4,453 research outputs found
Ogbu and the debate on educational achievement: an exploration of the links between education, migration, identity and belonging
This paper looks at some of the issues raised by Ogbuās work in relation to the education of different minority ethnic groups. Ogbu poses questions such as the value attached to education,
its links to the future and its measurable outcomes in terms of āsuccessā as experienced by black participants. The desire for better life chances leads families to consider migration to a new country or resettlement within the same country, thus making migration both a local and a global phenomenon. As an example, attention is drawn to the situation facing South Asian
children and their families in the UK. In terms of ethnicity and belonging, the wider question that is significant for many countries in the West after āNine-Elevenā is the education of Muslim children. A consideration of this current situation throws Ogbuās identification of āautonomous minorityā into question. It is argued that a greater understanding of diverse needs has to be
accompanied by a concerted effort to confront racism and intolerance in schools and in society, thus enabling all communities to make a useful contribution and to avoid the āriskā of failure and disenchantment
Biodiesel production from Cannabis sativa oil from Pakistan
The present study was appraised using response surface methodology for process optimization owing to strong interaction of reaction variables: NaOCH3 catalyst concentration (0.25ā1.50%), methanol/oil molar ratio (3:1ā9:1), reaction time (30ā90 min), and reaction temperature (45ā65Ā°C). The quadratic polynomial equation was determined using response surface methodology for predicting optimum methyl esters yield from Cannabis sativa oil. The analysis of variance results indicated that molar ratio and reaction temperature were the key factors that appreciably influence the yield of Cannabis sativa oil methyl esters. The significant (p < 0.0001) variable interaction between molar ratio Ć catalyst concentration and reaction time Ć molar ratio was observed, which mostly affect the Cannabis sativa oil methyl esters yield. The optimum Cannabis sativa oil methyl esters yield, i.e., 86.01% was gained at 53Ā°C reaction temperature, 7.5:1 methanol/oil molar ratio, 65 min reaction time, and 0.80% catalyst concentration. The results depicted a linear relationship between observed and predicted values. The residual analysis predicted the appropriateness of the central composite design. The Cannabis sativa oil methyl esters, analyzed by gas chromatography, elucidated six fatty acid methyl esters (linoleic, Ī±-linolenic, oleic, palmitic, stearic, and Ī³-linolenic acids). In addition, the fuel properties, such as kinematic viscosity at 40Ā°C; cetane number; acid value; flash point; cloud, pour, and cold filter plugging points; ash content; density; and sulphur content, of Cannabis sativa oil methyl esters were evaluated and discussed with reference to ASTM D 6751 and EU 14214 biodiesel specifications
Plasmons in coupled bilayer structures
We calculate the collective charge density excitation dispersion and spectral
weight in bilayer semiconductor structures {\it including effects of interlayer
tunneling}. The out-of-phase plasmon mode (the ``acoustic'' plasmon) develops a
long wavelength gap in the presence of tunneling with the gap being
proportional to the square root (linear power) of the tunneling amplitude in
the weak (strong) tunneling limit. The in-phase plasmon mode is qualitatively
unaffected by tunneling. The predicted plasmon gap should be a useful tool for
studying many-body effects.Comment: 10 pages, 6 figures. to appear in Phys. Rev. Let
A GABAergic projection from the centromedial nuclei of the amygdala to ventromedial prefrontal cortex modulates reward behavior
The neural circuitry underlying mammalian reward behaviors involves several distinct nuclei throughout the brain. It is widely accepted that the midbrain dopamine (DA) neurons are critical for the reward-related behaviors. Recent studies have shown that the centromedial nucleus of the amygdala (CeMA) has a distinct role in regulating reward-related behaviors. However, the CeMA and ventromedial PFC (vmPFC) interaction in reward regulation remains poorly understood. Here, we identify and dissect a GABAergic projection that originates in the CeMA and terminates in the vmPFC (VGat-Cre(CeMA-vmPFC)) using viral-vector-mediated, cell-type-specific optogenetic techniques in mice. Pathway-specific optogenetic activation of the VGat-Cre(CeMA-vmPFC) circuit in awake, behaving animals produced a positive, reward-like phenotype in real-time place preference and increased locomotor activity in open-field testing. In sucrose operant conditioning, the photoactivation of these terminals increased nose-poking effort with no effect on licking behavior and robustly facilitated the extinction of operant behavior. However, photoactivation of these terminals did not induce self-stimulation in the absence of an external reward. The results described here suggest that the VGat-Cre(CeMA-vmPFC) projection acts to modulate existing reward-related behaviors. SIGNIFICANCE STATEMENT Many studies have shown that the interactions between the centromedial nucleus of the amygdala (CeMA) and ventromedial PFC (vmPFC) have critical roles for emotional regulation. However, most studies have associated this circuit with fear and anxiety behaviors and emphasized top-down processing from vmPFC to CeMA. Here, we provide new evidence for bottom-up CeMA to vmPFC influence on reward-related behaviors. Although previous work implicated the CeMA in incentive salience, our results isolate the investigation to a specific CeMA GABAergic projection to the vmPFC. This long-range GABAergic interaction between amygdala and frontal cortex adds a new dimension to the complex regulation of reward-related behaviors
Inter-observer agreement of canine and feline paroxysmal event semiology and classification by veterinary neurology specialists and non-specialists
Background: Advances in mobile technology mean vets are now commonly presented with videos of paroxysmal events by clients, but the consistency of the interpretation of these videos has not been investigated. The objective of this study was to investigate the level of agreement between vets (both neurology specialists and non-specialists) on the description and classification of videos depicting paroxysmal events, without knowing any results of diagnostic workup. An online questionnaire study was conducted, where participants watched 100 videos of dogs and cats exhibiting paroxysmal events and answered questions regarding: epileptic seizure presence (yes/ no), seizure type, consciousness status, and the presence of motor, autonomic and neurobehavioural signs. Agreement statistics (percentage agreement and kappa) calculated for each variable, with prevalence indices calculated to aid their interpretation.
Results: Only a fair level of agreement (kappa = 0.40) was found for epileptic seizure presence. Overall agreement of seizure type was moderate (kappa = 0.44), with primary generalised seizures showing the highest level of agreement (kappa = 0.60), and focal the lowest (kappa = 0.31). Fair agreement was found for consciousness status and the presence of autonomic signs (kappa = 0.21-0.40), but poor agreement for neurobehavioral signs (kappa = 0.16). Agreement for motor signs ranged from poor (kappa = <= 0.20) to moderate (kappa = 0.41-0.60). Differences between specialists and non-specialists were identified.
Conclusions: The relatively low levels of agreement described here highlight the need for further discussions between neurology experts regarding classifying and describing epileptic seizures, and additional training of non-specialists to facilitate accurate diagnosis. There is a need for diagnostic tools (e.g. electroencephalogram) able to differentiate between epileptic and non-epileptic paroxysms
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