1,243 research outputs found

    Vector valued switching in the products of signed graphs

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    A signed graph is a graph whose edges are labeled either as positive or negative. The concept of vector valued switching and balancing dimension of signed graphs were introduced by S. Hameed et al. In this paper, we deal with the balancing dimension of various products of signed graphs, namely the Cartesian product, the lexicographic product, the tensor product and the strong product

    Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

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    Activities within the period from July 1, 1992 through December 31, 1992 by Georgia Tech researchers in millimeter and submillimeter wavelength tropospheric remote sensing have been centered around the calibration of the Millimeter-wave Imaging Radiometer (MIR), preliminary flight data analysis, and preparation for TOGA/COARE. The MIR instrument is a joint project between NASA/GSFC and Georgia Tech. In the current configuration, the MIR has channels at 90, 150, 183(+/-1,3,7), and 220 GHz. Provisions for three additional channels at 325(+/-1,3) and 8 GHz have been made, and a 325-GHz receiver is currently being built by the ZAX Millimeter Wave Corporation for use in the MIR. Past Georgia Tech contributions to the MIR and its related scientific uses have included basic system design studies, performance analyses, and circuit and radiometric load design, in-flight software, and post-flight data display software. The combination of the above millimeter wave and submillimeter wave channels aboard a single well-calibrated instrument will provide unique radiometric data for radiative transfer and cloud and water vapor retrieval studies. A paper by the PI discussing the potential benefits of passive millimeter and submillimeter wave observations for cloud, water vapor and precipitation measurements has recently been published, and is included as an appendix

    Investigation of passive atmospheric sounding using millimeter and submillimeter wavelength channels

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    Activities within the period from January 1, 1992 through June 30, 1992 by Georgia Tech researchers in millimeter and submillimeter wavelength tropospheric remote sensing have been centered around the integration and initial data flights of the MIR on board the NASA ER-2. Georgia Tech contributions during this period include completion of the MIR flight software and implementation of a 'quick-view' graphics program for ground based calibration and analysis of the MIR imagery. In the current configuration, the MIR has channels at 90, 150, 183 +/- 1,3,7, and 220 GHz. Provisions for three additional channels at 325 +/-1,3 and 9 GHZ have been made, and a 325-GHz receiver is currently being built by the ZAX Millimeter Wave Corporation for use in the MIR. The combination of the millimeter wave and submillimeter wave channels aboard a single well-calibrated instrument will provide the necessary aircraft radiometric data for radiative transfer and cloud and water vapor retrieval studies. A paper by the PI discussing the potential benefits of passive millimeter and submillimeter wave observations for cloud, water vapor and precipitation measurements has recently been accepted for publication (Gasiewski, 1992), and is included as Appendix A. The MIR instrument is a joint project between NASA/GSFC and Georgia Tech. Other Georgia Tech contributions to the MIR and its related scientific uses have included basic system design studies, performance analyses, and circuit and radiometric load design

    Contaminazione dell’acqua e tasso di infezioni nel parto in acqua

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    Introduzione: sono sempre di più le cliniche e gli ospedali che offrono il parto in acqua. Gli scettici, tuttavia, mettono in guardia dal rischio infettivo. Scopo di questo studio è stato di analizzare la carica microbica presente nella vasca in cui avviene il parto e di confrontare il tasso di infezioni dei neonati partoriti in acqua con quello dei bambini nati in modo tradizionale. Metodi: a partire dal 2001 è stato avviato uno studio prospettico in collaborazione con il Laboratorio Biologico della Provincia Autonoma di Bolzano per l’analisi microbiologica dell’acqua contenuta nella vasca da parto. Sono stati prelevati due campioni di acqua, il primo dopo aver riempito la vasca con acqua potabile (campione A) e il secondo a parto avvenuto (campione B). I pediatri hanno documentato i segni di sospetta infezione nei neonati partoriti dentro o fuori dall’acqua durante la loro permanenza in reparto. Risultati: dei 986 parti in acqua avvenuti dal 2001 al 2004 sono stati analizzati 300 campioni d’acqua. Nel campione A, prima dell’installazione di un sistema di filtri, sono state trovate legionelle nel 29%, Pseudomonas aeruginosa nel 22%, enterococchi nel 18%, coliformi nel 32% ed Escherichia coli nell’8% dei casi. Dopo l’installazione del sistema di filtri è stato possibile ridurre nettamente la contaminazione per alcuni tipi di germi: le legionelle non sono più state isolate, mentre Pseudomonas aeruginosa e i coliformi erano presenti solo nel 3 e nel 13% dei campioni. Nei campioni di tipo B sono state riscontrate contaminazioni elevate di coliformi totali nell’82% dei casi e Escherichia coli nel 64% con concentrazioni fino a 105 ufc/100 ml, oltre ad una contaminazione moderata (8-21%) da Pseudomonas aeruginosa, Staphylococcus aureus e lieviti. Nell’1,22% dei bambini nati in acqua (12 su 986) è stato somministrato un antibiotico sulla base di segni di infezione iniziale, sia clinici (tachipnea, alitamento delle pinne nasali, cianosi) che biochimici (aumento della PCR, emocromo), rispetto al 2,63% dei neonati partoriti con metodi tradizionali (17 su 647) (p <0,05). Conclusioni: l’installazione del sistema di filtri ha ridotto significativamente la contaminazione dell’acqua in entrata nella vasca, eliminando in particolare la presenza di legionelle. È evidente come, durante il periodo espulsivo, venga eliminato materiale fecale nella vasca e l’acqua possa essere contaminata da diversi microrganismi. Dopo il parto in acqua non è stata osservata una maggiore frequenza di infezioni neonatali rispetto ai parti tradizionali

    SILVER NANOPARTICLES FROM TRIANTHEMA PORTULACASTRUM: GREEN SYNTHESIS, CHARACTERIZATION, ANTIBACTERIAL AND ANTICANCER PROPERTIES

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    ABSTRACTObjective: In this study, silver nanoparticles (SNPs) were synthesized using an aqueous extract of Trainthema portulacastrum and silver ions (Ag+)which have been proven against certain pathogenic bacterial strains and hepatocellular carcinoma (HepG2) cell line.Methods: The bio fabricated nanoparticles were confirmed by surface plasmon resonance which were characterized by biophysical measuresutilizing the ultraviolet-visible spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray, and transmission electron microscope(TEM), Fourier transform infrared spectroscopy, particle size analyzer, and X-ray diffraction. Antibacterial efficacy against Enterobacter aerogens,Proteus mirabilis, Escherichia coli, Staphylococcus epidermis, and Bacillus subtilis. The effect of SNPs tested against HepG2 and NIH/3T3 cell lineexhibits a dose-dependent toxicity.Results and Conclusion: The SEM and TEM images confirmed the presence of spherical and hexagonal shape (0.3-4 μm) of nanocrystalline particleswith the size range of 11.5-29.2 nm. The average particles size of SNPs is 190.3±17.0 nm. Antibacterial activity was carried out by agar well diffusionmethod against different pathogenic bacteria of which B. subtilis showed a significant zone of inhibition 8.66 mm and 12.0 mm for aqueous plantextract and synthesized SNPs. The effect of SNPs tested against HepG2 and NIH/3T3 cell line exhibits a dose-dependent toxicity. In case of HepG2, thecell viability was decreased to 50% (IC50) at the concentration of 173.8±0.84 μg/mL. From the results, it can be concluded that the SNPs fabricatedusing green synthesis method will be a promising candidate in the biomedical field, due to its high bioactive properties.Keywords: Silver nanoparticles, Trainthema portulacastrum, Antibacterial activity, Cytotoxic activity

    Vector Valued Switching in Signed Graphs

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    A signed graph is a graph with edges marked positive and negative; it is unbalanced if some cycle has negative sign product. We introduce the concept of vector valued switching function in signed graphs, which extends the concept of switching to higher dimensions. Using this concept, we define balancing dimension and strong balancing dimension for a signed graph, which can be used for a new classification of degree of imbalance of unbalanced signed graphs. We provide bounds for the balancing and strong balancing dimensions, and calculate these dimensions for some classes of signed graphs.Comment: 15 pp., 5 figs. V2 12 pp., 4 figs., more data, slightly shorte

    Clinician Recognition of First Episode Psychosis

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    Purpose: Psychotic disorders develop during mid-adolescence through early adulthood, with the initial few months a “critical period” offering the greatest promise for recovery. However, the duration of untreated psychosis is typically over a year. This study aimed to identify aspects of care episodes contributing to delays in diagnosis of a first psychotic episode. Methods: Study subjects included 161 adolescents and young adults referred to a first episode psychosis treatment program. We captured the various ways that people who experience a severe mental illness engage in treatment using standardized interviews with patients and informants (e.g., family member) and medical record review. Results: A psychotic disorder diagnosis was not given for 38% of subjects at their initial episode of care. Time to first care episode was virtually the same for subjects that did and did not receive a psychosis diagnosis; 50% within 1 month and 84% within 6 months. Compared to initial care episodes with a psychosis diagnosis, those without a psychosis diagnosis less often involved emergency services (80% vs. 38%, respectively; p value = 1 × 10−7) and more often outpatient primary care (6% vs. 18%; p value = .032) and mental health (32% vs. 49%; p value = .045) services. However, dangerousness indicators were similar (29% vs. 28%; p value = 1). Dangerousness indicators increased to 54% (p value = .002) by the time of eventual diagnosis for those requiring multiple care episodes. Conclusions: Clinicians were important contributors to delays in diagnosis and treatment of psychosis. Interventions targeting outpatient health care providers may be fruitful in reducing the duration of untreated psychosis

    Ukupni i specifični mortalitet u radnika izloženih azbestu od 1907. do 1985. godine

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    Total and cause-specific mortality data for the 1907 -1985 period were compared between cohorts of male asbestos-cement workers (N = 1908) and referents (N = 726), using Poisson regression modelling. The rate ratio (RR) for total mortality was significantly increased (1.3) among the exposed workers, as was mortality from non-malignant respiratory disease (RR= 2.2). Numerically, but not statistically significantly, raised ratios were found for respiratory (RR= 1.6) and gastrointestinal (RR= 1.3) cancers. The trend in the rate ratio for total mortality with time was better fitted with a curved line, than with a monotonic one, because of a period of increased risk up to the 1950s, and another one starting after 1970.Ukupni i specifični mortalitet za razdoblje od 1907. do 1985. godine uspoređen je u kohortama muških radnika koji su bili izloženi azbestu (N = 1908) s kontrolama (N = 726) pomoću Poissonove regresijske analize. Koeficijent regresije (RR) za ukupni mortalitet, kao i mortalitet od nemalignih respiratornih bolesti bio je statistički značajno viši i iznosio je 1,3, odnosno 2,2. Povećanje ovog koeficijenta nađeno je i za plućni (1,6) i gastrointestinalni karcinom (1,3), ali vrijednosti nisu statistički značajne
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