8 research outputs found
FeverDots
FeverDots are wearable temperature sensitive stickers that change color from black to pink at 99°F when placed on the temple or forehead. The objective of this project was to develop an efficient manufacturing method for FeverDots, and manufacture a device along with it. To create the FeverDots manufacturing device, the full design process was executed. The team went through a thorough ideation phase before ultimately defining and specifying the scope of the project.
The key customer requirements of this device include that it is lightweight, portable, durable, simple to assemble, easy to use, and able to generate uniform ink and force distribution. One additional requirement from the sponsors was feedback from human use of FeverDots. The key requirements were analyzed and translated into quantifiable engineering specifications. The lightweight and portable requirement is quantified by a 30 lb maximum weight measurement. Durability was also quantified by a maximum total length of cracking in the wood set at 10 inches. A maximum number of 10 steps to go through a full cycle of stamping was set to quantify simple assembly. Ease of use was quantified with a spec of 27 ± 4N required to start the motion of the device. Finally, the deviceâs ability to generate uniform ink and force distribution was quantified with a 0.015 ± 0.002 g/in2 measurement for dry weight of ink and a minimum of 85% of the sticker paper receiving a uniform application of force per cycle.
An initial conceptual model was developed to test out the initial mechanical ideas; as these ideas were further defined and developed, the final design was selected. The transition from conceptual to final design occurred with a central focus on obtaining equal force and ink distribution. Four total iterations of the prototype were created throughout the life of the project, including the initial and final prototypes. The various iterations were made to fine-tune the ink stamping mechanism and the interactions between assembly pieces.
The team conducted 7 different tests to analyze if it met the specified metrics outlined above. These tests were for: weight and portability, durability, simple assembly, dry weight specification for ink, ink distribution, force uniformity, and minimum force. The purpose of the Weight and Portability test was to identify if the device was not excessively heavy. Next, the Durability test was designed to assess if the parts would be able to remain assembled during stamping, and the Simple Assembly test analyzed if the device requires too many operational steps for use. Also, the Dry Weight Specification of Ink Test allowed the team to observe if the device could apply the correct amount of ink onto the substrate, while the Ink Distribution Test evaluated how well the ink spread across the substrate. Similarly, the Force Uniformity Test noted how force was applied throughout the lid of the device. Lastly, the Minimum Force Test determined if the force threshold to move the device was feasible. To gain data on the human use of FeverDots, a human use study was conducted; survey results were analyzed and presented to our sponsors.
The device achieved uniform force as it met the specification of 85% during the force uniformity test. Additionally, it met the specifications for simple assembly and easy to use as the number of operational steps include only 9 and that it showed to only require a range of 23 N to 31 N to be able to move the lid, respectively. It also passed the portability test as its weight was only 12.2 lbs.
However, it failed the customer requirement of generating uniform ink application. This was revealed as it was unable to meet the specifications of 0.015 g/inÂČ for the dry weight of the ink and 85% of the sticker paper area covered with ink. Lastly, it also failed the durability test as the total crack length summed to over 10 inches
The James Webb Space Telescope
The James Webb Space Telescope (JWST) is a large (6.6m), cold (50K),
infrared-optimized space observatory that will be launched early in the next
decade. The observatory will have four instruments: a near-infrared camera, a
near-infrared multi-object spectrograph, and a tunable filter imager will cover
the wavelength range, 0.6 to 5.0 microns, while the mid-infrared instrument
will do both imaging and spectroscopy from 5.0 to 29 microns. The JWST science
goals are divided into four themes. The End of the Dark Ages: First Light and
Reionization theme seeks to identify the first luminous sources to form and to
determine the ionization history of the early universe. The Assembly of
Galaxies theme seeks to determine how galaxies and the dark matter, gas, stars,
metals, morphological structures, and active nuclei within them evolved from
the epoch of reionization to the present day. The Birth of Stars and
Protoplanetary Systems theme seeks to unravel the birth and early evolution of
stars, from infall on to dust-enshrouded protostars to the genesis of planetary
systems. The Planetary Systems and the Origins of Life theme seeks to determine
the physical and chemical properties of planetary systems including our own,
and investigate the potential for the origins of life in those systems. To
enable these observations, JWST consists of a telescope, an instrument package,
a spacecraft and a sunshield. The telescope consists of 18 beryllium segments,
some of which are deployed. The segments will be brought into optical alignment
on-orbit through a process of periodic wavefront sensing and control. The JWST
operations plan is based on that used for previous space observatories, and the
majority of JWST observing time will be allocated to the international
astronomical community through annual peer-reviewed proposal opportunities.Comment: 96 pages, including 48 figures and 15 tables, accepted by Space
Science Review
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers âŒ99% of the euchromatic genome and is accurate to an error rate of âŒ1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Modeling of Combined Processing Steps for Reducing Escherichia coli O157:H7 Populations in Apple Cider
Probabilistic models were used as a systematic approach to describe the response of Escherichia coli O157:H7 populations to combinations of commonly used preservation methods in unpasteurized apple cider. Using a complete factorial experimental design, the effect of pH (3.1 to 4.3), storage temperature and time (5 to 35°C for 0 to 6 h or 12 h), preservatives (0, 0.05, or 0.1% potassium sorbate or sodium benzoate), and freeze-thaw (F-T; â20°C, 48 h and 4°C, 4 h) treatment combinations (a total of 1,600 treatments) on the probability of achieving a 5-log(10)-unit reduction in a three-strain E. coli O157:H7 mixture in cider was determined. Using logistic regression techniques, pH, temperature, time, and concentration were modeled in separate segments of the data set, resulting in prediction equations for: (i) no preservatives, before F-T; (ii) no preservatives, after F-T; (iii) sorbate, before F-T; (iv) sorbate, after F-T; (v) benzoate, before F-T; and (vi) benzoate, after F-T. Statistical analysis revealed a highly significant (P < 0.0001) effect of all four variables, with cider pH being the most important, followed by temperature and time, and finally by preservative concentration. All models predicted 92 to 99% of the responses correctly. To ensure safety, use of the models is most appropriate at a 0.9 probability level, where the percentage of false positives, i.e., falsely predicting a 5-log(10)-unit reduction, is the lowest (0 to 4.4%). The present study demonstrates the applicability of logistic regression approaches to describing the effectiveness of multiple treatment combinations in pathogen control in cider making. The resulting models can serve as valuable tools in designing safe apple cider processes
Fermentable Carbohydrate Restriction Reduces Luminal Bifidobacteria and Gastrointestinal Symptoms in Patients with Irritable Bowel Syndrome
Preliminary studies indicate that dietary restriction of fermentable short-chain carbohydrates improves symptoms in irritable bowel syndrome (IBS). Prebiotic fructo-oligosaccharides and galacto-oligosaccharides stimulate colonic bifidobacteria. However, the effect of restricting fermentable short-chain carbohydrates on the gastrointestinal (GI) microbiota has never been examined. This randomized controlled trial aimed to investigate the effects of fermentable carbohydrate restriction on luminal microbiota, SCFA, and GI symptoms in patients with IBS. Patients with IBS were randomized to the intervention diet or habitual diet for 4 wk. The incidence and severity of symptoms and stool output were recorded for 7 d at baseline and follow-up. A stool sample was collected and analyzed for bacterial groups using fluorescent in situ hybridization. Of 41 patients randomized, 6 were withdrawn. At follow-up, there was lower intake of total short-chain fermentable carbohydrates in the intervention group compared with controls (P = 0.001). The total luminal bacteria at follow-up did not differ between groups; however, there were lower concentrations (P < 0.001) and proportions (P < 0.001) of bifidobacteria in the intervention group compared with controls when adjusted for baseline. In the intention-to-treat analysis, more patients in the intervention group reported adequate control of symptoms (13/19, 68%) compared with controls (5/22, 23%; P = 0.005). This randomized controlled trial demonstrated a reduction in concentration and proportion of luminal bifidobacteria after 4 wk of fermentable carbohydrate restriction. Although the intervention was effective in managing IBS symptoms, the implications of its effect on the GI microbiota are still to be determined
Mitotic chromosome alignment ensures mitotic fidelity by promoting interchromosomal compaction during anaphase.
Chromosome alignment at the equator of the mitotic spindle is a highly conserved step during cell division; however, its importance to genomic stability and cellular fitness is not understood. Normal mammalian somatic cells lacking KIF18A function complete cell division without aligning chromosomes. These alignment-deficient cells display normal chromosome copy numbers in vitro and in vivo, suggesting that chromosome alignment is largely dispensable for maintenance of euploidy. However, we find that loss of chromosome alignment leads to interchromosomal compaction defects during anaphase, abnormal organization of chromosomes into a single nucleus at mitotic exit, and the formation of micronuclei in vitro and in vivo. These defects slow cell proliferation and are associated with impaired postnatal growth and survival in mice. Our studies support a model in which the alignment of mitotic chromosomes promotes proper organization of chromosomes into a single nucleus and continued proliferation by ensuring that chromosomes segregate as a compact mass during anaphase