3,787 research outputs found
El Sexting no siempre es deseado: consecuencias sobre la satisfacción y el papel de la coerción sexual y la victimización sexual en línea
The understanding of sexting as a new form of interpersonal communication is increasing; however, little is known about whether the incidence, correlates, and outcomes of sexting vary depending on whether such behavior is done willingly or not. In this non-experimental study, we aimed to investigate the prevalence, predictors, and consequences of sexting among 310 Spanish young adults, who completed an online survey re-garding their previous experiences of wanted and unwanted sexting behav-iors, their sexual coercion and online sexual victimization experiences, and their levels of sexual and life satisfaction. The results showed that more than half and one third of the sample had been involved in wanted and unwanted sexting behaviors, respectively. Additionally, sexual coercion and online sexual victimization predicted a higher probability of engaging in unwanted sexual behaviors and, with that, a decrease of life satisfaction. Finally, having experienced more instances of sexual coercion was associated with lower life satisfaction by increasing the likelihood of suffering online sexual victimization experiences and engaging in additional unwanted sexting behaviors. Our findings show the importance of discerning between wanted and unwanted sexting and how doing so differently conditions the predictors and consequences of this phenomena.La comprensión del sexting como una nueva forma de comunicación interpersonal es cada vez mayor; sin embargo, poco se sabe sobre si la incidencia, correlatos y resultados del sexting varían en función de si se realiza de forma voluntaria o no. En este estudio no experimental, nos proponemos investigar la prevalencia, los predictores y las consecuencias del sexting entre 310 jóvenes españoles, que completaron una encuesta online sobre sus experiencias previas de sexting deseado y no deseado, coerción sexual y victimización sexual online, así como sus niveles de satisfacción sexual y vital. Los resultados mostraron que la mitad y un tercio de la muestra habían estado involucrados en comportamientos de sexting deseados y no deseados, respectivamente. Además, la coerción sexual y la victimización sexual online predijeron una mayor probabilidad de participar en conductas sexuales no deseadas y, con ello, una disminución de la satisfacción vital. Por último, haber experimentado mayor coerción sexual se asoció con menor satisfacción vital al aumentar la probabilidad de sufrir victimización sexual online y de participar en conductas adicionales de sexting no deseado. Nuestros hallazgos muestran la importancia de discernir entre el sexting deseado y el no deseado y cómo el hacerlo de forma diferente condiciona los predictores y las consecuencias de este fenómeno
To be or not to be better pollinated: Differences between sex morphs in marginal gynodioecious populations
PREMISE OF THE STUDY: Changes in the pollinator communities of marginal plant populations can affect their pollination quantity or quality. Geographic variation in pollination success can alter the reproductive advantage that female plants require to persist within gynodioecious populations. Particularly valuable is determining the pollination success at the prezygotic stage in self-compatible gynodioecious species whose females do not exhibit enhanced seed production. METHODS: In core and marginal populations of Daphne laureola, we analyzed the differences between hermaphrodites and females in the proportion of flowers visited, the stigma pollen loads, and the quantity of pollen tubes in styles. We also examined the relationship between the number of pollen tubes in styles vs. the number of pollen grains on stigmas using piecewise regression and binomial generalized linear mixed models. KEY RESULTS: Pollinators deposited larger pollen loads on flowers in marginal populations. In marginal populations, female flowers received more pollinator visits and more pollen grains on their stigmas, and they had more pollen tubes in their styles than did female flowers in core populations. Both piecewise regression and binomial GLMM analyses showed that females in marginal populations had a lower proportion of grains that developed tubes than females in the core populations, which suggests decreased pollination quality. CONCLUSIONS: More efficient pollination services in marginal populations decreased the overall differences in the prezygotic pollination success between the sex morphs. Our results also suggest that pollination quality is lower in females of marginal populations, which could be counteracting the increased pollination in females in marginal populations.Peer Reviewe
Work and energy in inertial and non inertial reference frames
It is usual in introductory courses of mechanics to develop the work and
energy formalism from Newton's laws. On the other hand, literature analyzes the
way in which forces transform under a change of reference frame.
Notwithstanding, no analogous study is done for the way in which work and
energy transform under those changes of reference frames. We analyze the
behavior of energy and work under such transformations and show explicitly the
expected invariance of the formalism under Galilean transformations for one
particle and a system of particles. The case of non inertial systems is also
analyzed and the fictitious works are characterized. In particular, we show
that the total fictitious work in the center of mass system vanishes even if
the center of mass defines a non inertial frame. Finally, some subtleties that
arise from the formalism are illustrated by examples.Comment: 4 pages, 2 figures. LaTeX2e. Part of the approach has been changed
but results are unaltered. Version to appear im American Journal of Physic
MSAP markers and global cytosine methylation in plants: a literature survey and comparative analysis for a wild-growing species
Methylation of DNA cytosines affects whether transposons are silenced and genes are expressed, and is a major epigenetic mechanism whereby plants respond to environmental change. Analyses of methylation-sensitive amplification polymorphism (MS-AFLP or MSAP) have been often used to assess methyl-cytosine changes in response to stress treatments and, more recently, in ecological studies of wild plant populations. MSAP technique does not require a sequenced reference genome and provides many anonymous loci randomly distributed over the genome for which the methylation status can be ascertained. Scoring of MSAP data, however, is not straightforward, and efforts are still required to standardize this step to make use of the potential to distinguish between methylation at different nucleotide contexts. Furthermore, it is not known how accurately MSAP infers genome-wide cytosine methylation levels in plants. Here, we analyse the relationship between MSAP results and the percentage of global cytosine methylation in genomic DNA obtained by HPLC analysis. A screening of literature revealed that methylation of cytosines at cleavage sites assayed by MSAP was greater than genome-wide estimates obtained by HPLC, and percentages of methylation at different nucleotide contexts varied within and across species. Concurrent HPLC and MSAP analyses of DNA from 200 individuals of the perennial herb Helleborus foetidus confirmed that methyl-cytosine was more frequent in CCGG contexts than in the genome as a whole. In this species, global methylation was unrelated to methylation at the inner CG site. We suggest that global HPLC and context-specific MSAP methylation estimates provide complementary information whose combination can improve our current understanding of methylation-based epigenetic processes in nonmodel plants.Peer reviewe
Electrostatic internal energy using the method of images
For several configurations of charges in the presence of conductors, the
method of images permits us to obtain some observables associated with such a
configuration by replacing the conductors with some image charges. However,
simple inspection shows that the potential energy associated with both systems
does not coincide. Nevertheless, it can be shown that for a system of a
grounded or neutral conductor and a distribution of charges outside, the
external potential energy associated with the real charge distribution embedded
in the field generated by the set of image charges is twice the value of the
internal potential energy associated with the original system. This assertion
is valid for any size and shape of the conductor, and regardless of the
configuration of images required. In addition, even in the case in which the
conductor is not grounded nor neutral, it is still possible to calculate the
internal potential energy of the original configuration through the method of
images. These results show that the method of images could also be useful for
calculations of the internal potential energy of the original system.Comment: 5 pages, 3 figures. New discussions added. Minor change
Strain balanced quantum posts
Quantum posts are assembled by epitaxial growth of closely spaced quantum dot
layers, modulating the composition of a semiconductor alloy, typically InGaAs.
In contrast with most self-assembled nanostructures, the height of quantum
posts can be controlled with nanometer precision, up to a maximum value limited
by the accumulated stress due to the lattice mismatch. Here we present a strain
compensation technique based on the controlled incorporation of phosphorous,
which substantially increases the maximum attainable quantum post height. The
luminescence from the resulting nanostructures presents giant linear
polarization anisotropy.Comment: Submitted to Applied Physics Letters (7th March 2011). 4 pages, 4
figure
Monero - Privacy in the Blockchain
Monero is a cryptocurrency that aims to provide transaction confidentiality and untraceability to its users. This is achieved through various cryptographic schemes, which allow concealing amounts and parties in transactions.
Unfortunately, there has been a severe lack of literature describing with sufficient precision the cryptographic schemes at hand.
With this report we aim at bridging this gap, by supplying detailed descriptions of the algorithms used in Monero to warrant privacy to its users. Furthermore, we do so minimizing the use of technicisms, so as to appeal to a broad readership
Salmonella enterica serovars Typhimurium and Enteritidis causing mixed infections in febrile children in Mozambique
Background and purpose: Invasive nontyphoidal salmonellosis,
mostly caused by serovars Typhimurium and Enteritidis of
Salmonella enterica, has emerged as a major public health
problem in sub-Saharan Africa. The aim of this study was the
clinical and microbiological characterization of nontyphoidal
salmonellosis episodes affecting febrile children in Mozambique.
Patients and methods: The clinical records of the patients were
evaluated, and S. enterica isolates were characterized with
regard to serovar, phage type, antimicrobial resistance
(phenotype/responsible genes), plasmid content, pulsed-field gel
electrophoresis, and multilocus sequence typing. Results:
Fifteen S. Typhimurium and 21 S. Enteritidis isolates were
recovered from blood samples of 25 children, the majority with
underlying risk factors. With regard to phage typing, most
isolates were either untypeable or reacted but did not conform,
revealing that a number of previously unrecognized patterns are
circulating in Mozambique. Most isolates were
multidrug-resistant, with nearly all of the responsible genes
located on derivatives of serovar-specific virulence plasmids.
ST313 and ST11 were the predominant sequence types associated
with S. Typhimurium and S. Enteritidis, respectively, and the
uncommon ST1479 was also detected in S. Enteritidis. A distinct
XbaI fragment of ~350 kb was associated with pulsed-field gel
electrophoresis patterns of multidrug-resistant isolates of S.
Enteritidis. Nearly half of the children were coinfected with
both serovars, a fact expected to aggravate the disease and
hamper the treatment. However, particularly poor outcomes were
not observed for the coinfected patients. Conclusion: Mixed
Salmonella infections could frequently occur in febrile children
in Mozambique. Additional studies are required to determine
their actual impact and consequences, not only in this country,
but also in other African countries
Using Multi-granular Fuzzy Linguistic Modelling Methods to Represent Social Networks Related Information in an Organized Way
Social networks are the preferred mean for experts to share their knowledge and provide information.
Therefore, it is one of the best sources that can be used for obtaining data that can
be used for a high amount of purposes. For instance, determining social needs, identifying problems,
getting opinions about certain topics, ... Nevertheless, this kind of information is difficult
for a computational system to interpret due to the fact that the text is presented in free form and
that the information that represents is imprecise. In this paper, a novel method for extracting information from social networks and represent it in a fuzzy ontology is presented. Sentiment analysis
procedures are used in order to extract information from free text. Moreover, multi-granular
fuzzy linguistic modelling methods are used for converting the information into the most suitable
representation mean.This work has been supported by the ’Juan de la Cierva Incorporación’ grant from the Spanish
Ministry of Economy and Competitiveness and by the Grant from the FEDER funds provided by the
Spanish Ministry of Economy and Competitiveness (No. TIN2016-75850-R)
Work and energy in rotating systems
Literature analyzes the way in which Newton's second law can be used when
non-inertial rotating systems are used. However, the treatment of the work and
energy theorem in rotating systems is not considered in textbooks. In this
paper, we show that the work and energy theorem can still be applied to a
closed system of particles in a rotating system, as long as the work of
fictitious forces is properly included in the formalism. The coriolis force
does not contribute to the work coming from fictitious forces. It worths
remarking that real forces that do not do work in an inertial reference frame
can do work in the rotating reference frame and viceversa. The combined effects
of acceleration of the origin and rotation of the non-inertial system are also
studied.Comment: 6 pages, 3 figures, LaTeX2
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