Miracle-dz/UniFAR-FTUs huggingface dataset:
ILR Collection 2-28-2010 Differences in Persistence Patterns Between Life and Physical Science Majors : The Role of Grades , Peers , and Preparation

Using longitudinal administrative data from a large elite research university, this paper separately analyzes the determinants of persistence for life and physical science majors. My results confirm much of the previous research on major persistence in the sciences, but I document that many findings are solely driven by persistence patterns in the physical sciences. For example, I show that the previously documented gender gap in science major persistence is due entirely to a large gap in the physical sciences. Despite large differences in persistence patterns between physical and life science, persistence in both fields is similarly influenced by grades. I provide suggestive evidence that students in both fields are “pulled away” by their high grades in nonscience courses and “pushed out” by their low grades in their major field. In the physical sciences, analyses using within course and cohort variation show that peer quality in a student’s introductory courses has a lasting impact on the probability of persisting.
Biogeochemical effects of macroalgal decomposition on intertidal microbenthos: a microcosm experiment

The decomposition of macroalgal detritus (tubular and planar Ulva spp.) was studied in a microcosm under a daily light:dark cycle to simulate the decomposition on intertidal sediment. The consequences of bloom decay were evaluated in the bulk water phase and in the sediment. Inorganic nutrients (NO3 - , NO2 - , NH4 + , PO4 3- and SiO3 2- ), dissolved organic carbon (DOC) and inorganic car- bon (DIC) were measured in the inflowing and outflowing seawater. Vertical microprofiles of O2, pH and H2S at the sediment-water interface, sediment contents of organic matter (OM), inorganic and organic carbon (Corg), total nitrogen (N) and inorganic nutrients were measured before and after addition of macroalgal detritus. Changes in the taxonomic composition of microphytobenthos were studied by optical microscopy and by the analysis of photosynthetic pigments. Macroalgal detritus vanished from the sediment surface in 6 d. Macroalgal decomposition shifted the microcosm net balance to higher releases of DOC, DIC and inorganic nutrients, suggesting rapid release from macroalgal biomass. Besides being released to the water column, a fraction of macroalgal carbon and of nitrogen was incorporated into the sediment as indicated by a transient increase in Corg and N. Aerobic mineralization of macroalgal detritus reduced O2 in the water column and the sediment. Microbenthos photosynthetic activity was initially suppressed but recovered from the third day as macroalgal detritus decomposed. Photosynthetic O2 production by microbenthos largely determined the fraction of macroalgal detritus that was aerobically mineralised. Decomposition of macroalgal detritus favoured the dominance of cyanobacteria over diatoms in the microbenthos.
Technical Efficiency of Irrigated and Rain-Fed Smallholder Agriculture in Tigray, Ethiopia: A Comparative Stochastic Frontier Production Function Analysis

Stochastic production frontiers of irrigated and rain-fed smallholder agriculture in Tigray, Ethiopia, were fitted to a random sample of irrigated and rain-fed plots to compare their technical efficiencies. Propensity Score Matching Method was applied to select rain-fed plots with comparable bio-physical attributes to irrigated plots that might have blurred the true efficiency differences between the two systems. Irrigated farms are on a higher production frontier with significant inefficiencies, while rain-fed farms are on a lower production frontier with high efficiency levels. Thus, there is considerable potential for increasing outputs by improving the efficiency of irrigation farms. Rain-fed systems need interventions in soil moisture management to move to a higher production frontier. The study underlines the need for correcting the sequence and mix of yield boosting technologies such as irrigation, improved seeds, and fertilizer that are promoted in arid environments such as Tigray. We recommend that water control must precede or implemented in tandem with improved seeds and fertilizer technologies. Unless soil moisture is improved by investing in moisture improving technologies, the use of seed and fertilizer in moisture stressed areas such as Tigray may have adverse effects.
Do Neets Need Grit?

This paper investigates the relationship between personality traits in adolescence and education and labour market choices. In particular, we investigate the impact of grit (a tendency and ability to sustain interest in long term goals - perseverance) on the risk of youths being NEET – "Not in Education, Employment or Training". Thus, our focus is on early drop-out from the labour market and education at age 18-20. Individuals with high levels of grit are less likely to be out of education or employment, while low self-esteem and external locus of control increase the chances of experiencing these conditions. We use propensity score matching to control for a rich set of adolescent and family characteristics and our results show that personality traits do affect education and employment choices. We test the robustness of our results using the methodology proposed by Altonji et al. (2005) that consists of making hypotheses about the correlation between the unobservables and observables that determine the outcomes and the unobservables that influence personality.
Specific nutrient supplementation of defined serum-free medium for the improvement of CHO cells growth and t-PA production

Recombinant CHO TF70R cells are able to grow and produce t-PA on serum-free medium BIOPRO1 (BioWhitaker Europe, Belgium). The purpose of the present study was to determine the effect of medium supplementation with vitamins, lipids, and specific amino acids on cell growth, t-PA production and biological functionality. Among vitamins, only biotin, folic acid, cobalamine and benzoic acid were required for improving growth and t-PA production. Lipid supplement allowed a significant increase cell concentration and t-PA specific activity and concentration, though its specific production rate decreased slightly. Medium supplementation with proline, serine and asparagine had also positive effects on cell growth. Besides, the addition of asparagine (even in the presence of glutamine) was essential for the production and biological quality of the t-PA. This systematic approach for media supplementation produced an increase in cell concentration around 100% and in t-PA production around 80%, with no detrimental effect on its biological activity. The effect of asparagine on t-PA production was unexpected and needs to be further studied. The above modifications of the production medium did not produce a significant effect on the metabolism of the main carbon and energy sources (glucose and glutamine) and the level of by-product formation (lactate and ammonia).
Bacterial reduction of crystalline Fe3+ oxides in single phase suspensions and subsurface materials

Abstract Microbiologic reduction of synthetic and geologic Fe3+ oxides associated with four Pleistocene- age, Atlantic coastal plain sediments was investigated using a dissimilatory Fe reducing bacterium (Shewanella putrefaciens, strain CN32) in bicarbonate buffer. Experiments investigated whether phosphate and anthraquinone-2, 6-disulfonate, (AQDS, a humic acid analogue) influenced the extent of crystalline Fe3+ oxide bioreduction and whether crystalline Fe3+ oxides in geologic materials are more or less reducible than comparable synthetic phases. Anaerobic incubations (108 organisms/mL) were performed both with and without PO4 and AQDS that functions as an electron repository and shuttle. The production of Fe2+ (solid and aqueous) was followed with time, as was mineralogy by Xray diffraction. The synthetic oxides were reduced in a qualitative trend consistent with their surface area and free energy: hydrous ferric oxide (HFO). goethite.hematite. Bacterial reduction of the crystalline oxides was incomplete in spite of excess electron donor. Biogenic formation of vivianite [Fe3(PO4)2·8H2O] and siderite (FeCO3) was observed; the conditions of their formation was consistent with their solubility. The geologic Fe3+ oxides showed a large range in reducibility, approaching 100% in some materials. The natural oxides were equally or more reducible than their synthetic counterparts, in spite of association with non-reducible mineral phases (e.g., kaolinite). The reducibility of the synthetic and geologic oxides was weakly effected by PO4, but was accelerated by AQDS. CN32 produced the hydroquinone form of AQDS (AHDS), that, in turn, had thermodynamic power to reduce the Fe3+ oxides. As a chemical reductant, it could reach physical regions of the oxide not accessible by the organism. Electron microscopy showed that crystallite size was not the primary factor that caused differences in reducibility between natural and synthetic crystalline Fe3+ oxide phases. Crystalline disorder and microheterogeneities may be more important.
A NEW INTERPRETATION FOR THE GARNET ZONING IN METAPELITIC ROCKS OF THE SILGARÁ FORMATION, SOUTHWESTERN SANTANDER MASSIF, COLOMBIA

A Barrovian sequence of the Silgara Formation at the southwestern Santander Massif, Colombian Andes, contains zoned garnets in which major and trace element zoning correlates with distribution of mineral inclusions, which may indicate that garnet growth rate varied through time and affected both composition and texture of garnets, although different garnet producing reactions have also played an important role in the chemical zoning of garent. However, a local metasomatism process associated to the action of late magmatic fluids associated to the emplacement of the Pescadero Pluton (external forcing mechanism) would be also considered. In particular, Ca, Mn and Y zoning patterns in some garnets correspond with inclusion-rich vs. inclusion-free zones, although the distribution of inclusions does not correlate with chemical zoning (i.e., the same inclusions are found in Ca-rich and Ca-poor zones of the garnet). There is a similar lack of correlation with accessory phases (apatite, monazite, xenotime, ilmenite or rutile). In a garnet from the garnet-staurolite zone, a high Mn core contains abundant and randomly oriented apatite, monazite and ilmenite inclusions, while a euhedral low Ca mantle zone is inclusion-free and the high Ca / low Mn rim zone contains apatite, monazite and ilmenite aligned parallel to the margins of the garnet. Inclusions in garnet can also represent mineral phases were not completely consumed during garnet growth. Association of garnet zoning trends and patterns with inclusion distribution may help differentiate between processes that identically affect major-element zoning but that produced variable textures in the garnet.
On the hedonic determinants of art photography prices

The economics of paintings and sculpture have extensively been analysed, but the literature records no application to photography. This article estimates a hedonic model to relate the prices of auctioned photographs to their attributes. Our model explains 53 percent of variations across photographs' values, emphasising the importance of sale location, career period of the photographer, and the presence of a pre-sale estimate. There is insufficient evidence whether photographs can be a valuable financial asset.
Growth and anti-listerial activity of a nisin Z producer in a pork lean meat broth fermentation system

Listeria monocytogenes is widely distributed in nature and has been isolated from numerous sources such as meat and fermented meat products. This pathogenic microorganism can resist conditions of low pH, low water activity (Aw), high salt (NaCl) concentrations and the presence of sodium nitrite, being able to survive the commercial sausage manufacturing process. The aim of this work was to evaluate the antilisterial activity of a lactic acid bacterium (Lactococcus lactis subsp. lactis PD 6.9) isolated from Italian-style salami in conditions that simulate salami fermentation. L. lactis PD 6.9 produces nisin Z and grows well in pork lean meat broth, a feature that would be useful to compete with food-borne pathogens. The peak of nisin Z production by L. lactis PD 6.9 in pork lean meat broth occurred after 14 h of fermentation, but the inhibitory activity decreased if the producer organism was maintained in stationary phase. When L. lactis PD 6.9 (107CFU ml-1) and Listeria monocytogenes LMA 20 (106CFU ml-1) were co-inoculated in pork lean meat broth, growth of L. lactis PD 6.9 was unaffected. The decrease in viable cell number of Listeria coincided with an increase in bacteriocin activity produced by L. lactis PD 6.9 in pork lean meat broth. Co-culture experiments indicated that L. lactis PD 6.9 was able to control the growth of L. monocytogenes even if the Listeria population was 1000-fold greater than the L. lactis population. These results demonstrate the potential application of L. lactis PD 6.9 in controlling the growth of L. monocytogenes during salami fermentation and its usefulness as a starter culture for fermented sausages. Key words: Listeria monocytogenes, bacteriocins, lactic acid bacteria, co-cultivation, salami.
Seroprevalence of Brucellosis in Small Ruminants in Thailand, 2013

Brucellosis is a zoonotic disease caused by Gram-negative coccobacilli bacteria, Brucella melitensis, commonly found in small ruminants. It caused outbreaks among humans in several provinces of Thailand. The Department of Livestock Development has implemented a surveillance system for brucellosis in small ruminants since 1997. This study aimed to describe the seroprevalence of brucellosis in small ruminants and identify factors associated with spread of brucellosis in Thailand using the national surveillance data in 2013. The surveillance data in small ruminants during 2013 included herd management, movement history, location and laboratory results of tested animals from all eight veterinary laboratories in Thailand. Association between disease status at herd level and all those factors was analyzed by multivariate logistic regression analysis. The seroprevalence of brucellosis was 12.1% (438/3,626) at herd level for both goats and sheep. At individual animal level, seroprevalence were 1.4% (1,297/94,722) and 1.6% (139/8,658) for goats and sheep respectively. Free-ranging was the only one management practice significantly associated with brucellosis infection in small ruminants at herd level. Improving biosecurity of herd management, especially avoid sharing pasture and communal area should be concern to prevent introduction and spreading of brucellosis in Thailand.
The Potentialof Renewable Energy: Using The Environmental Kuznets Curve Model

This study examines the potential of Renewable Energy Sources (RES) in reducing the impact of carbon emission in Malaysia and the Greenhouse Gas (GHG) emissions, which leads to global warming. Using the Environmental Kuznets Curve (EKC) hypothesis, this study analyses the impact of electricity generated using RES on the environment and trade openness for the period 1980-2009. Using the Autoregressive Distributed Lag (ARDL) approach the results show that the elasticities of electricity production from renewable sources with respect to CO2 emissions are negative and significant in both the short and long-run. This implies the potential of renewable energy in controlling CO2 emissions in both short and long-run in Malaysia. Renewable energy can ensure sustainability of electricity supply and at the same time can reduce CO2 emissions. Trade openness has a significant negative effect on CO2 emissions in the long-run. The Granger causality test based on Vector Error Correction Mode (VECM) indicates that there is an evidence of positive bi-directional Granger causality relationship between economic growth and CO2 emissions in the short and long-run suggesting that carbon emissions and economic growth are interrelated to each other. Furthermore, there is a negative long-run bi-directional Granger causality relationship between electricity production from renewable sources and CO2 emissions. The short-run Granger causality shows a negative uni-directional causality for electricity production from renewable sources to CO2 emissions. This result suggests that there is an inverted U-shaped relationship between CO2 emissions and economic growth.
On gravity currents driven by constant fluxes of saline and particle-laden fluid in the presence of a uniform flow

Experiments are reported on the sustained release of saline and particle-laden fluid into a long, but relatively narrow, flume, filled with fresh water. The dense fluid rapidly spread across the flume and flowed away from the source: the motion was then essentially two-dimensional. In the absence of a background flow in the flume, the motion was symmetric, away from the source. However, in the presence of a background flow the upstream speed of propagation was slowed and the downstream speed was increased. Measurements of this motion are reported and, when the excess density was due to the presence of suspended sediment, the distribution of the deposited particles was also determined. Alongside this experimental programme, new theoretical models of the motion were developed. These were based upon multi-layered depth-averaged shallow-water equations, in which the interfacial drag and mixing processes were explicitly modelled. While the early stages of the motion are independent of these interfacial phenomena to leading order, they play an increasingly important dynamical role as the the flow is slowed, or even arrested. In addition a new integral model is proposed. This does not resolve the interior dynamics of the flow, but may be readily integrated and obviates the need for more lengthy numerical calculations. It is shown that the predictions from both the shallow-layer and integral models are in close agreement with the experimental observations.
Individual Distinctiveness in the Fine Structural Features and Repertoire Characteristics of the Songs of White-eared Ground-sparrows

Communication between social animals is often more effective when signals facilitate individual recognition. Two critical requirements for individual recognition are the occurrence of characteristics that are unique to each individual, and the consistency of these characteristics through time. In some animals, characteristics of acoustic signals are known to vary over time due to changes in a variety of factors, including physiological and environmental features. Such temporal variation requires careful evaluation when exploring the individual distinctiveness of animal signals. In this study, we evaluate individual distinctiveness in the songs of male white-eared ground-sparrows Melozone leucotis and the persistence of distinctive characteristics over time. We collected focal recordings from populations of banded ground-sparrows during two consecutive breeding seasons, including multiple recording sessions within each breeding season. We evaluated individual distinctiveness in fine structural acoustic features of songs. We also extended our analysis to repertoire characteristics, focusing on whether the relative frequency of song type use may provide cues to individual identity. We found that each male white-eared ground-sparrow sang individually distinctive songs, although their fine structural features varied between recording sessions. We found the frequency with which males sang different song types was also individually distinctive, and this feature varied little between recording sessions. Receivers may be able to use these distinctive characteristics to differentiate individuals over extended time periods; this may be especially important for species that engage in long-term social interactions, such as tropical birds that defend territories against rival conspecific animals throughout the year.
Thallium-based high-temperature superconductors for beam impedance mitigation in the Future Circular Collider

CERN has recently started a design study for a possible next-generation high-energy hadron–hadron collider (Future Circular Collider—FCC-hh). The FCC-hh study calls for an unprecedented center-of-mass collision energy of 100 TeV, achievable by colliding counter-rotating proton beams with an energy of 50 TeV steered in a 100 km circumference tunnel by superconducting magnets which produce a dipole field of 16 T. The beams emit synchrotron radiation at high power levels, which, to optimize cryogenic efficiency, is absorbed by a beam-facing screen, coated with copper, and held at 50 K in the current design. The surface impedance of this screen has a strong impact on beam stability, and copper at 50 K allows for a limited beam stability margin only. This motivates the exploration of whether high-temperature superconductors (HTS), the only known materials possibly having a surface impedance lower than copper under the required operating conditions, would represent a viable alternative. This paper summarizes the FCC-hh requirements and focuses on identifying the best possible HTS material for this purpose. It reviews in particular the properties of Tl-based HTS, and discusses the consequent motivation for developing a deposition process for such compounds, which should be scalable to the size of the FCC components.
On the representation of aerosol activation and its influence on model-derived estimates of the aerosol indirect effect

Abstract. Interactions between aerosol particles and clouds contribute a great deal of uncertainty to the scientific community's understanding of anthropogenic climate forcing. Aerosol particles serve as the nucleation sites for cloud droplets, establishing a direct linkage between anthropogenic particulate emissions and clouds in the climate system. To resolve this linkage, the community has developed parameterizations of aerosol activation which can be used in global climate models to interactively predict cloud droplet number concentrations (CDNCs). However, different activation schemes can exhibit different sensitivities to aerosol perturbations in different meteorological or pollution regimes. To assess the impact these different sensitivities have on climate forcing, we have coupled three different core activation schemes and variants with the CESM-MARC (two-Moment, Multi-Modal, Mixing-state-resolving Aerosol model for Research of Climate (MARC) coupled with the National Center for Atmospheric Research's (NCAR) Community Earth System Model (CESM; version 1.2)). Although the model produces a reasonable present-day CDNC climatology when compared with observations regardless of the scheme used, ΔCDNCs between the present and preindustrial era regionally increase by over 100 % in zonal mean when using the most sensitive parameterization. These differences in activation sensitivity may lead to a different evolution of the model meteorology, and ultimately to a spread of over 0.8 W m−2 in global average shortwave indirect effect (AIE) diagnosed from the model, a range which is as large as the inter-model spread from the AeroCom intercomparison. Model-derived AIE strongly scales with the simulated preindustrial CDNC burden, and those models with the greatest preindustrial CDNC tend to have the smallest AIE, regardless of their ΔCDNC. This suggests that present-day evaluations of aerosol-climate models may not provide useful constraints on the magnitude of the AIE, which will arise from differences in model estimates of the preindustrial aerosol and cloud climatology.