1,571 research outputs found
Co-Surgeons in Breast Reconstructive Microsurgery: What Do They Bring to the Table?
No full textAs the content in this document has been previously published in the journal Microsurgery, an internal indefinite embargo will be placed on this document through the department of Medical Student Research at UT Southwestern. This will ensure that this document will not be published online and will remain only within the UT Southwestern system to not infringe upon copyright regulations established between the authors and Microsurgery.The general metadata -- e.g., title, author, abstract, subject headings, etc. -- is publicly available, but access to the submitted files is restricted to UT Southwestern campus access and/or authorized UT Southwestern users.INTRODUCTION: Current research within other surgical specialties suggests that a co-surgeon approach may reduce operative times and complications associated with complex bilateral procedures, possibly leading to improved patient and surgical outcomes. We sought to evaluate the role of the co-surgery team and its development in free flap breast reconstruction.
METHODS: A retrospective review of free-flap breast reconstruction by two surgeons from 2011-2016 was conducted. We analyzed 128 patients who underwent bilateral-DIEP breast. Surgical groups were: single-surgeon reconstruction (SSR; 35 patients), Co-Surgery where both surgeons are present for entire reconstruction (CSR-I; 69 patients), and Co-Surgery reconstruction where co-surgeons appropriately assist in two concurrent or staggered cases (CSR-II; 24 patients). Efficiency data collected was OR time and patient length-of-stay (LOS). The rate of flap-failure, return to OR, infection, wound breakdown, seroma, hematoma and PE/DVT were compared.
RESULTS: Single-surgeon reconstruction had significantly longer OR time (678 vs 485 minutes, p< 0.0001), LOS (5 vs 3.9 days, p<0.001), higher wound occurrences of the umbilical site that required surgical correction [11.4 percent (n=4) versus 1.5 percent,(n=1); p<0.043] compared to CSR-I. Similarly, SSR had significantly longer average OR time (678 vs 527 minutes p< 0.0001), average LOS (5 days vs 4 days, p=0.0005) when compared to CSR-II. There were no total increased patient related complications associated with co-surgery (CSR- I or II).
CONCLUSION: The addition of a Co-surgeon, even with concurrent surgery, reduces operative time, average patient LOS, and post-operative complications. This work lends a strong credence that Co-surgery model is associated with increased operative efficiency
The maternal immune system during pregnancy and its influence on fetal development
No full textThe maternal immune system plays a critical role in the establishment, maintenance, and completion of a healthy pregnancy. However, the specific mechanisms utilized to achieve these goals are not well understood. Various cells and molecules of the immune system are key players in the development and function of the placenta and the fetus. Effector cells of the immune system act to promote and yet limit placental development. The T helper 1 (Th1)/T helper 2 (Th2) immune shift during pregnancy is well established. A fine balance between proinflammatory and anti-inflammatory influences is required. We herein review the evidence regarding maternal tolerance of fetal tissues and the underlying cell-mediated immune and humoral (hormones and cytokines) mechanisms. We also note the many unanswered questions in our understanding of these mechanisms. In addition, we summarize the clinical manifestations of an altered maternal immune system during pregnancy related to susceptibility to common viral, bacterial, and parasitic infections, as well as to autoimmune diseases.Peer reviewe
External interventions and the duration of civil wars
No full textThe authors combine an empirical model of external intervention, with a theoretical model of civil war duration. Their empirical model of intervention allows them to analyze civil war duration, using"expected"rather than"actual"external intervention as an explanatory variable in the duration model. Unlike previous studies, they find that external intervention is positively associated with the duration of civil war. They distinguish partial third-party interventions that extend the length of war, from multilateral"peace"operations, which have a mandate to restore peace without taking sides - and which typically take place at war's end, or at least when both sides have agreed to a cease-fire. In a future paper, the authors will examine whether partial third-party interventions - whatever their effect on a war's duration - increase the risk of war's recurrence. If that proves true, then even if interventions reduce the length of civil war, they may do so at the cost of further destabilizing the political system, and sowing the seeds of future rebellion.Children and Youth,Peace&Peacekeeping,Post Conflict Reconstruction,Post Conflict Reconstruction,International Affairs,Post Conflict Reconstruction,Social Conflict and Violence,Peace&Peacekeeping,Post Conflict Reconstruction,International Affairs
Intermittent Fasting Promotes Fat Loss with Lean Mass Retention, Increased Hypothalamic Norepinephrine Content, and Increased Neuropeptide Y Gene Expression in Diet-Induced Obese Male Mice
No full textClinical studies indicate alternate day, intermittent fasting (IMF) protocols result in meaningful weight loss in obese individuals. To further understand the mechanisms sustaining weight loss by IMF, we investigated the metabolic and neural alterations of IMF in obese mice. Male C57/BL6 mice were fed a high-fat diet (HFD; 45% fat) ad libitum for 8 weeks to promote an obese phenotype. Mice were divided into 4 groups and either maintained on ad libitum HFD (HFD), received alternate day access to HFD (IMF- HFD), switched to ad libitum low fat diet (LFD; 10% fat), or received IMF of LFD (IMF- LFD). After 4 weeks, IMF-HFD (~13%) and IMF-LFD (~18%) had significantly lower body weights than HFD. Body fat was also lower (~40-52%) in all diet interventions. Lean mass was increased in the IMF-LFD (~12-13%) compared with HFD and IMF-HFD groups. Oral glucose tolerance AUC was lower in the IMF-HFD (~50%), whereas insulin tolerance AUC was reduced in all diet interventions (~22-42%). HPLC measurements of hypothalamic tissue homogenates indicated higher (~55-60%) norepinephrine (NE) content in the anterior regions of the medial hypothalamus of IMF compared with ad libitum fed groups, whereas NE content was higher (~19-32%) in posterior regions in the IMF-LFD group only. Relative gene expression of Npy in the arcuate nucleus was increased (~65-75%) in IMF groups. Our novel findings indicate that intermittent fasting produces alterations in hypothalamic NE and NPY, suggesting an involvement in the counter regulatory processes of short-term weight loss are associated with an IMF dietary strategy.Peer reviewe
Gq Protein-Coupled Membrane-Initiated Estrogen Signaling Rapidly Excites Corticotropin-Releasing Hormone Neurons in the Hypothalamic Paraventricular Nucleus in Female Mice
No full textCRH neurons in the hypothalamic paraventricular nucleus (PVN) play a central role in regulating the hypothalamus-pituitary-adrenal (HPA) axis and are directly influenced by 17β-estradiol (E2). Although compelling evidence has suggested the existence of membrane-associated estrogen receptors (mERs) in hypothalamic and other central nervous system neurons, it remains unknown whether E2 impacts CRH neuronal excitability through this mechanism. The purpose of the current study is to examine the existence and function of mER signaling in PVN CRH neurons. Whole-cell recordings were made from CRH neurons identified by Alexa Fluor 594 labeling and post hoc immunostaining in ovariectomized female mice. E2 (100nM) rapidly suppressed the M-current (a voltage-dependent K(+) current) and potentiated glutamatergic excitatory postsynaptic currents. The putative Gq-coupled mER (Gq-mER) characterized in hypothalamic proopiomelanocortin neurons initiates a phospholipase C-protein kinase C-protein kinase A pathway; therefore, we examined the involvement of this pathway using selective inhibitors. Indeed, the ER antagonist ICI 182780 and inhibitors of Gq-phospholipase C-protein kinase C-protein kinase A blocked E2's actions, suggesting dependence on the Gq-mER. Furthermore, STX, a selective ligand for the Gq-mER, mimicked E2's actions. Finally, to examine the in vivo effect of Gq-mER activation, E2 or STX injection increased c-fos expression in CRH neurons in the PVN, suggesting CRH neuronal activation. This corresponded to an increase in plasma corticosterone. We conclude that the Gq-mER plays a critical role in the rapid regulation of CRH neuronal activity and the HPA axis. Our findings provide a potential underlying mechanism for E2's involvement in the pathophysiology of HPA-associated mood disorders.Peer reviewe
Cogitations on our quest to find a silver lining in the shroud of the COVID cloud
No full textIn this article, the author shares on: 1) how he first learnt of SARS-CoV-2; 2) crucial factors that likely facilitated the rapid and widespread transmission of SARS-CoV-2, and COVID-19's ability to inflict significant harm; 3) consideration of the 1918 pandemic, and why COVID-19 may linger indefinitely even with an approved vaccine; 4) the positive things that have arisen possibly as a result of the pandemic
Characterization and structure in the development of Tudor comedy
No full textThe role of characterization in dramatic structure is assessed by theoretical criteria.
Characters who perform actions necessary for the completion of the narrative sequence are
said to be "bound" to the narrative; those without such obligations are "free". Characters
who maintain a single, constant meaning during the course of a play are said to be "static";
characters who change or develop into new roles are "dynamic". Horatian decorum
demanded that comic characters be static, and the characters of Plautine and Terentian
tradition were almost always bound to narrative intrigue. However, evaluations of six
Tudor comedies show an increasing use of non-classical characterization within the comic
form.
In the early comedies lohan lohan and Roister Doister all characters are bound and
static, yet the impetus to enlarge the role of characterization is evident. The characters of
lohan lohan are expanded from their French source, and Roister Doister includes
extraneous episodes in which Udall displays his braggart hero. Free characters abound in
Misogonus; as well the play brings dynamic characterization into the scope of comedy with
the conversion of its prodigal son.
Free characters offer new possibilities of non-narrative plotting. In comedies of the
1580s favourite traditional characters appear as diversions outside the action, and thematic
arrangements of characters inform the increasingly complex plots. Lyly stresses the
symbolic potential of characters in Endimion, whereas Greene uses dynamic
characterization to heighten the illusion of independent figures in Friar Bacon and Friar
Bungay. Love's Labour's Lost exposes the limitations of comic artifice by pulling the
characters between convention and individualization.
By the end of the sixteenth century free and dynamic characters had become
common, and characterization had established a sizable claim on the design of English
comedy. These developments set the English form apart from its neoclassical counterparts
Author(s): Ezra Brown and Nicholas Loehr Source
No full textJSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. . Why is PSL(2, 7) = GL(3, 2)? Mathematical Association of America Ezra Brown and Nicholas Loehr 1. INTRODUCTION. The groups of invertible matrices over finite fields are among the first groups we meet in a beginning course in modern algebra. Eventually, we find out about simple groups and that the unique simple group of order 168 has two representations as a group of matrices. And this is where we learn that the group of 2x2 unimodular matrices over a seven-element field, with / and -/ identified, is isomorphic to the group of invertible 3x3 matrices over a 2-element field. In short, it is a fact that PSL(2, 7) = GL(3, 2). Many of us are surprised by this fact: why should a group of 2 x 2 matrices with mod-7 integer entries be isomorphic to a group of 3 x 3 binary matrices? There are a number of proofs of this remarkable theorem. Dickson [1, p. 303] gives a proof based on his general theorem giving uniform sets of generators and relations for the family of groups SL(2, q), where q is any prime power. One checks that the relations appearing in Dickson's presentation of PSL(2, 7) are satisfied by certain generators of GL(3, 2), implying that these groups have the same presentations and are therefore isomorphic. Dummit and Foote [2, show that every simple group of order 168 is necessarily isomorphic to the automorphism group Aut(.F) of the Fano plane T. They then show that Aut(^) = GL(3, 2) and that PSL(2, 7) is a simple group of order 168; the isomorphism theorem follows. Rotman gives the result as an exercise [5, Exercise 9.26, p. 281]. A hint is to begin with a simple group G of order 168 and use the seven conjugates of a Sylow 2-subgroup P of G to construct a sevenpoint projective plane; the proof is similar to Dummit and Foote's proof. Jeurissen [4] proves the result by showing that both PSL(2, 7) and GL(3, 2) are subgroups of index 2 of the automorphism group of a Coxeter graph. Elkies The aim of this paper is to give a proof that PSL(2, 7) = GL(3, 2) that is elementary in the sense that it uses neither simplicity, nor projective geometry, nor block designs. We will not prove the fact that any two simple groups of order 168 are isomorphic, nor will we use this fact in our proof. What makes our proof work is that: (a) we can identify GL(3, 2) with the set of invertible F2-linear transformations on the finite field with eight elements; (b) 7 = 23 -1; (c) the nonzero squares mod 7 are precisely the powers of 2 mod 7; (d) squaring mod 2 is additive (the Freshman's Dream); and (e) the mapping k h+ -i/k mod 7 translates to a bit-switch mod 2 -which is linear. We begin by giving functional descriptions for both groups, determining their sizes
Distributed human computation framework for linked data co-reference resolution
No full textDistributed Human Computation (DHC) is a technique used to solve computational problems by incorporating the collaborative effort of a large number of humans. It is also a solution to AI-complete problems such as natural language processing. The Semantic Web with its root in AI is envisioned to be a decentralised world-wide information space for sharing machine-readable data with minimal integration costs. There are many research problems in the Semantic Web that are considered as AI-complete problems. An example is co-reference resolution, which involves determining whether different URIs refer to the same entity. This is considered to be a significant hurdle to overcome in the realisation of large-scale Semantic Web applications. In this paper, we propose a framework for building a DHC system on top of the Linked Data Cloud to solve various computational problems. To demonstrate the concept, we are focusing on handling the co-reference resolution in the Semantic Web when integrating distributed datasets. The traditional way to solve this problem is to design machine-learning algorithms. However, they are often computationally expensive, error-prone and do not scale. We designed a DHC system named iamResearcher, which solves the scientific publication author identity co-reference problem when integrating distributed bibliographic datasets. In our system, we aggregated 6 million bibliographic data from various publication repositories. Users can sign up to the system to audit and align their own publications, thus solving the co-reference problem in a distributed manner. The aggregated results are published to the Linked Data Cloud
Challenges Associated with Internal Mammary Vessels in Multiple Free Flap Breast Reconstruction
No full textThe 55th Annual Medical Student Research Forum at UT Southwestern Medical Center (Monday, January 17, 2017, 2-5 p.m., D1.600)INTRODUCTION: As breast reconstructive microsurgeons increase their armamentarium of flaps with experience, the need for stacked and multiple flaps may generate an improved aesthetic outcome. Bi-pedicled and stacked flaps have been performed by microsurgeons using the cranial and caudal internal mammary system. We present our experience utilizing this system for flap reliability.
METHOD: 736 flaps for breast reconstruction were performed from 2010-2016 (DIEP/SIEA and PAP flaps) by 2 senior surgeons at a university hospital. 220 (30%) of those flaps were either: Stacked PAP flaps, 4-flap (Bilateral PAP+DIEP flap), or Double-pedicle DIEP/SIEA flaps. Specific data regarding number, type, and locality of anastomosis was analyzed.
RESULTS: 454 anastomosis were performed in 87 patients who underwent 220 flaps. Out of 454 anastomosis, 167 were to Caudal IMA/V (37%), 171 were to Cranial IMA/V (38%), and 116 were intra-flap (25%). There were 0 flap losses in Double-pedicle DIEP group (58-patients, 116-flaps), 3 flap losses in 4-Flap group (23-patients, 92-flaps), and 0 in Stacked-PAP group (6-patients, 12-flaps). In the 3 flap losses of 4-Flap group, 2 flaps were to Caudal IMA/V (1 arterial thrombosis, 1 venous thrombosis), and 1 cranial IMA/V (venous thrombosis). Also, in the 4-Flap group, 3 flaps were salvaged by converting to intra-flap anastomosis due to intraoperative caudal arterial thrombosis. In the Stacked-PAP group, there were 2 flaps salvaged, 1 by converting to intra-flap artery from caudal IMA, and other was venous congestion from caudal IMV pedicle kink seen POD#1. In the Double-pedicle DIEP group, 1 flap was salvaged by converting 1 arterial anastomosis from caudal IMA to intra-flap. Total flap loss rate in entire group was 1.4%. Flap loss avoidance by either conversion to intra-flap anastomosis or early suspicion of caudal system compromise was 2.7%.
CONCLUSION: Caudal IMA/V system remains a viable and safe option for anastomosis in multiple flap procedures. However, based on our large experience with stacked and multiple flaps, we add caution utilizing the caudal system, particularly in patients with radiation, anastomosis mismatch and intraoperative spasm. The enthusiasm towards usage of caudal IMA/V system should be appropriately attenuated in certain circumstances with preference towards intra-flap anastomosis.Southwestern Medical Foundatio
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