277 research outputs found
Anatomy of flower and fruit of Vassobia breviflora (Solanaceae) in the south of the southern Yungas (Argentina)
Solanaceae es una familia con aproximadamente 2400 especies de distribución cosmopolita. Vassobia breviflora es la única especie del género presente en Argentina. El objetivo de este trabajo fue revisar y caracterizar la anatomÃa de la flor y fruto de V. breviflora a partir de muestras recolectadas en poblaciones de las Yungas del noroeste argentino. Se aplicaron técnicas anatómicas convencionales. Los resultados mostraron que la mayorÃa de las estructuras de la flor, el fruto y la semilla no difirieron de lo previamente reportado respecto de la organización estructural descripta para otras especies de Solanaceae. No obstante, por primera vez, describimos el androceo, el fruto, la semilla, pedicelo floral y frutal, cinco tipos de tricomas y cinco tipos de estomas en el perianto. Encontramos diferencias en la forma del tejido de transmisión y del tipo de óvulo respecto de lo previamente descripto. Además, localizamos el parénquima y las células epidérmicas secretoras del nectario. En el contexto de la familia Solanaceae, discutimos la función y valor diagnóstico de las estructuras descriptas.Solanaceae is a family with nearly 2400 species of cosmopolitan distribution. Vassobia breviflora is the only species of the genus present in Argentina. The goal of this work was to review and characterize the anatomy of the flower and fruit of V. breviflora from samples collected in populations of Yungas in the argentine Northwest. Conventional anatomical techniques were applied. The results showed that most flower, fruit and seed structures did not differ from those previously reported regarding the structural organization described for other species of the Solanaceae family. However, for the first time, we described the androecium, fruit, seed, floral and fruit pedicels, five types of tricomes and five types of stomata in the perianth. We found some differences in the shape of the transmission tissue and in the type of ovule with respect to that previously reported. Also, we located the parenchyma and the epidermic secretory cells of the nectary. In the context of the family Solanaceae, we discussed the function and diagnostic value of the described structures.Fil: Bernacki, F. G.. Fundación Miguel Lillo; ArgentinaFil: Albornoz, P. L.. Fundación Miguel Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaFil: Valoy, M.. Fundación Miguel Lillo; ArgentinaFil: Ordano, Mariano Andrés. Fundación Miguel Lillo; Argentina. Consejo Nacional de Investigaciones CientÃficas y Técnicas; Argentin
Predicting STEM Achievement with Learning Management System Data: Prediction Modeling and a Test of an Early Warning System
ABSTRACT Learning management systems log users' behaviors, which can be used to predict achievement in a course. This paper examines the implications of data representations (e.g., dichotomous vs. count vs. principled, per learning theory) and applies forward selection algorithms to predict achievement in a biology course. Accuracy is compared across models. The paper closes with a description of an ongoing experiment that employs the prediction model, tests how multiple versions of an early alert message impact students' access of learning resources, and compares the influence of messaging approaches related to personalization and feedback
Adherence and Concordance between Serious Illness Care Planning Conversations and Oncology Clinician Documentation among Patients with Advanced Cancer
Background:Serious illness conversations are part of advance care planning (ACP) and focus on prognosis, values, and goals in patients who are seriously ill. To be maximally effective, such conversations must be documented accurately and be easily accessible. Objectives:The two coprimary objectives of the study were to assess concordance between written documentation and recorded audiotaped conversations, and to evaluate adherence to the Serious Illness Conversation Guide questions. Methods:Data were obtained as part of a trial in patients with advanced cancer. Clinicians were trained to use a guide to conduct and document serious illness conversations. Conversations were audiotaped. Two researchers independently compared audiorecordings with the corresponding documentation in an electronic health record (EHR) template and free-text progress notes, and rated the degree of concordance and adherence. Results:We reviewed a total of 25 audiorecordings. Clinicians addressed 87% of the conversation guide elements. Prognosis was discussed least frequently, only in 55% of the patients who wanted that information. Documentation was fully concordant with the conversation 43% of the time. Concordance was best when documenting family matters and goals, and least frequently concordant when documenting prognostic communication. Most conversations (64%) were documented in the template, a minority (28%) only in progress notes and two conversations (8%) were not documented. Concordance was better when the template was used (62% vs. 28%). Conclusion:Clinicians adhered well to the conversation guide. However, key information elicited was documented and fully concordant less than half the time. Greater concordance was observed when clinicians used a prespecified template. The combined use of a guide and EHR template holds promise for ACP conversations
The clinical and therapeutic uses of MDM2 and PSMA and their potential interaction in aggressive cancers
Prostate-specific membrane antigen (PSMA) overexpression is observed in the neovasculature of solid tumors, but not in the vasculature of normal tissues. Increased PSMA expression is positively associated with tumor stage and grade, although its function in cancer remains unclear. Mouse double minute 2 (MDM2) is a negative regulator of the p53 tumor suppressor and is reported to regulate VEGF expression and angiogenesis. Both proteins have been considered as biomarkers and therapeutic targets for advanced solid tumors. Our work and a recent microarray-based gene profiling study suggest there could be signaling interplay between MDM2 and PSMA. We herein review the mechanisms underlining the outgrowth of tumors associated with PSMA and MDM2, their potential interaction and how this may be applied to anticancer therapeutics
A Qualitative Study of Serious Illness Conversations in Patients with Advanced Cancer
BACKGROUND: Conversations with seriously ill patients about their values and goals have been associated with reduced distress, a better quality of life, and goal-concordant care near the end of life. Yet, little is known about how such conversations are conducted. OBJECTIVE: To characterize the content of serious illness conversations and identify opportunities for improvement. DESIGN: Qualitative analysis of audio-recorded, serious illness conversations using an evidence-based guide and obtained through a cluster randomized controlled trial in an outpatient oncology setting. Setting/Measurements: Clinicians assigned to the intervention arm received training to use the "Serious Illness Conversation Guide" to have a serious illness conversation about values and goals with advanced cancer patients. Conversations were de-identified, transcribed verbatim, and independently coded by two researchers. Key themes were analyzed. RESULTS: A total of 25 conversations conducted by 16 clinicians were evaluated. The median conversation duration was 14 minutes (range 4-37), with clinicians speaking half of the time. Thematic analyses demonstrated five key themes: (1) supportive dialogue between patients and clinicians; (2) patients' openness to discuss emotionally challenging topics; (3) patients' willingness to articulate preferences regarding life-sustaining treatments; (4) clinicians' difficulty in responding to emotional or ambiguous patient statements; and (5) challenges in discussing prognosis. CONCLUSIONS: Data from this exploratory study suggest that seriously ill patients are open to discussing values and goals with their clinician. Yet, clinicians may struggle when disclosing a time-based prognosis and in responding to patients' emotions. Such skills should be a focus for additional training for clinicians caring for seriously ill patients
Quantum Optics and Photonics
Contains table of contents for Part II, table of contains for Section 1 and reports on three research projects.Charles Stark Draper LaboratoryJoint Services Electronics Program (Contract DAAL03-86-K-0002)National Science Foundation (Grant PHY 82-10369)U.S. Air Force - Office of Scientific Research (Contract F49620-82-C-0091)U.S. Air Force - Rome Air Development Cente
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Hybrid optics for the visible produced by bulk casting of sol-gel glass using diamond-turned molds
Recent combinations of diffractive and refractive functions in the same optical component allow designers additional opportunities to make systems more compact and enhance performance. This paper describes a research program for fabricating hybrid refractive/diffractive components from diamond-turned molds using the bulk casting of sol-gel silica glass. The authors use the complementary dispersive nature of refractive and diffractive optics to render two-color correction in a single hybrid optical element. Since diamond turning has matured as a deterministic manufacturing technology, techniques previously suitable only in the infrared are now being applied to components used at visible wavelengths. Thus, the marriage of diamond turning and sol-gel processes offers a cost-effective method for producing highly customized and specialized optical components in high quality silica glass. With the sol-gel casting method of replication, diamond-turned mold costs can be shared over many pieces. Diamond turning takes advantage of all of the available degrees of freedom in a single hybrid optical element: aspheric surface to eliminate spherical aberration, kinoform surface for control of primary chromatic aberration, and the flexibility to place the kinoform on non-planar surfaces for maximum design flexibility. The authors discuss the critical issues involved in designing the hybrid element, single point diamond-turning the mold, and fabrication in glass using the sol-gel process
Quantum Optics and Photonics
Contains reports on five research projects.Joint Services Electronics Program (Contract DAALO3-86-K-0002)National Science Foundation (Grant PHY 82-10369)U.S. Air Force - Office of Scientific Research (Contract F49620-82-C-0091)U.S. Air Force - Rome Air Development Cente
Quantum Optics and Photonics
Contains reports on nine research projects.U.S. Air Force - Office of Scientific Research (Contract F49620-82-C-0091)U.S. Air Force - Rome Air Development CenterJoint Services Electronics Program (Contract DAAG29-83-K-0003)National Science Foundation Grant (Grant PHY 82-710369
Linking plastic deformation to recrystallization in metals using digital microstructures
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