Comparison between the performance of conventional and selective RAKE receiver schemes

In this paper, we determine the effects of different diversity schemes on the behavior of a direct-sequence spread-spectrum RAKE receiver that operates with random sequences in a multipath fading channel with an arbitrary power-delay profile. Two different receiver architectures, the former employing the L instantaneously strongest paths out of the N/sub r/ resolved ones and the latter simply the L strongest on average paths out of the received N/sub r/, are confronted in terms of symbol-error probability, when an M-level phase-shift keying system is assumed. The analytical approach devised for assessing such a comparison gives the symbol-error probability in terms of simple elementary integrals and immediately evidences the influence on system behavior of the number of resolved paths, bandwidth occupancy of the signal- and power-delay profiles with a remarkably moderate computational effort.     

Fibrinolytic and coagulation factors in very old subjects: association with lipoprotein profile and anthropometric variables

BACKGROUND: We evaluated plasminogen activator inhibitor-1 (PAI-1), factor VII activity (FVII), and fibrinogen in a sample of octo-nonagenarians. Furthermore, we investigated the relationship of these fibrinolytic and coagulation parameters with lipoprotein profile and anthropometric variables in the absence or presence of disability. METHODS: We enrolled a population of 162 octo-nonagenarians, divided in two groups on the basis of presence or absence of disability in the activity of daily living (ADL). All the anthropometric determinations were carried out according to standardized methods. Blood samples for hemostatic and lipid determinations were collected after overnight fasting and resting. RESULTS: PAI-1 activity and fibrinogen levels were significantly higher in disabled (DIS) compared to free-living (FL) adults, whereas FVII did not show differences in the two groups. PAI-1 activity and FVII positively correlated to anthropometric parameters (body mass index, subscapular and tricipital skinfold thickness) in both DIS and FL. No correlations were found between fibrinogen and other variables in FL, whereas a negative relation with high density lipoprotein-cholesterol levels emerged in DIS. FVII was positively related with total cholesterol low density lipoprotein-cholesterol, and apolipoprotein B in both FL and DIS. CONCLUSIONS: In a sample of octo-nonagenarians, PAI-1 activity and FVII show a significant correlation with several anthropometric and lipoprotein parameters, suggesting that these variables are strongly associated with body composition and lipid metabolism independent from age and disability. DIS presented higher PAI-1 and fibrinogen levels; this observation may take in account the high prevalence of vascular diseases and also occult inflammation, which are known to affect these parameters.     

Evaluation of Different Conditions of Contact for Caprolactam Migration from Multilayer Polyamide Films into Food Simulants

Caprolactam, the polyamide 6 (PA‐6) monomer, can migrate during food processing. At cooking temperatures, migration is accelerated and plastic components could degrade, giving off low molecular mass compounds, which can migrate into food. In this work, caprolactam migration from multilayer films containing PA‐6 for meat foodstuffs and cheese packaging was performed at contact conditions of 40°C/10 days and 100°C/30 min. The migration into water ranged from 0.89 to 1.22 mg/dm² and 0.92 to 1.21 mg/dm², into 3% acetic acid from 1.29 to 1.74 mg/dm² and 1.13 to 1.62 mg/dm² and into olive oil from 1.18 to 1.98 mg/dm² and 0.50 to 0.80 mg/dm² for films intended for meat foodstuffs for 10 days at 40°C and 30 min at 100°C, respectively. Among PA‐6 films used for cheese, caprolactam migration into water ranged from 0.17 to 0.91 mg/dm² and 0.74 to 1.04 mg/dm², into 3% acetic acid from 1.15 to 1.26 mg/dm² and 1.11 to 1.37 mg/dm² and into olive oil from 0.23 to 0.83 mg/dm² and 0.37 to 0.56 mg/dm² for 10 days at 40°C and 30 min at 100°C, respectively. Caprolactam migration evaluation into water and 3% acetic acid at 100°C/30 min could replace the need to apply the test at 40°C/10 days, since similar results were obtained under both conditions. In the case of PA‐6 for meat foodstuffs, caprolactam migration into olive oil was highly affected by different conditions of contact, showing values two to three times higher at 40°C/10 days than at 100°C/30 min. For cheese films, caprolactam migration into olive oil was higher at 40°C for 10 days. Copyright © 2013 John Wiley & Sons, Ltd.     

A single FKS homologue in Yarrowia lipolytica is essential for viability

The synthesis of beta-1,3-glucan, the structural component of the yeast cell wall which gives shape to the cell, occurs at the plasma membrane and is the result of the activity of at least a two-component complex. Fks1p is the catalytic subunit directly responsible for the synthesis of beta-1,3-glucan, whilst the second subunit, Rho1p, has a GTP-dependent regulatory role. FKS1 has been characterized in Saccharomyces cerevisiae, where its function is at least partially redundant with that of FKS2/GSC2. FKS homologues have also been identified in several other fungal species, including Candida albicans, Schizosaccharomyces pombe, Aspergillus nidulans, Cryptococcus neoformans and Paracoccidiodes brasiliensis. In this work, we have used degenerate oligonucleotides derived from the conserved regions of Fks1ps to isolate the possible FKS homologue genes of the strictly aerobic non-conventional yeast Yarrowia lipolytica. Using this approach, we have isolated a single FKS homologue which we have named YlFKS1; this codes a 1961 amino acid protein that shows a high degree of homology with other Fksps. Expression analysis of YlFKS1 under different conditions affecting the cell wall did not reveal significant differences. Finally, attempts to obtain a Y. lipolytica strain containing a disrupted YlFKS1 allele failed, despite having used two different techniques. Taken together, these results suggest that, unlike S. cerevisiae, YlFKS1 is the only FKS1 homologue in Y. lipolytica and is essential for growth.     

Isolation of the MNN9 gene of Yarrowia lipolytica (YlMNN9) and phenotype analysis of a mutant ylmnn9 Delta strain

In this work we describe the isolation of the Yarrowia lipolytica homologue of Saccharomyces cerevisiae MNN9 gene, which we have named YlMNN9, and the phenotype analysis of a Y. lipolytica strain containing the disrupted YlMNN9 allele. YlMNN9 was cloned using degenerate consensus oligonucleotides to generate specific probes that were in turn used to screen mini-gene libraries. The gene is defined by a 1014 bp ORF predicted to encode a protein 337 amino acids long that shares significant homology with the Mnn9ps of S. cerevisiae, Candida albicans and Hansenula polymorpha, including a putative N-terminal transmembrane domain. Disruption of YlMNN9 leads to phenotypes such as resistance to sodium orthovanadate and sensitivity to hygromycin B, compatible with a glycosylation defect, and hypersensitivity to Calcofluor white, Congo red or zymolyase, characteristic of cell wall defects. Analysis of cell wall proteins present in beta-mercaptoethanol and zymolyase extracts showed significant differences between the parental and the ylmnn9 Delta strain. These results suggest that, as has been the case with the mnn9 strain of S. cerevisiae, the ylmnn9 Delta strain we present in this work, could be used to study the cell wall proteins of Y. lipolytica and how they are organized into the cell wall.     

A voltammetric and nanogravimetric study of ZnSe electrodeposition from an acid bath containing Zn(II) and Se(IV)

The negative potential sweep of a polycrystalline Au electrode in a solution containing 5 × 10^− 4 mol L^− 1 SeO₂, 0.2 mol L^− 1 Zn(ClO₄)₂ and 0.5 mol L^− 1 HClO₄ was analyzed at 0.05 V s^− 1. The simultaneously collected voltammetric and nanogravimetric responses allowed to analyze the several electrochemical processes occurring in the studied range of potential, finishing with the formation of a thin film of ZnSe. The association of results obtained using both techniques was applied to identify the species involved in the AuO reduction as (AuO)₂H₂SeO₃, which was desorbed during the oxide reduction with a mass variation much larger than that one observed in the supporting electrolyte. Initially, the Se(IV) reduction results in Se_ads coverage, followed by a further reduction to H₂Se, which is a gas and desorbs from the electrode surface. Finally, the Zn(II) reduction inhibits the H₂Se formation and generates a thin film of ZnSe, as the final coating. The strong dependence of the nature of reacting compound and the mass as well as the charge variations allowed to postulate a reaction mechanism.     

Goodput and delay analysis of a radio link control protocol operating over a multicarrier DS-CDMA architecture

This work proposes an analytical model to investigate the behavior of a radio link control (RLC) protocol on the forward link of a mobile radio system and to relate its performance to transmission design. As a reference case, a multicarrier DS-CDMA architecture employing Walsh and quasi-orthogonal channelization codes, similar to the current cdma2000 system, is considered. Jointly modelling the features of the data link layer and of the underlying physical channels, it is possible to identify the interaction between transmission parameters and the RLC protocol behavior. The latter is assessed by analysis, determining the RLC protocol goodput and the average delivery time suffered by a data unit transferred over the radio channel, when two different coding approaches are adopted: namely, rate compatible punctured convolutional codes and code combining.