ahmed khalid - Academia.edu (original) (raw)

Papers by ahmed khalid

The Journal of Nutrition, 2013

We showed previously that dietary supplementation with oil from the marine zooplankton Calanus fi... more We showed previously that dietary supplementation with oil from the marine zooplankton Calanus finmarchicus (Calanus oil) attenuates obesity, inflammation, and glucose intolerance in mice. More than 80% of Calanus oil consists of wax esters, i.e., long-chain fatty alcohols linked to long-chain fatty acids. In the present study, we compared the metabolic effects of Calanus oil-derived wax esters (WE) with those of purified eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA) ethyl esters (E/D) in a mouse model of diet-induced obesity. C57BL/6J mice received a high-fat diet (HFD; 45% energy from fat). After 7 wk, the diet was supplemented with either 1% (wt:wt) WE or 0.2% (wt:wt) E/D. The amount of EPA + DHA in the E/D diet was matched to the total amount of n-3 (v-3) polyunsaturated fatty acids (PUFAs) in the WE diet. A third group was given an unsupplemented HFD throughout the entire 27-wk feeding period. WE reduced body weight gain, abdominal fat, and liver triacylglycerol by 21%, 34%, and 52%, respectively, and significantly improved glucose tolerance and aerobic capacity. In abdominal fat depots, WE reduced macrophage infiltration by 74% and downregulated expression of proinflammatory genes (tumor necrosis factor-a, interleukin-6, and monocyte chemoattractant protein-1), whereas adiponectin expression was significantly upregulated. By comparison, E/D primarily suppressed the expression of proinflammatory genes but had less influence on glucose tolerance than WE. E/D affected obesity parameters, aerobic capacity, or adiponectin expression by <10%. These results show that the wax ester component of Calanus oil can account for the biologic effects shown previously for the crude oil. However, these effects cannot exclusively be ascribed to the content of n-3 PUFAs in the wax ester fraction.

British Journal of Nutrition, 2013

The aim of the present study was to investigate the effects of oil extracted from the zooplankton... more The aim of the present study was to investigate the effects of oil extracted from the zooplanktonCalanus finmarchicus(Calanus oil) on diet-induced obesity and obesity-related disorders in mice. C57BL/6J mice fed a high-fat diet (HFD, 45 % energy from fat) exhibited increased body weight and abdominal fat accumulation as well as impaired glucose tolerance compared with mice fed a normal chow diet (10 % energy from fat). Supplementing the HFD with 1·5 % (w/w) Calanus oil reduced body-weight gain, abdominal fat accumulation and hepatic steatosis by 16, 27 and 41 %, respectively, and improved glucose tolerance by 16 %. Calanus oil supplementation reduced adipocyte size and increased the mRNA expression of adiponectin in adipose tissue. It also reduced macrophage infiltration by more than 70 %, accompanied by reduced mRNA expression of pro-inflammatory cytokines (TNF-α, IL-6 and monocyte chemotactic protein-1). The effects of Calanus oil were not only preventive, but also therapeutic, as...

Journal of Molecular and Cellular Cardiology, 2008

Fenofibrate modulates cardiac and hepatic metabolism and increases ischemic tolerance in diet-ind... more Fenofibrate modulates cardiac and hepatic metabolism and increases ischemic tolerance in diet-induced obese mice.

Journal of Applied Physiology, 2011

Aims: although exercise training induces hypertrophy with improved contractile function, the effe... more Aims: although exercise training induces hypertrophy with improved contractile function, the effect of exercise on myocardial substrate metabolism and cardiac efficiency is less clear. High intensity training has been shown to produce more profound effects on cardiovascular function and aerobic capacity than isocaloric low and moderate intensity training. The aim of the present study was to explore metabolic and mechanoenergetic changes in the heart following endurance exercise training of both high and moderate intensity. Methods and Results: C57BL/6J mice were subjected to 10 wk treadmill running, either high intensity interval training (HIT) or distance-matched moderate intensity training (MIT), where HIT led to a pronounced increase in maximal oxygen uptake. Although both modes of exercise were associated with a 10% increase in heart weight-to-body weight ratio, only HIT altered cardiac substrate utilization, as revealed by a 36% increase in glucose oxidation and a concomitant r...

Cardiovascular Research, 2009

Time for primary review: 21 days Aims Myocardial fatty acid (FA) oxidation is regulated acutely b... more Time for primary review: 21 days Aims Myocardial fatty acid (FA) oxidation is regulated acutely by the FA supply and chronically at the transcriptional level owing to FA activation of peroxisome proliferator-activated receptor-a (PPARa). However, in vivo administration of PPARa ligands has not been shown to increase cardiac FA oxidation. In this study we have examined the cardiac response to in vivo administration of tetradecylthioacetic acid (TTA, 0.5% w/w added to the diet for 8 days), a PPAR agonist with primarily PPARa activity. Methods and results Despite the fact that TTA treatment decreased plasma concentrations of lipids [FA and triacylglycerols (TG)], hearts from TTA-treated mice showed increased mRNA expression of PPARa target genes. Cardiac substrate utilization, ventricular function, cardiac efficiency, and susceptibility to ischaemia-reperfusion were examined in isolated perfused hearts. In accordance with the mRNA changes, myocardial FA oxidation was increased 2.5-fold with a concomitant reduction in glucose oxidation. This increase in FA oxidation was abolished in PPARa-null mice. Thus, it appears that the metabolic effects of TTA on the heart must be owing to a direct stimulatory effect on cardiac PPARa. Hearts from TTA-treated mice also showed a marked reduction in cardiac efficiency (because of a twofold increase in unloaded myocardial oxygen consumption) and decreased recovery of ventricular contractile function following low-flow ischaemia. Conclusion This study for the first time observed that in vivo administration of a synthetic PPARa ligand elevated FA oxidation, an effect that was also associated with decreased cardiac efficiency and reduced post-ischaemic functional recovery.

American Journal of Physiology-Heart and Circulatory Physiology, 2011

Tetradecylthioacetic acid (TTA) is a novel peroxisome proliferator-activated receptor (PPAR) liga... more Tetradecylthioacetic acid (TTA) is a novel peroxisome proliferator-activated receptor (PPAR) ligand with marked hypolipidemic and insulin-sensitizing effects in obese models. TTA has recently been shown to attenuate dyslipidemia in patients with type 2 diabetes, corroborating the potential for TTA in antidiabetic therapy. In a recent study on normal mice, we showed that TTA increased myocardial fatty acid (FA) oxidation, which was associated with decreased cardiac efficiency and impaired postischemic functional recovery. The aim of the present study was, therefore, to elucidate the effects of TTA treatment (0.5%, 8 days) on cardiac metabolism and function in a hyperlipidemic type 2 diabetic model. We found that TTA treatment increased myocardial FA oxidation, not only in nondiabetic ( db/+) mice but also in diabetic ( db/db) mice, despite a clear lipid-lowering effect. Although TTA had deleterious effects in hearts from nondiabetic mice (decreased efficiency and impaired mitochondri...

American Journal of Physiology-Endocrinology and Metabolism, 2007

Hearts from type 2 diabetic ( db/ db) mice demonstrate altered substrate utilization with high ra... more Hearts from type 2 diabetic ( db/ db) mice demonstrate altered substrate utilization with high rates of fatty acid oxidation, decreased functional recovery following ischemia, and reduced cardiac efficiency. Although db/ db mice show overall insulin resistance in vivo, we recently reported that insulin induces a marked shift toward glucose oxidation in isolated perfused db/ db hearts. We hypothesize that such a shift in metabolism should improve cardiac efficiency and consequently increase functional recovery following low-flow ischemia. Hearts from db/ db and nondiabetic ( db/+) mice were perfused with 0.7 mM palmitate plus either 5 mM glucose (G), 5 mM glucose and 300 μU/ml insulin (GI), or 33 mM glucose and 900 μU/ml insulin (HGHI). Substrate oxidation and postischemic recovery were only moderately affected by GI and HGHI in db/+ hearts. In contrast, GI and particularly HGHI markedly increased glucose oxidation and improved postischemic functional recovery in db/ db hearts. Cardi...

International Journal of Computer Science and Application, 2015

Feature Selection is a very important step that select a few number of feature used for the class... more Feature Selection is a very important step that select a few number of feature used for the classification in order to reduce execution time, to improve accuracy and to enhance performance of the identification system. In this paper we propose new feature selection methods by combining between relief, mutual information and sequential selection. The new approach is compared with other existing and we demonstrate some improvement when they are applied to a random dataset and on real data acquired from wind turbine bearings aiming to detect fault in the turbine using vibration signal.

Journal of Taibah University Medical Sciences, 2021

The Professional Medical Journal, 2021

Objective: To know the association between different anthropometric parameters for overweight and... more Objective: To know the association between different anthropometric parameters for overweight and obese individuals to prevalence of prehypertension. Study Design: Correlational study. Setting: Vicinity of Kharian and at Outpatient Department, CMH Kharian Cantt. Period: February 2019 and January 2020. Material & Methods: Correlational study carried out in the vicinity of Kharian by employing different anthropometric measurements in accordance with guidelines to look at how blood pressure figure behaves in overweight, obese and morbidly obese population and further is there a difference in overall outcome if we use waist circumference rather than BMI and its significance in targeting preventive strategies. Results: Our results show a staircase pattern of increase in blood pressure, initially lying in different phases of prehypertension among normal weight (BMI 23±1.65; waist circumference (WC): 86.45±8.78; Systolic BP:127±11.99; Diastolic BP:80.44 ±9.45), overweight (BMI 27.35 ±1.23;...

2005 IEEE International Conference on Microelectronic Systems Education (MSE'05)

We present the design and use of McGumps laboratory kit for teaching microprocessor and embedded ... more We present the design and use of McGumps laboratory kit for teaching microprocessor and embedded systems. The kit facilitates efficient learning of relevant hardware and software design techniques that will not get outdated soon. We describe the typical use of this kit in our courses.

48th Midwest Symposium on Circuits and Systems, 2005., 2005

In this paper, we describe a wireless system infrastructure made for data collection and sharing ... more In this paper, we describe a wireless system infrastructure made for data collection and sharing during educational and business conferences. The system is designed to be flexible and rapidly reprogrammable, while keeping low-power and low-cost as the primary design objectives. The system comprises of three distinct components-embedded nodes with user interface, network coordination and routing unit, as well as the WWW and database subsystem. The hardware and the software were designed to be modular and expandable. Our Wireless Conference Manager-WCM has already been deployed at two high-profile IEEE 1 international conferences. Testing and verification results collected at these events demonstrate its suitability as well as expendability for new requirements and applications.

International Journal of Advanced Computer Science and Applications, 2014

Classification is one of the most frequently encountered problems in data mining. A classificatio... more Classification is one of the most frequently encountered problems in data mining. A classification problem occurs when an object needs to be assigned in predefined classes based on a number of observed attributes related to that object. Neural networks have emerged as one of the tools that can handle the classification problem. Feed-forward Neural Networks (FNN's) have been widely applied in many different fields as a classification tool. Designing an efficient FNN structure with optimum number of hidden layers and minimum number of layer's neurons, given a specific application or dataset, is an open research problem. In this paper, experimental work is carried out to determine an efficient FNN structure, that is, a structure with the minimum number of hidden layer's neurons for classifying the Wisconsin Breast Cancer Dataset. We achieve this by measuring the classification performance using the Mean Square Error (MSE) and controlling the number of hidden layers, and the number of neurons in each layer. The experimental results show that the number of hidden layers has a significant effect on the classification performance and the best classification performance average is attained when the number of layers is 5, and number of hidden layer's neurons are small, typically 1 or 2.

2017 20th Conference on Innovations in Clouds, Internet and Networks (ICIN), 2017

In this demonstration we present MiniNAM, a utility that provides real-time animation of networks... more In this demonstration we present MiniNAM, a utility that provides real-time animation of networks created by the Mininet emulator. Mininet is one of the most well-known network emulators in research and academia. Although Mininet is capable of emulating both traditional and software-defined networks, it does not provide a tool to visually observe and monitor the packets flowing over the created network topology. Our utility includes all the components required to initiate, visualize and modify Mininet network flows in real-time. MiniNAM provides a graphical user interface that allows dynamic modification of preferences and packet filters: a user can view selective flows with options to color code packets based on packet type and/or source node. This establishes MiniNAM as a very powerful tool for debugging network protocols or teaching, learning and understanding network concepts. This demonstration illustrates a number of sample use cases and examples of using MiniNAM to create networks and view the generated network flows with customized preferences.

IEEE International Conference on Computer Design: VLSI in Computers and Processors, 2004. ICCD 2004. Proceedings.

A thesis submitted to McGill University in partial fulfilment of the requirements of the degree o... more A thesis submitted to McGill University in partial fulfilment of the requirements of the degree of Master of Engineering.

It is well understood that bond markets play an important role in the development of the overall ... more It is well understood that bond markets play an important role in the development of the overall financial sector. Bond markets also help to make efficient investment and financing decisions, to improve efficiency in the design and implementation of monetary ...

International Journal of Infectious Diseases, 2011

BMC Cancer, 2007

Background Quality of life (QOL) issues are of interest in cancer because effective methods of tr... more Background Quality of life (QOL) issues are of interest in cancer because effective methods of treatment and detection have led to an increase in the number of long-term survivors. The objectives of the study were: to assess the subjective QOL of stable Sudanese women cancer outpatients and their family caregivers, using the WHO 26-item QOL Instrument; compare with matched general population groups, as well as diabetic and psychiatric patient groups; examine patient-caregiver concordance in ratings; and assess the variables associated with their QOL, with a view to identifying factors that can enhance quality of care. Methods Responses of oncology outpatients with breast cancer (117), cervical cancer (46) and ovarian cancer (18) (aged 44.6, SD 11.5) were compared with those of their family caregivers and matched general population groups. Data were analyzed by univariate and multivariate statistics. Results The cancer groups had similar QOL domain scores, which were significantly lo...