Evolution Of Feeding Shapes Swimming Kinematics Of Barnacle Naupliar Larvae: A Comparison Between Trophic Modes

A central goal in evolutionary biology is connecting morphological features with ecological functions. For marine invertebrate larvae, appendage movement determines locomotion, feeding, and predator avoidance ability. Barnacle larvae are morphologically diverse, and the morphology of non-feeding lecithotrophic nauplii are distinct from those that are planktotrophic. Lecithotrophic larvae have a more globular body shape and simplified appendages when compared with planktotrophs. However, little is known about whether and how such morphological changes affect kinematics, hydrodynamics, and ecological functions. Here, we compared the nauplii kinematics and hydrodynamics of a lecithotrophic Rhizocephalan species, Polyascus planus, against that of the planktotrophic nauplii of an intertidal barnacle, Tetraclita japonica. High-speed, micro-particle image velocimetry analysis showed that the Polyascus nauplii swam faster and had higher amplitude and more synchronous appendage beating than the Tetraclita nauplii. This fast swimming was accompanied by a faster attenuation of induced flow with distance, suggesting reduced predation risk. Tetraclita nauplii had more efficient per beat cycles with less backward displacement during the recovery stroke. This “anchoring effect” resulted from the anti-phase beating of appendages. This movement, together with a high-drag body form, likely helps direct the suction flow toward the ventral food capturing area. In sum, the tradeoff between swimming speed and predation risks may have been an important factor in the evolution of the observed larval forms

Iliac Vein Compression Syndrome in an Active and Healthy Young Female

Iliac vein compression syndrome is a condition involving external compression of the left common iliac vein by the right iliac artery, which was first described in the 1850s. It predominates in females typically between the third and fourth decade of life and has been associated with thrombophilias. Importantly, the syndrome is amenable to endovascular treatment. Here, we describe a case of a young athletic female with an incidental finding of a left iliac vein thrombosis while taking oral contraceptives, who was identified as having iliac vein compression syndrome on follow-up MR venography with positive testing for Factor V Leiden mutation

Scaffolding Discourse in Asynchronous Learning Networks

Discourse, a form of collaborative learning, is fundamentally a communications process. This in-progress study adapts Clark and Brennan’s grounding in communications principles to investigate how to “scaffold” asynchronous discourse. Scaffolding is defined as providing support for the learner at his or her level until the support is no longer needed. This paper presents early results from an experimental study measuring learning effectiveness. In the experiment, content and process scaffolding are manipulated based on pedagogic principles. A major contribution of the study is building and testing a technologymediated, discourse-centered, teaching and learning model called the Asynchronous Learning Networks Cognitive Discourse Model (ALNCDM). As discourse is one of the most widely used online methods of teaching and learning, the results of the study are expected to add to the body of knowledge on how to structure asynchronous online discourse assignments for more effective student learning

Expression of HES and HEY genes in infantile hemangiomas

Background: Infantile hemangiomas (IHs) are the most common benign tumor of infancy, yet their pathogenesis is poorly understood. IHs are believed to originate from a progenitor cell, the hemangioma stem cell (HemSC). Recent studies by our group showed that NOTCH proteins and NOTCH ligands are expressed in hemangiomas, indicating Notch signaling may be active in IHs. We sought to investigate downstream activation of Notch signaling in hemangioma cells by evaluating the expression of the basic HLH family proteins, HES/HEY, in IHs. Materials and Methods: HemSCs and hemangioma endothelial cells (HemECs) are isolated from freshly resected hemangioma specimens. Quantitative RT-PCR was performed to probe for relative gene transcript levels (normalized to beta-actin). Immunofluorescence was performed to evaluate protein expression. Co-localization studies were performed with CD31 (endothelial cells) and NOTCH3 (peri-vascular, non-endothelial cells). HemSCs were treated with the gamma secretase inhibitor (GSI) Compound E, and gene transcript levels were quantified with real-time PCR. Results: HEY1, HEYL, and HES1 are highly expressed in HemSCs, while HEY2 is highly expressed in HemECs. Protein expression evaluation by immunofluorescence confirms that HEY2 is expressed by HemECs (CD31+ cells), while HEY1, HEYL, and HES1 are more widely expressed and mostly expressed by perivascular cells of hemangiomas. Inhibition of Notch signaling by addition of GSI resulted in down-regulation of HES/HEY genes. Conclusions: HES/HEY genes are expressed in IHs in cell type specific patterns; HEY2 is expressed in HemECs and HEY1, HEYL, HES1 are expressed in HemSCs. This pattern suggests that HEY/HES genes act downstream of Notch receptors that function in distinct cell types of IHs. HES/HEY gene transcripts are decreased with the addition of a gamma-secretase inhibitor, Compound E, demonstrating that Notch signaling is active in infantile hemangioma cells

Quality Indicators for the Diagnosis and Management of Primary Hyperparathyroidism

IMPORTANCE Primary hyperparathyroidism (pHPT) is a common endocrine disorder with many diagnostic and treatment challenges. Despite high-quality guidelines, care is variable, and there is low adherence to evidence-based treatment pathways. OBJECTIVE To develop quality indicators (QIs) to evaluate the diagnosis and treatment of pHPT that could measure, improve, and optimize quality of care and outcomes for patients with this disease. DESIGN, SETTING, AND PARTICIPANTS This quality improvement study used a guideline-based approach to develop QIs that were ranked by a Canadian 9-member expert panel of 3 endocrinologists, 3 otolaryngologists, and 3 endocrine surgeons. Data were analyzed between September 2020 and May 2021. MAIN OUTCOMES AND MEASURES Candidate indicators (CIs) were extracted from published primary hyperparathyroidism guidelines and summarized with supporting evidence. The 9-member expert panel rated each CI on the validity, reliability, and feasibility of measurement. Final QIs were selected from CIs using the modified RAND-University of California, Los Angeles appropriateness methodology. All panelists were then asked to rank the top 5 QIs for primary, endocrine, and surgical care. RESULTS Forty QIs were identified and evaluated by the expert panel. After 2 rounds of evaluations and discussion, a total of 18 QIs were selected as appropriate measures of high-quality care. The top 5 QIs for primary, endocrine, and surgical care were selected following panelist rankings. CONCLUSIONS AND RELEVANCE This quality improvement study proposes 18 QIs for the diagnosis and management of pHPT. Furthermore, the top 5 QIs applicable to physicians commonly treating pHPT, including general physicians, internists, endocrinologists, otolaryngologists, and surgeons, are included. These QIs not only assess the quality of care to guide the process of improvement, but also can assess the implementation of evidence-based guideline recommendations. Using these indicators in clinical practice and health system registries can improve quality and cost-effectiveness of care for patients with pHPT