IMPORT DEMANDS FOR U.S. FRESH GRAPEFRUIT: EFFECT OF U.S. PROMOTION PROGRAMS AND TRADE POLICIES OF IMPORTING NATIONS

This study estimates import demands for U.S. fresh grapefruit in Japan, France, Canada, and the Netherlands. Historically, these nations have imported about 90 percent of U.S. grapefruit exports. Four import demand functions were specified and estimated by joint generalized least squares based on the sample period 1969I to 1988IV. Results show that U.S. FOB price, per capita income of importing countries, exchange rates, price of substitutes, U.S. grapefruit promotion programs, and removal of trade restrictions have had an important effect on U.S. fresh grapefruit exports. Analyses suggest that U.S. producers can effectively promote fresh grapefruit in foreign markets, and that trade concessions have an important influence on grapefruit exports.International Relations/Trade,

An analytical model for gas overpressure in slug-driven explosions:insights into Strombolian volcanic eruptions

Strombolian eruptions, common at basaltic volcanoes, are mildly explosive events that are driven by a large bubble of magmatic gas (a slug) rising up the conduit and bursting at the surface. Gas overpressure within the bursting slug governs explosion dynamics and vigor and is the main factor controlling associated acoustic and seismic signals. We present a theoretical investigation of slug overpressure based on magma-static and geometric considerations and develop a set of equations that can be used to calculate the overpressure in a slug when it bursts, slug length at burst, and the depth at which the burst process begins. We find that burst overpressure is controlled by two dimensionless parameters: V', which represents the amount of gas in the slug, and A', which represents the thickness of the film of magma that falls around the rising slug. Burst overpressure increases nonlinearly as V' and A' increase. We consider two eruptive scenarios: (1) the "standard model," in which magma remains confined to the vent during slug expansion, and (2) the " overflow model," in which slug expansion is associated with lava effusion, as occasionally observed in the field. We find that slug overpressure is higher for the overflow model by a factor of 1.2-2.4. Applying our model to typical Strombolian eruptions at Stromboli, we find that the transition from passive degassing to explosive bursting occurs for slugs with volume >24-230 m(3), depending on magma viscosity and conduit diameter, and that at burst, a typical Strombolian slug (with a volume of 100-1000 m(3)) has an internal gas pressure of 1-5 bars and a length of 13-120 m. We compare model predictions with field data from Stromboli for low-energy " puffers," mildly explosive Strombolian eruptions, and the violently explosive 5 April 2003 paroxysm. We find that model predictions are consistent with field observations across this broad spectrum of eruptive styles, suggesting a common slug-driven mechanism; we propose that paroxysms are driven by unusually large slugs (large V')

Mapping functional traits: comparing abundance and presence-absence estimates at large spatial scales

Efforts to quantify the composition of biological communities increasingly focus on functional traits. The composition of communities in terms of traits can be summarized in several ways. Ecologists are beginning to map the geographic distribution of trait-based metrics from various sources of data, but the maps have not been tested against independent data. Using data for birds of the Western Hemisphere, we test for the first time the most commonly used method for mapping community trait composition – overlaying range maps, which assumes that the local abundance of a given species is unrelated to the traits in question – and three new methods that as well as the range maps include varying degrees of information about interspecific and geographic variation in abundance. For each method, and for four traits (body mass, generation length, migratory behaviour, diet) we calculated community-weighted mean of trait values, functional richness and functional divergence. The maps based on species ranges and limited abundance data were compared with independent data on community species composition from the American Christmas Bird Count (CBC) scheme coupled with data on traits. The correspondence with observed community composition at the CBC sites was mostly positive (62/73 correlations) but varied widely depending on the metric of community composition and method used (R2: 5.6×10−7 to 0.82, with a median of 0.12). Importantly, the commonly-used range-overlap method resulted in the best fit (21/22 correlations positive; R2: 0.004 to 0.8, with a median of 0.33). Given the paucity of data on the local abundance of species, overlaying range maps appears to be the best available method for estimating patterns of community composition, but the poor fit for some metrics suggests that local abundance data are urgently needed to allow more accurate estimates of the composition of communities

Clonally related, Notch-differentiated spinal neurons integrate into distinct circuits

Shared lineage has diverse effects on patterns of neuronal connectivity. In mammalian cortex, excitatory sister neurons assemble into shared microcircuits. I

Comparative analysis of drivers to BIM adoption among AEC firms in developing countries : a case of Nigeria

Purpose – Building information modelling (BIM) adoption is vital to productivity and competitive nature of the construction sector. However, BIM adoptions have not been generally embraced by many Architecture, Engineering, and Construction (AEC) firms, particularly in developing countries; and studies that investigate the important drivers to BIM adoptions among construction professionals through quantitative approach are limited. The study purpose is to address the aforementioned gap. Design/methodology/approach – The study used a literature review, a pilot study and a questionnaire survey. The primary data were carried out using structured questionnaire distributed to the four different, selected BIM adopters’ AEC firms. These comprised architectural firms, facility management firms, quantity surveying firms and structural engineering firms in Lagos, Nigeria. Data obtained were analyzed using mean score, standard deviation, Kruskal-Wallis test, and factor analysis. Findings – The study identified 23 drivers to BIM adoption and the relative importance of the identified drivers was gauged from each selected BIM adopters’ AEC firm category. The result of the Kruskal-Wallis test showed that there is no statistically significant difference in the perceptions of the four selected AEC firms in the mean ranking of the identified 23 drivers to BIM adoption. The findings from factor analysis categorized the identified drivers into two major factors to include: cost and time savings, and improved communication; and BIM awareness and government supports. Practical implications – The study empirically identified important drivers to BIM adoption which will be useful for construction stakeholders to formulate strategies to adopt the full implementation of BIM in the Nigerian AEC firms and other developing countries. Also, this study is very important as it identified, analyzed, and compared the drivers to BIM adoptions from four different AEC firms; thereby providing robust and more reliable findings. Originality/value – The study findings would inform the decisions of policymakers and construction stakeholders to make some policy recommendations capable of positively influencing the widespread adoption of BIM in AEC firms and construction industry at large. This study is important because the studies that comparatively and empirically analysed BIM drivers in AEC firms are rare, particularly in developing countries. Hence, this study could be used to benchmark future studies in developing countries

Exploration of gender norms and socialization among early adolescents : the use of qualitative methods for the global early adolescent study

Purpose: The Global Early Adolescent Study (GEAS) was launched in 2014 with the primary goal of understanding the factors in early adolescence that predispose young people to subsequent sexual risks, and conversely, those that promote healthy sexuality across different cultural contexts. The present article describes the methodology that was used for the first phase of GEAS, which consisted of conducting qualitative research to understand the gendered transitions into adolescence and the role that gender norms play within the key relationships of adolescents. Researchers from each of the sites that had completed data collection were also elicited for their feedback on the key strengths, challenges, and lessons learned from conducting research among 11- to 14-year-old adolescents. The purpose of this article is to present the description of each of the methods that were used in GEAS, as well as the researchers' perspectives of using the methods among early adolescents in their sites. Methods: The GEAS is being implemented through a collaboration of university and nongovernmental institutions from 15 cities: Assiut (Egypt) Baltimore (U.S.), Blantyre (Malawi), Cape Town (South Africa), Cochabomba (Bolivia), Cuenca (Ecuador), Edinburgh (Scotland), Ghent (Belgium), Hanoi (Vietnam), Ile-Ife (Nigeria), Kinshasa (DRC), Nairobi (Kenya), New Delhi (India), Ouaga-dougou (Burkina Faso), and Shanghai (China). Approximately 30 in-depth interviews among adolescents and 30 in-depth interviews with their parent/guardian were conducted at each site, with adults and adolescents interviewed separately. To build trust and increase engagement among the adolescent participants, we used two different visual research methods: (1) timeline exercise which was small group based and (2) the Venn diagram exercise which was conducted individually and used at the start of the in-depth interview. Results: The visual aspects of both the timeline and the Venn diagrams not only helped to produce data for the purposes of the study, but also were a successful way of engaging the adolescent participants across sites. While the narrative interviews produced extremely rich data, researchers did notice that there were a few challenges among the younger adolescents. Challenges were related to the length of the interview, comprehension of questions, as some of the questions were either too abstract or asked adolescents about an experience they had not yet had and therefore could not address or articulate. Conclusions: Conducting the first phase of GEAS revealed important insights for research with participants who are in this developmental phase of early adolescence. Methods that involve greater engagement and those that are visual were shown to work well irrespective of the cultural setting

Effect of influenza-induced fever on human bioimpedance values

BACKGROUND AND AIMS: Bioelectrical impedance analysis (BIA) is a widely used technique to assess body composition and nutritional status. While bioelectrical values are affected by diverse variables, there has been little research on validation of BIA in acute illness, especially to understand prognostic significance. Here we report the use of BIA in acute febrile states induced by influenza. METHODS: Bioimpedance studies were conducted during an H1N1 influenza A outbreak in Venezuelan Amerindian villages from the Amazonas. Measurements were performed on 52 subjects between 1 and 40 years of age, and 7 children were re-examined after starting Oseltamivir treatment. Bioelectrical Impedance Vector Analysis (BIVA) and permutation tests were applied. RESULTS: For the entire sample, febrile individuals showed a tendency toward greater reactance (p=0.058) and phase angle (p=0.037) than afebrile individuals, while resistance and impedance were similar in the two groups. Individuals with repeated measurements showed significant differences in bioimpedance values associated with fever, including increased reactance (p<0.001) and phase angle (p=0.007), and decreased resistance (p=0.007) and impedance (p<0.001). CONCLUSIONS: There are bioelectrical variations induced by influenza that can be related to dehydration, with lower extracellular to intracellular water ratio in febrile individuals, or a direct thermal effect. Caution is recommended when interpreting bioimpedance results in febrile states

Application of Machine Learning Identification and Classification of Muturu and Keteku Cattle Species for a Smart Agricultural Practice in Developing Countries such as Nigeria

Smart technologies have drastically reshaped the traditional methods of practicing agriculture as witnessed in husbandry. In this paper, a novel application of machine learning identification and classification of Muturu and Keteku cattle species in Nigeria was proposed as the mainstream model that enables the precision and intelligence perception of animal husbandry for a smart agricultural practice using enhanced mask region-based convolutional neural networks (mask R-CNN). A performance accuracy of 0.92 mAP (mean Average Precision) was achieved by the enhanced mask R-CNN model, making it on a par with the existing models