3,250 research outputs found
Altered sleep and EEG power in the P301S Tau transgenic mouse model
OBJECTIVE: Sleep disturbances are prevalent in human tauopathies yet despite the importance of sleep, little is known about its relationship with tau pathology. Here, we investigate this interaction by analyzing sleep and tau pathology throughout tauopathy disease progression in P301S human tau transgenic mice. METHODS: P301S and wild‐type mice were analyzed by electroencephalography (EEG)/electromyography at 3, 6, 9, and 11 months of age for sleep/wake time, EEG power, and homeostatic response. Cortical volume and tau pathology was also assessed by anti‐phospho‐tau AT8 staining. RESULTS: P301S tau mice had significantly decreased rapid eye movement (REM) sleep at 9 months of age and decreased REM and non‐REM (NREM) sleep as well as increased wakefulness at 11 months. Sleep loss was characterized by fewer wake, REM, and NREM bouts, increased wake bout duration, and decreased sleep bout duration. Decreased REM and NREM sleep was associated with increased brainstem tau pathology in the sublaterodorsal area and parafacial zone, respectively. P301S mice also showed increased EEG power at 6 and 9 months of age and decreased power at 11 months. Decreased EEG power was associated with decreased cortical volume. Despite sleep disturbances, P301S mice maintained homeostatic response to sleep deprivation. INTERPRETATION: Our results indicate that tau pathology is associated with sleep disturbances that worsen with age and these changes may be related to tau pathology in brainstem sleep regulating regions as well as neurodegeneration. Tau‐induced sleep changes could affect disease progression and be a marker for therapeutic efficacy in this and other tauopathy models
An Evaluation of Reputation Management in Selected Federal Universities in South West Nigeria
This study evaluates reputation management in selected federal universities in South West Nigeria. Questionnaire (for 423 respondents), interview and focus group discussion were used to generate the needed data. Findings show that most of the respondents were not oblivious of the concept of reputation management in a university environment. Their knowledge of these institutions’ reputation also created a favorable impression although a category of stakeholders were unimpressed, owing to lack access to the required information or updates about these institutions. The study notes that universities stand a good chance of building a good reputation if they establish and sustain good relationships with one another
An Evaluation of Reputation Management in Selected Federal Universities in South West Nigeria
This study evaluates reputation management in selected federal universities in South West Nigeria. Questionnaire (for 423 respondents), interview and focus group discussion were used to generate the needed data. Findings show that most of the respondents were not oblivious of the concept of reputation management in a university environment. Their knowledge of these institutions’ reputation also created a favorable impression although a category of stakeholders were unimpressed, owing to lack access to the required information or updates about these institutions. The study notes that universities stand a good chance of building a good reputation if they establish and sustain good relationships with one another
Survivorship of Cancer Patients in Nigeria: An Evidence for Aggressive Measures against Cancer in Developing Countries
More than 60% of the world’s total new annual cancer cases occur in Africa, Asia and Central and South America. The aim of this study was to build a predictive model for the two possible outcomes of cancer patients and to examine which of the several types of cancer was more deadly. Secondary data of 335 patients aged 11 to 90 years who received treatment for liver, lung, colon, colorectal, prostate, breast or skin cancer at LAUTECH teaching hospital between 2004 and 2010 was used for this analysis. Logistic regression analysis was conducted. The Hosmer and Lemeshow and Likelihood Ratio tests were used to determine the fit and significance of parameters of the model. Only the type of cancer suffered by patients contributed significantly to the prediction model. The odds of dying for patients with lung cancer were about 4 times that of other types of cancer. However, the incidence of liver, lung, colon, colorectal, prostate, breast and skin cancer was prevalent across patients aged 11 and 90 years, irrespective of sex. Lung cancer was found to be more deadly than other types of cancer observed in the sample
SUSTAINING AGRICULTURAL PRODUCTION IN A DEREGULATED ECONOMY
This paper reuiews the policy framework for Nlgelian agriculture and gauges Its Impact plior to and since
the commencement of economic deregulation. It investigates the prospects, analyses tile constraints and ouUlnes
a feasible strategy for sustaining ag~icultural growth In a deregulated enabling environment. The paper notes that
In the period, 1970 to 1982, the deterioration In ag~icultural pe1jormance In Nlge1ia was the result not only of
extemal shocks and erwironmental and/or edaphfc foctors, but of distorted policy pursuits which created
clislncentiues for farming. Howeuer, following attemptS to deregulate the economy with the adopUon of the
Structural Adjustment Pl:o!P·amme In 1986 and the consequent eff01t to get price lncenUues right for agriculture,
there was some Improvement in ag~icultural performance. It Is noted that agricultural sector growth has recently
been lwmpered by increased costs 01ising mainly from genera/deregulation. An lnuestlgatlon of the resource base
and prospects shows that ag~kulture can contlibute more to g~·owth than In recent years. But success wlll require
engendering a conducive enabling environment and Incentives, avaliC!bility of technology and Inputs as well as
Infrastructure. This calls for an oction plan which glues the prluate and Informal sectors bigger roles In the execution
of development prog~·ammes. In addition, the public section would need to refocus current policies and priolitles
with more uigorous implementation of known successful approoches based on factor endowments for stimulating
growth
Dual Band Electrodes in Generator-Collector Mode: Simultaneous Measurement of Two Species
A computational model for the simulation of a double band collector-generator
experiment is applied to the situation where two electrochemical reactions
occur concurrently. It is shown that chronoamperometric measurements can be
used to take advantage of differences in diffusion coefficients to measure the
concentrations of both electroactive species simultaneously, by measuring the
time at which the collection efficiency reaches a specific value. The
separation of the electrodes is shown to not affect the sensitivity of the
method (in terms of percentage changes in the measured time to reach the
specified collection efficiency), but wider gaps can provide a greater range of
(larger) absolute values of this characteristic time. It is also shown that
measuring the time taken to reach smaller collection efficiencies can allow for
the detection of smaller amounts of whichever species diffuses faster. The case
of a system containing both ascorbic acid and opamine in water is used to
exemplify the method, and it is shown that mole fractions of ascorbic acid
between 0.055 and 0.96 can, in principle, be accurately measured.Comment: 34 pages, 8 figure
Slow fatigue and highly delayed yielding via shear banding in oscillatory shear
We study theoretically the dynamical process of yielding in cyclically
sheared amorphous materials, within a thermal elastoplastic model and the soft
glassy rheology model. Within both models we find an initially slow
accumulation, over many cycles after the inception of shear, of low levels of
damage in the form strain heterogeneity across the sample. This slow fatigue
then suddenly gives way to catastrophic yielding and material failure. Strong
strain localisation in the form of shear banding is key to the failure
mechanism. We characterise in detail the dependence of the number of cycles
before failure on the amplitude of imposed strain, the working temperature, and
the degree to which the sample is annealed prior to shear. We discuss our
finding with reference to existing experiments and particle simulations, and
suggest new ones to test our predictions.Comment: 4 pages, 5 figure
Optimal Control of Superconducting N-level quantum systems
We consider a current-biased dc SQUID in the presence of an applied
time-dependent bias current or magnetic flux. The phase dynamics of such a
Josephson device is equivalent to that of a quantum particle trapped in a D
anharmonic potential, subject to external time-dependent control fields, {\it
i.e.} a driven multilevel quantum system. The problem of finding the required
time-dependent control field that will steer the system from a given initial
state to a desired final state at a specified final time is formulated in the
framework of optimal control theory. Using the spectral filter technique, we
show that the selected optimal field which induces a coherent population
transfer between quantum states is represented by a carrier signal having a
constant frequency but which is time-varied both in amplitude and phase. The
sensitivity of the optimal solution to parameter perturbations is also
addressed
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