236 research outputs found
The Mad Science of Hip-Hop: History, Technology, and Poetics of Hip-Hop\u27s Music, 1975-1991
In 1979, the first commercial recordings of hip-hop music were released. The music\u27s transition from the parks and clubs of the Bronx to recorded media resulted in hip-hop music being crafted and mediated in a recording studio before reaching the ears of listeners. In this dissertation I present a comprehensive investigation into the history of the instrumental component of hip-hop music heard on recordings, commonly referred to as beats. My historical narrative is formed by: the practices involved in the creation of hip-hop beats; the technologies that facilitated and defined those practices; and the debates around these two aspects that established the aesthetics of the music. The span of years covered in the dissertation are bookended by the establishment of precision breakbeat compositions on turntables in 1975 and the technological, economic, and legal developments in hip-hop music and culture that became a turning point for the practice of beat making and the sound of hip-hop music beginning in 1991. Beat makers, producers, and engineers--the recordists predominantly responsible for the sound of a hip-hop recording--are cultural producers involved in the social practice of cultural production. As such, the history in this study is informed by ethnographic research in the form of interviews and participant observation. Musical analyses are also utilized to illuminate the historical development of hip-hop music, particularly to display the ways that beat makers created their sound arrangements through the functions of certain technologies. This dissertation explores the intermingling of technology and human practice and serves as a foundation for further inquiry into the effect of technology on music making practices
Africa and Technology in Higher Education: Trends, Challenges, and Promise
Showing that technology in higher education in African countries is lagging behind the developed world and also that Internet connectivity is on the rise in African nations, this paper describes and analyzes trends in the use of ICTs as well as the impact that the shortage in technological use and capacity has on Africa, particularly that needed to address the changing demands within the higher education sector. Challenges to the proposed widespread implementation of technology exist, particularly because most institutions of higher education have very limited technological capacity and basic resources, such as electricity, equipment, and funding; brain drain, improper use of ICT, and the colonial mindset are also factors. It is suggested that ICT be integrated into education with a purpose and within the context of postcolonial theory and a critical pedagogy perspective. Key uses of ICT in education, including mobile technology, are access, support, and communication, making learning available to anyone anywhere and enhancing learning as an interactive process, with much potential for collaboration and problem-solving. Four salient components related to incorporating ICTs into higher education are discussed: (a) teacher education; (b) curriculum; (c) distance learning; and (d) educational policy, planning, and management. Examples of technological initiatives in higher education as well as recommendations are given. Ghana, Kenya, and Tanzania, representative of other African nations to varying degrees, are highlighted in regard to ICT infrastructure and its relevancy to higher education. It is concluded that African higher education has high potential for catching up in the technological race
Geographic variations of childhood asthma hospitalization and outpatient visits and proximity to ambient pollution sources at a U.S.-Canada border crossing
BACKGROUND: Childhood asthma is a significant public health problem in the United States and evidence is accumulating regarding the contribution from traffic and ambient air pollution. This study is a companion piece of a related Buffalo asthma study in adults recently published in the July 2004 issue of American Journal of Public Health. This study focuses on children under 18 years of age diagnosed with asthma during a three-year period (2000–2002). In order to determine the effects of particulate air pollution on public health, we conducted an ecologic study of childhood asthma and point-source respirable particulate air pollution in patients diagnosed with asthma (n = 6,425). Patients diagnosed with gastroenteritis (n = 5,132) were used as controls. RESULTS: Although the results of this study show spatial patterns similar to the ones observed in the adult study, a multiple-comparison test shows that EPA-designated focus sites located in Buffalo's east side are statistically (p < 0.008) more linked to childhood asthma than sites located elsewhere. CONCLUSION: Findings of this study can be useful in geographic targeting and in the design of optimal and preventive measures
ABC Transporter Required for Intercellular Transfer of Developmental Signals in a Heterocystous Cyanobacterium
In the filamentous cyanobacterium Anabaena, patS and hetN encode peptide-derived signals with many of the properties of
morphogens. These signals regulate the formation of a periodic pattern of heterocysts by lateral inhibition of differentiation.
Here we show that intercellular transfer of the patS- and hetN-dependent developmental signals from heterocysts to vegetative cells requires HetC, a predicted ATP-binding cassette transporter (ABC transporter). Relative to the wild type, in a hetC mutant differentiation resulted in a reduced number of heterocysts that were incapable of nitrogen fixation, but deletion of patS or hetN restored heterocyst number and function in a hetC background. These epistasis results suggest that HetC is necessary for conferring self-immunity to the inhibitors on differentiating cells. Nine hours after induction of differentiation, HetC was required for neither induction of transcription of patS nor intercellular transfer of the patS-encoded signal to neighboring cells. Conversely, in strains lacking HetC, the patS- and hetN-encoded signals were not transferred from heterocyst cells to adjacent vegetative cells. The results support a model in which the patS-dependent signal is initially transferred between vegetative cells in a HetC-independent fashion, but some time before morphological differentiation of heterocysts is complete, transfer of both signals transitions to a HetC-dependent process
Adapting a Family-Focused Diabetes Prevention Program for a Federally Qualified Health Center: A Qualitative Report
Purpose The purpose of the study was to explore the needs of high-risk Latinx/Hispanic women with a history of gestational diabetes who were patients at a Federally Qualified Health Center (FQHC) in anticipation of a future family-based program. Methods Six focus group studies were conducted in partnership with El Rio Community Health Center, an FQHC in Tucson, Arizona. Thirty-nine women participated, each identified as Latinx/Hispanic, self-reported a history of gestational diabetes or prediabetes, and had at least 1 child aged 8 to 13. Three investigators independently reviewed transcripts from the focus groups to identify themes that reflected thematic saturation from participants' responses. Data coding and results were discussed as a group and any differences were collectively adjudicated. Results All participants had a family member with diabetes and worried about their and their immediate family members' risk for developing the disease. The possible benefits of participating in a lifestyle prevention program were universally recognized, but multiple barriers to participation were described, including scheduling conflicts, access to childcare, transportation, and the need to involve additional family members to reinforce program objectives. Conclusions There is a strong willingness to participate in a diabetes prevention program among respondents, but to be successful, interventions must be tailored to specific needs and challenges. Trying to apply existing prevention curricula with low-income Latinx/Hispanic populations may not be successful without adaptations.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]
An early chondrichthyan and the evolutionary assembly of a shark body plan
Although relationships among the major groups of living gnathostomes are well established, the relatedness of early jawed vertebrates to modern clades is intensely debated. Here, we provide a new description of
Gladbachus
, a Middle Devonian (Givetian approx. 385-million-year-old) stem chondrichthyan from Germany, and one of the very few early chondrichthyans in which substantial portions of the endoskeleton are preserved. Tomographic and histological techniques reveal new details of the gill skeleton, hyoid arch and jaws, neurocranium, cartilage, scales and teeth. Despite many features resembling placoderm or osteichthyan conditions, phylogenetic analysis confirms
Gladbachus
as a stem chondrichthyan and corroborates hypotheses that all acanthodians are stem chondrichthyans. The unfamiliar character combination displayed by
Gladbachus
, alongside conditions observed in acanthodians, implies that pre-Devonian stem chondrichthyans are severely under-sampled and strongly supports indications from isolated scales that the gnathostome crown group originated at the latest by the early Silurian (approx. 440 Ma). Moreover, phylogenetic results highlight the likely convergent evolution of conventional chondrichthyan conditions among earliest members of this primary gnathostome division, while skeletal morphology points towards the likely suspension feeding habits of
Gladbachus
, suggesting a functional origin of the gill slit condition characteristic of the vast majority of living and fossil chondrichthyans.
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Aquatic biosurvey of the Lovell River on UNH land
We assessed the physical, chemical and biological conditions at two sites along the Lovell River on University of New Hampshire (UNH) -owned conservation land. The discharge was 4.4 m3 s-1 at Site 1 and 5.7 m3 s -1 downstream at Site 2. Canopy coverage ranged from 8-25%. Canopy was dominated by Eastern Hemlock (79-84%). Much of the stream was strewn with large boulders and the substrate consisted of rocks of highly variable sizes ( 3-549 cm dia.). Specific conductivity (22.1-23.3 µS), pH (6.4) and temperature (7.9-8.3 °C) varied little between sites. Macro-invertebrate bio-indices indicated either excellent water quality with no apparent organic pollution (3.0/10) or good water quality with possible slight organic pollution (4.4/10)
Expanding the Direct HetR Regulon in Anabaena sp. Strain PCC 7120
In response to a lack of environmental combined nitrogen, the filamentous cyanobacterium Anabaena sp. strain PCC 7120 differentiates nitrogen-fixing heterocyst cells in a periodic pattern. HetR is a transcription factor that coordinates the regulation of this developmental program. An inverted repeat-containing sequence in the hepA promoter required for proheterocyst-specific transcription was identified based on sequence similarity to a previously characterized binding site for HetR in the promoter of hetP. The binding affinity of HetR for the hepA site is roughly an order of magnitude lower than that for the hetP binding site. A BLAST search of the Anabaena genome identified 166 hepA-like sites that occur as single or tandem sites (two binding sites separated by 13 bp). The vast majority of these sites are present in predicted intergenic regions. HetR bound five representative single binding sites in vitro, and binding was abrogated by transversions in the binding sites that conserved the inverted repeat nature of the sites. Binding to four representative tandem sites was not observed. Transcriptional fusions of the green fluorescent protein gene gfp with putative promoter regions associated with the representative binding sites indicated that HetR could function as either an activator or repressor and that activation was cell-type specific. Taken together, we have expanded the direct HetR regulon and propose a model in which three categories of HetR binding sites, based on binding affinity and nucleotide sequence, contribute to three of the four phases of differentiation
The trpE Gene Negatively Regulates Differentiation of Heterocysts at the Level of Induction in Anabaena sp. Strain PCC 7120
Levels of 2-oxoglutarate (2-OG) reflect nitrogen status in many bacteria. In heterocystous cyanobacteria, a spike in the 2-OG level occurs shortly after the removal of combined nitrogen from cultures and is an integral part of the induction of heterocyst differentiation. In this work, deletion of one of the two annotated trpE genes in Anabaena sp. strain PCC 7120 resulted in a spike in the 2-OG level and subsequent differentiation of a wild-type pattern of heterocysts when filaments of the mutant were transferred from growth on ammonia to growth on nitrate. In contrast, 2-OG levels were unaffected in the wild type, which did not differentiate under the same conditions. An inverted-repeat sequence located upstream of trpE bound a central regulator of differentiation, HetR, in vitro and was necessary for HetR-dependent transcription of a reporter fusion and complementation of the mutant phenotype in vivo. Functional complementation of the mutant phenotype with the addition of tryptophan suggested that levels of tryptophan, rather than the demonstrated anthranilate synthase activity of TrpE, mediated the developmental response of the wild type to nitrate. A model is presented for the observed increase in 2-OG in the trpE mutant
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