inflationary dynamics. It automatically includes information from sub-leading terms in slow roll, and facilitatesthe inclusion of priors based on the duration on inflation. We show that at low inflationary scales the Hamilton-Jacobi equations simplify considerably. We provide a new classification scheme for inflationary models, based solely on the number of parameters needed to specify the potential, and provide forecasts for likely bounds on the slow roll parameters from future datasets. A minimal running of the spectral index, induced solely by the first two slow roll parameters (\epsilon and \eta) appears to be effectively undetectable by realistic Cosmic Microwave Background experiments. However, we show that the ability to detect this signal increases with the lever arm in comoving wavenumber, and we conjecture that high redshift 21 cm data may allow tests of second order consistency conditions on inflation. Finally, we point out that the second order corrections to the spectral index are correlated with the inflationary scale, and thus the amplitude of the CMB B-mode.Comment: 32 pages. v