896 research outputs found
Comparison of Inedible Egg Product and Spray-Dried Plasma as Sources of Protein for Weanling Pigs
Pigs were weaned at approximately 18 days of age and fed diets containing inedible egg product, spray-dried plasma (SDP), or the combination of both for 2 weeks postweaning. They then received a common diet for an additional 2 weeks after the treatment period. The impact of these dietary ingredients on growth performance was evaluated.
Inedible egg product did not improve growth or feed efficiency of pigs compared with those fed the control diet during the 2-week treatment period. However, SDP increased body weight gain and feed efficiency during the treatment period. The improved performance over the control group that resulted from feeding a combination of SDP and egg product was primarily dependent upon the SDP. In the third week, a trend occurred for improved performance of pigs fed the egg product compared with those fed 4% SDP; however, the difference was not significant. During this same period, pigs previously fed SDP gained weight slower and consumed less feed than those that had not been fed SDP. Therefore, the response to SDP was partially lost when it was removed from the diet. In summary, the outcome of this study demonstrated that inedible egg product was an adequate source of protein for the weanling pig but did not provide measurable improvements over the control diet. Inedible egg product did not have an additive effect when combined with SDP. The improved feed efficiency associated with SDP resulted in increased weanling pig growth
Why We Read Wikipedia
Wikipedia is one of the most popular sites on the Web, with millions of users
relying on it to satisfy a broad range of information needs every day. Although
it is crucial to understand what exactly these needs are in order to be able to
meet them, little is currently known about why users visit Wikipedia. The goal
of this paper is to fill this gap by combining a survey of Wikipedia readers
with a log-based analysis of user activity. Based on an initial series of user
surveys, we build a taxonomy of Wikipedia use cases along several dimensions,
capturing users' motivations to visit Wikipedia, the depth of knowledge they
are seeking, and their knowledge of the topic of interest prior to visiting
Wikipedia. Then, we quantify the prevalence of these use cases via a
large-scale user survey conducted on live Wikipedia with almost 30,000
responses. Our analyses highlight the variety of factors driving users to
Wikipedia, such as current events, media coverage of a topic, personal
curiosity, work or school assignments, or boredom. Finally, we match survey
responses to the respondents' digital traces in Wikipedia's server logs,
enabling the discovery of behavioral patterns associated with specific use
cases. For instance, we observe long and fast-paced page sequences across
topics for users who are bored or exploring randomly, whereas those using
Wikipedia for work or school spend more time on individual articles focused on
topics such as science. Our findings advance our understanding of reader
motivations and behavior on Wikipedia and can have implications for developers
aiming to improve Wikipedia's user experience, editors striving to cater to
their readers' needs, third-party services (such as search engines) providing
access to Wikipedia content, and researchers aiming to build tools such as
recommendation engines.Comment: Published in WWW'17; v2 fixes caption of Table
Asynchronous Training of Word Embeddings for Large Text Corpora
Word embeddings are a powerful approach for analyzing language and have been
widely popular in numerous tasks in information retrieval and text mining.
Training embeddings over huge corpora is computationally expensive because the
input is typically sequentially processed and parameters are synchronously
updated. Distributed architectures for asynchronous training that have been
proposed either focus on scaling vocabulary sizes and dimensionality or suffer
from expensive synchronization latencies.
In this paper, we propose a scalable approach to train word embeddings by
partitioning the input space instead in order to scale to massive text corpora
while not sacrificing the performance of the embeddings. Our training procedure
does not involve any parameter synchronization except a final sub-model merge
phase that typically executes in a few minutes. Our distributed training scales
seamlessly to large corpus sizes and we get comparable and sometimes even up to
45% performance improvement in a variety of NLP benchmarks using models trained
by our distributed procedure which requires of the time taken by the
baseline approach. Finally we also show that we are robust to missing words in
sub-models and are able to effectively reconstruct word representations.Comment: This paper contains 9 pages and has been accepted in the WSDM201
North-South cooperation through BIOTA: An interdisciplinary monitoring programme in arid and semi-arid southern Africa
Connecting disciplines in a north– South collaboration has many advantages: mutualisms evolve, synergies are created and spin-offs emerge. The BIOTA South (Biodiversity Monitoring Transect Analysis in southern Africa) programme, with its long-term vision to generate knowledge of biodiversity along a north–south transect in southern Africa, is providing opportunities for research, technology transfer and capacity building while focusing on potential solutions for critical challenges that face this environmentally vulnerable part of the subcontinen
LACHESIS restricts gametic cell fate in the female gametophyte of Arabidopsis
In flowering plants, the egg and sperm cells form within haploid gametophytes. The female gametophyte of Arabidopsis consists of two gametic cells, the egg cell and the central cell, which are flanked by five accessory cells. Both gametic and accessory cells are vital for fertilization; however, the mechanisms that underlie the formation of accessory versus gametic cell fate are unknown. In a screen for regulators of egg cell fate, we isolated the lachesis (lis) mutant which forms supernumerary egg cells. In lis mutants, accessory cells differentiate gametic cell fate, indicating that LIS is involved in a mechanism that prevents accessory cells from adopting gametic cell fate. The temporal and spatial pattern of LIS expression suggests that this mechanism is generated in gametic cells. LIS is homologous to the yeast splicing factor PRP4, indicating that components of the splice apparatus participate in cell fate decisions
Ocean change within shoreline communities: from biomechanics to behaviour and beyond
Humans are changing the physical properties of Earth. In marine systems, elevated carbon dioxide concentrations are driving notable shifts in temperature and seawater chemistry. Here, we consider consequences of such perturbations for organism biomechanics and linkages amongst species within communities.In particular,we examine case examples of altered morphologies and material properties, disrupted consumer–prey behaviours, and the potential for modulated positive (i.e. facilitative) interactions amongst taxa, as incurred through increasing ocean acidity and rising temperatures. We focus on intertidal rocky shores of temperate seas as model systems, acknowledging the longstanding role of these communities in deciphering ecological principles. Our survey illustrates the broad capacity for biomechanical and behavioural shifts in organisms to influence the ecology of a transforming worl
Gender and Videogames: The political valency of Lara Croft
The Face: Is Lara a feminist icon or a sexist fantasy? Toby Gard: Neither and a bit of both. Lara was designed to be a tough, self-reliant, intelligent woman. She confounds all the sexist cliches apart from the fact that she’s got an unbelievable figure. Strong, independent women are the perfect fantasy girls—the untouchable is always the most desirable (Interview with Lara’s creator Toby Gard in The Face magazine, June 1997)
Wavelet Based Fractal Analysis of Airborne Pollen
The most abundant biological particles in the atmosphere are pollen grains
and spores. Self protection of pollen allergy is possible through the
information of future pollen contents in the air. In spite of the importance of
airborne pol len concentration forecasting, it has not been possible to predict
the pollen concentrations with great accuracy, and about 25% of the daily
pollen forecasts have resulted in failures. Previous analysis of the dynamic
characteristics of atmospheric pollen time series indicate that the system can
be described by a low dimensional chaotic map. We apply the wavelet transform
to study the multifractal characteristics of an a irborne pollen time series.
We find the persistence behaviour associated to low pollen concentration values
and to the most rare events of highest pollen co ncentration values. The
information and the correlation dimensions correspond to a chaotic system
showing loss of information with time evolution.Comment: 11 pages, 7 figure
Analysis of the spectra of trivalent erbium in multiple sites of hexagonal aluminum nitride
The 12 K cathodoluminescence spectra of Er3+ doped into single crystals of aluminum nitride (2H-AlN) in the hexagonal phase are reported between 320 nm and 775 nm. The emission spectra represent transitions from the lower Stark level of 2P(3/2) to the Stark levels of the 4I(15/2), 4I(13/2), 4I(11/2), 4I(9/2), 4F(9/2), and 4S(3/2) multiplet manifolds of Er3+(4f(11)). Emission spectra from 4S(3/2) to 4I(15/2) are also reported. All observed strong line emission are accounted for in terms of two principle sites, denoted site a and site b , with a few line spectra attributed to additional sites. A parameterized Hamiltonian that includes the atomic and crystal-field terms for Er3+(4f(11)) (2S+1)L_J was used to determine the symmetry and the crystal field splitting of the a and b sites. A descent in symmetry calculation was carried out to determine if distortion due to the size difference between Er, Al and the vacancies can be discerned. Modeling results assuming C_3v and C_1h are discussed. It appears that the sensitivity to a C_1h model is not sufficient to invalidate the choice of C_3v as an approximate symmetry for both sites. The g-factors reported from an EPR study of Er3+ in single-crystal AlN are in reasonable agreement with calculated g-factors for Er3+ in the a site assuming C_3v symmetry
Communication calls produced by electrical stimulation of four structures in the guinea pig brain
One of the main central processes affecting the cortical representation of conspecific vocalizations is the collateral output from the extended motor system for call generation. Before starting to study this interaction we sought to compare the characteristics of calls produced by stimulating four different parts of the brain in guinea pigs (Cavia porcellus). By using anaesthetised animals we were able to reposition electrodes without distressing the animals. Trains of 100 electrical pulses were used to stimulate the midbrain periaqueductal grey (PAG), hypothalamus, amygdala, and anterior cingulate cortex (ACC). Each structure produced a similar range of calls, but in significantly different proportions. Two of the spontaneous calls (chirrup and purr) were never produced by electrical stimulation and although we identified versions of chutter, durr and tooth chatter, they differed significantly from our natural call templates. However, we were routinely able to elicit seven other identifiable calls. All seven calls were produced both during the 1.6 s period of stimulation and subsequently in a period which could last for more than a minute. A single stimulation site could produce four or five different calls, but the amygdala was much less likely to produce a scream, whistle or rising whistle than any of the other structures. These three high-frequency calls were more likely to be produced by females than males. There were also differences in the timing of the call production with the amygdala primarily producing calls during the electrical stimulation and the hypothalamus mainly producing calls after the electrical stimulation. For all four structures a significantly higher stimulation current was required in males than females. We conclude that all four structures can be stimulated to produce fictive vocalizations that should be useful in studying the relationship between the vocal motor system and cortical sensory representation
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