A review of insect infestation of maize in farm storage in Africa with special reference to the ecology and control of Prostephanus truncatus (NRI Bulletin No. 18)

African farmers operate traditional methods of integrated pest control when storing maize. They dry the maize well, store it on the cob in suitable structures and avoid protracted storage whenever possible. Such traditional methods are reasonably effective and studies have shown that under normal conditions they can keep losses down to less than 5% per year (Adams, 1977; Golob, 1981 a and 1981 b). Recent changes in farming systems have, however, interfered with traditional storage practices, resulting in the more frequent occurrence of serious losses. In particular, where high-yielding varieties of maize have been introduced, a dramatic increase in losses has often resulted. Other changes in farming systems have affected cropping patterns, causing farmers to store maize that is too wet, increasing its susceptibility to attack by insects and fungi. The recent accidental introduction of the larger grain borer (Prostephanus truncatus) into Africa has added a new dimension to these problems, through its remarkable ability to damage well-dried maize, even when stored on the cob. This beetle is currently a more serious pest in parts of sub-Saharan Africa than in its native Central America, indicating that in Africa there are ecological, agricultural or socio-economic factors associated with maize storage which favour its success. Certainly, where P. truncatus has become established in Africa, it has commonly increased the loss levels sustained in traditional maize stores to a point at which intensified pest control by the farmer is an economic necessity (McFarlane, 1988). There is thus a need to revise recommended methods for the control of insect pests of maize in farm storage, taking into account the changes which have reduced the effectiveness of traditional practices. This bulletin attempts to summarize available data from studies of pest infestation in traditional maize stores, relevant to current and future research in this field. The emphasis on P. truncatus in parts of the text reflects the importance currently attached to the development of integrated pest management strategies for this pest, in order to limit its spread in maize-producing regions of Africa

ALDH2*2 and peer drinking in East Asian college students

Background: The ALDH2*2 allele (A-allele) at rs671 is more commonly carried by Asians and is associated with alcohol-related flushing, a strong adverse reaction to alcohol that is protective against drinking. Social factors, such as having friends who binge drink, also contribute to drinking in Asian youth. Objectives: This study examined the interplay between ALDH2*2, peer drinking, and alcohol consumption in college students. We hypothesized that the relationship between ALDH2*2 and standard grams of ethanol per month would vary based on the level of peer drinking. Methods: Subjects (N = 318, 63.25% female) were East Asian college students in the United States who reported drinking alcohol. Data were from the freshman year of a university survey that included a saliva DNA sample. ALDH2*2 status was coded ALDH2*2(+) (A/G and A/A genotypes) and ALDH2*2(−) (G/G genotype). Peer drinking was students’ perception of how many of their friends “got drunk”. Results: Main effects of ALDH2*2(−) and having more friends who got drunk were associated with greater alcohol consumption. The ALDH2*2 × peer drunkenness interaction showed a stronger positive association with alcohol consumption for ALDH2*2(−) versus ALDH2*2(+) at increasing levels of peer drunkenness. Follow-up comparisons within each peer drunkenness level identified significantly higher alcohol consumption for ALDH2*2(−) compared to ALDH2*2(+) at the all friends got drunk level. Conclusion: There was evidence of a stronger effect for ALDH2*2(−) compared to ALDH2*2(+) with greater alcohol use when students were more exposed to peer drinking. Findings contribute to a growing literature on the interrelationships between genetic influences and more permissive environments for alcohol consumption

Bionomic variation among populations of the southern cowpea weevil, Callosobruchus maculatus, and their responses to different varieties of the primary host

Geographical variation among three "strains" of Callosobruchus maculatus F. (Coleoptera : Bruchidae), a cosmopolitan pest of stored legume seeds, has been studied. The fecundity, fertility and adult productivity of the strains were measured on seeds of the primary host, the cowpea. The number of eggs laid by females of each strain depended on the number of cowpeas to which she had access. Females of the Nigerian strain laid more eggs on a small number of cowpeas than females of the strains from Yemen and Brazil. The Yemen strain produced fewer adults from individual seeds than the other two strains when similar numbers of hatched eggs were present. Experiments were performed to examine this difference. The results indicated that Yemen individuals were heavier, on average, and consumed a larger quantity of cowpea during development than individuals of the Nigerian or Brazilian strains. All three strains crossed to produce viable and fertile progeny. Hybrids of crosses between the Yemen strain and either of the two smaller strains were of intermediate size and were produced in numbers which were intermediate to those of the two strains involved. The response of the three strains to a cowpea variety (TVu 2027) known to exhibit resistance to bruchid attack was measured. The Brazilian strain suffered much higher mortality on TVu 2027 than the other two strains. The Yemen strain suffered slightly higher mortality than the Nigerian strain, but the mean development period of the Yemen strain was shorter. Progeny of inter-strain crosses suffered an intermediate level of mortality on TVu 2027. The proportion of Yemen and Nigerian individuals which could survive on TVu 2027 increased when successive generations were bred on the resistant variety. The consequences of geographical variation in this beetle pest, for the success of new cowpea lines which incorporate the resistant properties of TVu 2027, are discussed.<p

Chapter XV: Success Factors for the Global Implementation of ERP / HRMS Software

This research observes a global implementation of enterprise resource planning (ERP)/human resources management system (HRMS) software at an international company. The software was implemented in 16 countries. Variables such as cultural differences, communication-distance, management support, trust, and resistance to change were evaluated in the literature review. These variables have an impact on implementation success during global HRMS implementation. Further analyses on specific success factors faced with global implementations were evaluated using semi-structured interviews. The authors prepared a questionnaire to further explore the data. Respondents rated questions related to management support the highest overall. An interesting find was that the semi-structured interview results indicated that the software chosen was not a perfect fit for the global community. The mean for questions related to global HRMS success was higher for respondents located in the United States than those located in other locations

Carbon cycling in the deep eastern North Pacific benthic food web: Investigating the effect of organic carbon input

The deep ocean benthic environment plays a role in long-term carbon sequestration. Understanding carbon cycling in the deep ocean floor is critical to evaluate the impact of changing climate on the oceanic systems. Linear inverse modeling was used to quantify carbon transfer between compartments in the benthic food web at a long time-series study site in the abyssal northeastern Pacific (Station M). Linear inverse food web models were constructed for three separate years in the time-series when particulate organic carbon (POC) flux was relatively high (1990: 0.63 mean mmol C m?2 d?1), intermediate (1995: 0.24) and low (1996: 0.12). Carbon cycling in all years was dominated by the flows involved in the microbial loop; dissolved organic carbon uptake by microbes (0.80–0.95 mean mmol C m?2 d?1), microbial respiration (0.52–0.61), microbial biomass dissolution (0.09–0.18) and the dissolution of refractory detritus (0.46–0.65). Moreover, the magnitude of carbon flows involved in the microbial loop changed in relation to POC input, with a decline in contribution during the high POC influxes, such as those recently experienced at Station M. Results indicate that during high POC episodic pulses the role of faunal mediated carbon cycling would increase. Semi-labile detritus dominates benthic faunal diets and the role of labile detritus declined with increased total POC input. Linear inverse modeling represents an effective framework to analyze high-resolution time-series data and demonstrate the impact of climate change on the deep ocean carbon cycle in a coastal upwelling system

Patterns of substance use across the first year of college and associated risk factors

Starting college is a major life transition. This study aims to characterize patterns of substance use across a variety of substances across the first year of college and identify associated factors. We used data from the first cohort (N = 2056, 1240 females) of the “Spit for Science” sample, a study of incoming freshmen at a large urban university. Latent transition analysis was applied to alcohol, tobacco, cannabis, and other illicit drug uses measured at the beginning of the fall semester and midway through the spring semester. Covariates across multiple domains – including personality, drinking motivations and expectancy, high school delinquency, peer deviance, stressful events, and symptoms of depression and anxiety – were included to predict the patterns of substance use and transitions between patterns across the first year. At both the fall and spring semesters, we identified three subgroups of participants with patterns of substance use characterized as: (1) use of all four substances; (2) alcohol, tobacco, and cannabis use; and (3) overall low substance use. Patterns of substance use were highly stable across the first year of college: most students maintained their class membership from fall to spring, with just 7% of participants in the initial low substance users transitioning to spring alcohol, tobacco, and cannabis users. Most of the included covariates were predictive of the initial pattern of use, but covariates related to experiences across the first year of college were more predictive of the transition from the low to alcohol, tobacco, and cannabis user groups. Our results suggest that while there is an overall increase in alcohol use across all students, college students largely maintain their patterns of substance use across the first year. Risk factors experienced during the first year may be effective targets for preventing increases in substance use