Measurement of current distribution in the land channel direction of a proton exchange membrane fuel cell

A fully functional proton exchange membrane fuel cell with single land channel geometry on the cathode and segmented anode current collector with 9 mm2 active area with a 350μm spatial resolution was utilized to measure the local current distribution in the land channel direction. A distinguished printed circuit board approach was used for the data acquisition to adapt to any flow field design. Performance of this segmented cell was examined at dry, wet and moderate humidity settings to study the water transport phenomenon in the PEMFC. In the dry condition at 60 ͦ C with 0% relative humidity, the non-uniform water production and dehydrated membrane revealed high current localization under the land region. Conversely, in the wet condition at 60 ͦ C with 80% relative humidity, due to the severe flooding in the catalyst layer resulted in very small limiting current density under the channel region. Individual segment performance analysis for the moderate settings at 60 ͦ C with 60% relative humidity displayed the uniform current distribution at higher cell potential whereas irregular local current generation at low cell voltages due to higher water accumulation under the land region

Sharing economy-based on-demand peer-to-peer tutoring and resource sharing

The sharing economy is a socio-economic ecosystem built around the sharing of human and physical resources. This is considered to be a new and alternate socio-economic system which is currently in its early stages and has tremendous potential. The sharing economy combines the need to direct demand towards supply by adding the point of view of collaboration based on the social networks and preferences of various entities involved. This is based on the economic model of Collaborative Consumption in which participants share access to resources rather than having individual ownership over them. We propose the novel idea of a sharing economy-based model for knowledge sharing amongst peers in a classroom setting. Students often find themselves stuck on trivial implementation details like syntax, best practices and which tools to use. Many times, help is difficult to find, even though the solution might be known to one of the student's peers. Moreover, many large classes do not have enough teaching assistants to help out students and the use of such a platform can be useful to offload simple questions within the classroom itself, saving office hours for more complex questions. This, coupled with the benefits of a collaborative learning environment for students, has motivated us towards the development of an on-demand peer-to-peer tutoring and knowledge sharing platform. Such a platform can also help us understand how different incentive mechanisms motivate people to share knowledge: Are people motivated by social reputation or money? We develop an Android application called "Quet" which can be used by students to request help from their peers for questions related to their coursework on-demand. Preliminary observations show that an application like Quet is useful; and we wish to deploy this in multiple courses in subsequent semesters to realize its full potential and utility to students and instructors alike

Study of endometriosis in women of reproductive age, laparoscopic management and its outcome

Background: The prevalence of endometriosis is seen to be from 10% to 20% in the reproductive age group. The prevalence of endometriosis is 30% to 70% among women presenting with infertility. In our study the incidence of endometriosis appears to be on the higher side. The objective is to find out the prevalence of endometriosis in the female population in the reproductive age and to study the outcome after laparoscopic surgery in infertile women with endometriosisMethods: A total of 200 patients who presented with symptoms of dysmenorrhoea, dyspareunia, chronic pelvic pain with or/without infertility were studied in the women of reproductive age group. The diagnostic/operative laparoscopy was performed in 75 patients. Endometriosis was identified by laparoscopy in 50 cases and confirmed by histopathological examination.Results: Out of the above 200 patients, 25% (50 cases) were diagnosed as cases of endometriosis. Out of which, 50% (25 cases) patients had moderate to severe endometriosis. The prevalence of infertility was 22.5% (45cases out of 200). Endometriosis was the cause of infertility in 33 patients. 25 patients had moderate to severe endometriosis and remaining 8 cases minimal to mild disease. The prevalence of endometriosis was 73.33% in infertile women. The fertility rate after surgery, during the 2 years follow up is 36.36% (12 cases conceived out of 33 cases).Conclusions: The prevalence of endometriosis in infertile women is higher and the outcome after laparoscopic surgery is encouraging. The symptoms and clinical signs should raise the suspicion of pelvic endometriosis

The role of diagnostic hysteroscopy in abnormal uterine bleeding and its histopathological correlation following blind dilatation and curettage

Background: Abnormal uterine bleeding (AUB) is a common gynecological disorder in women. To render appropriate treatment it is vital to establish the correct diagnosis, in this backdrop we have studied the utility of hysteroscopy as a diagnostic procedure against a blind dilatation and curettage. The objectives of the study were hysteroscopic evaluation of abnormal uterine bleeding in reproductive and post-menopausal women. Hysteroscopic findings were compared with the histopathological reports following blind dilatation and curettage.Methods: It is a prospective study on women with symptoms of AUB for a period of one year from Oct 2014 to Nov 2015. Detailed history and clinical examination with an ultrasound (USG) of pelvis to see for endometrial thickness and any structural abnormality was done. 50 cases were included for hysteroscopy. Endometrial biopsy was taken by blind dilation and curettage (D & C) and sent for histopathological examination (HPE). The hysteroscopic and histopathological findings were analyzed.Results: Both hysteroscopy and (D & C) were accurate when an abnormality was diagnosed, giving a specificity of 96.4% and 96.4% respectively and positive predictive value of (95.2% versus 94.4%). The ability to diagnose a lesion was more with hysteroscopy i.e. sensitivity in comparison to curettage, (90.9% versus 77.4%), while a negative diagnosis was less wrongly made with hysteroscopy in comparison to curettage (false negative rate: 9.1% versus 22.7%). In intracavitary lesions like polyp, hysteroscopy gave 100% accuracy.Conclusions: Hysteroscopy is a sensitive diagnostic procedure that provides useful information in all intracavitary lesions and has a higher sensitivity and specificity. A blind D & C for AUB may miss focal lesions including endometrial carcinoma, hence hysteroscopy is advisable

Role of magnetic resonance spectroscopy in brain space occupying lesions for detection of malignancy and grading of malignant lesions

Background: Magnetic resonance (MR) spectroscopy is a non-invasive technique that enables tissue characterization on a biochemical level using radio frequency signals emitted by the nuclei in the tissue. Primary aim is at determining the utility of MR spectroscopy to differentiate malignant from benign lesions and to assess its role in grading of gliomas as secondary objectives.Methods: MR system with proton spectroscopic capability using standard head coils and quantum gradients used in a sample size of 50 patients with intracranial space occupying lesions in conventional MRI. The diagnostic accuracy of the spectroscopic data based on the Cho/Naa ratios was used to detect the malignant lesions and distinguish them from the benign lesions.Results: The lesion characterization using the MR spectroscopic data in distinguishing malignant lesions from benign was statistically compared with the histopathological data using chi square tests proved to be significant with p value of less than 0.05. Grading of the malignant space occupying lesion with the available spectroscopic data was done with the corresponding histopathology that proved statistically not significant.Conclusions: Statistical data proves utility of MR spectroscopic data in differentiating malignant occupying lesions from benign. Role of spectroscopic data in grading the malignant lesion to differentiate to low and high grade could not be determined statistically which may be attributed to low sample size in the secondary objective

The Design Space of Generative Models

Card et al.'s classic paper "The Design Space of Input Devices" established the value of design spaces as a tool for HCI analysis and invention. We posit that developing design spaces for emerging pre-trained, generative AI models is necessary for supporting their integration into human-centered systems and practices. We explore what it means to develop an AI model design space by proposing two design spaces relating to generative AI models: the first considers how HCI can impact generative models (i.e., interfaces for models) and the second considers how generative models can impact HCI (i.e., models as an HCI prototyping material)

Worker-Centered Design: Expanding HCI Methods for Supporting Labor

HCI has long considered sites of workplace collaboration. From airline cockpits to distributed groupware systems, scholars emphasize the importance of supporting a multitude of tasks and creating technologies that integrate into collaborative work settings. More recent scholarship highlights a growing need to consider the concerns of workers within and beyond established workplace settings or roles of employment, from steelworkers whose jobs have been eliminated with post-industrial shifts in the economy to contractors performing the content moderation that shapes our social media experiences. This one-day workshop seeks to bring together a growing community of HCI scholars concerned with the labor upon which the future of work we envision relies. We will discuss existing methods for studying work that we find both productive and problematic, with the aim of understanding how we might better bridge current gaps in research, policy, and practice. Such conversations will focus on the challenges associated with taking a worker-oriented approach and outline concrete methods and strategies for conducting research on labor in changing industrial, political, and environmental contexts

The stilbene biosynthetic pathway and its regulation in Scots pine

Conifers dominate the boreal forests of the Northern Hemisphere, and especially members of the family Pinaceae have great economic and ecological significance. Part of their success is thought to arise from the vast array of secondary metabolites they produce. The products of secondary metabolism are essential for plants to survive in the ever-changing environment. In Scots pine (Pinus sylvestris L.), two groups of secondary metabolites, stilbenes and resin acids, are crucial for decay resistance of heartwood timber and for active defense responses against herbivores and fungal pathogens. Several studies have shown that stilbenes improve decay resistance of pine heartwood. Since there is wide variation in the concentration of stilbenes between individuals and the trait has high heritability, it may be possible to breed heartwood that is more decay-resistant. However, breeding for heartwood properties is slow, since the decay resistance characteristics can be estimated at the earliest from 30-year-old trees. Early selection methods utilizing genetic markers or chemical screening are needed, but we do not yet understand which genes control the biosynthesis of stilbenes and what the genetic differences are between individuals that explain the variation in the capacity to produce stilbenes. Importantly, there is genetic correlation between stress-induced stilbene biosynthesis in seedlings and the heartwood stilbene content in their adult mother trees. Here, we examined the pine transcriptional responses under two conditions that were previously known to activate stilbene biosynthesis: heartwood formation in adult trees and ultraviolet (UV)-C treatment of needles in seedlings. We found that these two conditions had very little in common, except for the activation of stilbene pathway genes. For example, the regulators of the two responses seemed not to be shared. The activation of the stilbene pathway in response to UV-C treatment occurred a few hours after the onset of the treatment and was independent of translation. Stilbene biosynthesis seems to be an early defense response in Scots pine. Heartwood formation, an important developmental process in the senescence of secondary xylem, is poorly understood. Based on transcriptomic analysis, stilbene biosynthesis occurs in situ in the transition zone between the sapwood and heartwood, but resin acids were synthesized primarily in the sapwood. Bifunctional nuclease, an enzyme involved in the process of developmentally programmed cell death (dPCD), is a useful marker for heartwood formation and aided us in defining the timing of the process, from spring to late autumn. Expression of this marker, which is strictly confined to dPCD conditions, further clarified that heartwood formation truly is a process that is initiated by intrinsic programming instead of environmental cues. The transcriptomic data revealed that the expression of the previously characterized pinosylvin O-methyltransferase gene, PMT1, was not induced under stilbene-forming conditions. A new PMT-encoding gene, PMT2, was identified by coexpression analysis. The gene showed an inducible expression pattern very similar to that of the stilbene synthase gene under all conditions studied. PMT2 furthermore methylated pinosylvin with high specificity, in contrast to PMT1, which accepted several substrates.Pohjoisen pallonpuoliskon kasvillisuus on havumetsien hallitsemaa ja etenkin mäntykasvien (Pinaceae) heimoon kuuluu taloudellisesti ja ekologisesti merkittäviä lajeja. Yksi selitys havupuiden menestykselle saattaa olla niiden kyky tuottaa laaja kirjo erilaisia sekundaariyhdisteitä. Männyn (Pinus sylvestris L.) tärkeimpiin sekundaariyhdisteisiin kuuluvat stilbeenit ja terpeenit toimivat puolustuksessa tuholaisia ja patogeenejä vastaan. Aikaisemmat tutkimukset ovat osoittaneet, että aktiivisen puolustuksen lisäksi etenkin stilbeenit parantavat männyn sydänpuun lahonkestävyyttä. Sydänpuun stilbeenien määrä vaihtelee huomattavasti yksilöiden välillä ja ominaisuus on periytyvä, mikä mahdollistaa sydänpuun lahonkestävyyden parantamisen jalostuksen keinoin. Sydänpuun laatuominaisuuksien jalostus on kuitenkin hidasta ja varhaisvalintaan soveltuvien geenimerkkien tunnistaminen nopeuttaisi jalostusprosessia. Emme kuitenkaan vielä tiedä, mitkä geenit säätelevät stilbeenien biosynteesiä ja selittävät erot sydänpuun stilbeenien määrässä. Stilbeenien tuotanto käynnistyy erilaisten stressitekijöiden vaikutuksesta neulasissa ja mantopuussa. Indusoituva tuotanto korreloi sydänpuun stilbeenien määrän kanssa ja tätä voidaan mahdollisesti hyödyntää kemiallisessa seulonnassa taimien varhaisvalinnassa. Tässä väitöskirjassa tutkittiin muutoksia männyn transkriptomissa sydänpuun muodostumisen aikana ja UV-C käsittelyn seurauksena. Stilbeenien biosynteesireitin entsyymejä koodavat geenit aktivoituivat kummassakin tapauksessa, mutta muuten transkriptomeilla oli hyvin vähän yhteistä. Esimerkiksi yhteisiä transkriptiota sääteleviä tekijöitä ei löydetty ja vaikuttaakin siltä, että eri transkriptiofaktorit säätelevät stilbeenien biosynteesireittiä sydänpuun kehityksen aikana ja stressitekijöiden vaikutuksesta. Sydänpuun muodostumisen aikana puussa tapahtuvat kemialliset ja rakenteelliset muutokset tunnetaan joillakin lajeilla hyvin, mutta itse prosessin ajoittuminen sekä käynnistymiseen ja säätelyyn vaikuttavat tekijät ovat vielä suurelta osin tuntemattomia. Stilbeenin biosynteesistä vastaavat geenit ilmenivät vaihettumisvyöhykkeellä mantopuun ja sydänpuun välissä, jossa sydänpuun muodostuminen käynnistyy ja näin tukee aiempaa käsitystä stilbeenien in situ biosynteesistä. Hartsihappojen biosynteesistä vastaavat geenit taas ilmenivät lähinnä mantopuussa, jolloin ne todennäköisesti kuljetetaan vaihettumisvyöhykkeelle sen ulkopuolelta. Ohjelmoidulla solukuolemalla on suuri merkitys sekä kasvin kehityksessä, että stressivasteissa. Bifunktionaalinen nukleaasi (BFN) on entsyymi, joka on yhdistetty aiemmissa tutkimuksissa spesifisesti kasvien kehityksellisiin tapahtumiin. Entsyymiä koodaavan geenin havaittiin ilmenevän ainoastaan vaihettumisvyöhykkeellä. Tämä tukee hypoteesia, jonka mukaan sydänpuun muodostuminen on sisäisesti säädelty eikä ympäristötekijöiden laukaisema tapahtuma. Bifunktionaalinen nukleaasi toimi myös hyödyllisenä markkerina sydänpuun muodostumisen ajoittamisessa keväästä myöhäiseen syksyyn. Transkriptiodata paljasti, että aiemmin tunnistettu stilbeenireitin viimeistä reaktiota katalysoiva metyylitransferaasientsyymiä (PMT1) koodaava geeni ei indusoitunut tutkituissa stilbeenejä tuottavissa olosuhteissa. Tunnistimme uuden metyylitransferaasia koodaavan geenin (PMT2), jonka ekspressioprofiili vastasi stilbeenireitin toisen entsyymin, stilbeenisyntaasin ekspressiota kaikissa tutkituissa olosuhteissa. PMT2 metyloi spesifisesti pinosylviiniä kun taas PMT1 metyloi stilbeenien lisäksi useita rakenteellisesti erilaisia substraatteja