Fluctuation-induced forces between inclusions in a fluid membrane under tension

We discuss the fluctuation-induced force, a finite-temperature analog of the Casimir force, between two inclusions embedded in a fluid membrane under tension. We suggest a method to calculate this Casimir interaction in the most general case, where membrane fluctuations are governed by the combined action of surface tension, bending modulus, and the Gaussian rigidity. We find that the surface tension strongly modifies the power law in the separation dependence of the Casimir interaction. This results in a strong suppression of the Casimir force at separations beyond a characteristic length, which could affect protein aggregation dynamics in cell membranes.Comment: 4 pages, 1 figur

Socio-economic Impact of Flooding on the Riverine Communities of River Benue in Adamawa State, Nigeria

This paper examines the impact of floods on the socioeconomic lives of residents of the flood plain of River Benue in the Adamawa area. The specific objectives of the paper include examining people’s perception of the causes of flooding in the study area, assessing the impacts of flooding on the socioeconomic activities in the study area, analyzing the People’s Response/Adjustment to Flood in the study area. Three Riverine communities were purposively selected and data for the study was elicited through questionnaires administered to randomly selected respondents in the selected riverine communities in the area. The results obtained indicate that majority of the respondents over 80% are aware of the devastating effects of flooding but they fail to act because of their preference of occupying the location despite their experience. Thousands of hectares of farmlands and other properties have been destroyed by flood over the years. Another finding shows that the impact of flood on transportation is, perhaps, the most devastating such that agricultural productivity in the area is limited as a result of lack of effective means of mobility. Changes in modal split were also found to be associated with the flood regimes. Traditional responses to the menace of flooding have been on the increase due to the ad hoc manner of government participation in providing an enduring solution. The rescheduling of field crops planting and levee construction were among the common responses of the people. Keywords: Flood, River Benue, Transportation, Socio-economic, Environmen

Larvicidal activity of some selected medicinal plant extracts against the vector of filariasis

The present study assessed the role of larvicidal activities of hexane, ethyl acetate and methanol dried leaf and bark extracts of Ocimum gratissimum, Gleditsia triacanthos, Eucalyptus sglobulus and Azadirachta aindica against the fourth instar larvae of filariasis vector, Culex quinquefasciatus mosquito (Diptera: Culicidae). Larvicidal activities of four medicinal plant extracts were studied in the range of 4.69 to 1000 mg/l in the laboratory bioassays against early 4th instar larvae of Culex quinquefasciatus. The mortality data were subjected to probit analysis to determine the lethal concentrations (LC50 and LC90) to kill 50 and 90 per cent of the treated larvae of the respective species. All plant extracts showed moderate effects after 24 h of exposure; however, the highest toxic effect of leaf methanol extract of Ocimum gratissimum, bark ethyl acetate extract of Eucalyptus globulus, methanol extract of Azadirachta indicia and methanol bark extract of Gleditsia triacanthos against the larvae of Culex quinquefasciatus with LC50=43.00, 41.02, 40.12 and 20.36 mg/l; LC90=278.32, 218.72, 215.01 and 86.29 mg/l respectively. The result of findings shows that leaf and bark extract of G. tricantha, A .indica, O. gratissimum and E .globulus can be developed as ecofriendly larvicides

Anti-microbial activities and phytochemical screening of some commonly used chewing sticks in Kano, Nigeria

This research work was aimed to determine the antibacterial activity of aqueous and ethanolic extract of plants commonly used in Kano on a clinical isolate of Staphylococcus and Streptococcus species obtained from the dental problem with a view to find the most efficacious one among them. The sensitivity disc method was used to test the antibacterial activity of chewing sticks, Eucalyptus globulus, Salvadora persica, Gledistsia triacanthos, Azadirachta indica and Jatropha curcas were the plants. It was found that none of the plants ‘aqueous extract had activity on the two species of the bacterial isolate at various concentrations. But ethanolic extract was active against all the test bacterial isolate obtained from the dental problem with a greater zone of inhibition in A. Indica, followed by E. globulus and a smaller zone of inhibition in J. curcas. Some of the secondary metabolites were all present with high content in ethanolic extract. The extracts of these plants may serve as sources for chemotherapeutic agents of the management of orofacial infection

Control of filariasis vector using Ovillanta in Gwale local Government area of Kano State, Nigeria

The study was aimed at finding the effectiveness of a physical method of controlling filariasis vector larvae. Four ovillanta traps were placed in four different sites (north, south, west and east) of Gwale Local Government area of Kano state. The eggs and immature stage(larvae) of the filariasis vector were collected and destroyed. A total of 134667 larvae were collected altogether. 25% from site A, 23% from site B, 28% from site C and 24% from site D.The finding of the study shows that ovillanta trap is an effective method in controlling filariasis vector. &nbsp

Quantum and thermal Casimir interaction between a sphere and a plate: Comparison of Drude and plasma models

We calculate the Casimir interaction between a sphere and a plate, both described by the plasma model, the Drude model, or generalizations of the two models. We compare the results at both zero and finite temperatures. At asymptotically large separations we obtain analytical results for the interaction that reveal a non-universal, i.e., material dependent interaction for the plasma model. The latter result contains the asymptotic interaction for Drude metals and perfect reflectors as different but universal limiting cases. This observation is related to the screening of a static magnetic field by a London superconductor. For small separations we find corrections to the proximity force approximation (PFA) that support correlations between geometry and material properties that are not captured by the Lifshitz theory. Our results at finite temperatures reveal for Drude metals a non-monotonic temperature dependence of the Casimir free energy and a negative entropy over a sizeable range of separations.Comment: 11 pages, 5 figure

Feedback Design for Devising Optimal Epidemic Control Policies

For reliable epidemic monitoring and control, this paper proposes a feedback mechanism design to effectively cope with data and model uncertainties. Using past epidemiological data, we describe methods to estimate the parameters of general epidemic models. Because the data could be noisy, the estimated parameters may not be accurate. Therefore, under uncertain parameters and noisy measurements, we provide an observer design method for robust state estimation. Then, using the estimated model and state, we devise optimal control policies by minimizing a predicted cost functional. Finally, the effectiveness of the proposed method is demonstrated through its implementation on a modified SIR epidemic model

KARAKTERISTIK SEMEN SEGAR SAPI BANGSA LIMOUSIN DAN SIMMENTAL DI BALAI INSEMINASI BUATAN LEMBANG

FRESH SEMEN CHARACTERISTICS OF LIMOUSIN AND SIMMENTAL BULLS AT THE ARTIFISIAL INSEMINATION CENTER, LEMBANG. This study was conducted to evaluate the characteristics of fresh semen in Limousin and Simmental bulls at the artificial insemination center in Lembang. Results of this study showed that ejaculation frequency of Simmental bull was significantly higher than that of Limousin with the average of 5.37 and 4.60, respectively. Variables of volume, pH and motility were not significantly different between both bulls with volume ranging of 7.17 – 7.20 ml, pH ranging of 6.65 – 6.66 and motility ranging of 58.08 – 59.29%, respectively. The fresh semen colour of Limousin and Simmental bulls were indicated by dominant color of milk white color. Semen consistency of fresh semen from both bulls was moderate. The ejaculation frequency and pH variables indicated the correlation of -0.32 in Limousine bulls, meaning that the higher the ejaculation frequency, the lower the pH  (acid), but the ejaculation frequency and motility of semen had the correlation of 0,34, indicating the more the semen ejaculation frequency, the higher the motility of spermatozoa. The motility of semen had the negative correlation with pH (-0.49). The higher the pH (base), the motility of spermatozoa tended to decline. Simmental bull showed also that semen ejaculation frequency with volume had correlation of -0.40, indicating that the higher the semen ejaculation frequency yakni, the lower the semen volume. Semen ejaculation frequency had correlation of 0.5 with mortality, indicating that the higher the semen ejaculation frequency, the higher the motility of spermatozoa.Keywords: Semen, ejaculation, volume, color, consistency, pH, motilit

Secure Set-Based State Estimation for Linear Systems under Adversarial Attacks on Sensors

When a strategic adversary can attack multiple sensors of a system and freely choose a different set of sensors at different times, how can we ensure that the state estimate remains uncorrupted by the attacker? The existing literature addressing this problem mandates that the adversary can only corrupt less than half of the total number of sensors. This limitation is fundamental to all point-based secure state estimators because of their dependence on algorithms that rely on majority voting among sensors. However, in reality, an adversary with ample resources may not be limited to attacking less than half of the total number of sensors. This paper avoids the above-mentioned fundamental limitation by proposing a set-based approach that allows attacks on all but one sensor at any given time. We guarantee that the true state is always contained in the estimated set, which is represented by a collection of constrained zonotopes, provided that the system is bounded-input-bounded-state stable and redundantly observable via every combination of sensor subsets with size equal to the number of uncompromised sensors. Additionally, we show that the estimated set is secure and stable irrespective of the attack signals if the process and measurement noises are bounded. To detect the set of attacked sensors at each time, we propose a simple attack detection technique. However, we acknowledge that intelligently designed stealthy attacks may not be detected and, in the worst-case scenario, could even result in exponential growth in the algorithm's complexity. We alleviate this shortcoming by presenting a range of strategies that offer different levels of trade-offs between estimation performance and complexity