51,983 research outputs found
Tunable Brownian Vortex at the Interface
A general kind of Brownian vortexes are demonstrated by applying an external
nonconservative force field to a colloidal particle bound by a conservative
optical trapping force at a liquid-air interface. As the liquid medium is
translated at a constant velocity with the bead trapped at the interface, the
drag force near the surface provide enough rotational component to bias the
particle's thermal fluctuations in a circulatory motion. The interplay between
the thermal fluctuations and the advection of the bead in constituting the
vortex motions is studied, inferring that the angular velocity of the
circulatory motion offers a comparative measure of the interface fluctuations.Comment: Accepted for publication in Phys. Rev.
On Energy Efficiency and Delay Minimization in Reactive Protocols in Wireless Multi-hop Networks
In Wireless Multi-hop Networks (WMhNs), routing protocols with energy
efficient and delay reduction techniques are needed to fulfill users demands.
In this paper, we present Linear Programming models (LP_models) to assess and
enhance reactive routing protocols. To practically examine constraints of
respective LP_models over reactive protocols, we select AODV, DSR and DYMO. It
is deduced from analytical simulations of LP_models in MATLAB that quick route
repair reduces routing latency and optimizations of retransmission attempts
results efficient energy utilization. To provide quick repair, we enhance AODV
and DSR. To practically examine the efficiency of enhanced protocols in
different scenarios of WMhNs, we conduct simulations using NS- 2. From
simulation results, enhanced DSR and AODV achieve efficient output by
optimizing routing latencies and routing load in terms of retransmission
attempts
Beliefs and Attitudes of Medical Students from Public and Private Universities in Malaysia towards Individuals with HIV/AIDS
We describe the findings from a survey assessing the beliefs regarding testing, confidentiality, disclosure, and environment of care and attitudes towards care of people with HIV/AIDS (PLHWA), in 1020, 4th and 5th year medical students, from public and private medical universities in Malaysia. A self-administered validated questionnaire based on the UNAIDS Model Questionnaire with a 5-point Likert scale (5, strongly disagree; 4, disagree; 3, neutral; 2, agree; 1, strongly agree) was used as a survey tool. The survey included demographic data and data on undergraduate training received on HIV/AIDS. Statistical significance in the demographic data and training received by respondents was evaluated using the chi-square test while the independent Student's t-test was used for comparison of means between public and private universities. A P value of <0.05 was considered statistically significant with 95% confidence interval. Our study revealed less than 20% of medical students received adequate training to care for PLHWA. They had prevalent negative beliefs regarding testing, confidentiality, disclosure and environment of care towards PLHWA although in giving care to PLHWA, their attitudes were largely positive and nondiscriminatory.Article Link:
http://www.hindawi.com/journals/tswj/2013/462826
Optical tweezer for probing erythrocyte membrane deformability
We report that the average rotation speed of optically trapped crenated
erythrocytes is direct signature of their membrane deformability. When placed
in hypertonic buffer, discocytic erythrocytes are subjected to crenation. The
deformation of cells brings in chirality and asymmetry in shape that make them
rotate under the scattering force of a linearly polarized optical trap. A
change in the deformability of the erythrocytes, due to any internal or
environmental factor, affects the rotation speed of the trapped crenated cells.
Here we show how the increment in erythrocyte membrane rigidity with adsorption
of ions can be exhibited through this approach.Comment: Published in Appl. Phys. Lett. 95, 233703 (2009); Two supplementary
multimedia files are available at the journal page:
http://link.aip.org/mm/APPLAB/1.3272269/083949aplv1.mov and
http://link.aip.org/mm/APPLAB/1.3272269/083949aplv2.mo
On using Multiple Quality Link Metrics with Destination Sequenced Distance Vector Protocol for Wireless Multi-Hop Networks
In this paper, we compare and analyze performance of five quality link
metrics forWireless Multi-hop Networks (WMhNs). The metrics are based on loss
probability measurements; ETX, ETT, InvETX, ML and MD, in a distance vector
routing protocol; DSDV. Among these selected metrics, we have implemented ML,
MD, InvETX and ETT in DSDV which are previously implemented with different
protocols; ML, MD, InvETX are implemented with OLSR, while ETT is implemented
in MR-LQSR. For our comparison, we have selected Throughput, Normalized Routing
Load (NRL) and End-to-End Delay (E2ED) as performance parameters. Finally, we
deduce that InvETX due to low computational burden and link asymmetry
measurement outperforms among all metrics
HEER: Hybrid Energy Efficient Reactive Protocol for Wireless Sensor Networks
Wireless Sensor Networks (WSNs) consist of numerous sensors which send sensed
data to base station. Energy conservation is an important issue for sensor
nodes as they have limited power.Many routing protocols have been proposed
earlier for energy efficiency of both homogeneous and heterogeneous
environments. We can prolong our stability and network lifetime by reducing our
energy consumption. In this research paper, we propose a protocol designed for
the characteristics of a reactive homogeneous WSNs, HEER (Hybrid Energy
Efficient Reactive) protocol. In HEER, Cluster Head(CH) selection is based on
the ratio of residual energy of node and average energy of network. Moreover,
to conserve more energy, we introduce Hard Threshold (HT) and Soft Threshold
(ST). Finally, simulations show that our protocol has not only prolonged the
network lifetime but also significantly increased stability period.Comment: 2nd IEEE Saudi International Electronics, Communications and
Photonics Conference (SIECPC 13), 2013, Riyadh, Saudi Arabi
Client Satisfaction Towards Quality of Health Services: an Assessment at Primary Healthcare of District Gujranwala
This survey designed to evaluate the satisfaction level and the factors that affect the patient satisfaction regarding health care delivery services with the aim to improve the services in the primary health care settings of Gujranwala. A Cross Sectional Study done on randomly selected patients attending the basic health units of Gujranwala, with more than18 years of age. Pretested structured "Liker scale questionnaire" was used for data collection. Out of total respondents, 62 (41.3%) clients were satisfied with the services provided by the basic health units of Gujranwala. The factors identified to determine patient satisfaction were accessibility of services, behavior of staff, health education, level of cleanliness, drug availability and miscellaneous services. Not a single ranked area of satisfaction noticed. Client\u27s occupation and income had significant relationship with the patient satisfaction level. Gender, age, and education of clients were not contributing factors; they not affect the client satisfaction level.Less than half clients were satisfied with the services provided by the basic health units. Management of health facilities needs to improve the services
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