132 research outputs found
Prototype Using Ultrasonic Sensor to Assist Visually Impaired Individual in the Philippines
People who are visually impaired deals with number of difficulties when exercising the most basic things in daily life. Some are frequently rely on others, which makes them less confident in an unusual setting and some use tools like white cane or simple sticks, but for some cirsumstances these could put their lives at risk while traveling. Since the Philippines has limited access to technological resources that could reduce the risk, the researchers came up with the idea of using an ultrasonic sensor to detect obstacles that are above or in front of the user. The study aims to develop a functional prototype that helps visually impaired individual and determine how well the functional prototype responds to the needs of the blind individual. Utilizing a problem-based approach to problem solving, the Design Thinking Methodology was the methodology employed in this study. As a result, using different sound and vibration frequencies the prototype can identify minimum distances of 120 cm, 80 cm, and 30 cm as an output. The study concludes that a successful tool could be a design prototype that uses sensor-equipped sticks to assist blind individuals in moving around and increasing their awareness of their surroundings. However, the scope of this study is limited as it is unable to determine the material of the obstruction or whether a hole exists in front of the user because the tool used in this work can only detect barriers above and in front of the user
Imaging ambipolar diffusion of photocarriers in GaAs thin films
Images of the steady-state luminescence of passivated GaAs self-standing
films under excitation by a tightly-focussed laser are analyzed as a function
of light excitation power. While unipolar diffusion of photoelectrons is
dominant at very low light excitation power, an increased power results in a
decrease of the diffusion constant near the center of the image due to the
onset of ambipolar diffusion. The results are in agreement with a numerical
solution of the diffusion equations and with a physical analysis of the
luminescence intensity at the centre of the image, which permits the
determination of the ambipolar diffusion constant as a function of electron
concentration.Comment: 5 figure
A systematic study of spin-dependent recombination in GaAsN as a function of nitrogen content
A systematic study of spin-dependent recombination (SDR) under steady-state
optical pumping conditions in dilute nitride semiconductors as a function of
nitrogen content is reported. The alloy content is determined by a fit of the
photoluminescence (PL) intensity using a Roosbroeck-Shockley relation and
verified by a study of the GaN-like LO phonon peak in a Raman spectroscopy
map. PL spectra taken from alloys of the form GaAsN where exhibit PL intensity increases when switching from a linearly- to a
circularly-polarized pump up to a factor of 5 for . This work used a
1.39 eV laser with a radius of 0.6 m. The observed SDR ratio monotonically
decreases with increasing , reaching 1.5 for . Moreover, the
excitation power required to obtain maximum SDR systematically increases with
increasing , varying from 0.6 mW for to 15 mW for .
These observations are consistent with an increase in the density of
electronically active defects with increasing nitrogen content, both those
responsible for the SDR as well as other, standard Shockley-Read-Hall (SRH)
centers.Comment: 11 pages, 5 figures; work presented at the International Conference
on the Physics of Semiconductors, Sydney, 202
Design and in vitro effectiveness evaluation of Echium amoenum extract loaded in bioadhesive phospholipid vesicles tailored for mucosal delivery
The Echium amoenum Fisch. and C.A. Mey. (E. amoenum) is an herb native from Iranian shrub, and its blue-violet flowers are traditionally used as medical plants. In the present study, an antioxidant phytocomplex was extracted from the flowers of E. amoenum by ultrasounds-assisted hydroalcoholic maceration. The main components, contained in the extract, have been detected using HPLC-DAD, and rosmarinic acid was found to be the most abundant. The antioxidant power of the extract along with the phenolic content were measured using colorimetric assays. The extract was loaded in liposomes, which were enriched adding different bioadhesive polymers (i.e., mucin, xanthan gum and carboxymethyl cellulose sodium salt) individually or in combination. The main physico-chemical properties (i.e. size, size distribution, surface charge) of the prepared vesicles were measured as well as their stability on storage. The viscosity of dispersion and the ability of vesicles to interact with mucus were evaluated measuring their stability in a mucin dispersion and mobility in a mucin film. The biocompatibility and the ability of the formulations to protect keratinocytes from damages caused by hydrogen peroxide and to promote the cell migration were measured in vitro
A Comparison of the Effectiveness of Cocos nucifera (Coconut) Water as a Rooting Hormone in a Hydroponic and Conventional Set-up in Growing Ocimum basilicum (Basil)
Food shortage is still a problem in the Philippines since millions of people may be classified as undernourished. Efforts to augment the insufficiency include developing an efficient planting method as a source of food. This experimental study tested the effectiveness of coconut water as a rooting hormone on hydroponically and conventionally grown basil plants by measuring the height, fresh weight, leaf length, and root length for three weeks, which also served as the dependent variables. Consequently, two (2) hydroponic set-ups and two (2) conventional set-ups utilize a randomized block design. The set-ups containing coconut water served as the independent variables, while the ones without served as the control. Before the data gathering procedures, the containers were sterilized, the tap water was exposed to sunlight, and the basil seeds were soaked in coconut water. Six hours later, the seeds were planted. After three weeks, the leaf length and root length were measured using a digital caliper, while the height and weight were measured using a standard ruler and digital scale. The nutrient solution and pH level were also monitored. Data was analyzed using two-way ANOVA for leaf length and plant weight, while one-way ANOVA was used for plant height and root length. In addition, a post-hoc test was used for variables that had a significant effect. Descriptive statistics was used to analyze the mean. The hydroponic setup was effective on producing a higher yield for root length (M=112), while the conventional setup was effective on plant height (M=99.7) and leaf length (M=44.1). While the intervention had no significant contribution (p\u3e0.05), hydroponics as an alternative planting technique still has potential in the agricultural sector
Using blood cytokine measures to define high inflammatory biotype of schizophrenia and schizoaffective disorder
Background: Increases in pro-inflammatory cytokines are found in the brain and blood of people with schizophrenia. However, increased cytokines are not evident in all people with schizophrenia, but are found in a subset. The cytokine changes that best define this subset, termed the “elevated inflammatory biotype”, are still being identified. Methods: Using quantitative RT-PCR, we measured five cytokine mRNAs (IL-1β, IL-2 IL-6, IL-8 and IL-18) from peripheral blood of healthy controls and of people with schizophrenia or schizoaffective disorder (n = 165). We used a cluster analysis of the transcript levels to define those with low and those with elevated levels of cytokine expression. From the same cohort, eight cytokine proteins (IL-1β, IL-2, IL-6, IL-8, IL-10, IL-12, IFNγ and TNFα) were measured in serum and plasma using a Luminex Magpix-based assay. We compared peripheral mRNA and protein levels across diagnostic groups and between those with low and elevated levels of cytokine expression according to our transcription-based cluster analysis. Results: We found an overall decrease in the anti-inflammatory IL-2 mRNA (p = 0.006) and an increase in three serum cytokines, IL-6 (p = 0.010), IL-8 (p = 0.024) and TNFα (p < 0.001) in people with schizophrenia compared to healthy controls. A greater percentage of people with schizophrenia (48%) were categorised into the elevated inflammatory biotype compared to healthy controls (33%). The magnitude of increase in IL-1β, IL-6, IL-8 and IL-10 mRNAs in people in the elevated inflammation biotype ranged from 100 to 220% of those in the non-elevated inflammatory biotype and was comparable between control and schizophrenia groups. Blood cytokine protein levels did not correlate with cytokine mRNA levels, and plasma levels of only two cytokines distinguished the elevated and low inflammatory biotypes, with IL-1β significantly increased in the elevated cytokine control group and IL-8 significantly increased in the elevated cytokine schizophrenia group. Conclusions: Our results confirm that individuals with schizophrenia are more likely to have elevated levels of inflammation compared to controls. We suggest that efforts to define inflammatory status based on peripheral measures need to consider both mRNA and protein measures as each have distinct advantages and disadvantages and can yield different results.Danny Boerrigter, Thomas W. Weickert, Rhoshel Lenroot, Maryanne O’Donnell, Cherrie Galletly, Dennis Liu, Martin Burgess, Roxanne Cadiz, Isabella Jacomb, Vibeke S. Catts, Stu G. Fillman, and Cynthia Shannon Weicker
Amebiasis in HIV-1-Infected Japanese Men: Clinical Features and Response to Therapy
Invasive amebic diseases caused by Entamoeba histolytica are increasing among men who have sex with men and co-infection of ameba and HIV-1 is an emerging problem in developed East Asian countries. To characterize the clinical and epidemiological features of invasive amebiasis in HIV-1 patients, the medical records of 170 co-infected cases were analyzed retrospectively, and E. histolytica genotype was assayed in 14 cases. In this series of HIV-1-infected patients, clinical presentation of invasive amebiasis was similar to that described in the normal host. High fever, leukocytosis and high CRP were associated with extraluminal amebic diseases. Two cases died from amebic colitis (resulting in intestinal perforation in one and gastrointestinal bleeding in one), and three cases died from causes unrelated to amebiasis. Treatment with metronidazole or tinidazole was successful in the other 165 cases. Luminal treatment was provided to 83 patients following metronidazole or tinidazole treatment. However, amebiasis recurred in 6 of these, a frequency similar to that seen in patients who did not receive luminal treatment. Recurrence was more frequent in HCV-antibody positive individuals and those who acquired syphilis during the follow-up period. Various genotypes of E. histolytica were identified in 14 patients but there was no correlation between genotype and clinical features. The outcome of metronidazole and tinidazole treatment of uncomplicated amebiasis was excellent even in HIV-1-infected individuals. Luminal treatment following metronidazole or tinidazole treatment does not reduce recurrence of amebiasis in high risk populations probably due to amebic re-infection
Dielectric disorder in two-dimensional materials
Understanding and controlling disorder is key to nanotechnology and materials science. Traditionally, disorder is attributed to local fluctuations of inherent material properties such as chemical and structural composition, doping or strain. Here, we present a fundamentally new source of disorder in nanoscale systems that is based entirely on the local changes of the Coulomb interaction due to fluctuations of the external dielectric environment. Using two-dimensional semiconductors as prototypes, we experimentally monitor dielectric disorder by probing the statistics and correlations of the exciton resonances, and theoretically analyse the influence of external screening and phonon scattering. Even moderate fluctuations of the dielectric environment are shown to induce large variations of the bandgap and exciton binding energies up to the 100 meV range, often making it a dominant source of inhomogeneities. As a consequence, dielectric disorder has strong implications for both the optical and transport properties of nanoscale materials and their heterostructures
Profiles of Parental Burnout Around the Globe: Similarities and Differences Across 36 Countries
Parental burnout (PB) is a pervasive phenomenon. Parenting is embedded in cultural values, and previous research has shown the role of individualism in PB. In this paper, we reanalyze previously collected data to identify profiles based on the four dimensions of PB, and explore whether these profiles vary across countries' levels of collectivistic-individualistic (COL-IND) values. Our sample comprised 16,885 individuals from 36 countries (73% women; 27% men), and we used a latent profile approach to uncover PB profiles. The findings showed five profiles: Fulfilled, Not in PB, Low risk of PB, High risk of PB and Burned out. The profiles pointed to climbing levels of PB in the total sample and in each of the three country groups (High COL/Low IND, Medium COL-IND, Low COL/High IND). Exploratory analyses revealed that distinct dimensions of PB had the most prominent roles in the climbing pattern, depending on the countries' levels of COL/IND. In particular, we found contrast to be a hallmark dimension and an indicator of severe burnout for individualistic countries. Contrary to our predictions, emotional distance and saturation did not allow a clear differentiation across collectivistic countries. Our findings support several research avenues regarding PB measurement and intervention
Parental Burnout Around the Globe: a 42-Country Study
High levels of stress in the parenting domain can lead to parental burnout, a condition that has severe consequences for both parents and children. It is not yet clear, however, whether parental burnout varies by culture, and if so, why it might do so. In this study, we examined the prevalence of parental burnout in 42 countries (17,409 parents; 71% mothers; M_{age} = 39.20) and showed that the prevalence of parental burnout varies dramatically across countries. Analyses of cultural values revealed that individualistic cultures, in particular, displayed a noticeably higher prevalence and mean level of parental burnout. Indeed, individualism plays a larger role in parental burnout than either economic inequalities across countries, or any other individual and family characteristic examined so far, including the number and age of children and the number of hours spent with them. These results suggest that cultural values in Western countries may put parents under heightened levels of stress
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