The effects of subcurative praziquantel treatment on life-history traits and trade-offs in drug-resistant Schistosoma mansoni

Natural selection acts on all organisms, including parasites, to maximize reproductive fitness. Drug resistance traits are often associated with life-history costs in the absence of treatment. Schistosomiasis control programmes rely on mass drug administration to reduce human morbidity and mortality. Although hotspots of reduced drug efficacy have been reported, resistance is not widespread. Using Bayesian state-space models (SSMs) fitted to data from an in vivo laboratory system, we tested the hypothesis that the spread of resistant Schistosoma mansoni may be limited by life-history costs not present in susceptible counterparts. S. mansoni parasites from a praziquantel-susceptible (S), a praziquantel-resistant (R) or a mixed line of originally resistant and susceptible parasites (RS) were exposed to a range of praziquantel doses. Parasite numbers at each life stage were quantified in their molluscan intermediate and murine definitive hosts across four generations, and SSMs were used to estimate key life-history parameters for each experimental group over time. Model outputs illustrated that parasite adult survival and fecundity in the murine host decreased across all lines, including R, with increasing drug pressure. Trade-offs between adult survival and fecundity were observed in all untreated lines, and these remained strong in S with praziquantel pressure. In contrast, trade-offs between adult survival and fecundity were lost under praziquantel pressure in R. As expected, parasite life-history traits within the molluscan host were complex, but trade-offs were demonstrated between parasite establishment and cercarial output. The observed trade-offs between generations within hosts, which were modified by praziquantel treatment in the R line, could limit the spread of R parasites under praziquantel pressure. Whilst such complex life-history costs may be difficult to detect using standard empirical methods, we demonstrate that SSMs provide robust estimates of life-history parameters, aiding our understanding of costs and trade-offs of resistant parasites within this system and beyond

Recruitment in Social Network Sites: The Interplay Between Usefulness and Risks in Explaining Jobseekers\u27 Intentions

Employers are increasingly turning to social networking sites (SNSs) to find candidates for their workforce or to gather intelligence about potential employees. However, apart from assessing the extent to which human resource professionals scan SNSs for information about job candidates, research on online recruitment in the context of SNSs is almost non-existent. In this study, we are investigating predictors of jobseekers’ intentions to apply for jobs in the context of SNSs. We propose a model that integrates classic technology adoption/utilization theories with salient factors such as privacy concerns that have increased in significance with the growing use of SNSs as an online recruitment source. This study will make a methodological and theoretical contribution to information systems research with the validation of the proposed model and associated scales in the online social computing context. It will also have practical implications for SNSs offering recruitment services; recruiters/potential employers; and jobseekers

The millimeter and submillimeter laboratory spectrum of methyl formate in its ground symmetric torsional state

Over 200 rotational lines of methyl formate in its ground (v-t = 0), symmetric (A) torsional state have been measured in the frequency range 140-550 GHz. Analysis of these and lower frequency transitions permits accurate prediction (≤0.1 MHz) of over 10,000 transitions at frequencies below 600 GHz with angular momentum J ≤ 50. The measured spectral lines have permitted identification of over 100 new methyl formate lines in Orion

Unit organization of the topic art in the home.

Thesis (M.A.)--Boston University This item was digitized by the Internet Archive

Organizational Structure and Resources of Alumni Associations at Public Senior Universities in the Southeastern United States

The purpose of the quantitative study was to analyze the staffing patterns, organizational structures, funding resources, practice of resource allocation, technology use, size of alumni population, size of institution enrollment, and age of the institutions at senior public colleges and universities in the southeastern United States. These institutions were derived from the membership of the Council for Advancement and Support of Education [CASE] during the academic years 2010-2012 in the United States District III region, generally the Southeast to lower Mid-Atlantic states. The study was further limited to public, comprehensive institutions as determined by the Carnegie Classification system. Data were collected through an online internet survey to test 11 research questions and gather demographic information relevant to the study. Of the 100 potential institutions for response, 16 completed surveys were received. The overall results of the tests reflect that 3 of the 11 results were statistically significant. Specifically, resource allocation scores were significantly higher than funding resource scores. Also there were strong positive correlations between technology use and age of institution and between size of alumni and the size of the institution

The laboratory millimeter-wave spectrum of methyl formate in its ground torsional E state

Over 250 rotational transitions of the internal rotor methyl formate (HCOOCH_3) in its ground v_t = 0 degenerate (E) torsional substate have been measured in the millimeter-wave spectral region. These data and a number of E-state lines identified by several other workers have been analyzed using an extension of the classical principal-axis method in the high barrier limit. The resulting rotational constants allow accurate prediction of the v_t = 0 E substate methyl formate spectrum below 300 GHz between states with angular momentum J ≤ 30 and rotational energy E_(rot)≤ 350cm^(-1). The calculated transition frequencies for the E state, when combined with the results of the previous analysis of the ground-symmetric, nondegenerate state, account for over 200 of the emission lines observed toward Orion in a recent survey of the 215-265 GHz band