208 research outputs found
Identification of metrics used by decision makers to determine the efficacy of wireless communication systems in higher education
This research described the wireless network technologies that are available for use in higher education, determined the categories of metrics used to evaluate wireless network efficacy, and yielded a self-assessment instrument for guiding small college administrators considering wireless local area network systems.;The features and benefits of contemporary wireless systems in higher education were identified through a review of the professional journals, government publications, and standards industry documentation. The literature identified three categories of metrics beneficial for the evaluation of efficacy of wireless campus local area networks: cost, speed, and reliability. After identification of these categories of metrics, a modified Delphi technique was administered to ten wireless network experts in higher education. The expert group was made up of seven higher education wireless decision makers and three wireless industry professionals.;The wireless experts responded to Instrument One which identified 27 metrics in the three categories of metrics. The experts generated 19 essential metrics: four in the category of cost, seven in the category of speed, and eight in the category of reliability. Eight supplemental metrics were also identified in Instrument One: four in the category of cost, two in the category of speed, and two in the category of reliability.;Instrument Two generated 27 questions that could guide wireless decision makers in higher education. These metrics offer a timeless guide to wireless system planning on small college campuses. The self-assessment instrument will assist in gathering information specific to the small college environment, and in gathering current specifications for wireless network systems. The analysis of information gained from the use of this tool will help wireless campus networks to operate as an integrated part of teaching and learning
Water buffalo mozzarella cheese stored in polysaccharide-based gels: correlation between prolongation of the shelf-life and physicochemical parameters.
An innovative packaging system has been developed, based on natural gels, that has shown the peculiar characteristic to strongly increase the shelf life of water buffalo Mozzarella cheese. To explain the mechanism of action of the gel, measurements of Ca and Na in the cheese and in the storage liquid were carried out, together with pH determination. A correlation has been found between the constant level of Ca and pH in the cheese and the prolongation of nutritional characteristics; in fact, both parameters diminish significantly in the absence of gel. At the same time, the weight of the cheese in gel remained constant for as long as 30 d. Confocal laser microscopy gave direct evidence of the persistent physical structure of proteins and lipids of Mozzarella when stored in gel
Migratory crustaceans as biomonitors of metal pollution in their nursery areas. The Lesina lagoon (SE Italy) as a case study
The Lesina lagoon is located on the
southern Adriatic coast of Italy; many marine species,
such as the shrimp M. kerathurus, use the Lesina
lagoon as a nursery, spending their initial growth
phase there. In order to assess the usefulness of
migratory species as biomonitors of the environmental
quality of this nursery area, we evaluated the metal
content of the M. kerathurus juveniles at the end of
their growth phase in the lagoon (October), when they
are assumed to have bioaccumulated the maximum
level of metals from the lagoon environment. The
concentrations of Cr, Cd, Pb, Zn, Mn and Cu were
measured in the muscle and exoskeleton of the
shrimp, and in the sediments and waters of three
areas of the Lesina Lagoon. Both the water and
sediment levels of the investigated metals tended to
fall within the ranges recorded for other lagoon
environments characterized by similar anthropic impact
and texturally similar sediment; the juveniles of
the shrimp M. kerathurus proved to be strong
bioaccumulators of heavy metals such as Zn and Cu
(biota-sediment accumulation factors â BSAFs â 6.01
and 25.0 respectively), which derive from agricultural
activities; therefore, at the end of their growing phase
in the lagoon they can be considered useful biomonitors
of metal contamination of agricultural origin in
their nursery area
Bilingualism alters childrenâs frontal lobe functioning for attentional control
Bilingualism is a typical linguistic experience, yet relatively little is known about its impact on childrenâs cognitive and brain development. Theories of bilingualism suggest that early dualâ language acquisition can improve childrenâs cognitive abilities, specifically those relying on frontal lobe functioning. While behavioral findings present much conflicting evidence, little is known about its effects on childrenâs frontal lobe development. Using functional nearâ infrared spectroscopy (fNIRS), the findings suggest that Spanishâ English bilingual children (nĂ =Ă 13, ages 7â 13) had greater activation in left prefrontal cortex during a nonâ verbal attentional control task relative to ageâ matched English monolinguals. In contrast, monolinguals (nĂ =Ă 14) showed greater right prefrontal activation than bilinguals. The present findings suggest that early bilingualism yields significant changes to the functional organization of childrenâs prefrontal cortex for attentional control and carry implications for understanding how early life experiences impact cognition and brain development.This fNIRS study investigated the impact of bilingual exposure on childrenâs brain organization for attentional control (N = 27, ages 7â 13). During a nonâ verbal attention task, bilinguals showed greater left frontal lobe activation than monolinguals. Monolinguals showed greater right frontal lobe activation than bilinguals. The findings suggest that bilingualism affects the functionality of childrenâs left prefrontal cortex for attentional control.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/1/desc12377-sup-0001-FigS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/2/desc12377.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/3/desc12377_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136694/4/desc12377-sup-0003-SupInfo.pd
Infant Rule Learning: Advantage Language, or Advantage Speech?
<div><p>Infants appear to learn abstract rule-like regularities (e.g., <em>la la da</em> follows an AAB pattern) more easily from speech than from a variety of other auditory and visual stimuli (Marcus et al., 2007). We test if that facilitation reflects a specialization to learn from speech alone, or from modality-independent communicative stimuli more generally, by measuring 7.5-month-old infantsâ ability to learn abstract rules from sign language-like gestures. Whereas infants appear to easily learn many different rules from speech, we found that with sign-like stimuli, and under circumstances comparable to those of Marcus et al. (1999), hearing infants were able to learn an ABB rule, but not an AAB rule. This is consistent with results of studies that demonstrate lower levels of infant rule learning from a variety of other non-speech stimuli, and we discuss implications for accounts of speech-facilitation.</p> </div
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The threshold hypothesis revisited: bilingual lexical knowledge and non-verbal IQ development
The threshold hypothesis (Cummins 1976 et passim) is one of the most influential theoretical frameworks on the relation between bilingualism and cognition. The aim of our study is to contribute towards an operationalisation of the threshold hypothesis. We analyse data from 100 Turkish-English successive bilingual children and from their parents, and investigate the relation between bilingualism and cognition. When compared with monolingual control groups, the bilinguals in our study have smaller vocabulary sizes in both languages. However, when both vocabularies are taken together and the total conceptual vocabulary is computed no bilingual disadvantage can be identified. Children with parental support for L1 outperform the monolingual control groups in our study in terms of non-verbal intelligence scores. The originality of the present study resides in the fact that, to our knowledge, for the first time parental support for L1 and dominance in L1 is linked to the cognitive development of the children
Language experience impacts brain activation for spoken and signed language in infancy: Insights from unimodal and bimodal bilinguals
Recent neuroimaging studies suggest that monolingual infants activate a left lateralised fronto-temporal brain network in response to spoken language, which is similar to the network involved in processing spoken and signed language in adulthood. However, it is unclear how brain activation to language is influenced by early experience in infancy. To address this question, we present functional near infrared spectroscopy (fNIRS) data from 60 hearing infants (4-to-8 months): 19 monolingual infants exposed to English, 20 unimodal bilingual infants exposed to two spoken languages, and 21 bimodal bilingual infants exposed to English and British Sign Language (BSL). Across all infants, spoken language elicited activation in a bilateral brain network including the inferior frontal and posterior temporal areas, while sign language elicited activation in the right temporo-parietal area. A significant difference in brain lateralisation was observed between groups. Activation in the posterior temporal region was not lateralised in monolinguals and bimodal bilinguals, but right lateralised in response to both language modalities in unimodal bilinguals. This suggests that experience of two spoken languages influences brain activation for sign language when experienced for the first time. Multivariate pattern analyses (MVPA) could classify distributed patterns of activation within the left hemisphere for spoken and signed language in monolinguals (proportion correct = 0.68; p = 0.039) but not in unimodal or bimodal bilinguals. These results suggest that bilingual experience in infancy influences brain activation for language, and that unimodal bilingual experience has greater impact on early brain lateralisation than bimodal bilingual experience
Psychoimmunological effects of dioscorea in ovariectomized rats: role of anxiety level
<p>Abstract</p> <p>Background</p> <p>Anxiety levels in rats are correlated with interleukin-2 (IL-2) levels in the brain. The aim of the present study was to investigate the effects of dioscorea (wild yam), a Chinese medicine, on emotional behavior and IL-2 levels in the brain of ovariectomized (OVX) rats.</p> <p>Methods</p> <p>One month after ovariectomy, female Wistar rats were screened in the elevated plus-maze (EPM) test to measure anxiety levels and divided into low anxiety (LA) and high anxiety (HA) groups, which were then given dioscorea (250, 750, or 1500 mg/kg/day) by oral gavage for 27 days and were tested in the EPM on day 23 of administration and in the forced swim test (FST) on days 24 and 25, then 3 days later, the brain was removed and IL-2 levels measured.</p> <p>Results</p> <p>Compared to sham-operated rats, anxiety behavior in the EPM was increased in half of the OVX rats. After chronic dioscorea treatment, a decrease in anxiety and IL-2 levels was observed in the HA OVX rats. Despair behavior in the FST was inhibited by the highest dosage of dioscorea.</p> <p>Conclusion</p> <p>These results show that OVX-induced anxiety and changes in neuroimmunological function in the cortex are reversed by dioscorea treatment. Furthermore, individual differences need to be taken into account when psychoneuroimmunological issues are measured and the EPM is a useful tool for determining anxiety levels when examining anxiety-related issues.</p
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Segmentation of British Sign Language (BSL): Mind the gap!
This study asks how users of British Sign Language (BSL) recognize individual signs in connected sign sequences. We examined whether this is achieved through modality-specific or modality-general segmentation procedures. A modality-specific feature of signed languages is that, during continuous signing, there are salient transitions between sign locations. We used the sign-spotting task to ask if and how BSL signers use these transitions in segmentation. A total of 96 real BSL signs were preceded by nonsense signs which were produced in either the target location or another location (with a small or large transition). Half of the transitions were within the same major body area (e.g., head) and half were across body areas (e.g., chest to hand). Deaf adult BSL users (a group of natives and early learners, and a group of late learners) spotted target signs best when there was a minimal transition and worst when there was a large transition. When location changes were present, both groups performed better when transitions were to a different body area than when they were within the same area. These findings suggest that transitions do not provide explicit sign-boundary cues in a modality-specific fashion. Instead, we argue that smaller transitions help recognition in a modality-general way by limiting lexical search to signs within location neighbourhoods, and that transitions across body areas also aid segmentation in a modality-general way, by providing a phonotactic cue to a sign boundary. We propose that sign segmentation is based on modality-general procedures which are core language-processing mechanisms
Impedance analysis of secondary phases in a Co-implanted ZnO single crystal
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