Fate of the Universe, Age of the Universe, Dark Matter, and the Decaying Vacuum Energy

It is shown that in the cosmological models based on a vacuum energy decaying as a^{-2}, where a is the scale factor of the universe, the fate of the universe in regard to whether it will collapse in future or expand forever is determined not by the curvature constant k but by an effective curvature constant k_{eff}. It is argued that a closed universe with k=1 may expand forever, in other words simulate the expansion dynamics of a flat or an open universe because of the possibility that k_{eff}=0 or -1, respectively. Two such models, in one of which the vacuum does not interact with matter and in another of which it does, are studied. It is shown that the vacuum equation of state p_{vac}= -\rho_{vac} may be realized in a decaying vacuum cosmology provided the vacuum interacts wuth matter. The optical depths for gravitational lensing as a function of the matter density and other parameters in the models are calculated at a source redshift of 2. The age of the universe is discussed and shown to be compatible with the new Hipparcos lower limit of 11Gyr. The possibility that a time-varying vacuum energy may serve as dark matter is suggested.Comment: AAS LaTex, 29 pages, published in the Astrophysical Journal, 520, 45, 199

The relationship between serum bilirubin level with interleukin.6, interleukin.10 and mortality scores in patients with sepsis

Context: Bilirubin has been shown to influence the mechanisms of both apoptosis and inflammation.Aims: The aim of the following study is to investigate the relationship between the serum bilirubin level with sepsis progression.Settings and Design: A total of 20 patients from intensive care unit were included for this study.Materials and Methods: Patients were divided into two groups: Patients diagnosed with sepsis according to the American College of Chest  Physicians/Society of Clinical Care Medicine consensus conference criteria (n = 10) and patients treated for various other diagnoses (n = 10). Blood samples were collected for both groups at the time of origin (defined as the time of diagnosis) and 24 and 48 h after diagnosis. Serum interleukin (IL).6, IL.10 and bilirubin levels were analyzed and compared. Acute physiology and chronic health evaluation (APACHE) II and sepsis related organ failure (SOFA) scores of the patients were also evaluated. Statistical Analysis Used: We used Statistical Package for Social Sciences (SPSS for Windows, version 17.0, SPSS Inc. 233 South Wacker Drive, Chicago) for statistical analysis.Results: At all.time intervals, serum IL.6, IL.10 and total, direct and  indirect serum bilirubin levels were significantly higher in the sepsis group (P < 0.05); APACHE II and SOFA scores were also significantly higher. Both SOFA scores and serum IL.10 levels were positively correlated with bilirubin levels 24 h after diagnosis (P < 0.05, r = .0.76).Conclusions: Although levels of bilirubin and other associated parameters were higher for the sepsis group, only SOFA score and bilirubin levels were correlated. Because bilirubin is already a SOFA parameter, this correlation was not considered as clinically significant.Key words: Acute physiology and chronic health evaluation, bilirubin, interleukin.6, interleukin.10, sepsi

Effects of user experience and method in the inflation of endotracheal tube pilot balloon on cuff pressure

Context: Endotracheal tube cuff pressure (ETCP) is recommended to be maintained between 20.30 cmH2O limits. While insufficient inflation of ETC may cause aspirations, over.inflation of it may lead to damage in tracheal epithelium.Aims: We planned to investigate the effects of user experience and cuff pressure inflation method differences following endotracheal tube cuff pressure and complaints about it.Patients and Methods: Two hundred and fifty patients planned for general anaesthesia were included in this study. ETC was inflated by users with different experience according to leakage or pilot balloon palpation techniques. ETCPs were measured by manometer at three periods (5 and 60 minutes after endotracheal intubation, and before extubation). Complaints about it were recorded in post anaesthetic care unit and 24 hours postoperatively.Results: Though we found experience of user had significant effect on the ETCP regulations, we observed inflation methods did not have any effect. However we found ETCP was higher than normal range with experienced users. A correlation was observed between cuff pressure and anaesthesia duration with postoperative complaints.Conclusions: Our study concluded that the methods used do not have any significant advantage over one another. While ETC inflated at normal pressure increases as userfs experience increases, experience alone is not enough in adjusting ETCP. A manometer should be used in routine inflation of ETC instead of conventional methods. CP and anaesthesia duration have correlations with some postoperative complaints.Key words: Endotracheal tube cuff pressure, experience of user, inflation method

Comparison of anaesthetic cost in open and laparoscopic appendectomy

Context: Appendectomy is generally conducted as open or by laparoscopic surgical techniques under general anesthesia.Aims: This study aims to compare the anesthetic costs of the patients, who underwent open or laparoscopicappendectomy under general anesthesia.Settings and Design: The design is retrospective and records of 379 patients who underwent open or laparoscopicappendectomy under general anesthesia, falling under the category of I‑III risk group according to the American Societyof Anesthesiologists (ASA) classification between the years 2011 and 2013, and aged 18-77.Subjects and Methods: Open (Group I) or laparoscopic (Group II) appendectomy operation under general anesthesiawere evaluated retrospectively by utilizing hospital automation and anesthesia observation records. This study evaluatedthe anesthesia time of the patients and total costs (Turkish Lira ₺, US dollar $) of anesthetic agents used (induction,maintenance), necessary medical materials (connecting line, endotracheal tube, airway, humidifier, branule, aspirationprobe), and intravenously administered fluids were evaluated.Statistical Analysis Used: We used Statistical Package for the Social Sciences software (SPSS version 17.0) forstatistical analysis.Results: Of the patients, 237 were males (62.53$) in Group I and 83.09 ± 26.85₺ (41.29 ± 13.34$) inGroup II (P > 0.05). A correlation was observed between cost and operation times (P = 0.002, r = 0.158).Conclusions: Although a statistical difference was not established in this study in terms of time and costs inappendectomy operations conducted as open and laparoscopically, changes may occur in time in market conditionsof drugs, patent rights, legal regulations, and prices. Therefore, we believe that it would be beneficial to update andrevise cost analyses from time to time.Keywords: Cost, cost comparison laparoscopic appendectomy, open appendectom

Perceptions de la variabilité climati que et stratégies d’adaptation dans le système oasien de Gouré (Sud-est Niger)

Les savoirs liés au temps et à l’espace, et l’identification des stratégies paysannes pour affronter les problèmes climatiques sont indispensables pour toute compréhension des questions climatiques. Pour mieux apprécier les perceptions de la variabilité climatique et les stratégies d’adaptation utilisées, une enquête semi structuré qui a concerné 60 personnes repartie dans 4 villages du département de Gouré, situé dans l’Est du Niger est conduite selon une approche qualitative et quantitative. Les effets de la variabilité climatique ressentis par les agriculteurs sont l’aridité du climat, l’augmentation de la température et le caractère aléatoire des pluies. Les éleveurs la perçoivent de façon indirecte à travers la réduction du fourrage et de la disponibilité d’eau. Ces effets ont poussé ces populations à adopter des stratégies d’adaptation comme la recherche de nouvelles variétés à cycle court et supportant les poches de sécheresse, la pratique des techniques de fixation des dunes pour la restauration du couvert herbacé, l’utilisation de la fumure organique, la modification des dates de semis, le stockage de fourrage, le déstockage des animaux pendant la soudure, les prières collectives de demande de pluies. Elles sont toutefois insuffisantes du fait de la persistance des effets négatifs de la variabilité climatiques au Niger.Mots clés: Variabilité climatique, perception, stratégies d’adaptation, Gouré, NigerEnglish Title: Farmers perception and adaptation strategies to climate change in the oasis system of Goure (Southeast Niger)English AbstractKnowledge related to the perception of time and space, and identification of farmers’ strategies for dealing with climate change is a perequisite for a good understanding of climate issues. Farmers’ climate variability perceptions and adaptation strategies was studied using a survey conducted with sixty (60) farmers in the department of Gouré, located in eastern Niger. Results showed that farmers directly experience changes in  climate variability through temperature increase, frequent drought and erratic rainfall. By contrast, herders sense the effects of climate change indirectly through fodder reduction and scarce water availability. These effects have prompted farmers to adopt coping strategies such as the use of improved varieties, early and drought tolerant, sand dune stabilization and land reclamation, use of organic manure, changing of planting dates, storage of fodder, the destocking of animals during drought periods, collective prayers for rain. These strategies, however, appear to be insufficient for addressing the negative effects of climate change in this part of Niger.Keywords: climate variability, perception, strategies of adaptation, Goure, Nige

Investigating Performance of High-Rate GNSS-PPP and PPP-AR for Structural Health Monitoring: Dynamic Tests on Shake Table

© 2020 American Society of Civil Engineers. This paper investigates the usability of Global Navigation Satellite System (GNSS) Precise Point Positioning (PPP) methods, traditional PPP with a float-ambiguity solution and with ambiguity resolution (PPP-AR), in structural health monitoring applications based on experimental tests using a single-axis shake table. To evaluate the performance of the PPP methodologies, harmonic oscillations of the motion table with amplitudes ranging from 5 to 10 mm and frequency between 0.1 and 3 Hz were generated representing a wide range of possible structural motions. In addition, ground motion similar to those experienced during a real earthquake, the 1995 Kobe earthquake, and step motions were generated on the shake table. GNSS PPP-derived positioning results at 20 Hz were compared, in both of the frequency and time domains, with reference data comprising LVDT data and relative positioning data. Results show that both PPP methods' measurements can be used in the computation of harmonic oscillation frequencies compared to the LVDT and relative positioning values. The observed amplitudes of the harmonic oscillations are slightly different from the LVDT values on the order of millimeters. The results of a step motion experiment demonstrated that PPP-AR is better than traditional PPP in exhibiting quasi-static or static displacement. Moreover, the capabilities of traditional PPP and PPP-AR methods are evaluated with respect to the natural frequency of a small-scale structural model excited on the shake table. The frequency spectrum of this small-scale structural model derived from the PPP methods is consistent with finite-element model (FEM)-predicted values and relative positioning. The research presented here demonstrates the potential of the high-rate GNSS PPP and PPP-AR methods to reliably monitor structural and earthquake-induced vibration frequencies and amplitudes for both structural and seismological applications. Specifically, all results reveal that high-rate PPP-AR is more accurate than traditional PPP for both dynamic and static displacement detection

Biosorption of Cr(VI) by free and immobilized Pediastrum boryanum biomass: equilibrium, kinetic, and thermodynamic studies

15th International Symposium on Toxicity Assessment (ISTA) -- JUL 03-08, 2011 -- City Univ Hong Kong, Hong Kong, PEOPLES R CHINAWOS: 000306790200053PubMed ID: 22374187The biosorption of Cr(VI) from aqueous solution has been studied using free and immobilized Pediastrum boryanum cells in a batch system. The algal cells were immobilized in alginate and alginate-gelatin beads via entrapment, and their algal cell free counterparts were used as control systems during biosorption studies of Cr(VI). The changes in the functional groups of the biosorbents formulations were confirmed by Fourier transform infrared spectra. The effect of pH, equilibrium time, initial concentration of metal ions, and temperature on the biosorption of Cr(VI) ion was investigated. The maximum Cr(VI) biosorption capacities were found to be 17.3, 6.73, 14.0, 23.8, and 29.6 mg/g for the free algal cells, and alginate, alginate-gelatin, alginate-cells, and alginate-gelatin-cells at pH 2.0, which are corresponding to an initial Cr(VI) concentration of 400 mg/L. The biosorption of Cr(VI) on all the tested biosorbents (P. boryanum cells, alginate, alginate-gelatin, and alginate-cells, alginate-gelatin-cells) followed Langmuir adsorption isotherm model. The thermodynamic studies indicated that the biosorption process was spontaneous and endothermic in nature under studied conditions. For all the tested biosorbents, biosorption kinetic was best described by the pseudo-second-order model.PROCORE-France/Hong Kong Joint Res Scheme, Croucher Fdn, KC Wong Educ Fd

Higher spin fields and the problem of cosmological constant

The cosmological evolution of free massless vector or tensor (but not gauge) fields minimally coupled to gravity is analyzed. It is shown that there are some unstable solutions for these fields in De Sitter background. The back reaction of the energy-momentum tensor of such solutions to the original cosmological constant exactly cancels the latter and the expansion regime changes from the exponential to the power law one. In contrast to the adjustment mechanism realized by a scalar field the gravitational coupling constant in this model is time-independent and the resulting cosmology may resemble the realistic one.Comment: 15 pages, Latex twic

Thermodynamics of Decaying Vacuum Cosmologies

The thermodynamic behavior of vacuum decaying cosmologies is investigated within a manifestly covariant formulation. Such a process corresponds to a continuous irreversible energy flow from the vacuum component to the created matter constituents. It is shown that if the specific entropy per particle remains constant during the process, the equilibrium relations are preserved. In particular, if the vacuum decays into photons, the energy density $\rho$ and average number density of photons $n$ scale with the temperature as $\rho \sim T^{4}$ and $n \sim T^{3}$. The temperature law is determined and a generalized Planckian type form of the spectrum, which is preserved in the course of the evolution, is also proposed. Some consequences of these results for decaying vacuum FRW type cosmologies as well as for models with ``adiabatic'' photon creation are discussed.Comment: 21 pages, uses LATE