Diffusion of the internet : a cross-country analysis

This paper analyzes the process of Internet diffusion across the world using a panel of 199 countries during 1990-2004. The authors group countries in two categories-low and high-income countries-and show that the Internet diffusion process is well characterized by an S-shape curve for both groups. Low-income countries display a steeper diffusion curve that is equivalent to a right shift of the diffusion curve for high-income countries. The estimated diffusion curves provide evidence of a"catching-up"process, although a very slow one. The paper explores the determinants of Internet diffusion at the country level and across the same income groups. The most novel finding is that network effects seem to be crucial-the number of Internet users in a country in a given year is positively associated with the number of users in the previous year. The findings also show that the degree of competition in the provision of Internet service contributes positively to its diffusion, and there are significant positive language externalities.Technology Industry,Information Security&Privacy,E-Business,Income,Education for the Knowledge Economy

The diffusion of Internet: a cross-country analysis

This paper analyzes the process of Internet diffusion across the world using a panel of 214 countries during the period 1990-2004. Countries are classified as low and high-income and it is shown that the diffusion process is characterized by a different S-shape in each group. The estimated diffusion curves provide evidence of very slow "catching up". The paper also explores the determinants of Internet diffusion and shows that network effects are crucial to explain this process. One important finding is that the degree of competition in the provision of Internet contributes positively to its diffusion.Technological diffusion, Internet, S-shape curve, Network externalities, Digital divide

Success of Senegal's first nationwide distribution of long-lasting insecticide-treated nets to children under five - contribution toward universal coverage

<p>Abstract</p> <p>Background</p> <p>In 2009, the first national long-lasting insecticide-treated net (LLIN) distribution campaign in Senegal resulted in the distribution of 2.2 million LLINs in two phases to children aged 6-59 months. Door-to-door teams visited all households to administer vitamin A and mebendazole, and to give a coupon to redeem later for an LLIN.</p> <p>Methods</p> <p>A nationwide community-based two-stage cluster survey was conducted, with clusters selected within regions by probability proportional to size sampling, followed by GPS-assisted mapping, simple random selection of households in each cluster, and administration of a questionnaire using personal digital assistants (PDAs). The questionnaire followed the Malaria Indicator Survey format, with rosters of household members and bed nets, and questions on campaign participation.</p> <p>Results</p> <p>There were 3,280 households in 112 clusters representing 33,993 people. Most (92.1%) guardians of eligible children had heard about the campaign, the primary sources being health workers (33.7%), neighbours (26.2%), and radio (22.0%). Of eligible children, 82.4% received mebendazole, 83.8% received vitamin A, and 75.4% received LLINs. Almost all (91.4%) LLINs received during the campaign remained in the household; of those not remaining, 74.4% had been given away and none were reported sold. At least one insecticide-treated net (ITN) was present in 82.3% of all households, 89.2% of households with a child < 5 years and 57.5% of households without a child < 5 years. Just over half (52.4%) of ITNs had been received during the campaign. Considering possible indicators of universal coverage, 39.8% of households owned at least one ITN per two people, 21.6% owned at least one ITN per sleeping space and 34.7% of the general population slept under an ITN the night before the survey. In addition, 45.6% of children < 5 years, and 49.2% of pregnant women had slept under an ITN.</p> <p>Conclusions</p> <p>The nationwide integrated LLIN distribution campaign allowed household ITN ownership of one or more ITNs to surpass the RBM target of 80% set for 2010, though additional distribution strategies are needed to reach populations missed by the targeted campaign and to reach the universal coverage targets of one ITN per sleeping space and 80% of the population using an ITN.</p

Senegalia Senegal response to inoculation with rhizobial strains vary in relation to seed provenance and soil type

Aims: The focus of the study was to determine the symbiotic and growth response of three Senegalia Senegal (Syn. Acacia Senegal, gum arabic tree) provenances, namely Dahra (Senegal), Tera (Niger) and Makueni (Kenya) to inoculation with selected S. Senegal-nodulating rhizobia in soils from Dahra and Goudiry regions of Senegal, representing typical soil and enviromental conditions for establishing gum arabic production plantations. Methods: A greenhouse experiment was performed to evaluate the effect of 11 rhizobial strains on nodulation and growth of three S. Senegal provenances in two field soils, differing in nutrient status and indigenous rhizobia. After 4 months, plants were harvested for determination of nodulation, shoot and root dryweight. Results: Nodulation and growth of S. Senegal varied in relation to rhizobial strain, provenance, soil type, and their interactions. Generally, nodulation was higher in Dahra than Goudiry soils, while Makueni provenance was the most compatible host. Inoculation had a significant effect on all parameters measured in Dahra field soil. By contrast, inoculation had a significant effect on height (shoot length), and shoot, root and total dry matter but not on nodulation. In the two field soils, seed provenance effect was significant for all parameters measured. The interaction between inoculation and provenance showed a significant effect on all parameters measured except nodule number in Dahra field soil while in Goudiry, the interaction had a significant effect on seedling height and shoot, root, and total dry matter but this effect was not significant with nodulation parameters. Conclusions: S. Senegal is variable in its response to inoculation, it is therefore advantageous to select and match effective rhizobia-provenance symbionts for each site

Major Reduction in Anti-Malarial Drug Consumption in Senegal after Nation-Wide Introduction of Malaria Rapid Diagnostic Tests

BACKGROUND: While WHO recently recommended universal parasitological confirmation of suspected malaria prior to treatment, debate has continued as to whether wide-scale use of rapid diagnostic tests (RDTs) can achieve this goal. Adherence of health service personnel to RDT results has been poor in some settings, with little impact on anti-malarial drug consumption. The Senegal national malaria control programme introduced universal parasite-based diagnosis using malaria RDTs from late 2007 in all public health facilities. This paper assesses the impact of this programme on anti-malarial drug consumption and disease reporting. METHODS AND FINDINGS: Nationally-collated programme data from 2007 to 2009 including malaria diagnostic outcomes, prescription of artemisinin-based combination therapy (ACT) and consumption of RDTs in public health facilities, were reviewed and compared. Against a marked seasonal variation in all-cause out-patient visits, non-malarial fever and confirmed malaria, parasite-based diagnosis increased nationally from 3.9% of reported malaria-like febrile illness to 86.0% over a 3 year period. The prescription of ACT dropped throughout this period from 72.9% of malaria-like febrile illness to 31.5%, reaching close equivalence to confirmed malaria (29.9% of 584,873 suspect fever cases). An estimated 516,576 courses of inappropriate ACT prescription were averted. CONCLUSIONS: The data indicate high adherence of anti-malarial prescribing practice to RDT results after an initial run-in period. The large reduction in ACT consumption enabled by the move from symptom-based to parasite-based diagnosis demonstrates that effective roll-out and use of malaria RDTs is achievable on a national scale through well planned and structured implementation. While more detailed information on management of parasite-negative cases is required at point of care level to assess overall cost-benefits to the health sector, considerable cost-savings were achieved in ACT procurement. Programmes need to be allowed flexibility in management of these funds to address increases in other programmatic costs that may accrue from improved diagnosis of febrile disease

Preclinical development of a stabilized RH5 virus-like particle vaccine that induces improved antimalarial antibodies

Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is a leading blood-stage malaria vaccine antigen target, currently in a phase 2b clinical trial as a full-length soluble protein/adjuvant vaccine candidate called RH5.1/Matrix-M. We identify that disordered regions of the full-length RH5 molecule induce non-growth inhibitory antibodies in human vaccinees and that a re-engineered and stabilized immunogen (including just the alpha-helical core of RH5) induces a qualitatively superior growth inhibitory antibody response in rats vaccinated with this protein formulated in Matrix-M adjuvant. In parallel, bioconjugation of this immunogen, termed "RH5.2," to hepatitis B surface antigen virus-like particles (VLPs) using the "plug-and-display" SpyTag-SpyCatcher platform technology also enables superior quantitative antibody immunogenicity over soluble protein/adjuvant in vaccinated mice and rats. These studies identify a blood-stage malaria vaccine candidate that may improve upon the current leading soluble protein vaccine candidate RH5.1/Matrix-M. The RH5.2-VLP/Matrix-M vaccine candidate is now under evaluation in phase 1a/b clinical trials

HER2-Specific Chimeric Antigen Receptor–Modified Virus-Specific T Cells for Progressive Glioblastoma: A Phase 1 Dose-Escalation Trial

Glioblastoma is an incurable tumor, and the therapeutic options for patients are limited. To determine whether the systemic administration of HER2-specific chimeric antigen receptor (CAR)-modified virus-specific T cells (VSTs) is safe and whether these cells have antiglioblastoma activity. In this open-label phase 1 dose-escalation study conducted at Baylor College of Medicine, Houston Methodist Hospital, and Texas Children's Hospital, patients with progressive HER2-positive glioblastoma were enrolled between July 25, 2011, and April 21, 2014. The duration of follow-up was 10 weeks to 29 months (median, 8 months). Monotherapy with autologous VSTs specific for cytomegalovirus, Epstein-Barr virus, or adenovirus and genetically modified to express HER2-CARs with a CD28.ζ-signaling endodomain (HER2-CAR VSTs). Primary end points were feasibility and safety. The key secondary end points were T-cell persistence and their antiglioblastoma activity. A total of 17 patients (8 females and 9 males; 10 patients ≥18 years [median age, 60 years; range, 30-69 years] and 7 patients <18 years [median age, 14 years; range, 10-17 years]) with progressive HER2-positive glioblastoma received 1 or more infusions of autologous HER2-CAR VSTs (1 × 106/m2 to 1 × 108/m2) without prior lymphodepletion. Infusions were well tolerated, with no dose-limiting toxic effects. HER2-CAR VSTs were detected in the peripheral blood for up to 12 months after the infusion by quantitative real-time polymerase chain reaction. Of 16 evaluable patients (9 adults and 7 children), 1 had a partial response for more than 9 months, 7 had stable disease for 8 weeks to 29 months, and 8 progressed after T-cell infusion. Three patients with stable disease are alive without any evidence of progression during 24 to 29 months of follow-up. For the entire study cohort, median overall survival was 11.1 months (95% CI, 4.1-27.2 months) from the first T-cell infusion and 24.5 months (95% CI, 17.2-34.6 months) from diagnosis. Infusion of autologous HER2-CAR VSTs is safe and can be associated with clinical benefit for patients with progressive glioblastoma. Further evaluation of HER2-CAR VSTs in a phase 2b study is warranted as a single agent or in combination with other immunomodulatory approaches for glioblastoma

Angiosperm phylogeny: 17 genes, 640 taxa

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/1/ajb20704-sup-0010.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/2/ajb20704.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/3/ajb20704-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/4/ajb20704-sup-0016.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/5/ajb20704-sup-0017.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/6/ajb20704-sup-0021.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/7/ajb20704-sup-0003.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/8/ajb20704-sup-0002.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/9/ajb20704-sup-0011.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/10/ajb20704-sup-0019.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/11/ajb20704-sup-0015.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/12/ajb20704-sup-0006.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/13/ajb20704-sup-0020.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/14/ajb20704-sup-0013.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/15/ajb20704-sup-0004.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/16/ajb20704-sup-0012.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/17/ajb20704-sup-0005.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/18/ajb20704-sup-0018.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/19/ajb20704-sup-0009.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/20/ajb20704-sup-0014.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/21/ajb20704-sup-0007.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142064/22/ajb20704-sup-0008.pd