Low-Cost and High-Reduction Approaches for Power Droop during Launch-On-Shift Scan-Based Logic BIST

During at-speed test of high performance sequential ICs using scan-based Logic BIST, the IC activity factor (AF) induced by the applied test vectors is significantly higher than that experienced during its in field operation. Consequently, power droop (PD) may take place during both shift and capture phases, which will slow down the circuit under test (CUT) signal transitions. At capture, this phenomenon is likely to be erroneously recognized as due to delay faults. As a result, a false test fail may be generated, with consequent increase in yield loss. In this paper, we propose two approaches to reduce the PD generated at capture during at-speed test of sequential circuits with scan-based Logic BIST using the Launch-On-Shift scheme. Both approaches increase the correlation between adjacent bits of the scan chains with respect to conventional scan-based LBIST. This way, the AF of the scan chains at capture is reduced. Consequently, the AF of the CUT at capture, thus the PD at capture, is also reduced compared to conventional scan-based LBIST. The former approach, hereinafter referred to as Low-Cost Approach (LCA), enables a 50% reduction in the worst case magnitude of PD during conventional logic BIST. It requires a small cost in terms of area overhead (of approximately 1.5% on average), and it does not increase the number of test vectors over the conventional scan-based LBIST to achieve the same Fault Coverage (FC). Moreover, compared to three recent alternative solutions, LCA features a comparable AF in the scan chains at capture, while requiring lower test time and area overhead. The second approach, hereinafter referred to as High-Reduction Approach (HRA), enables scalable PD reductions at capture of up to 87%, with limited additional costs in terms of area overhead and number of required test vectors for a given target FC, over our LCA approach. Particularly, compared to two of the three recent alternative solutions mentioned above, HRA enables a significantly lower AF in the scan chains during the application of test vectors, while requiring either a comparable area overhead or a significantly lower test time. Compared to the remaining alternative solutions mentioned above, HRA enables a similar AF in the scan chains at capture (approximately 90% lower than conventional scan-based LBIST), while requiring a significantly lower test time (approximately 4.87 times on average lower number of test vectors) and comparable area overhead (of approximately 1.9% on average)

Increased CO₂ loss from vegetated drained lake tundra ecosystems due to flooding

Tundra ecosystems are especially sensitive to climate change, which is particularly rapid in high northern latitudes resulting in significant alterations in temperature and soil moisture. Numerous studies have demonstrated that soil drying increases the respiration loss from wet Arctic tundra. And, warming and drying of tundra soils are assumed to increase CO2 emissions from the Arctic. However, in this water table manipulation experiment (i.e., flooding experiment), we show that flooding of wet tundra can also lead to increased CO2 loss. Standing water increased heat conduction into the soil, leading to higher soil temperature, deeper thaw and, surprisingly, to higher CO2 loss in the most anaerobic of the experimental areas. The study site is located in a drained lake basin, and the soils are characterized by wetter conditions than upland tundra. In experimentally flooded areas, high wind speeds (greater than ~4 m s−1) increased CO2 emission rates, sometimes overwhelming the photosynthetic uptake, even during daytime. This suggests that CO2 efflux from C rich soils and surface waters can be limited by surface exchange processes. The comparison of the CO2 and CH4 emission in an anaerobic soil incubation experiment showed that in this ecosystem, CO2 production is an order of magnitude higher than CH4 production. Future increases in surface water ponding, linked to surface subsidence and thermokarst erosion, and concomitant increases in soil warming, can increase net C efflux from these arctic ecosystems

Bi-Legendrian manifolds and paracontact geometry

We study the interplays between paracontact geometry and the theory of bi-Legendrian manifolds. We interpret the bi-Legendrian connection of a bi-Legendrian manifold M as the paracontact connection of a canonical paracontact structure induced on M and then we discuss many consequences of this result both for bi-Legendrian and for paracontact manifolds. Finally new classes of examples of paracontact manifolds are presented.Comment: to appear in Int. J. Geom. Meth. Mod. Phy

Temperature Response of Respiration Across the Heterogeneous Landscape of the Alaskan Arctic Tundra

AbstractPredictions of the response of ecosystem respiration to warming in the Arctic are not well constrained, partly due to the considerable spatial heterogeneity of these permafrost‐dominated areas. Accurate calculations of in situ temperature sensitivities of respiration (Q10) are vital for the prediction of future Arctic emissions. To understand the impact of spatial heterogeneity on respiration rates and Q10, we compared respiration measured from automated chambers across the main local polygonized landscape forms (high and low centers, polygon rims, polygon troughs) to estimates from the flux‐partitioned net ecosystem exchange collected in an adjacent eddy covariance tower. Microtopographic type appears to be the most important variable explaining the variability in respiration rates, and low‐center polygons and polygon troughs show the greatest cumulative respiration rates, possibly linked to their deeper thaw depth and higher plant biomass. Regardless of the differences in absolute respiration rates, Q10 is surprisingly similar across all microtopographic features, possibly indicating a similar temperature limitation to decomposition across the landscape. Q10 was higher during the colder early summer and lower during the warmer peak growing season, consistent with an elevated temperature sensitivity under colder conditions. The respiration measured by the chambers and the estimates from the daytime flux‐partitioned eddy covariance data were within uncertainties during early and peak seasons but overestimated respiration later in the growing season. Overall, this study suggests that it is possible to simplify estimates of the temperature sensitivity of respiration across heterogeneous landscapes but that seasonal changes in Q10 should be incorporated into model simulations

Emergency Department as an epidemiological observatory of Human Mobility: the experience of the Moroccan population

We conducted a retrospective study of the accesses to the Emergency Department registered from January 2000 to December 2014 in 5 major hospitals in the Metropolitan Area of Rome. We extrapolated data relating to patients of Moroccan origin from about 5 million total accesses, so we compared with Italians data which, in the same period, came to ED. The Moroccan population is distinguished by a larger number of diagnoses belonging to the ICD-9 code of Infectious Diseases and, more precisely, to Respiratory Infectious Diseases. There are also no differences in the assignment of such diagnoses to Moroccans with Italian citizenship, and this led to think that this could play an important role in the use of the ED and moreover that enrollment to the National Health Service may reduce its inappropriate use. Regarding to Degenerative Disorders, the result of our analysis is quite emblematic, showing that the accesses to the ED is due to Cardiovascular Diseases: 6.33% of Italians' accesses against 1.81% of Moroccans and 2.36% of Moroccans with Italian citizenship. The main explanation for this difference is, obviously, due to the age of the population: about 60% of Moroccans who accessed to ED was less than 40 years old. It is interesting how, in the field of ​​Cardiovascular Diseases, Moroccans have a lower percentage of diagnosis compared to Italians for acute diseases and a greater percentage of diagnoses for chronic diseases, suggesting once again that accesses to ED for migrants often is due to the inability to use the general services of the National Health Service. In conclusion, from the point of view of the Emergency Department, Migration Medicine still has Infectious Diseases as the main reason for access. Degenerative Disorders remain a prerogative of the Italians, but we could certainly assume that the Moroccan population would develop at some point with the aging

In vitro evaluation of antiviral and virucidal activity of a high molecular weight hyaluronic acid.

BACKGROUND: hyaluronic acid (HA), a non-sulphated glycosaminoglycan, is present in synovial fluid, vitreous humour serum and many connective tissues. Pharmaceutical preparations of HA are used in clinical practice for wound healing, joint pain, kerato-conjunctivitis, asthma, mouth care, oesophageal-reflux, and gastritis. Moreover, it is used as a filler to counteract ageing and facial lipoatrophy. Our study aims at investigating the in vitro antiviral activity of a high molecular weight HA.METHODS: the MTT test was used to rule out the potential toxic effects of HA on the different cell lines used in the antiviral assays. The antiviral activity of HA against Coxsackievirus B5, Herpes simplex virus-1, Mumps virus, Adenovirus-5, Influenza Virus A/H1N1, Human Herpesvirus-6, Porcine Parvovirus, Porcine Reproductive and Respiratory Syndrome Virus was assessed by virus yield assays.RESULTS: the most effective inhibition was observed against Coxsackievirus B5, with 3Log reduction of the virus yield at 4mg/ml, and a reduction of 3.5Log and 2Log, at 2mg/ml and 1mg/ml, respectively: the selectivity index was 16. Mumps virus was highly inhibited too showing a reduction of 1.7Log at 1mg/ml and 1Log at 4mg/ml and 2mg/ml (selectivity index = 12). The selectivity index for Influenza Virus was 12 with the highest inhibition (1Log) observed at 4mg/ml. Herpes simplex virus-1 and Porcine Parvovirus were mildly inhibited, whereas no antiviral activity was observed with respect to Adenovirus-5, Human Herpesvirus-6, Porcine Reproductive and Respiratory Syndrome Virus. No HA virucidal activity was ever observed against any of the viruses tested. Kinetic experiments showed that both Coxsackievirus B5 and Herpes simplex virus-1 replication were consistently inhibited, not influenced by the time of HA addition, during the virus replication cycle.CONCLUSIONS: the spectrum of the antiviral activity exhibited by HA against both RNA and DNA viruses, known to have different structures (with or without envelope) and replication strategies, suggests a non specific mechanism of action, probably involving cell membrane-virus interaction steps. The results of the kinetic experiments support this hypothesis

An in vitro system for the comparison of excision and wet-dry swabbing for microbiological sampling of beef carcasses.

An in vitro system for the comparison of wet-dry swabbing and surface tissue excision was developed to ascertain whether the commonly accepted statement of the advantage (in terms of bacterial recovery) of the tissue excision method is also legitimate when different kinds of bacteria are used. A total of 1,770 sections (2.5 by 10 cm) of bovine skin were individually inoculated on the subcutaneous fat side by spreading various suspensions of marker organisms (nalidixic acid-resistant Escherichia coli, vancomycin-resistant Enterococcus faecalis, and methicillin-resistant Staphylococcus aureus) at different concentrations and sampled by two standard methods: cotton wet-dry swabbing and excision. Most counts from cuts sampled by excision were significantly (P < 0.05) higher than the wet-dry swabs; however, no differences were observed between the control and the sampling method when sections were inoculated with bacterial solutions at a concentration of 10(3) CFU/ml and sampled by excision. For sections inoculated with bacterial solutions at a concentration of 10(3) CFU/ml, counts given as log CFU/25 cm2 ranged from 1.97 (S. aureus sampled by wet-dry swab) to 3.06 (S. aureus sampled by excision). For sections inoculated at a concentration of 10(4), counts given as log CFU/25 cm(2) ranged from 2.15 (E. faecalis sampled by wet-dry swab) to 3.19 (S. aureus sampled by excision). For sections inoculated at 10(5), counts given as log CFU/25 cm(2) ranged from 2.94 (E. faecalis, wet-dry swab) to 3.98 (S. aureus, excision), and for sections inoculated at 106, counts given as log CFU/25 cm(2) ranged from 3.53 (E. coli, wet-dry swab) to 4.69 (S. aureus, excision). The proposed system, which enabled a considerable amount of samples to be analyzed under controlled experimental conditions and a large number of data to be generated in a short time, demonstrated among the tested microorganisms that whereas the excision method recovered the highest number of bacteria, control means were always (with the exception of an inoculum of 10(3)/ml) significantly higher than means from either of the sampling methods. Our results indicate that particular attention should be paid to the diverse microflora that can contaminate carcasses in a given slaughterhouse and that it is not appropriate to generalize by saying that the destructive method is the reference technique for the bacteriological sampling of carcasses in slaughterhouses, especially when the contamination is higher than 10(3) CFU/25 cm(2)

3-quasi-Sasakian manifolds

In the present paper we carry on a systematic study of 3-quasi-Sasakian manifolds. In particular we prove that the three Reeb vector fields generate an involutive distribution determining a canonical totally geodesic and Riemannian foliation. Locally, the leaves of this foliation turn out to be Lie groups: either the orthogonal group or an abelian one. We show that 3-quasi-Sasakian manifolds have a well-defined rank, obtaining a rank-based classification. Furthermore, we prove a splitting theorem for these manifolds assuming the integrability of one of the almost product structures. Finally, we show that the vertical distribution is a minimum of the corrected energy.Comment: 17 pages, minor modifications, references update

Remarkable diversity of intron-1 of the para voltage-gated sodium channel gene in an Anopheles gambiae/Anopheles coluzzii hybrid zone.

BACKGROUND: Genomic differentiation between Anopheles gambiae and Anopheles coluzzii--the major malaria vectors in sub-Saharan Africa--is localized into large "islands" toward the centromeres of chromosome-X and the two autosomes. Linkage disequilibrium between these genomic islands was first detected between species-specific polymorphisms within ribosomal DNA genes (IGS-rDNA) on the X-chromosome and a single variant at position 702 of intron 1 (Int-1702) of the para Voltage-Gated Sodium Channel (VGSC) gene on chromosome arm 2 L. Intron-1 sequence data from West and Central Africa revealed two clearly distinct and species-specific haplogroups, each characterized by very low polymorphism, which has been attributed to a selective sweep. The aim of this study was to analyse Int-1 sequence diversity in A. gambiae and A. coluzzii populations from the Far-West of their range, in order to assess whether this selective-sweep signature could persist in a zone of high interspecific hybridization. METHODS: A 531 bp region of VGSC Int-1 was sequenced in 21 A. coluzzii, 31 A. gambiae, and 12 hybrids from The Gambia and Guinea Bissau, located within the Far-West geographical region, and in 53 A. gambiae s.l. samples from the rest of the range. RESULTS: Far-West samples exhibit dramatic Int-1 polymorphism, far higher within each country than observed throughout the rest of the species range. Moreover, patterning of haplotypes within A. coluzzii confirms previous evidence of a macro-geographic subdivision into a West and a Central African genetic cluster, and reveals a possible genetic distinction of A. coluzzii populations from the Far-West. CONCLUSIONS: The results suggest a relaxation of selective pressures acting across the VGSC gene region in the hybrid zone. Genetic differentiation in the Far-West could be attributable to a founder effect within A. coluzzii, with subsequent extensive gene flow with secondarily-colonizing A. gambiae, potentially yielding a novel insight on the dynamic processes impacting genetic divergence of these key malaria vectors

Spatial analysis of individual- and village-level sociodemographic characteristics associated with age at marriage among married adolescents in rural Niger.

BACKGROUND: Niger has the highest prevalence of child marriage in the world. While child marriage in Niger is clearly normative in the sense that it is commonly practiced, the social and contextual factors that contribute to it are still unclear. METHODS: Here, we tested the importance of village-level factors as predictors of young age at marriage for a group of married adolescent girls (N = 1031) in the Dosso district of rural Niger, using multi-level and geographic analyses. We aggregated significant individual level factors to determine whether, independent of a girl's own sociodemographic characteristics, the impact of each factor is associated at the village level. Finally, we tested for spatial dependence and heterogeneity in examining whether the village-level associations we find with age at marriage differ geographically. RESULTS: The mean age of marriage for girls in our study was 14.20 years (SD 1.8). Our statistical results are consistent with other literature suggesting that education is associated with delayed marriage, even among adolescent girls. Younger ages at marriage are also associated with a greater age difference between spouses and with a greater likelihood of women being engaged in agricultural work. Consistent with results at the individual level, at the village level we found that the proportion of girls who do agricultural work and the mean age difference between spouses were both predictive of a lower age at marriage for individual girls. Finally, mapping age at marriage at the village level revealed that there is geographical variation in age at marriage, with a cluster of hot spots in the Hausa-dominated eastern area where age at marriage is particularly low and a cluster of cold spots in the Zarma-dominated western areas where age at marriage is relatively high. CONCLUSIONS: Our findings suggest that large-scale approaches to eliminating child marriage in these communities may be less successful if they do not take into consideration geographically and socially determined contextual factors at the village level