334 research outputs found
Designing research tools : empirical knowledge as a base for future beekeeping.
The world-wide phenomenon of the disappearance of bees with the consequential imbalance of ecosystems is a problem that needs to be addressed in order to guarantee a sustainable future. Beekeeping is an activity, generally associated to agriculture, that allows small farmers to generate more food and income, this reality has had a shift in recent years with the number of small beekeepers decreasing, and big corporations gaining control over the industry. Regulations and the Colony Collapse Disorder, among other factors, may have a major role in these phenomena.
With the intent to contribute to a more sustainable beekeeping practice, this research is being conducted to better understand this reality, looking for design driven opportunities.
The challenge is to gain a deeper understanding of the beekeepers, a practice that is understudied by designers, particularly considering in-depth research methods. This paper discusses an experimental design study in the Turkish Aegean region that was conducted with local beekeepers to better understand the existing specifications: by discussing their business models, in order to understand and analyze socio-cultural factors that contributed to the existing system, and propose changes for a more sustainable practice. As a starting point for a first phase survey, the intent is to generate original data which will serve as the foundation for future works.
Beekeepers in this scenario are mainly senior male farmers that belong to a low literacy audience, who learned the practice from their predecessors. In order to identify the problems of beekeepers, we needed to design and adjust our research methods according to the specifications of the audience. For this reason, a three stage inquiry was designed to better communication in order to extract measurable data from their empirical knowledge through a series of workshops.
The case study reports the workshop sessions for identifying the design strategies with a focus on voicing the beekeepers problems. The first level draws upon explicit knowledge to identify the audience. For the second level an illustrated questionnaire was designed to visually represent the quantitative data about the business. The process is exercised with a new design because the content of knowledge is tacit and personal. Finally, the third level is an interview session to validate the data gathered from the previous stages.
This paper will present the findings of the workshops with the aim to formulate an appropriate way to employ new approaches to exploring and defining design problems with visual representations. We also seek to extend our research in other contexts that will help discuss the role of design as a tool for developing new methodologies of design research.
As a consequence we will propose prototypes of artifacts that will consider the implementation into beekeeping of new biomaterials, technology, branding and commercialization planning, etc., that may help create a more sustainable beekeeping practice. Beekeepers will be invited to analyze proposals and give their contributions. This process will render into redesigned optimized artifacts that will merge empirical knowledge with the needs of sustainable beekeeping.
Keywords design research tools, beekeeping, sustainability, eco-innovation, cooperatio
Evidence for Nonradiative Energy Transfer in Graphene-Oxide-Based Hybrid Structures
Cataloged from PDF version of article.Solution processed graphene variants including graphene oxide (GO) and reduced graphene oxide (RGO) are promising materials for potential optoelectronic applications. To date, efficiency of the excitation energy transfer into GO and RGO thin layers has not been investigated in terms of donor-acceptor separation distance. In the present work, we study nonradiative energy transfer (NRET) from CdSe/CdS quantum dots into single and/or double layer GO or RGO using time-resolved fluorescence spectroscopy. We observe shorter lifetimes as the separation distance between the QDs and GO or RGO decreases. In accordance with these lifetimes, the rates reveal the presence of two different mechanisms dominating the NRET. Here we show that excitonic NRET is predominant at longer intervals while both excitonic and nonexcitonic NRET exist at shorter distances. In addition, we find the NRET rate behavior to be strongly dependent on the reduction degree of the GO-based layers. We obtain high NRET efficiency levels of similar to 97 and similar to 89% for the closest separation of the QD-RGO pair and the QD-GO pair, respectively. These results indicate that strong NRET from QDs into thin layer GO and RGO makes these solution-processable thin films promising candidates for light harvesting and detection systems
Physical applications of second-order linear differential equations that admit polynomial solutions
Conditions are given for the second-order linear differential equation P3 y"
+ P2 y'- P1 y = 0 to have polynomial solutions, where Pn is a polynomial of
degree n. Several application of these results to Schroedinger's equation are
discussed. Conditions under which the confluent, biconfluent, and the general
Heun equation yield polynomial solutions are explicitly given. Some new classes
of exactly solvable differential equation are also discussed. The results of
this work are expressed in such way as to allow direct use, without preliminary
analysis.Comment: 13 pages, no figure
Impaired respiratory burst contributes to infections in PKCδ-deficient patients
Patients with autosomal recessive protein kinase C δ (PKCδ) deficiency suffer from childhood-onset autoimmunity, including systemic lupus erythematosus. They also suffer from recurrent infections that overlap with those seen in patients with chronic granulomatous disease (CGD), a disease caused by defects of the phagocyte NADPH oxidase and a lack of reactive oxygen species (ROS) production. We studied an international cohort of 17 PKCδ-deficient patients and found that their EBV-B cells and monocyte-derived phagocytes produced only small amounts of ROS and did not phosphorylate p40phox normally after PMA or opsonized Staphylococcus aureus stimulation. Moreover, the patients' circulating phagocytes displayed abnormally low levels of ROS production and markedly reduced neutrophil extracellular trap formation, altogether suggesting a role for PKCδ in activation of the NADPH oxidase complex. Our findings thus show that patients with PKCδ deficiency have impaired NADPH oxidase activity in various myeloid subsets, which may contribute to their CGD-like infectious phenotype
Diurnal and nocturnal drooling in Parkinson’s disease
Drooling as symptom of Parkinson’s disease (PD) has thus far been poorly defined. This uncertainty is reflected by high variations in published prevalence rates. The aim of this study was to investigate the prevalence of saliva loss versus accumulation of saliva as a possible preliminary stage, and diurnal drooling versus nocturnal drooling. In addition, we evaluated the association between drooling severity and the severity of facial and oral motor disorders. We collected age, disease duration, UPDRS III and Hoehn & Yahr stage from 104 consecutive outpatients with PD. Diurnal and nocturnal drooling was evaluated with a validated questionnaire (ROMP-saliva). A speech pathologist, blinded for drooling severity, rated facial expression, involuntary mouth opening and difficulty with nose breathing and also interviewed patients about sleeping position and nose-breathing during the night. Thirty patients (29%) had no complaints with saliva control (‘non-droolers’), 45 patients (43%) experienced accumulation of saliva or only nocturnal drooling (‘pre-droolers’), and 29 (28%) had diurnal drooling (24 of which also drooled during the night; ‘droolers’). The droolers had longer disease duration (10 vs. 7 years, p = 0.01) and drooling was independently associated with involuntary mouth opening (OR = 2.0; 95% CI 1.02–3.99) and swallowing complaints (OR = 1.2; 95% CI 1.03–1.31). Diurnal drooling—defined as dribbling of saliva while awake—is present in about 28% of PD patients. This is less than usually reported. Diurnal drooling typically appeared later in the disease course. The association with oral motor behavior should encourage the development of behavioral treatment approaches
Biallelic loss-of-function mutation in NIK causes a primary immunodeficiency with multifaceted aberrant lymphoid immunity
Primary immunodeficiency disorders enable identification of genes with crucial roles in the human immune system. Here we study patients suffering from recurrent bacterial, viral and Cryptosporidium infections, and identify a biallelic mutation in the MAP3K14 gene encoding NIK (NF- B-inducing kinase). Loss of kinase activity of mutant NIK, predicted by in silico analysis and confirmed by functional assays, leads to defective activation of both canonical and non-canonical NF- B signalling. Patients with mutated NIK exhibit B-cell lymphopenia, decreased frequencies of class-switched memory B cells and hypogammaglobulinemia due to impaired B-cell survival, and impaired ICOSL expression. Although overall T-cell numbers are normal, both follicular helper and memory T cells are perturbed. Natural killer (NK) cells are decreased and exhibit defective activation, leading to impaired formation of NK-cell immunological synapses. Collectively, our data illustrate the non-redundant role for NIK in human immune responses, demonstrating that loss-of-function mutations in NIK can cause multiple aberrations of lymphoid immunity
Patients with primary immunodeficiencies are a reservoir of poliovirus and a risk to polio eradication
ABSTARCT: Immunodeficiency-associated vaccine-derived polioviruses (iVDPVs) have been isolated from primary immunodeficiency (PID) patients exposed to oral poliovirus vaccine (OPV). Patients may excrete poliovirus strains for months or years; the excreted viruses are frequently highly divergent from the parental OPV and have been shown to be as neurovirulent as wild virus. Thus, these patients represent a potential reservoir for transmission of neurovirulent polioviruses in the post-eradication era. In support of WHO recommendations to better estimate the prevalence of poliovirus excreters among PIDs and characterize genetic evolution of these strains, 635 patients including 570 with primary antibody deficiencies and 65 combined immunodeficiencies were studied from 13 OPV-using countries. Two stool samples were collected over 4 days, tested for enterovirus, and the poliovirus positive samples were sequenced. Thirteen patients (2%) excreted polioviruses, most for less than 2 months following identification of infection. Five (0.8%) were classified as iVDPVs (only in combined immunodeficiencies and mostly poliovirus serotype 2). Non-polio enteroviruses were detected in 30 patients (4.7%). Patients with combined immunodeficiencies had increased risk of delayed poliovirus clearance compared to primary antibody deficiencies. Usually, iVDPV was detected in subjects with combined immunodeficiencies in a short period of time after OPV exposure, most for less than 6 months. Surveillance for poliovirus excretion among PID patients should be reinforced until polio eradication is certified and the use of OPV is stopped. Survival rates among PID patients are improving in lower and middle income countries, and iVDPV excreters are identified more frequently. Antivirals or enhanced immunotherapies presently in development represent the only potential means to manage the treatment of prolonged excreters and the risk they present to the polio endgame. Keywords: Poliovirus eradication, Immunodeficiency-associated vaccine-derived polioviruses, Oral poliovirus vaccine, Humoral immunodeficiency, Combined immunodeficiency, Primary immunodeficienc
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