Channel Estimation for MIMO MC-CDMA Systems

The concepts of MIMO MC-CDMA are not new but the new technologies to improve their functioning are an emerging area of research. In general, most mobile communication systems transmit bits of information in the radio space to the receiver. The radio channels in mobile radio systems are usually multipath fading channels, which cause inter-symbol interference (ISI) in the received signal. To remove ISI from the signal, there is a need of strong equalizer. In this thesis we have focused on simulating the MIMO MC-CDMA systems in MATLAB and designed the channel estimation for them

Renin inhibition with aliskiren in hypertension: focus on aliskiren/hydrochlorothiazide combination therapy

Hypertension is a major risk factor for the development of cardiovascular and renal disease. The incidence of hypertension is increasing globally and the rate of blood pressure control remains inadequate. Renin-angiotensin-aldosterone system (RAAS) plays a crucial role in volume regulation and maintenance of blood pressure. Pathological activation of RAAS results in chronic hypertension and consequent end organ damage. Most patients with hypertension require combination therapy using agents with complimentary mechanisms of action. Hydrochlorothiazide (HCTZ) together with an agent blocking the RAAS such as an angiotensin converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) are widely used effective anti-hypertensive therapy. Aliskiren is an orally effective direct renin inhibitor that blocks the generation of angiotensin I from angiotensinogen, the rate limiting step of RAAS activation. Studies have shown equivalent antihypertensive efficacy of aliskiren when compared to existing medications such as HCTZ, ACE inhibitors and ARBs. Aliskiren has also been tested in combination therapies. The current review aims to look at the efficacy of aliskiren therapy in hypertension and the evidence for using aliskiren in combination with HCTZ

Evaluation of biosorption potential of Gracilaria corticata for the removal of hexavalent chromium from aqueous solutions using response surface methodology

In this study, the biosorption of chromium (VI) on Gracilaria corticata biomass marine algae, was investigated in a batch and continious system. The influence of process parameters including sorbent size (0.176 - 1.503 mm), sorbent dosage (3 -7 g/l), temperature (25 - 45°C), contact time (2 - 10 hrs) and agitation speed (50 - 250 rpm) on the sorption of chromium (VI) were performed using a full factorial central composite design (CCD). This result of the studies indicates that the optimum biosorption conditions of sorbent size, sorbent dosage, temperature, contact time  and agitation speed were 0.5284 mm, 5.12 g, 35°C , 2 hours 58 minutes and 140 rpm, respectively. A higher value coefficient of determination R2 0.9799 evidenced the fitness of response surface methodology. The Langmuir and Freundlich isotherm models were applied to the equilibrium data. The Langmuir adsorption model was better than the other model. The maximum adsorption capacity of Gracilaria corticata was found to be 62.5 mg/g. The thermodynamic parameters like enthalpy (ΔH◦) and entropy (ΔS◦) were 34.57 (kJ/mol) and 0.1308 (kJ/mol K) respectively. The results showed that the biosorption of chromium (VI) by Gracilaria corticata is more endothermic and spontaneous

Protocol for a randomised controlled trial to evaluate the effectiveness of the 'Care for Stroke' intervention in India: a smartphone-enabled, carer-supported, educational intervention for management of disabilities following stroke.

INTRODUCTION: The rising prevalence of stroke and stroke-related disability witnessed globally over the past decades may cause an overwhelming demand for rehabilitation services. This situation is of concern for low-income and middle-income countries like India where the resources for rehabilitation are often limited. Recently, a smartphone-enabled carer-supported educational intervention for management of physical disabilities following stroke was developed in India. It was found to be feasible and acceptable, but evidence of effectiveness is lacking. Hence, as a step forward, this study intends to evaluate clinical effectiveness of the intervention through a randomised controlled trial. METHODS: The objective of the study is to evaluate whether the 'Care for Stroke' intervention is clinically and cost-effective for the reduction of dependency in activities of daily living among stroke survivors in an Indian setting. This study is designed as a randomised controlled trial comparing people who received the intervention to those receiving standard care. The trial will be pragmatic and outcome assessor-blinded. The primary outcome for the study is dependency in daily living measured by the Modified Rankin Scale (MRS). A total of 266 adult stroke survivors who fulfil the eligibility criteria will be randomised to receive either 'Care for Stroke' intervention or standard treatment and will be followed up for 6 weeks. The main analyses will compare participants allocated to the 'Care for Stroke' intervention versus those allocated to the standard treatment group on an 'intention-to-treat' basis, irrespective of whether the participants received the treatment allocated or not. The dichotomised MRS scores (0-3 and 4-6) in both the groups will be used to calculate the effect estimates with a measure of precision (95% CI) and presented in the results of the trial. ETHICS AND DISSEMINATION: The Indian Institute of Public Health-Hyderabad/Public Health Foundation of India - Independent Institutional Ethics Committee and the Ethics Committee of the London School of HygieneandTropical Medicine. Dissemination will be through peer-reviewed publications. TRIAL REGISTRATION NUMBER: Clinical Trial Registry of India CTRI/2017/07/009014

Comparison of Post Operative Analgesia following Epidural Bupivacaine and Epidural Bupivacaine with Verapamil in Orthopaedic Lower Limb Surgeries

INTRODUCTION: Recent advances in neurosciences have demonstrated that peripheral tissue injury may lead to long alterations in central processing with reduction in threshold, amplification of response, expanded receptive fields and after discharges of dorsal horn neurons. Experimental studies have revealed that the input which are innocuous may also begin to pain. Comparable alterations may also occur in humans following surgical trauma, resulting in amplification and prolongation of postoperative pain. Nociceptive stimulation causes neurotransmitter release which is coupled with activation of voltage-dependent calcium conductance in synaptic terminal membranes of neurons. A disruption of calcium influx into cells interferes with normal sensory processing and contributes to antinociception. Peripheral tissue injury provokes both peripheral and central sensitization. Peripheral sensitization is a reduction in the threshold of nociceptor - afferent peripheral terminals, and central sensitization is an activity - dependent increase in the excitability of spinal neurons. There is considerable evidence that excitatory amino acids and neuropeptides are involved in nociceptive transmission in the dorsal horn of the spinal cord. The actions of excitatory amino acids are mediated by the N-methyl Daspartate (NMDA) receptor and non-NMDA receptors. Activation of NMDA receptors leads to Ca 2+ entry into the cell and initiates a series of central sensitization such as windup and long term potentiation in the spinal cord in the responses of cells to prolonged stimuli. This activation of NMDA receptors is responsible for the induction and the maintenance of enhanced responses for prolonged periods of time. This central sensitization may be prevented not only with NMDA antagonists such as ketamine and dextrometorphan, but also with calcium channel blockers that block Ca2+ entry into cells. This study was therefore designed to evaluate the analgesic efficacy of bupivacaine and verapamil mixture given through lumbar epidural route in patients undergoing elective orthopaedic lower limb surgeries and comparing the quality of analgesia with epidural plain bupivacaine. AIMS AND OBJECTIVES: 1. To evaluate the analgesic efficacy of bupivacaine and verapamil mixture given through lumbar epidural route for postoperative analgesia in patients undergoing elective orthopaedic lower limb surgeries. 2. To compare the quality of analgesia of epidural bupivacaine – verapamil mixture with epidural plain bupivacaine. 3. To evaluate the hemodynamic response of epidural verapamil. MATERIALS AND METHODS: The study population consisted of 40 ASA I & II patients in the age group of 18 years to 65 years admitted to undergo elective orthopaedic lower limb surgeries at Govt. Stanley Hospital, Chennai. After getting approval by the institutional ethics committee and after obtaining written informed consent from each patient the study was conducted. Exclusion Criteria: 1. Age more than 65 yrs, 2. Systemic Hypertension, 3. Ischemic heart disease / Rheumatic heart diseases, 4. Sinus bradycardia / heart blocks/ conduction defects, 5. Patients on Digitalis, calcium channel blockers and β- blockers, 6. Preoperative hypotension, 7. Local infection at lumbar area, 8. Pre-existing neurological disorders, 9. Coagulation defects & patients on anticoagulants, 10. Patient refusal. Preoperative Assessment: All the patients were examined prior to surgery. Routine clinical examination, Biochemical investigations, Electrocardiogram (12 leads) and chest X-ray were examined thoroughly for the conduct of anaesthesia. Conduct of Anaesthesia: Patients were allocated randomly in a double binded fashion into two equal groups (20 in each group). Group P (placebo) received 2 ml of Normal Saline along with the first dose of epidural 0.5% bupivacaine. Group V (Verapamil) received 5 mg (2ml) of injection Verapamil epidurally along with the first dose of 0.5% bupivacaine. No premedication was given. On arrival in the operating room, baseline cardiorespiratory parameters viz., Heart rate (HR), Systolic blood pressure (SBP), Diastolic Blood Pressure (DBP), Mean Arterial Pressure (MAP) and Respiratory rate (RR) were recorded. A good intravenous access was established at the non-operative side forearm of the patient using 18 G IV cannula. Preloading was done with crystalloids (10 ml/kg). With the patient in sitting posture, after informing the procedure to the patient & under strict aseptic precautions, epidural space was identified at L3-L4 or L2 - L3 interspace using 17G Tuohy needle by Loss of Resistance technique. 19G epidural catheter was threaded in a cephalad direction & 3-4 cm catheter length was kept inside the epidural space. A test dose of 3 cc of 1.5% lignocaine with adrenaline (5μg/ml) was given. Epidural catheter was fixed and secured with tapes. Patient turned into decubitus position. STATISTICS AND ANALYSIS: Forty patients posted for orthopaedic lower limb surgeries of ASA I & II were taken up for the study. They were allocated randomly in a double - blinded fashion into two groups in equal number of 20 each. Group P received 2 ml of placebo along with the first dose of epidural 0.5% bupivacaine and group V received 2 ml (5mg) of injection verapamil along with the first dose of epidural 0.5% bupivacaine. A standard anaesthetic technique was followed in all patients. The patients were assessed by the same observer in the postoperative period who was blinded for the group assignment. All the datas were expressed as mean + standard deviation (SD). Qualitative variables were compared with 'chisquare test'. Quantitative variables were compared with the 'student 't' test'. SUMMARY: This randomised double blind study was designed to evaluate the analgesic efficacy of bupivacaine with verapamil mixture given through lumbar epidural route for postoperative analgesia in patients undergoing elective orthopaedic lower limb surgeries and the quality of analgesia was compared with epidural plain bupivacaine. Forty ASA I & II patients undergoing elective orthopaedic lower limb surgical procedure under epidural anaesthesia were randomly allocated in a double blinded fashion to one of the two groups. Group P received 2 ml of normal saline along with first dose of 14 ml 0.5% bupivacaine. Group V received 2 ml (5 mg) of injection verapamil along with the first dose of 14 ml 0.5 % bupivacaine. Pain in the postoperative period was assessed using a verbal rating scale (VRS). Pain score were significantly less in group V at 2, 6, 12, 48 hours (P < 0.05) than in group P. Overall pain score over 48 hours period also revealed better pain relief in group V (P<0.05) as compared to Group P. Time of first rescue analgesic (TFA) and the supplementary analgesic doses required for 48 hours were noted for the two groups. Time of first rescue analgesic (TFA) in group V (6. 42 ±0.63 hours) was significantly prolonged compared with group P (3.84 ± 0.46 hours). The postoperative analgesic consumption was also significantly less in Group V (4.25 doses for 48 hours) than in Group P (6.35 doses for 48 hours). The incidence of hypotension did not differ significantly between the two groups & there was no bradycardia in both the groups. So this study demonstrates that addition of verapamil to bupivacaine definitely improves the quality of analgesia by reducing the over all pain score, prolonging the duration of the time of first rescue analgesia (TFA) and causing reduction of total analgesic consumption in the post operative period without any hemodynamic instability. CONCLUSION: 1. Single dose administration of verapamil and bupivacaine mixture given through lumbar epidural route provides effective postoperative analgesia in patients undergoing elective orthopaedic lower limb surgeries, without any hemodynamic instability. 2. Epidural verapamil significantly reduces the postoperative analgesic consumption

Self-organized metal nanostructures through laser driven thermocapillary convection

When ultrathin metal films are subjected to multiple cycles of rapid melting and resolidification by a ns pulsed laser, spatially correlated interfacial nanostructures can result from a competition among several possible thin film self-organizing processes. Here we investigate self-organization and the ensuing length scales when Co films (1-8 nm thick) on SiO_{\text{2}} surfaces are repeatedly and rapidly melted by non-uniform (interference) laser irradiation. Pattern evolution produces nanowires, which eventually break-up into nanoparticles exhibiting spatial order in the nearest neighbor spacing, \lambda_{NN2}.The scaling behavior is consistent with pattern formation by thermocapillary flow and a Rayleigh-like instability. For h_{0}\leq2 nm, a hydrodynamic instability of a spinodally unstable film leads to the formation of nanoparticles.Comment: 10 pages, 3 figure

Microbial insight into rhizosphere of arecanut palms of Wayanad using metagenomics

The rhizosphere bacterial diversity of a plant is considered to play an essential role in mediating plant as well as soil health. An attempt to explore the bacterial diversity in the rhizosphere of arecanut palms in Wayanad was done to obtain an understanding of dominant bacterial phylotypes and the status of nutrient concentrations in rhizosphere soil and plants. Since arecanut production in Wayanad is facing a decline, a study to understand the rhizosphere conditions of healthy palms essentially provided insight into what strategies needed to be adopted for improvement of arecanut cultivation. The nutrient imbalance involving increased iron in soil and deficiencies of calcium, magnesium, zinc, and boron in the Arecanut rhizosphere was found to be an evident reason for the decline in production. Apart from that, the biological activities in the rhizosphere by the diversity of microorganisms were studied to understand the dominant bacterial phyla and genera present in the Arecanut rhizosphere. The presence of various important bacterial phyla like Proteobacteria, Actinobacteria, Acidobacteria, Firmicutes, and Bacteroidetes revealed the presence of various beneficial soil microorganisms and emphasized the need to enhance or augment the population of native microflora for efficient nutrient cycling by increasing the organic content of the soil. Since organic carbon is an essential requirement to support bacterial diversity, proper management practice that encompasses organic carbon amendment along with proper nutritional management could enhance bacterial diversity as well as health of the arecanut palms. The study indicated that the dominant bacterial phyla contained various beneficial microorganisms that can be exploited for improving nutrient recycling in the arecanut rhizosphere

Development and evaluation of a Smartphone-enabled, caregiver-supported educational intervention for management of physical disabilities following stroke in India: protocol for a formative research study.

The incidence and prevalence of stroke in India has reached epidemic proportions. The growing magnitude of disability in patients with stroke in India poses a major public health challenge. Given the nature of the condition, affected individuals often become disabled with profound effects on their quality of life. The availability of rehabilitation services for people with disabilities is inadequate in India. Rehabilitation services are usually offered by private hospitals located in urban areas and many stroke survivors, especially those who are poor or live in rural areas, cannot afford to pay for, or do not have access to, such services. Thus, identification of cost-effective ways to rehabilitate people with stroke-related disability is an important challenge. Educational interventions in stroke rehabilitation can assist stroke survivors to make informed decisions regarding their on-going treatment and to self-manage their condition with support from their caregivers. Although educational interventions have been shown to improve patient knowledge for self-management of stroke, an optimal format for the intervention has not as yet been established, particularly in low- and middle-income countries. This formative research study aims to systematically develop an educational intervention for management of post-stroke disability for stroke survivors in India, and evaluate the feasibility and acceptability of delivering the intervention using Smartphones and with caregiver support. The research study will be conducted in Chennai, India, and will be organised in three different phases. Phase 1: Development of the intervention. Phase 2: Field testing and finalising the intervention. Phase 3: Piloting of the intervention and assessment of feasibility and acceptability. A mixed-methods approach will be used to develop and evaluate the intervention. If successful, it will help realise the potential of using Smartphone-enabled, carer-supported educational intervention to bridge the gaps in service access for rehabilitation of individuals with stroke-related disability in India. The proposed research will also provide valuable information for clinicians and policymakers

The Shallow-Water Crinoid Fauna of Lakshadweep Atolls, North-Western Indian Ocean

A biodiversity survey carried out from 2016 to 2018 by the Department of Science and Technology in the Lakshadweep Atolls, India, recorded six species of shallow-water feather stars new to the archipelago (Comanthus wahlbergii, Comaster schlegelii, Himerometra robustipinna, Dichrometra palmata, Stephanometra indica, and Phanogenia typica). Himerometra sol A.H. Clark, 1912, previously known only from the Maldive Islands, is synonymized under Himerometra robustipinna (Carpenter, 1881). This study brings the total number of shallow-water crinoids recorded from Lakshadweep to ten species. Of the four species collected previously from the archipelago, only Comatella nigra was found in this survey. Of those not collected, Comatella stelligera and Oligometra serripinna are widespread in the Indo-western Pacific region, whereas Heterometra compta is known only from Lakshadweep, and its validity remains uncertain. The known shallow-water crinoid fauna of the archipelago is substantially less diverse than that of the adjacent and environmentally similar Maldive Islands, emphasizing the need for additional research in this island group, in particular, to determine whether the differences are actual or not, and whether they are based on natural conditions versus anthropogenic impacts