MIMO Radio Frequency Identification: A Brief Survey.

In this paper, we briefly look at the latest state-ot-the-art in the domain of multi-input multi-output (MIMO) radio frequency identification (RFID) systems while detailing the work done in the domain of anti-collision, range enhancements, bit error rate (BER) improvements and security. Various passive ultra-high frequency (UHF) RFID implementations are considered that employ multiple antennas at the reader and single or multiple antennas at each tag. We look at several recent works those explored MIMO for RFID receivers. When using MIMO at the backscatter channel, significant improvements can be achieved in the BER as well as range extension. With the extra reliability and increased throughput, such systems can be deployed in many important applications like large tag reading scenarios and accurate tracking. Increased throughput is directly dependent on estimation of tag quantity in a bulk reading environment and usually estimators designed for single antenna systems under-perform in such settings causing low signal to noise ratio (SNR) when employed in MIMO systems where tag signal overlapping can happen more often. One of the key challenges is to keep the design of the RFID tag simple, cutting cost and power requirement when employing anti-collision schemes. We provide a brief survey in some of the recent developments related to MIMO RFID systems, the protocols and algorithms used, and improvements achieved.

Predictors of in-hospital mortality for intracerebral hemorrhage: a hospital-based study in Pakistani adults.

INTRODUCTION: Intracerebral hemorrhages (ICHs) comprise 5% to 30% of all strokes with a case fatality rate of 30% to 50%. With an increasing elderly population, nontraumatic ICH is likely to present as a recurring medical emergency in Pakistan. There is scarce documentation in Pakistan regarding the predictors for mortality in patients with ICH that can guide physicians in their management. We conducted a hospital-based study to determine the predictors of in-hospital mortality from ICH in patients admitted to a tertiary care facility. MATERIALS AND METHODS: We reviewed case records of patients above 17 years admitted to The Aga Khan University Hospital, Karachi, Pakistan, between July 1995 and December 1997, with the primary diagnosis of ICH confirmed on computed tomography scanning. Clinical and risk factors were also evaluated. RESULTS: The data of 221 patients was analyzed. Seventy-one (32%) patients died during hospital stay, half of whom died during the first 2 days of hospitalization. Patients who died during hospital stay were more likely on admission to have intraventricular extension of the primary hemorrhage (odds ratio = 10.6, P < .01), a Glasgow Coma Score less than 12 on admission (odds ratio = 4.8, P < .01), and a systolic blood pressure greater than or equal to 180 mm Hg (odds ratio = 2.7, P = .03). CONCLUSIONS: Our study suggests that Glasgow Coma Score and intraventricular extension are predictors of acute mortality, consistent with published results. Elevated systolic blood pressure at admission, also found to be a predictor of acute mortality from ICH, may be explained alternatively by internal and external stroke-induced stress factors. The actual mechanisms for high admission systolic blood pressure remain unclear.

Immunohistochemical localization of adenylyl cyclase isoforms in the lateral wall of the rat cochlea.

The enzymatic activity of adenylyl cyclase (AC) is attributable to nine isoforms with individual pharmacology and tissue distribution. Polyclonal antibodies for AC isoforms I-IV, VII and VIII were applied to sections of cochlear lateral wall, a tissue involved in ion transport contributing to the unique ion content of endolymph and electrical potential of scala media. Within the stria vascularis, immunoreactivity primarily to Ca(2+)/calmodulin-independent isoforms II, IV and VII was localized to sites consistent in position to the basolateral extensions of marginal cells. Little immunoreactivity was observed in the stria vascularis for Ca(2+)/calmodulin-dependent isoforms I, III and VIII. Within the spiral ligament, type II and type IV fibrocytes exhibited moderate staining for ACII, IV and VII, less staining for VIII and little for I and III. Immunoreactivity to ACII, IV, VII and VIII was observed in type I fibrocytes. The outer sulcus cells and root processes were highly immunoreactive for isoforms I and VIII, but not for III or the Ca(2+)/calmodulin-independent isoforms. The differential pattern of immunoreactivity in the lateral wall overall appears to reflect subfamily-specific expression with Ca(2+)/calmodulin-independent isoforms expressed in the stria vascularis and Ca(2+)/calmodulin-dependent isoforms expressed in the outer sulcus cells and root processes. cAMP-mediated modulation of ion transport by marginal cells is predicted to exhibit, in the microenvironment of basolateral membrane infoldings, pharmacological characteristics of the AC type II subfamily (II, IV and VII), including activation by protein kinase C (II and VII).

Expression of adenylyl cyclase type I in cochlear inner hair cells.

Expression of calcium/calmodulin-activated adenylyl cyclase type I (ACI) mRNA has been determined in the cochlea and in an organ-of-Corti subdissected tissue fraction by reverse transcriptase-polymerase chain reaction (RT-PCR) analysis. Amplification products of predicted size were obtained from the mouse cochlea and rat organ of Corti with nucleotide sequences corresponding to respective ACI brain transcripts. In addition, ACI template was detected in a rat inner hair cell cDNA library by PCR. Immunoreactivity to ACI has been localized within the organ of Corti to the inner hair cell, with diaminobenzidine staining found in both the cell body and in the stereocilia. Evidence, thus, has been obtained that both ACI transcript and protein are expressed in the inner hair cell, the primary mechanosensory receptor cell of the cochlea. We hypothesize that ACI is activated by calcium influx through a calcium/calmodulin interaction and that this adenytyl cyclase isoform may have a role in modulation of receptoneural afferent transmission and/or mechanosensory transduction in the cochlea.

Some simple methods of home processing and their implication with weaning foods.

One of the most practical solutions to combat protein energy malnutrition (PEM) in low income groups is the intelligent mixing of cereals and legumes to make available low cost weaning foods of high nutritional quality. One of the main obstacles to increase energy and nutrient density of weaning foods of cereals and legumes is the bulk factor. In this study some simple methods of home processing to improve the nutritional quality of the home prepared weaning foods were tested and the processed weaning foods were chemically and biologically evaluated. Biochemical evaluation revealed that the germination of wheat raised its protein and fat and reduced carbohydrate, while ther was almost no change on lentils. Comparing germination with a special "chapati" process, protein and fat content wee higher in the formula processed by the former method, while minerals were higher in the same formula but processed by the latter method. Biological evaluation of the formula processed by the two different methods showed that germination got the highest PER and NPU compared with chapati process figures were (2.02 and 81.0) and (1.70 and 40.0) respectively. Although further research is needed, germination of ingredients of weaning foods of vegetable origin seems to be a good option of the simple home processing technique.