6,244 research outputs found
First person – Ahmed Elbediwy
No full textFirst Person is a series of interviews with the first authors of a selection of papers published in Journal of Cell Science, helping early-career researchers promote themselves alongside their papers. Ahmed Elbediwy is the first author on ‘Enigma proteins regulate YAP mechanotransduction’, published in Journal of Cell Science. Ahmed is a postdoctoral fellow in the lab of Barry Thompson at The Francis Crick Institute, London, UK, investigating the cytoskeleton, RhoGTPases and the regulation of YAP/TAZ oncoproteins
Author Checklist - Full - Ahmed Essa_ 135540.pdf
No full textAttached is a required author checklist for animal research </p
The role of bone marrow derived cells in cardiac repair
No full textPhDCurrent pharmacological therapies fail to address the final end-point of cardiac
ischaemia — the death and dysfunction of cardiomyocytes. Advances in stem
cell biology have provided hope, for the first time, of addressing this underlying
pathology. The work performed here was designed to further understanding
of the mechanisms by which bone marrow derived cells improve damaged myocardium.
In situ hybridisation was used to detect sex chromosomes within ex-planted,
human, sex-mismatch hearts. Host derived cells were found at low frequency in
donor hearts, suggesting ongoing post-natal cardiac tissue repair.
Human mesenchymal stem cells were examined in vitro and in a rat model
of ischaemia-reperfusion injury. Cardiomyocytes were not formed when cultured
with either 5-azacytidine or ascorbic acid, and the cells failed to home to the ischaemic
heart or improve cardiac function.
In the same model, rat mononuclear cells significantly reduced infarct size
when administered immediately upon reperfusion. Cells were rarely identified
within the myocardium. No functional improvement was seen acutely, but at
seven days cardiac function had improved. The low frequency of cells retained
in the heart suggested that a process other than transdifferentiation accounted
for the observations.
Hence, evidence for paracrine actions was sought. In the same model, apoptosis
and necrosis in cardiomyocytes were found to be significantly reduced.
Western blots demonstrated activation of the reperfusion salvage kinase pathway,
analogous to that seen in ischaemic pre- and post-conditioning. Blocking
this pathway abolished the infarct size reduction. Global proteomic analysis confirmed
alterations in protein expression consistent with known cardioprotective
pathways.
In conclusion, endogenous myocardial repair processes are inadequate to
compensate for pathological insults. Supplementation with mononuclear cells in
an ischaemia-reperfusion model produced significant benefit to infarct size and
cardiac function. The mechanism of benefit appears to be induced by paracrine
effects activating pro-survival pathways.British Heart Foundatio
Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC)
No full textDegenerative and traumatic articular cartilage defects are common, difficult to treat, and progressive lesions that cause significant morbidity in the general population. There have been multiple approaches to treat such lesions, including arthroscopic debridement, microfracture, multiple drilling, osteochondral transplantation and autologous chondrocyte implantation (ACI) that are currently being used in clinical practice. Autologous bone-marrow mesenchymal cell induced chondrogenesis (MCIC) is a single-staged arthroscopic procedure. This method combines a modified microfracture technique with theapplication of a bone marrow aspirate concentrate (BMAC), hyaluronic acid and fibrin gel to treat articular cartilage defects. We reviewed the current literatures and surgical techniques for mesenchymal cell induced chondrogenesis
Impaired bone marrow homing of cytokine-activated CD34<sup>+</sup> cells in the NOD/SCID model
No full textThe reduced engraftment potential of hematopoietic stem/progenitor cells (HSPCs) after exposure to cytokines may be related to the impaired homing ability of actively cycling cells. We tested this hypothesis by quantifying the short-term horning of human adult CD34+ cells in nonobese diabetic/severe combined immunodeficient (NOD/SCID) animals. We show that the loss of engraftment ability of cytokine-activated CD34+ cells is associated with a reduction in homing of colony-forming cells (CFCs) to bone marrow (BM) at 24 hours after transplantation (from median 2.8% [range, 1.9%-6.1%] to 0.3% [0.0%-0.7%]; n = 3; P < .01), coincident with an increase in CFC accumulation in the lungs (P < .01). Impaired BM homing of cytokine-activated cells was not restored by using sorted cells in G 0G1 or by inducing cell cycle arrest at the G 1/S border. Blocking Fas ligation in vivo did not increase the BM homing of cultured cells. Finally, we tested cytokine combinations or culture conditions previously reported to restore the engraftment of cultured cells but did not find that any of these was able to reverse the changes in homing behavior of cytokine-exposed cells. We suggest that these changes in homing and, as a consequence, engraftment result from the increased migratory capacity of infused activated cells, leading to the loss of selectivity of the homing process. © 2004 by The American Society of Hematology
Abul Mansur Ahmed Research Essay 2023
No full textThis is a research essay submitted to the 'Abul Mansur Ahmed Smriti Parishad' in 2023 for primary selection for publication, however, in the end, it was decided by the author not to publish it in the local publisher's policy. Thus the author holds the sole copyright of this article and possesses intellectual property of the work and wishes to publish it in future in reputable platforms.An Intellectual Work on Abul Mansur Ahmed produced by Naywaz Shari
The three blind men and the elephant. In search of a holistic view of Somalia. A comment to Ahmed I. Samatar
No full textIn this article, the author comments on Ahmed I. Samatar contribution on main perspectives gleaned from books and articles by Somali scholars published in the recent years.Qoraagu wuxuu maqaalkaan kaga faalloonayaa shirweynihi Axmed I. Samatar, oo la xiriiray waxyaabaha ugu doorka roon ee laga filayo in ay ka soo baxaan qoraalladii ay soo saareen aqoonyahannada Soomaaliyeed sannadaahan dambe.In questo articolo, l'autore commenta l'intervento al congresso di Ahmed I. Samatar relativo alle principali prospettive che emergono dai lavori pubblicati negli ultimi anni da studiosi somali.M.S. Lilius (ed.
Interview with Ahmed al-Dajani
No full textفي هذه المقابلة، يتحدث الدكتور أحمد الدجاني، المفكر الفلسطيني، عن الفصائل الفلسطينية. أجرت المقابلة إيمان رافع.In this interview, Ahmed al-Dajani, a Palestinian author, speaks about Palestinian factions. The interview was conducted by Iman Rafi
Simultaneous Twin Kernel Learning Using Polynomial Transformations for Structured Prediction
No full textMany learning problems in computer vision can be posed as structured prediction problems, where the input and output instances are structured objects such as trees, graphs or strings rather than, single labels {+1, −1} or scalars. Kernel methods such as Structured Support Vector Machines , Twin Gaussian Processes (TGP), Structured Gaussian Processes, and vector-valued Reproducing Kernel Hilbert Spaces (RKHS), offer powerful ways to perform learning and inference over these domains. Positive definite kernel functions allow us to quantitatively capture similarity between a pair of instances over these arbitrary domains. A poor choice of the kernel function, which decides the RKHS feature space, often results in poor performance. Automatic kernel selection methods have been developed, but have focused only on kernels on the input domain (i.e.’one-way’). In this work, we propose a novel and efficient algorithm for learning kernel functions simultaneously, on both input and output domains. We introduce the idea of learning polynomial kernel transformations, and call this method Simultaneous Twin Kernel Learning (STKL). STKL can learn arbitrary, but continuous kernel functions, including ’one-way’ kernel learning as a special case. We formulate this problem for learning covariances kernels of Twin Gaussian Processes. Our experimental evaluation using learned kernels on synthetic and several real-world datasets demonstrate consistent improvement in performance of TGP’s.Peer reviewe
Interview with Nemat Ahmed Fouad
No full textمقابلة مع الكاتبة المصرية نعمت أحمد فؤاد عن تطورها المهني والذي تراوح بين موقعها القيادي في المجلس الأعلى للفنون وأعمالها وترجماتها العديدة. كما تتحدث عن عملها وأفكارها في حركة الكتابة النسائية المصرية وتحدثت عن تأثير مرشديها ولا سيما الدكتور احمد حسن الزيات. قامت بالمقابلة أمال سعيد.An interview with Egyptian author Nemat Ahmed Fouad about her professional progression, her leadership position in the Supreme Council of Arts, her works in and thoughts on the Egyptian women's writing movement, and the influence of her mentors, notably Dr. Ahmed Hassan Al-Zayat. The interview was conducted by Amal Saeed
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