2,336 research outputs found

    Great Bay Estuary Tidal Tributary Monitoring Program: Quality Assurance Project Plan, 2018

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    Impact of United States Corn-Based Ethanol Production on Land Use

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    This study measures the impact of corn-based ethanol production in the United States on land use in other countries, or indirect land use. Indirect land use is a change from non-cropland to cropland (e.g. deforestation) that may occur in response to increasing scarcity of cropland. As farmers worldwide respond to higher crop prices in order to maintain the global food supply and demand balance, pristine lands are cleared and converted to new cropland to replace the crops for feed and food that were diverted elsewhere to biofuel production. The results show that increasing ethanol production in the US has a positive and significant relation to U.S corn price. However, U.S. corn price does not have a significant impact on changes in corn acreage in Brazil and other countries such as Canada, Japan and China. Although many authors have hypothesized that increased ethanol production in the U.S. will increase corn prices, which will result in increased change in land use in other countries, these results suggest that the effect is minimal at best. This is important because although production of ethanol for fuel is often criticized for negatively impacting the environment because of indirect land use, this study was unable to prove the existence of indirect land use.ethanol, indirect land use, Agricultural and Food Policy, Demand and Price Analysis, Land Economics/Use, Marketing,

    Vascular endothelial growth factor directly inhibits primitive neural stem cell survival but promotes definitive neural stem cell survival

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    There are two types of neural stem cells (NSCs). Primitive NSCs [leukemia inhibitory factor (LIF) dependent but exogenous fibroblast growth factor (FGF) 2 independent] can be derived from mouse embryonic stem (ES) cells in vitro and from embryonic day 5.5 (E5.5) to E7.5 epiblast and E7.5-E8.5 neuroectoderm in vivo. Definitive NSCs (LIF independent but FGF2 dependent) first appear in the E8.5 neural plate and persist throughout life. Primitive NSCs give rise to definitive NSCs. Loss and gain of functions were used to study the role of vascular endothelial growth factor (VEGF)-A and its receptor, Flk1, in NSCs. The numbers of Flk1 knock-out mice embryo-derived and ES cell-derived primitive NSCs were increased because of the enhanced survival of primitive NSCs. In contrast, neural precursor-specific, Flk1 conditional knock-out mice-derived, definitive NSCs numbers were decreased because of the enhanced cell death of definitive NSCs. These effects were not observed in cells lacking Flt1, another VEGF receptor. In addition, the cell death stimulated by VEGF-A of primitive NSC and the cell survival stimulated by VEGF-A of definitive NSC were blocked by Flk1/Fc-soluble receptors and VEGF-A function-blocking antibodies. These VEGF-A phenotypes also were blocked by inhibition of the downstream effector nuclear factor kappa B (NF-kappa B). Thus, both the cell death of primitive NSC and the cell survival of definitive NSC induced by VEGF-A stimulation are mediated by bifunctional NF-kappa B effects. In conclusion, VEGF-A function through Flk1 mediates survival (and not proliferative or fate change) effects on NSCs, specifically

    Structure and stereochemistry of the base excision repair glycosylase MutY reveal a mechanism similar to retaining glycosidases.

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    MutY adenine glycosylases prevent DNA mutations by excising adenine from promutagenic 8-oxo-7,8-dihydroguanine (OG):A mismatches. Here, we describe structural features of the MutY active site bound to an azaribose transition state analog which indicate a catalytic role for Tyr126 and approach of the water nucleophile on the same side as the departing adenine base. The idea that Tyr126 participates in catalysis, recently predicted by modeling calculations, is strongly supported by mutagenesis and by seeing close contact between the hydroxyl group of this residue and the azaribose moiety of the transition state analog. NMR analysis of MutY methanolysis products corroborates a mechanism for adenine removal with retention of stereochemistry. Based on these results, we propose a revised mechanism for MutY that involves two nucleophilic displacement steps akin to the mechanisms accepted for 'retaining' O-glycosidases. This new-for-MutY yet familiar mechanism may also be operative in related base excision repair glycosylases and provides a critical framework for analysis of human MutY (MUTYH) variants associated with inherited colorectal cancer

    Entry, Descent and Landing Systems Analysis: Exploration Class Simulation Overview and Results

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    NASA senior management commissioned the Entry, Descent and Landing Systems Analysis (EDL-SA) Study in 2008 to identify and roadmap the Entry, Descent and Landing (EDL) technology investments that the agency needed to make in order to successfully land large payloads at Mars for both robotic and exploration or human-scale missions. The year one exploration class mission activity considered technologies capable of delivering a 40-mt payload. This paper provides an overview of the exploration class mission study, including technologies considered, models developed and initial simulation results from the EDL-SA year one effort

    Measurements of galactic cosmic ray shielding with the CRaTER instrument

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    [1] The Cosmic Ray Telescope for the Effects of Radiation (CRaTER) instrument aboard the Lunar Reconnaissance Orbiter has been measuring energetic charged particles from the galactic cosmic rays (GCRs) and solar particle events in lunar orbit since 2009. CRaTER includes three pairs of silicon detectors, separated by pieces of tissue-equivalent plastic that shield two of the three pairs from particles incident at the zenith-facing end of the telescope. Heavy-ion beams studied in previous ground-based work have been shown to be reasonable proxies for the GCRs when their energies are sufficiently high. That work, which included GCR simulations, led to predictions for the amount of dose reduction that would be observed by CRaTER. Those predictions are compared to flight data obtained by CRaTER in 2010–2011

    Aktivitas Promosi dalam Launching Produk Layanan Wisata Baru Buana Muda Pesona Tour Semarang Bidang Pekerjaan Project Officer

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    Backpacking merupakan salah pilihan dalam melakukan kegiatan wisata. Prinsip utama backpacking adalah kemandirian sehingga tidak bepergian bersama kelompok tur yang ditawarkan oleh agen perjalanan. Backpacker menekankan melakukan kegiatan wisata dengan cara dan biaya yang murah. Setiap pilihan tentu saja memiliki konsekuensi. Kegiatan wisata dengan menjadi seorang backpacker juga punya kekurangan. Karena liburan dilakukan secara mandiri maka resiko menjadi korban kejahatan, tersesat at au pun menjadi sasaran penipuan di tempat baru yang dikunjungipun semakin besar. Jika terjadi permasalahan dalam perjalanan maka backpackerharus menyelesaikan masalah secara mandiri. Selain itu, backpacker juga harus mempersiapkan dana cadangan kalau sewaktu-waktu muncul biaya yang diluar prediksi karena kondisi di lapangan seringkali berbeda dari infor masi yang didapatkan sebelumnya sehingga murah belum tentu menyenangkan.Pada bulan Januari 2014, Pesona Tour ingin melakukan pengembangan USAha. Mereka akan meluncurkan layanan wisata baru bernama Buana Muda. Buana Muda mengangkat konsep wisata yaitu Destination Management Company dan budgettravelling sehingga anak muda tetap dapat merasakan perjalanan wisata murah sesuai dengan daya beli yang mereka miliki tanpa harus repot mempersiapkan segala kebutuhan wisata dan tidak perlu merasa khawatir dengan munculnya biaya tambahan karena semua biaya telah dihitung di awal.Aktivitas promosi yang dilakukan menggunakan event marketing sebagai fondasi utama dan didukung oleh alat promosi lain seperti periklanan, marketing public relation,publisitas, point of purchase material, E communication dan relationship marketing. Event Marketing berbentuk kontes fotografi yang berjudul Buana Muda “Feel The New Experience” bertujuan untuk memperkenalkan dan menarik minat khalayak sasaran di semarang mengenai layanan wisata baru Buana Muda. Setelah aktivitas promosi dilakukan selama satu bulan terjadi kenaikan awaraness sebesar 39% dan minat sebesar 32%. Selain itu berhasil dibentuk komunitas buana muda guna menjaga keberlangsungan pesan komunikasi pemasaran

    Additive drug-specific and sex-specific risks associated with co-use of marijuana and tobacco during pregnancy: Evidence from 3 recent developmental cohorts (2003-2015).

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    BACKGROUND: Methodologic challenges related to the concomitant use (co-use) of substances and changes in policy and potency of marijuana contribute to ongoing uncertainty about risks to fetal neurodevelopment associated with prenatal marijuana use. In this study, we examined two biomarkers of fetal neurodevelopmental risk-birth weight and length of gestation-associated with prenatal marijuana use, independent of tobacco (TOB), alcohol (ALC), other drug use (OTH), and socioeconomic risk (SES), in a pooled sample (N = 1191) derived from 3 recent developmental cohorts (2003-2015) with state-of-the-art substance use measures. We examined differential associations by infant sex, and multiplicative effects associated with co-use of MJ and TOB. METHODS: Participants were mother-infant dyads with complete data on all study variables derived from Growing Up Healthy (n = 251), Behavior and Mood in Babies and Mothers (Cohorts 1 and 2; n = 315), and the Early Growth and Development Study (N = 625). We estimated direct effects on birth weight and length of gestation associated with MJ, TOB, and co-use (MJ x TOB), using linear regression analysis in the full sample, and in male (n = 654) and female (n = 537) infants, separately. RESULTS: Mean birth weight and length of gestation were 3277 g (SD = 543) and 37.8 weeks (SD = 2.0), respectively. Rates of prenatal use were as follows: any use, n = 748 (62.8%); MJ use, n = 273 (22.9%); TOB use, n = 608 (51.0%); co-use of MJ and TOB, n = 230 (19.3%); ALC use, n = 464 (39.0%); and OTH use n = 115 (9.7%.) For all infants, unique effects on birth weight were observed for any MJ use [B(SE) = -84.367(38.271), 95% C.I. -159.453 to -9.281, p = .028], any TOB use [B(SE) = -0.99.416(34.418), 95% C.I. -166.942 to -31.889, p = .004], and each cigarette/day in mean TOB use [B(SE) = -12.233(3.427), 95% C.I. -18.995 to -5.510, p \u3c .001]. Additional effects of co-use on birth weight, beyond these drug-specific effects, were not supported. In analyses stratified by sex, while TOB use was associated with lower birth weight in both sexes, MJ use during pregnancy was associated with lower birth weight of male infants [B(SE) = -153.1 (54.20); 95% C.I. -259.5 to -46.7, p = .005], but not female infants [B(SE) = 8.3(53.1), 95% C.I. -96.024 to 112.551, p = .876]. TOB, MJ, and their co-use were not associated with length of gestation. CONCLUSIONS: In this sample, intrauterine co-exposure to MJ and TOB was associated with an estimated 18% reduction in birth weight not attributable to earlier delivery, exposure to ALC or OTH drugs, nor to maternal SES. We found evidence for greater susceptibility of male fetuses to any prenatal MJ exposure. Examination of dose-dependence in relationships found in this study, using continuous measures of exposure, is an important next step. Finally, we underscore the need to consider (a) the potential moderating influence of fetal sex on exposure-related neurodevelopmental risks; and (b) the importance of quantifying expressions of risk through subtle alterations, rather than dichotomous outcomes
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