Hybrid Chaplygin gas and phantom divide crossing

Hybrid Chaplygin gas model is put forward, in which the gases play the role of dark energy. For this model the coincidence problem is greatly alleviated. The effective equation of state of the dark energy may cross the phantom divide $w=-1$. Furthermore, the crossing behaviour is decoupled from any gravity theories. In the present model, $w<-1$ is only a transient behaviour. There is a de Sitter attractor in the future infinity. Hence, the big rip singularity, which often afflicts the models with matter whose effective equation of state less than -1, is naturally disappear. There exist stable scaling solutions, both at the early universe and the late universe. We discuss the perturbation growth of this model. We find that the index is consistent with observations.Comment: 11 pages, 4 figures, V3: discussions on the perturbation growth added, V4: minor corrections, to match the published versio

MEDIA OPTIMIZATION FOR BIOPROTEINS PRODUCTION FROM CHEAPER CARBON SOURCE

There are high demands for animal and human food supply especially protein, which is an important dietary component. Agricultural wastes, cheap carbon sources- which are rich and have high energy, can be used for producing the value added bioprotein. A lab scale study was carried out to optimize the media composition for bioprotein production from a cheaper carbon source - wheat flour using potential strain, which was selected earlier by screening different microorganisms. The performance of the selected strain was enhanced by media optimization with varied substrate concentration, nitrogen sources and nutrient supplementation according to the central composite design from STATISTICA software. Statistical optimization was carried out to evaluate the polynomial regression model through effect of linear, quadratic and interaction of the factors. The maximum biomass produced was 21.89 g/L with optimum fermentation conditions of wheat flour (4 g/L), nitrogen concentration (0.5 g/L), nutrient concentration (0.1 g/L), and four days of fermentation

A new look at nonparasitized red cells of malaria-infected monkeys

Many reports have shown that malarial parasites can produce distinct morphological and molecular alterations in the membranes of the parasitized erythrocytes, but few studies have been carried out on nonparasitized erythrocytes of infected animals. We report here that the outer leaflet of the membrane bilayer of nonparasitized erythrocytes contains significantly larger amounts of aminophospholipids (phos-phatidylethanolamine (PE) and phosphatidylserine (PS)), than the normal red cell membrane. This alteration in nonparasitized red cells is probably caused by Ca2+-induced cross-linking of spectrin, and gradually disappears after chloroquine treatment. The external localization of PS in these cells together with defective structure of their cytoskeletal network provide a strong basis for the complications associated with malaria infection like thrombosis, infarction and severe anaemia

Condoms, trust and stealthing: the meanings attributed to unprotected hetero-sex

University students tend to have greater sexual health knowledge than the general public, yet condom use among this group continues to be a public health concern because effective condom use could reduce sexually transmitted infections and, for heterosexual women, unwanted pregnancies. We report findings from a small, qualitative study of condom use among sexually active heterosexual university students in the UK. In interviews, students shared their views about condom use and sometimes their personal experiences too. This paper identifies some of the meanings attributed to condom use in the accounts of nine heterosexually active 20–25 year-olds. Participants explained that when they felt comfortable communicating with their partners, they were more likely to use condoms, and those with negative sexual experiences or under social or psychological pressure were less likely to use them. The findings highlight issues of trust and power between men and women in heterosexual relationships, and describe contexts for dishonest sexual practice, including the traditional notions of femininity that were linked to condom use by this group. The issue of stealthing arose in one woman’s account of her experience and in several others’ reports of what occurs commonly. Stealthing, the secretive removal of a condom by a (usually male) partner during sexual intercourse without a partner’s knowledge or permission, produces non-consensual unprotected sex. We present stealthing as a product of the sexual double-standards described and as a form of interpersonal violence (IPV) and, among these heterosexual partners, as a form of gender-based violence. This study provides a glimpse into university students’ decision-making regarding condom use and highlights how gendered inequalities shape heterosex, in particular, communication about safer sex, that in some cases, compromise women’s decisions about (safer) sex

Analisis Produksi dan Pendapatan USAhatani Padi Sawah dengan Pola Jajar Legowo di Desa Laantula Jaya Kecamatan Witaponda Kabupaten Morowali

Penelitian ini bertujuan mengetahui faktor-faktor yang mempengaruhi produksi dan pendapatan USAhatani padi sawah dengan Pola Jajar Legowo di Desa Laantula Jaya, Kecamatan Witaponda, Kabupaten Morowali. Penentuan responden dilakukan dengan menggunakan metode acak sederhana (simple random sampling). Jumlah sampel yang diambil dalam penelitian ini yakni sebanyak 30 responden dari populasi yang berjumlah 87 KK yang menerapkan pola tanam jajar legowo. Hasil Analisis Fungsi Cobb-douglas menunjukan bahwa secara simultan (bersama-sama) faktor luas lahan, benih, pupuk, tenaga kerja, dan pengalaman USAhatani. Berdasarkan hasil pengujian menunjukkan Fhitung = 198,09 dengan nilai sig 0,000 < 0,005 (α = 5 %) menunjukkan menolak hipotesis nol, artinya variabel bebas luas lahan (X1), benih (X2), pupuk (X3), tenaga kerja (X4), dan pengalaman berusahatani (X5) secara simultan (bersama-sama) mempengaruhi produksi gabah kering panen di Desa Laantula Jaya Kecamatan Witaponda. Hasil analisis pendapatan menunjukan bahwa penerimaan yang diperoleh petani padi sawah di Desa Laantula Jaya adalah sebesar Rp. 17.706.084,68/ha, total biaya atau Rp. 8.939.083,95/ha sehingga diperoleh pendapatan petani responden sebesar Rp. 8.767.000,73/ha dalam satu kali musim tanam

Statistical optimization of process parameters for the production of citric acid from oil palm empty fruit bunches

In this study, optimization of process parameters such as moisture content, incubation temperature and initial pH (fixed) for the improvement of citric acid production from oil palm empty fruit bunches through solid state bioconversion was carried out using traditional one-factor-at-a-time (OFAT) method and response surface methodology (RSM). The possible optimum level of moisture content, incubation temperature, and initial pH were found from the OFAT study to be 70%, 30 - 32oC and 5.5 - 8, respectively. The optimum moisture content of 70.3% (v/w) and incubation temperature of 33.1&#176;C with initial pH of 6.5 gave the maximum production of citric acid (369.16 g/kg of dry EFB). The analysis of variance (ANOVA) of the statistical optimization using central composite design showed that moisturecontent (p&lt;0.001) and incubation temperature (p&lt;0.0001) as well as the interaction of these two parameters were highly significant for the citric acid production

Lattice thermal conductivity of disordered NiPd and NiPt alloys

Numerical calculations of lattice thermal conductivity are reported for the binary alloys NiPd and NiPt. The present work is a continuation of an earlier paper by us [PRB, 72, 214207 (2005)]which had developed a theoretical framework for the calculation of configuration-averaged lattice thermal conductivity and thermal diffusivity in disordered alloys. The formulation was based on the augmented space theorem combined with a scattering diagram technique. In this paper we shall show dependence of the lattice thermal conductivity on a series of variables like phonon frequency, temperature and alloy composition. The temperature dependence of $\kappa(T)$ and its realtion to the measured thermal conductivity is discussed. The concentration dependence of $\kappa$ appears to justify the notion of a minimum thermal conductivity as discussed by Kittel, Slack and others. We also study the frequency and composition dependence of the thermal diffusivity averaged over modes. A numerical estimate of this quantity gives an idea about the location of mobility edge and the fraction of states in the frequency spectrum which is delocalized.Comment: 23 pages, 18 figure

On the Prospects for Laser Cooling of TlF

We measure the upper state lifetime and two ratios of vibrational branching fractions f_{v'v} on the B^{3}\Pi_{1}(v') - X^{1}\Sigma^{+}(v) transition of TlF. We find the B state lifetime to be 99(9) ns. We also determine that the off-diagonal vibrational decays are highly suppressed: f_{01}/f_{00} < 2x10^{-4} and f_{02}/f_{00} = 1.10(6)%, in excellent agreement with their predicted values of f_{01}/f_{00} < 8x10^{-4} and f_{02}/f_{00} = 1.0(2)% based on Franck-Condon factors calculated using Morse and RKR potentials. The implications of these results for the possible laser cooling of TlF and fundamental symmetries experiments are discussed.Comment: 5 pages, 2 figure