10,648 research outputs found
Evidence-Based Study of Medication Compliance Project in Hiv Prevention Using Pre-Exposure Prophylaxis (Prep) Antivirals for HIV-Negative Males
In 2012, emtricitabine/tenofovir was the only Food and Drug Administration-approved medication for pre-exposure prophylaxis (PrEP) used in human immunodeficiency virus (HIV) prevention. To date, there is little research on open-label and mixed-payer characteristics supporting medication compliance of men who have sex with men (MSM). The purpose of this research was to describe individual demographic variables associated with PrEP medication adherence and to examine the effect of a follow-up phone call from a nurse once a month for 3 months. A total of 30 MSM were recruited and data were collected using a demographic questionnaire, medication adherence tool and follow-up phone calls. Data were analyzed using a statistical package. Spearman’s rho correlations demonstrated high medication adherence in single men (rs (28) = −.375, p \u3c .05) with no mental health issues (rs (28) = .426, p \u3c .05) and a higher educational level (rs (28) = −.431, p \u3c .05). A between group Chi-square demonstrated men with high medication adherence and medium medication adherence did not statistically differ over 3 months (χ2 (2, N = 28) = .668, p = .71). Individuals who exhibited higher PrEP use in an open-label and mixed-payer structure appeared to be young, single, well educated, and employed Caucasian gay males with multiple partners. More information will be needed from ethnically diverse populations, especially non-Caucasians. Finally, clinical nurses, by supplying accountability by phone calls, could improve PrEP compliance by providing planned monthly reminders
On the sustainability of currency boards : evidence from Argentina and Hong Kong : [Version: September 2008]
This paper examines the sustainability of the currency board arrangements in Argentina and Hong Kong. We employ a Markov switching model with two regimes to infer the exchange rate pressure due to economic fundamentals and market expectations. The empirical results suggest that economic fundamentals and expectations are key determinants of a currency board’s sustainability. We also show that the government’s credibility played a more important role in Argentina than in Hong Kong. The trade surplus, real exchange rate and inflation rate were more important drivers of the sustainability of the Hong Kong currency board
A Dynamic Oligopoly Game of the US Airline Industry: Estimation and Policy Experiments
This paper studies the contribution of demand, costs, and strategic factors to the adoption of hub-and-spoke networks in the US airline industry. Our results are based on the estimation of a dynamic oligopoly game of network competition that incorporates three groups of factors that may explain hub-and-spoke networks: (1) travelers may value the services associated with the scale of operation of an airline in the hub airport; (2) operating costs and entry costs in a route may decline with the airline's scale of operation in the origin and destination airports (e.g., economies of scale and scope); and (3) a hub-and-spoke network may be an effective strategy to deter the entry of other carriers. We estimate the model using data from the Airline Origin and Destination Survey with information on quantities, prices, and entry and exit decisions for every airline company in the routes between the 55 largest US cities. As methodological contributions, we propose and apply a method to reduce the dimension of the state space in dynamic games, and a procedure to deal with the problem of multiple equilibria when using a estimated model to make counterfactual experiments. We find that the most important factor to explain the adoption of hub-and-spoke networks is that the cost of entry in a route declines importantly with the scale of operation of the airline in the airports of the route. For some of the larger carriers, strategic entry deterrence is the second most important factor to explain hub-and-spoke networks.Airline industry; Hub-and-spoke networks; Entry costs; Industry dynamics; Estimation of dynamic games; Counterfactual experiments in models with multiple equilibria.
A Dynamic Oligopoly Game of the US Airline Industry: Estimation and Policy Experiments
This paper studies the contribution of demand, costs, and strategic factors to the adoption of hub-and-spoke networks in the US airline industry. Our results are based on the estimation of a dynamic oligopoly game of network competition that incorporates three groups of factors which may explain the adoption of hub-and-spoke networks: (1) travelers value the services associated with the scale of operation of an airline in the hub airport (e.g., more convenient check-in and landing facilities); (2) operating costs and entry costs in a route may decline with an airline's scale operation in origin and destination airports (e.g., economies of scale and scope); and (3) a hub-and-spoke network may be an effective strategy to deter the entry of other carriers. We estimate the model using data from the Airline Origin and Destination Survey with information on quantities, prices, and entry and exit decisions for every airline company in the routes between the 55 largest US cities. As a methodological contribution, we propose and apply a simple method to deal with the problem of multiple equilibria when using the estimated model to predict the effects of changes in structural parameters. We find that the most important factor to explain the adoption of hub-and-spoke networks is that the cost of entry in a route declines very importantly with the scale of operation of the airline in the airports of the route. For some of the larger carriers, strategic entry deterrence is the second most important factor to explain hub-and-spoke networks.Airline industry; Hub-and-spoke networks; Entry costs; Industry dynamics; Estimation of dynamic games; Counterfactuals with multiple equilibria
A Dynamic Game of Airline Network Competition: Hub-and-Spoke Networks and Entry Deterrence
In a hub-and-spoke network, the total profit function of an airline is supermodular with respect to its entry decisions at different city-pairs. This source of complementarity implies that a hub-and-spoke network can be an effective strategy to deter entry of competitors. This paper presents a dynamic game of airlines network competition that incorporates this entry deterrence motive for using hub-and-spoke networks. We summarize the results of the estimation of the model, with particular attention to empirical evidence on the entry deterrence motive.Airline networks; Hub-and-spoke; Entry deterrence; Dynamic games; Supermodularity
Determination Of Pb(II), Cu(II) And Ni(II) In Water By Direct Measurement Using Uv/Vis Spectrophotometer
Logam berat merupakan unsur logam dengan ketumpatan yang tinggi dan
kebanyakannya bersifat toksik pada kepekatan yang rendah. Selain itu, kepekatan
logam berat dalam organisma akan semakin meningkat dengan masa disebabkan oleh
sifat bioakumulasi daripada logam berat dan tidak dapat diuraikan. Teknik terkini
untuk menentukan logam berat dalam air adalah melalui AAS, IC, ICP-AES, ICPMS,
XRF dan elektrokimia. Teknik-teknik ini dapat memberi ketepatan yang tinggi
dalam pengukuran tetapi memerlukan kos penyelenggaraan yang tinggi dan prosedur
penyediaan yang rumit. Dalam penyelidikan ini, analisis kuantitatif terhadap ion
Pb2+, Cu2+ dan Ni2+ dalam larutan akueus telah berjaya dijalankan dengan
menggunakan UV/VIS spektroskopi tanpa reagen kimia tambahan. Penyelidikan
bermula dengan mengenalpasti panjang gelombang yang berkesan untuk penyerapan
dan kemudiannya disahkan dengan bilangan sampel yang banyak. Daripada
penyelidikan ini, panjang gelombang berkesan untuk penyerapan di dalam julat UV
bagi Pb2+ dan Cu2+ adalah daripada 200 nm hingga 230 nm dan Cu2+ dan Ni2+
daripada 600 nm hingga 800 nm.
Heavy metal are metallic element with relatively high density and mostly
toxic at low concentration. Heavy metal does not degrade and tends to bioaccumulate
in organism over time. Current technique to determine heavy metals in water mostly
via AAS, IC, ICP-AES, ICP-MS, XRF and electrochemical method,these techniques
provide high precision in measurement but required high maintenance cost and
complicated preparation. In this research, quantitative analysis of Pb2+, Cu2+ and Ni2+
ions in aqueous solution was carried out successfully using UV/VIS spectroscopy
without additional chemical reagent. The research begins with identifying the
effective absorption wavelength and was later verified using large amount of
samples. From this research, the effective wavelength within UV range for Pb2+ and
Cu2+ is roughly from 200 nm to 230 nm and both the Cu2+ and Ni2+ have absorbance
from wavelength 600 nm to 800 nm
- …