Effects of shisha smoke inhalation on some long-term memory forms in adult male mice

Background: Shisha is a flavoured tobacco designed to be smoked in a water-pipe, but it effects on long-term memory has not been fully explored. This study was undertaken to evaluate the effect of Shisha smoke inhalation on some long-term memory models in adult male BALB/c mice. Methods: Twenty male mice were divided into 4 groups of five mice each. Group I (control): fresh air; group II: exposed to bonged Shisha; group III: exposed to unbonged Shisha; group IV: exposed to activated charcoal smoke only. Each group was exposed for thirty minutes daily for seven weeks. Long-term memory was assessed using elevated plus maze (EPM), novel object recognition test (NORT) and Barnes maze (BM). Results: There was statistically significant decrease (P<0.05) in novel object recognition in bonged Shisha group when compared with the control. There was statistically significant increase (P<0.05) in spatial learning and memory in bonged Shisha group when compared with control. There was statistically significant decrease (P<0.05) in acetylcholinesterase activity in bonged Shisha group when compared with control, but there was no statistically significant difference in anxiety related spatial memory in elevated plus maze when compared with the control. There was also increased in necrosis of hippocampal cells in bonged Shisha group and slight necrosis in unbonged and activated charcoal smoke when compared to control mice. Conclusion: The outcomes of this study suggest that bonged Shisha smoke is neurotoxic to the brain because of combined effect of various toxicants emanating from different Shisha smoke constituents used in the set-up Keywords: Shisha, Memory, Hippocampus, Acetylcholinesteras

Molecular mechanisms of aluminium neurotoxicity in animal models of Alzheimer’s disease

Alzheimer’s disease (AD) is the most common cause of dementia that affects one patient every seven seconds. With over 35 million people currently affected worldwide, it has been projected that the disease will affect about 115 million people by 2050. The disease is characterized by dysfunctional cellular and molecular networks and/or genomic and epigenomic interactions that affect the normal function of brain cells, leading to a defective cellular communication and function, and ultimately neurodegeneration. Aluminium (Al3+) is the third most abundant ubiquitous element in the earth crust which has gained easy access to humans and extensively used in daily life. It is an essential component of many materials used in households, such as clays, glasses, and alum. An increasing body of evidence implicates Al3+ in the progression of events that lead to neurodegenerative diseases, some of which remains controversial, but it is widely accepted that Al3+ is a recognised neurotoxin that could cause neurodegenerative diseases such as AD. The pathophysiological changes induced in Al3+ neurotoxicity leading to AD result in critical impairments of the central nervous system functions, which are essential for healthy brain ageing. These changes include; axonal transport, neurotransmitter synthesis and synaptic transmission, disruption of calcium homeostasis, alteration of energy metabolism, phosphorylation/dephosphorylation of proteins, protein degradation, gene expression, formation of reactive oxygen species and inflammatory responses, inhibition of DNA repair system, activation of glial cells, reduction of activities of antioxidant enzymes, alterations of pathways of NF-kB and JNK, binding DNA, cell death, motor and cognitive decline. These multi-faceted pathways provide a link between Al neurotoxicity and AD by modulating both tau and amyloid beta hypotheses of AD.Keywords: Alzheimer’s disease, Aluminium chloride, Amyloid beta, Tau, Animal model

Assessment of cognitive and motor endurance activities in male wistar rats administered carboxymethyl cellulose

Carboxymethyl cellulose (CMC) is generally believed to be biologically inert, non-toxic and non-allergic. Due to its bio-compatibility, bio-degradability and other rheological properties, it has found various uses in different aspects of human life, bio-medically and industrially; that includes, suspension of physiological extract (as a vehicle), drug delivery system, tissue regeneration, formation of smart materials, hydrogels, bone growth, surgical, ultrasound procedures and foodstuff formulations (thickening, binding), lubricant for drilling in oil industry and as a stabilizer and binder in cosmetic industry. In this study, we investigated the physiological effect of CMC on cognition and motor endurance. Wistar rats were orally administered with CMC, at 5mg/kg, 10mg/kg and 20mg/kg doses while a control group was given normal saline. Cognitive function was evaluated using novel object recognition task while motor endurance function was assessed using forepaw grip test. The results obtained showed that there was no significant difference (p > 0.05) in both working and long-term memory in all the groups when compared to the control. Although, not significant the group receiving 5mg/ml CMC showed a lower preference score (working memory) when compared to other groups. However, at the doses 5 mg/kg and 10 mg/kg, motor endurance was significantly improved. Findings in this study suggest that although CMC may not influence cognition in this study, it may not be completely physiologically inert since it influenced motor endurance which may not be undesirable, more studies should be carried out to ascertain its neurobehavioural activity, while caution is encouraged in its usage.Keywords: Carboxymethyl cellulose, learning, memory, motor endurance, inertAfr. J. Biomed. Res. Vol. 22 (May, 2019); 195- 19

Electrolyte and oxidative stress profile of healthy adult population in Zaria, Nigeria, and their relationship with experimental pain response

Background: Electrolyte imbalance and oxidative stress (OS) are known to impair physiological functions, which can alter health and wellbeing. The reactive species produced due to OS are detoxified by endogenous antioxidants to maintain homeostasis. This study investigated the electrolyte and oxidative stress profile of a healthy adult population in Zaria, Nigeria and their relationship with experimental pain outcome. Method: Participants were apparently healthy adult volunteers between the ages of 20 to 65 years and drawn from the city of Zaria and its environs. Experimental pain was induced using pressure algometry. About 5 ml of blood was collected for determination of serum electrolytes, malondialdehyde (MDA), reduced glutathione (GSH) and superoxide dismutase (SOD). Result: The results showed that serum concentrations of sodium, potassium and chloride as well as oxidative stress profile did not vary with sex, age and ethnicity among the studied population. There was a significant negative correlation between pressure pain threshold and serum concentration of potassium (r = 0.2330, p = 0.003) and chloride (r = 0.2126, p = 0.007), while serum sodium correlated positively (r = 0.3439, p = 0.000). Serum MDA, SOD and GSH did not show statistically significant correlation with pressure pain threshold (p > 0.05). Conclusion: Serum electrolytes, but not oxidative stress markers, correlate significantly with experimental pressure pain threshold among healthy adult population in Zaria, Nigeria Keywords: Electrolytes, oxidative stress, pressure pain, sex, age, ethnicit

Enhanced Integrated Indoor Positioning Algorithm Utilising Wi-Fi Fingerprint Technique

This paper describes an integrated positioning algorithm utilizing Wi-Fi fingerprint technique for indoor positioning. The main contribution of this work is the improvement of positioning accuracy for indoor localization even in extreme RSSI fluctuation which leads to variation of positioning error. Several layers of Wi-Fi positioning is proposed, which are based on deterministic techniques, iterative Bayesian estimation, and also Kalman filter to enhance accuracy due to noise presence. Here, accumulated accuracy is introduced where the distribution of location error is determined by estimation at each test point on path movement. The results show that the integrated algorithm enhances the estimation accuracy in several scenarios which are different Wi-Fi chipsets and movement directions. The error distribution shows an achievement of up to 65% for error less than 5m compared to the basic deterministic technique of only 45%

Analysis of WiMAX Positioning Using Received-Signal-Strength Method

This paper presents an analysis of WiMAX positioning by using received-signal-strength (RSS) method. A simulator was developed using MATLAB to demonstrate the ability of RSS method for WiMAX positioning. With this simulator, the user can specify their own data or parameters in analyzing and obtaining the target object location. In this study, the analysis was done in three different scenarios that simulate various conditions for WiMAX positioning. Result shows that channel or propagation models are crucial part in the process of analyzing the communication system where it will affect the performance of positioning detection. Selection of perfect model that resemble the real environment will led to better wireless positioning system. By the performance evaluation, the user can plan better simulation system and can create more accurate algorithms for radio positionin

Design of narrowband tunable filter for LTE Band 5

The objective of this project is to design and develop a tunable bandpass filter for LTE Band 5 that work within the frequency range of 869 MHZ - 894 MHz. The filter characteristic that being tuned in this design is the center frequency while the bandwidth remains the same. The tunability of the design is electronically controlled by adjusting the capacitance value in the filter network. The design is being constrict by the currently available lumped element component in the market. The design methodology of the tunable filter are being introduced in this project. Several thesis and article regarding RF microwave filter design are reviewed before coming up with the methodology for the design

Aspectos microscópicos da interação feijoeiro-Colletotrichum lindemuthianum mediados pelo silício

A antracnose, causada pelo fungo Colletotrichum lindemuthianum, é uma das doenças mais destrutivas que afetam a cultura do feijoeiro. Com o objetivo de encontrar alternativas para o controle dessa doença, o presente trabalho investigou, em nível microscópico, o efeito do silício (Si) na resistência do feijoeiro à infecção por C. lindemuthianum. Plantas de feijoeiro (cv. Pérola) foram cultivadas em solução nutritiva contendo 0 (-Si) ou 2 mM (+Si) de Si e inoculadas no estádio de crescimento V4 com uma suspensão de conídios de C. lindemuthianum. A severidade da antracnose decresceu cerca de 52% nas folhas das plantas supridas com Si (4,4%) em relação às folhas das plantas não supridas (8,5%). Observações de folhas de feijoeiro das plantas não supridas com Si no microscópio eletrônico de varredura revelaram alterações morfológicas nas nervuras em contraste com as folhas de plantas supridas com Si. Utilizando-se a microanálise de raios-X, verificou-se maior concentração dos minerais enxofre, potássio e Si nas folhas das plantas supridas com Si. Em conclusão, o suprimento de Si em plantas de feijoeiro foi importante para reduzir os sintomas da antracnose

Search for Tensor, Vector, and Scalar Polarizations in the Stochastic Gravitational-Wave Background

The detection of gravitational waves with Advanced LIGO and Advanced Virgo has enabled novel tests of general relativity, including direct study of the polarization of gravitational waves. While general relativity allows for only two tensor gravitational-wave polarizations, general metric theories can additionally predict two vector and two scalar polarizations. The polarization of gravitational waves is encoded in the spectral shape of the stochastic gravitational-wave background, formed by the superposition of cosmological and individually unresolved astrophysical sources. Using data recorded by Advanced LIGO during its first observing run, we search for a stochastic background of generically polarized gravitational waves. We find no evidence for a background of any polarization, and place the first direct bounds on the contributions of vector and scalar polarizations to the stochastic background. Under log-uniform priors for the energy in each polarization, we limit the energy densities of tensor, vector, and scalar modes at 95% credibility to Ω0T<5.58×10-8, Ω0V<6.35×10-8, and Ω0S<1.08×10-7 at a reference frequency f0=25 Hz. © 2018 American Physical Society

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society