2,284 research outputs found
Diode-pumped ultrafast Yb:KGW laser with 56 fs pulses and multi-100 kW peak power based on SESAM and Kerr-lens mode locking
A high-power sub-60 fs mode-locked diode-pumped Yb:KGW laser based on hybrid action of an InGaAs quantum-dot saturable absorber mirror and Kerr-lens mode locking was demonstrated. The laser delivered 56 fs pulses with 1.95 W of average power corresponding to 450 kW of peak power. The width of the generated laser spectrum was 20.5 nm, which was near the gain bandwidth limit of the Yb:KGW crystal. To the best of our knowledge, these are the shortest pulses generated from the monoclinic double tungstate crystals (and Yb:KGW laser crystal in particular) and the most powerful in the sub-60 fs regime. At the same time, they are also the shortest pulses produced to date with the help of a quantum-dot-based saturable absorber. High-power operation with a pulse duration of 90 fs and 2.85 W of average output power was also demonstrated
AN ANALYSIS OF GAY/LESBIAN INSTRUCTOR IDENTITY IN THE CLASSROOM
In this project I explore the connection between cultural and personal identity in the college classroom. Respondent interviews were conducted using open-ended questions, which began with a broad picture of the role the instructor played in the classroom and then focused more specifically on the issue of sexual orientation and the choices to disclose or not disclose orientation in the classroom. Thematic analysis was used to examine the interviews, upon the completion of the interviews being transcribed. RQ1: Do gay and lesbian instructors disclose their sexual orientation in the classroom? From this question, four themes emerged. These themes were disclosure not relevant, out of the classroom disclosure, students just know, and disclosure in the classroom. RQ2: What reasons do gay and lesbian instructors give for disclosing their sexual orientation in the classroom? Two themes, fears of disclosure and holding back, transpired from this question. RQ3: How do gay and lesbian instructors foster diversity in the classroom related to sexual orientation? Four themes were exposed from the question, and these themes were paradox of diversity, passing, mentoring, and identity not sexuality. INTRODUCTION In the last few years, researchers have been explored instructors multiple identities in the classroom in relation to identity negotiation, co-identities, and diversity in the last few years Critical communication pedagogy stresses the struggle between dominant academic practices and nondominant practices Individuals whose communication is restricted by cultural norms often find themselves marginalized and without power. In the classroom, instructors are automatically placed in a position of power. So how does the gay/lesbian instructor, who is often marginalized in the dominant culture but is empowered in their communication with their students in and out of the classroom? 1 Statement of Problem In this project I explore the connection between cultural and personal identity in the college classroom. Dominant culture influences development of an instructor's identity both in and out of the classroom. Co-cultural theory addresses the effects dominant culture on marginalized groups Instructors have more identities beyond being the individual teaching students. Instructors have an identity of race, sex, and sexual orientation, but could also have other identities based on roles they play in their lives such as parent or daughter. All of these multiple identities come with the instructor when he or she enter the classroom, the identity that often becomes a struggle for gay/lesbian instructors is his or her sexual identity, and thus will be the focus of this project. Harding (1997) argued that we should privilege marginalized voices because individuals at the margins understand how to function within the dominant culture as well as within their marginalized groups. Thus, by giving voice to individuals who are marginalized, researches 2 provide insight into how the dominant culture restricts the marginalized group. Harding privileges localized knowledge, claiming that knowledge is best understood within context (Heckman, 1997). Thus, I seek to give voice to gay/lesbian instructors to further our knowledge within the context of higher education. I will provide an understanding of how the disclosure of an instructor's sexual orientation in the classroom influences the instructor's identity through personal interviews. In the classroom heterosexual instructors disclose their sexual orientation without realizing they are announcing their status Co-Cultural Theory Co-cultural theory is the principle theory used both to explain how the dominant culture silences marginalized groups and to provide scholars insight into how marginalized groups can gain voice in the dominant culture. White men represent the dominant individuals in our culture, while women, non-whites, and non-westerners represent the marginalized other Five underlying assumptions inform co-cultural theory. The first assumption of cocultural theory is that experiences available to the members the dominant culture are not accessible to members of marginalized groups The second premise of co-culture theory originated from muted group theory. Orbe In the final assumption, co-cultural theorists have argued that marginalized groups find ways to communicate within the dominant society to cope with oppression by applying standpoint theory The servant, on the other hand, understands the master's perspective, the servant's own perspective on the labor of the object, and the relationship formed between the master and the object Martin, Reynolds, and Keith Teacher credibility is a key factor in student listening and learning. Students need to feel that their instructors are credible. Ewing, Stukas, and Sheehan (2003) studied whether students based instructor credibility on the instructor's sexual orientation by conducting an experiment in which instructors' who delivered lectures were not labeled or identified as homosexual. The study manipulated the lectures to determine whether students were prejudiced towards gay/lesbians by making one lecture weak and the other strong. The researchers found that the perceived quality of the lecture was not influenced by the gay/lesbian sexual orientation of the 15 lecturers. On the other hand, the quality of the lecture impacted the ratings of lecturers whose sexual orientation was not identified. The authors concluded that the students might have been subtle when evaluating the known gay/lesbian lecturer to avoid discriminating against a lecturer with a specified sexual orientation. The dominant culture consists of heterosexual individuals. Nixon and Givens Furthermore, scholars have claimed that coming out in the classroom decreases bias, negative attitudes, prejudices, and stereotypes of gay men and lesbians Instructor identity consists of an instructor identifying himself or herself to students in ways other than as an authority figure sharing knowledge. Instructors reveal their identity to their students through personal narratives Nixon and Givens (2004) respondents described the stress of negotiating two identities, one in the classroom as the instructor, and the other as lesbian. The interviewees expressed their frustration and feelings of dishonesty towards their students and themselves. Previous researchers Rationale Scholars rarely explore the multiple identities of instructors Critical pedagogy allows for scholars to examine oppression occurring in educational institutions, which reveals politics in the academic community Researchers discuss instructors disclosing sexual orientation in the classroom in only 20 published articles. Scholarly research on lesbian instructors, in particular, is limited to how to disclose sexual orientation Thus, I applied standpoint theory to marginalized groups not limited by gender, but rather sexual Data Analysis I used thematic analysis to examine the transcribed interviews. Thematic analysis is the process of examining transcribed interviews through multiple readings allowing for the emergence from themes Then I analyzed the results of the thematic analysis. If I found consensus, I was able to draw specific conclusions. If the all participants had answers that varied, I was not able to conclude anything specific from their answers. Using the qualitative method of respondent interviews allowed me to use thematic analysis to draw conclusion and to isolate patterns within regard to coming out or not coming out in the classroom. While this process of data analysis did not rely on predetermined categories the analysis was likely to be informed by the bodies of research addressed in the literature review of this project. 21 CHAPTER 4 RESULTS Thematic analysis of interviews of gay/lesbian instructors who taught at the university level was organized by the three research questions posed earlier in this project. The interview questions dealt with disclosing sexual orientation, reasons for disclosing or not disclosing, and if they disclosed, what strategies they used to disclose their sexual orientation. Other questions were asked related to dominant culture and how being a gay/lesbian instructor influenced cultural norms. Four themes emerged from RQ 1: Do gay and lesbian instructors disclose their sexual orientation in the classroom? The four themes for RQ1 were 1) disclosure not relevant; 2) out of the classroom disclosure; 3) students just know; and 4) discloses in class. Disclosure Not Relevant In RQ1 I sought to understand whether or not instructors' disclosed their sexual orientation in the classroom. Thus, I asked respondents whether or not they disclosed sexual orientation in the classroom. Gay/lesbian instructors gave five reasons for not disclosing their sexual orientation in the classroom. The first reason for not disclosing sexual orientation, gay/lesbian instructor felt disclosure was not relevant to course content. The second reason for not disclosing sexual orientation, gay/lesbian instructors avoided the subject. Thirdly, sexual orientation was not considered in regards to teaching. Fourthly, some gay/lesbian instructors did not want students to know about his or her personal life, and the fifth reason for not disclosing dealt with instructors having bad past experiences with disclosing their sexual orientation. The first reason gay/lesbian instructors chose not to disclose their sexual orientation was a belief that sexual orientation was not relevant to the course concepts in the classes they teach. Interviewee 22 9 (lesbian, Professor) explained how sexual orientation is not relevant in the classes she teaches in the following example: I've taught classroom management and curriculum development and have teaching styles and I don't know of a situation that would come up that I would talk about a romantic situation I don't know how that would come up if I would avoid it or not because I don't know how it would come up. Respondents who taught in the Department of Kinesiology, the Department of Radio Television and Film, and Music Education, indicated that they felt that their sexual orientation and personal relationships were not relevant to the content of their courses either
Triad representation of the Chern-Simons state in quantum gravity
We investigate a triad representation of the Chern-Simons state of quantum
gravity with a non-vanishing cosmological constant. It is shown that the
Chern-Simons state, which is a well-known exact wavefunctional within the
Ashtekar theory, can be transformed to the real triad representation by means
of a suitably generalized Fourier transformation, yielding a complex integral
representation for the corresponding state in the triad variables. It is found
that topologically inequivalent choices for the complex integration contour
give rise to linearly independent wavefunctionals in the triad representation,
which all arise from the one Chern-Simons state in the Ashtekar variables. For
a suitable choice of the normalization factor, these states turn out to be
gauge-invariant under arbitrary, even topologically non-trivial
gauge-transformations. Explicit analytical expressions for the wavefunctionals
in the triad representation can be obtained in several interesting asymptotic
parameter regimes, and the associated semiclassical 4-geometries are discussed.
In restriction to Bianchi-type homogeneous 3-metrics, we compare our results
with earlier discussions of homogeneous cosmological models. Moreover, we
define an inner product on the Hilbert space of quantum gravity, and choose a
natural gauge-condition fixing the time-gauge. With respect to this particular
inner product, the Chern-Simons state of quantum gravity turns out to be a
non-normalizable wavefunctional.Comment: Latex, 30 pages, 1 figure, to appear in Phys. Rev.
The role of bisphosphonates in breast cancer: The present and future role of bisphosphonates in the management of patients with breast cancer
At least 25% of patients with breast cancer develop skeletal metastases, with bone the site of disease producing the greatest morbidity. It is apparent that the bisphosphonates present an important component of the treatment strategy. They are now the treatment of choice in tumour-induced hypercalcaemia, and they can reduce bone pain and skeletal complications such as pathological fractures. In addition, bisphosphonates are being increasingly evaluated in the prevention of bone metastases and to prevent and treat cancer therapy-induced osteoporosis. Ongoing research is aimed at trying to define the optimum route, dose, schedule and type of bisphosphonate
Imputation of variants from the 1000 Genomes Project modestly improves known associations and can identify low-frequency variant-phenotype associations undetected by HapMap based imputation
notes: PMCID: PMC3655956This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.Genome-wide association (GWA) studies have been limited by the reliance on common variants present on microarrays or imputable from the HapMap Project data. More recently, the completion of the 1000 Genomes Project has provided variant and haplotype information for several million variants derived from sequencing over 1,000 individuals. To help understand the extent to which more variants (including low frequency (1% ≤ MAF <5%) and rare variants (<1%)) can enhance previously identified associations and identify novel loci, we selected 93 quantitative circulating factors where data was available from the InCHIANTI population study. These phenotypes included cytokines, binding proteins, hormones, vitamins and ions. We selected these phenotypes because many have known strong genetic associations and are potentially important to help understand disease processes. We performed a genome-wide scan for these 93 phenotypes in InCHIANTI. We identified 21 signals and 33 signals that reached P<5×10(-8) based on HapMap and 1000 Genomes imputation, respectively, and 9 and 11 that reached a stricter, likely conservative, threshold of P<5×10(-11) respectively. Imputation of 1000 Genomes genotype data modestly improved the strength of known associations. Of 20 associations detected at P<5×10(-8) in both analyses (17 of which represent well replicated signals in the NHGRI catalogue), six were captured by the same index SNP, five were nominally more strongly associated in 1000 Genomes imputed data and one was nominally more strongly associated in HapMap imputed data. We also detected an association between a low frequency variant and phenotype that was previously missed by HapMap based imputation approaches. An association between rs112635299 and alpha-1 globulin near the SERPINA gene represented the known association between rs28929474 (MAF = 0.007) and alpha1-antitrypsin that predisposes to emphysema (P = 2.5×10(-12)). Our data provide important proof of principle that 1000 Genomes imputation will detect novel, low frequency-large effect associations
Making things happen : a model of proactive motivation
Being proactive is about making things happen, anticipating and preventing problems, and seizing opportunities. It involves self-initiated efforts to bring about change in the work environment and/or oneself to achieve a different future. The authors develop existing perspectives on this topic by identifying proactivity as a goal-driven process involving both the setting of a proactive goal (proactive goal generation) and striving to achieve that proactive goal (proactive goal striving). The authors identify a range of proactive goals that individuals can pursue in organizations. These vary on two dimensions: the future they aim to bring about (achieving a better personal fit within one’s work environment, improving the organization’s internal functioning, or enhancing the organization’s strategic fit with its environment) and whether the self or situation is being changed. The authors then identify “can do,” “reason to,” and “energized to” motivational states that prompt proactive goal generation and sustain goal striving. Can do motivation arises from perceptions of self-efficacy, control, and (low) cost. Reason to motivation relates to why someone is proactive, including reasons flowing from intrinsic, integrated, and identified motivation. Energized to motivation refers to activated positive affective states that prompt proactive goal processes. The authors suggest more distal antecedents, including individual differences (e.g., personality, values, knowledge and ability) as well as contextual variations in leadership, work design, and interpersonal climate, that influence the proactive motivational states and thereby boost or inhibit proactive goal processes. Finally, the authors summarize priorities for future researc
Evolutionary Patterns in the Dentition of Duplicidentata (Mammalia) and a Novel Trend in the Molarization of Premolars
The cusp homology of Lagomorpha has long been problematic largely because their teeth are highly derived relative to their more typically tribosphenic ancestors. Within this context, the lagomorph central cusp has been particularly difficult to homologize with other tribosphenic cusps; authors have previously considered it the paracone, protocone, metacone, amphicone, or an entirely new cusp.Here we present newly described fossil duplicidentates (Lagomorpha and Mimotonidae) in the context of a well-constrained phylogeny to establish a nomenclatural system for cusps based on the tribosphenic pattern. We show that the central cusp of lagomorphs is homologous with the metaconule of other mammals. We also show that the buccal acquisition of a second cusp on the premolars (molarization) within duplicidentates is atypical with respect to other mammalian lineages; within the earliest lagomorphs, a second buccal cusp is added mesially to an isolated buccal cusp.The distal shift of the ‘ancestral’ paracone within early duplicidentates amounts to the changing of a paracone into a metacone in these lineages. For this reason, we support a strictly topological approach to cusp names, and suggest a discontinuity in nomenclature to capture the complexity of the interplay between evolutionary history and the developmental process that have produced cusp patterns in duplicidentates
Pathology of immune reconstitution inflammatory syndrome in multiple sclerosis with natalizumab-associated progressive multifocal leukoencephalopathy
Natalizumab is an approved medication for highly active multiple sclerosis (MS). Progressive multifocal leukoencephalopathy (PML) may occur as a severe side effect of this drug. Here, we describe pathological and radiological characteristics of immune reconstitution inflammatory syndrome (IRIS), which occurs in natalizumab-associated PML after the cessation of therapy, and we differentiate it from ongoing PML. Brain biopsy tissue and MRI scans from five MS patients with natalizumab-associated PML were analyzed and their histology compared with non-MS PML. Histology showed an extensive CD8-dominated T cell infiltrate and numerous macrophages within lesions, and in nondemyelinated white and grey matter, in four out of five cases. Few or no virally infected cells were found. This was indicative of IRIS as known from HIV patients with PML. Outstandingly high numbers of plasma cells were present as compared to non-MS PML and typical MS lesions. MRI was compatible with IRIS, revealing enlarging lesions with a band-like or speckled contrast enhancement either at the lesion edge or within lesions. Only the fifth patient showed typical PML pathology, with low inflammation and high numbers of virally infected cells. This patient showed a similar interval between drug withdrawal and biopsy (3.5 months) to the rest of the cohort (range 2.5–4 months). MRI could not differentiate between PML-associated IRIS and ongoing PML. We describe in detail the histopathology of IRIS in natalizumab-associated PML. PML–IRIS, ongoing PML infection, and MS exacerbation may be impossible to discern clinically alone. MRI may provide some clues for distinguishing different pathologies that can be differentiated histologically. In our individual cases, biopsy helped to clarify diagnoses in natalizumab-associated PML
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