The Benefits of Stereo Microscopes

Many people have trouble keeping one eye closed while peering through a microscope lens with the other eye. A stereo microscope eliminates the need to close one eye because it has two eyepieces. Stereo Microscopes have all of the features of conventional microscopes with some added advantages. First of all, stereo microscopes have two eyepieces. They allow for greater depth perception, allowing viewers to see objects in three dimensions. Many stereo microscopes have a zoom lens feature, and it is not uncommon to find a stereo microscope with two illuminators. A stereo microscope has two eyepieces. This is a major advantage over conventional microscopes. The two eyepieces allow viewers to keep both eyes open, making it easier to focus on the object they are looking at. Many stereo microscopes have comfortable rubber eye guards that make the microscopes even more user friendly. A major advantage of stereo microscopes is that they allow viewers to see objects in three dimensions. Most microscopes only show objects in two dimensions. People can look at insects, plants, coins, or anything else in all three dimensions, providing the most realistic viewing experience imaginable. Many stereo microscopes have a zoom lens feature. This provides nearly limitless options for resolution and gives users more control over focus. The zoom lens allows users to slowly enlarge the object they are viewing more easily than conventional microscopes , which have two knobs to adjust. Another feature found on many stereo microscopes is a dual illuminator system. A stereo microscope has the conventional illuminator below the stage as well as another one right above the objective lens. This provides more than enough light to view specimens in all of their three dimensional glory. Stereo microscopes are versatile and easy to use. They are perfect for students or anyone else who wants to explore the miniature world around them.

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Radial Arrangement of Janus-like Setae Permits Friction Control in Spiders
Radial Arrangement of Janus-like Setae Permits Friction Control in Spiders
Dynamic attachment is the key to move on steep surfaces, with mechanisms being still not well understood. The hunting spider Cupiennius salei (Arachnida, Ctenidae) possesses hairy attachment pads (claw tufts) at its distal legs, consisting of directional branched setae. The morphological investigation revealed that adhesive setae are arranged in a radial manner within the distal tarsus. Friction of claw tufts on smooth glass was measured to reveal the functional effect of seta arrangement within the pad. Measurements revealed frictional anisotropy in both longitudinal and transversal directions. Contact behaviour of adhesive setae was investigated in a reflection interference contrast microscope (RICM). Observations on living spiders showed, that only a small part of the hairy pads is in contact at the same time. Thus the direction of frictional forces is depending on leg placement and rotation. This may aid controlling the attachment to the substrate.Three living individuals of the hunting spider K 1877 (Ctenidae) were obtained from a laboratory stock of the Department of Neurobiology, University of Vienna, Austria. Spiders were kept in cylindrical glasses at the room temperature and 95% relative humidity and fed with house crickets () obtained from the local pet shop.The claw tufts were observed with aid of a stereo microscope (M205 A, Leica Microsystems, Wetzlar, Germany) under lateral and coaxial illumination in spiders resting upside-down on the smooth transparent surface of Plexiglas Petri dishes.Tarsi of the four pairs of walking legs of one body side were ablated with a scalpel in spiders anaesthetized with carbon dioxide. The samples were air dried, mounted on metal stubs and sputter coated with a 15 nm layer of gold-palladium. Samples were viewed in the SEM TM-3000 (Hitachi Ltd., Tokyo, Japan) at 15.0 kV using back-scattered electron (BSE) detector.The setup for force measurements was as previously described by Niederegger and Gorb and is displayed in . Freshly ablated tarsi of different walking legs from spiders anaesthetized with carbon dioxide were shaved at their dorsal side and mounted on a Plexiglas slide with bees wax. Tarsi were positioned in the wax so that the median surface of the setal array of the claw tuft was parallel to the Plexiglas slide. Those samples were attached with double sided adhesive tape to the distal cantilever of a load cell force transducer with 10 g force range (World Precision Instruments Inc., Sarasota, FL, USA). A second force transducer of the same type was attached to a micromanipulator (DC3001R with controller MS314, World Precision Instruments Inc., Sarasota, FL, USA) and placed perpendicularly to the first one. A clean glass cover slip was mounted on the lateral edge of the cantilever. Thus, normal force and friction force could be recorded simultaneously. Force curves were recorded with AcqKnowledge 3.7.0 software (Biopac Systems Ltd, Goleta, CA, USA). A laterally installed stereo microscope was used to monitor the sample movements and the proper contact formation between the claw tuft and smooth substrate.Experiments were performed at an environmental temperature of 20–23°C and a relative humidity of 20–25%. The cover slip was brought into contact with the claw tuft and loaded until normal force reached about 7 mN. Then it was horizontally moved for 3 s with the constant velocity of 200 μm·s in the proximal (simulating leg pushing) and distal (simulating leg pulling) direction, and the friction forces, resisting these movements, was recorded. Proximal and distal sliding experiments were done in a randomized order.Similar force measurements were repeated with the same but air dried samples after two days. Additionally, pro- and retrolateral shearing experiments were performed in the pro- and retrolateral lobes of the claw tuft on an air dried anterior leg tarsus. For this purpose, the leg sample was positioned in the way that the surface of respective lobe was oriented parallelly to the surface of the glass cover slip.Force data were obtained by respective processing of the recorded time-force curves. We have taken into account values recorded after two seconds after shear movement was started, to ensure that the contact between the pad and substrate was formed and friction forces have reached plateau. Friction coefficient μ was calculated as the quotient between friction and normal force. Data were statistically compared with R software package (version 2.13.2, ).Contact behaviour between tuft pad and glass substrate was visualized with an inverted light microscope (Axio Observer.A1, Carl Zeiss Microscopy GmbH, Göttingen, Germany). In the RICM mode, the light source is positioned in a way that light is reflected at the interface of direct (real) contact between the glass slide and the object. Zones of direct contact appear as dark spots on the bright background. Similar visualisation techniques were previously used in studies of attachment of cells and frogs.A cleaned glass cover slip was mounted on the stage and viewed at ×200–630 (oil immersion) magnification. The air dried claw tuft was glued onto a sample holder and positioned with the ventral side onto the cover slip. The stage was then manually moved vertically and laterally and the behaviour of spatulae in contact with glass was recorded with a high speed video camera (Photron Fastcam SA1.1, VKT Video Kommunikation GmbH, Pfullingen, Germany) at 500–1000 frames per second.
2021 06 25
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An Elasto-mechanical Unfeelability Cloak Made of Pentamode Metamaterials
An Elasto-mechanical Unfeelability Cloak Made of Pentamode Metamaterials
Metamaterial-based cloaks make objects different from their surrounding appear just like their surrounding. To date, cloaking has been demonstrated experimentally in many fields of research, including electrodynamics at microwave frequencies, optics, static electric conduction, acoustics, fluid dynamics, thermodynamics and quasi two-dimensional solid mechanics. However, cloaking in the seemingly simple case of three-dimensional solid mechanics is more demanding. Here, inspired by invisible core-shell nanoparticles in optics, we design an approximate elasto-mechanical core-shell 'unfeelability' cloak based on pentamode metamaterials. The resulting three-dimensional polymer microstructures with macroscopic overall volume are fabricated by rapid dip-in direct laser writing optical lithography. We quasi-statically deform cloak and control samples in the linear regime and map the displacement fields by autocorrelation-based analysis of recorded movies. The measured and the calculated displacement fields show very good cloaking performance. This means that one can elastically hide objects along these lines.For the fabrication of the mechanical cloak as well as the reference structures, we used the commercially available DLW system Photonic Professional GT (Nanoscribe GmbH, Germany). In this setup, a liquid photoresist (IP-S resist, Nanoscribe GmbH) was polymerized via multi-photon absorption using a frequency-doubled Erbium fibre laser with a center wavelength of 780 nm and with a pulse duration of about 90 fs. The 3D exposure pattern was addressed by laser scanning using a set of galvo-mirrors and mechanical stages. The samples were prepared by drop-casting the negative-tone photoresist on a glass cover slip (22 × 22 × 0.17 mm). To avoid depth-dependent aberrations, the objective lens ( × 25, numerical aperture=0.8, Carl Zeiss) was directly dipped into the resist. Structural data were created in STL file format using the open-source software Blender and COMSOL Multiphysics. The software package Describe (Nanoscribe GmbH) was used to compile the CAD data into machine code. The scan raster was set to 0.5 μm laterally and 1 μm axially. The structure was laterally split into 8 scan fields of about 500 × 500 μm footprint each that were stitched together. The writing speed was set to 5 cm s. After the DLW of the preprogrammed pattern, the exposed sample was developed for 20 min in mr-Dev 600 and acetone. The process was finished in a supercritical point dryer to avoid capillary forces during drying.The images used for the extraction of the strain field were recorded with a camera (Sony GigE Vision XCG-5005CR) attached to a stereo microscope (Leica Mz 125 and a 0.5 × adapter from Leica mount to C-Mount). To reduce data, the images were then cropped to show only the structure and its close vicinity. For each picture taken, a linear stage induced a different predefined strain into the sample. The strain was successively increased in 50 steps towards the maximum value and afterwards decreased in 50 steps back to the initial value with a strain rate of 2% per minute. The glass substrate with the sample was attached to a goniometer and a micrometre stage to allow for positioning and aligning the sample with respect to the rest of the setup. The stamp was moved with a linear stage to which part of a silicon wafer with well-defined surface was attached.The software used to extract the strain field was based on a freely available package. Here, selected markers with a set size of 15 × 15 image pixels were cross-correlated with the images from the measurement. The initial marker positions were fixed in a square grid with a spacing of 15 pixels in both dimensions spanning the entire size of the sample. This resulted in 67 markers along the horizontal direction and about 35 in the vertical. The tracking algorithm was set to a precision of 1/1,000 pixel. After cross-correlation, the position of each marker was known for each image. By subtracting the current marker positions from those of the reference frame, the displacement vector field was calculated for each image. Small movements of the glass substrate were corrected for. Movies of the reference, the obstacle and the cloak sample are given as . There, the full displacement vectors, multiplied by a factor of 4, are depicted. Additional colour coding of the modulus of the displacement vector helps to identify gradients. Colour coding and scales are identical for the three movies.We used the commercial software package COMSOL Multiphysics to numerically solve the static equations for linear elasticity. This means that neither a nonlinearity of the constituent material nor of the structure was accounted for. The geometry with the design parameters described in the main text was built using the internal kernel of COMSOL Multiphysics. The mesh consisted of about 640,000 tetrahedral elements (in COMSOL nomenclature: maximum element size=0.2 × , minimum element size=0.05 × , maximum element growth rate=16, resolution of curvature=0.7 and resolution of narrow regions=0.4) corresponding to 3–4 × 10 degrees of freedom. We used the direct solver MUMPS with a convergence tolerance of 10. As constituent material, we set an isotropic polymer with Young's modulus=1 GPa , Poisson's ratio =0.4 and mass density =1,200 kg m. Owing to the scalability of the underlying equations, Young's modulus and mass density did not even enter into the final results. The Poisson's ratio was not actually important. To deduce the displacements depicted in , we have tracked the connections with diameter in the middle of the extended fcc unit cell with respect to the direction. Further data processing was done like in the experiment.
2021 06 25
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An Elasto-mechanical Unfeelability Cloak Made of Pentamode Metamaterials
An Elasto-mechanical Unfeelability Cloak Made of Pentamode Metamaterials
Metamaterial-based cloaks make objects different from their surrounding appear just like their surrounding. To date, cloaking has been demonstrated experimentally in many fields of research, including electrodynamics at microwave frequencies, optics, static electric conduction, acoustics, fluid dynamics, thermodynamics and quasi two-dimensional solid mechanics. However, cloaking in the seemingly simple case of three-dimensional solid mechanics is more demanding. Here, inspired by invisible core-shell nanoparticles in optics, we design an approximate elasto-mechanical core-shell 'unfeelability' cloak based on pentamode metamaterials. The resulting three-dimensional polymer microstructures with macroscopic overall volume are fabricated by rapid dip-in direct laser writing optical lithography. We quasi-statically deform cloak and control samples in the linear regime and map the displacement fields by autocorrelation-based analysis of recorded movies. The measured and the calculated displacement fields show very good cloaking performance. This means that one can elastically hide objects along these lines.For the fabrication of the mechanical cloak as well as the reference structures, we used the commercially available DLW system Photonic Professional GT (Nanoscribe GmbH, Germany). In this setup, a liquid photoresist (IP-S resist, Nanoscribe GmbH) was polymerized via multi-photon absorption using a frequency-doubled Erbium fibre laser with a center wavelength of 780 nm and with a pulse duration of about 90 fs. The 3D exposure pattern was addressed by laser scanning using a set of galvo-mirrors and mechanical stages. The samples were prepared by drop-casting the negative-tone photoresist on a glass cover slip (22 × 22 × 0.17 mm). To avoid depth-dependent aberrations, the objective lens ( × 25, numerical aperture=0.8, Carl Zeiss) was directly dipped into the resist. Structural data were created in STL file format using the open-source software Blender and COMSOL Multiphysics. The software package Describe (Nanoscribe GmbH) was used to compile the CAD data into machine code. The scan raster was set to 0.5 μm laterally and 1 μm axially. The structure was laterally split into 8 scan fields of about 500 × 500 μm footprint each that were stitched together. The writing speed was set to 5 cm s. After the DLW of the preprogrammed pattern, the exposed sample was developed for 20 min in mr-Dev 600 and acetone. The process was finished in a supercritical point dryer to avoid capillary forces during drying.The images used for the extraction of the strain field were recorded with a camera (Sony GigE Vision XCG-5005CR) attached to a stereo microscope (Leica Mz 125 and a 0.5 × adapter from Leica mount to C-Mount). To reduce data, the images were then cropped to show only the structure and its close vicinity. For each picture taken, a linear stage induced a different predefined strain into the sample. The strain was successively increased in 50 steps towards the maximum value and afterwards decreased in 50 steps back to the initial value with a strain rate of 2% per minute. The glass substrate with the sample was attached to a goniometer and a micrometre stage to allow for positioning and aligning the sample with respect to the rest of the setup. The stamp was moved with a linear stage to which part of a silicon wafer with well-defined surface was attached.The software used to extract the strain field was based on a freely available package. Here, selected markers with a set size of 15 × 15 image pixels were cross-correlated with the images from the measurement. The initial marker positions were fixed in a square grid with a spacing of 15 pixels in both dimensions spanning the entire size of the sample. This resulted in 67 markers along the horizontal direction and about 35 in the vertical. The tracking algorithm was set to a precision of 1/1,000 pixel. After cross-correlation, the position of each marker was known for each image. By subtracting the current marker positions from those of the reference frame, the displacement vector field was calculated for each image. Small movements of the glass substrate were corrected for. Movies of the reference, the obstacle and the cloak sample are given as . There, the full displacement vectors, multiplied by a factor of 4, are depicted. Additional colour coding of the modulus of the displacement vector helps to identify gradients. Colour coding and scales are identical for the three movies.We used the commercial software package COMSOL Multiphysics to numerically solve the static equations for linear elasticity. This means that neither a nonlinearity of the constituent material nor of the structure was accounted for. The geometry with the design parameters described in the main text was built using the internal kernel of COMSOL Multiphysics. The mesh consisted of about 640,000 tetrahedral elements (in COMSOL nomenclature: maximum element size=0.2 × , minimum element size=0.05 × , maximum element growth rate=16, resolution of curvature=0.7 and resolution of narrow regions=0.4) corresponding to 3–4 × 10 degrees of freedom. We used the direct solver MUMPS with a convergence tolerance of 10. As constituent material, we set an isotropic polymer with Young's modulus=1 GPa , Poisson's ratio =0.4 and mass density =1,200 kg m. Owing to the scalability of the underlying equations, Young's modulus and mass density did not even enter into the final results. The Poisson's ratio was not actually important. To deduce the displacements depicted in , we have tracked the connections with diameter in the middle of the extended fcc unit cell with respect to the direction. Further data processing was done like in the experiment.
2021 06 25
read more
Radial Arrangement of Janus-like Setae Permits Friction Control in Spiders
Radial Arrangement of Janus-like Setae Permits Friction Control in Spiders
Dynamic attachment is the key to move on steep surfaces, with mechanisms being still not well understood. The hunting spider Cupiennius salei (Arachnida, Ctenidae) possesses hairy attachment pads (claw tufts) at its distal legs, consisting of directional branched setae. The morphological investigation revealed that adhesive setae are arranged in a radial manner within the distal tarsus. Friction of claw tufts on smooth glass was measured to reveal the functional effect of seta arrangement within the pad. Measurements revealed frictional anisotropy in both longitudinal and transversal directions. Contact behaviour of adhesive setae was investigated in a reflection interference contrast microscope (RICM). Observations on living spiders showed, that only a small part of the hairy pads is in contact at the same time. Thus the direction of frictional forces is depending on leg placement and rotation. This may aid controlling the attachment to the substrate.Three living individuals of the hunting spider K 1877 (Ctenidae) were obtained from a laboratory stock of the Department of Neurobiology, University of Vienna, Austria. Spiders were kept in cylindrical glasses at the room temperature and 95% relative humidity and fed with house crickets () obtained from the local pet shop.The claw tufts were observed with aid of a stereo microscope (M205 A, Leica Microsystems, Wetzlar, Germany) under lateral and coaxial illumination in spiders resting upside-down on the smooth transparent surface of Plexiglas Petri dishes.Tarsi of the four pairs of walking legs of one body side were ablated with a scalpel in spiders anaesthetized with carbon dioxide. The samples were air dried, mounted on metal stubs and sputter coated with a 15 nm layer of gold-palladium. Samples were viewed in the SEM TM-3000 (Hitachi Ltd., Tokyo, Japan) at 15.0 kV using back-scattered electron (BSE) detector.The setup for force measurements was as previously described by Niederegger and Gorb and is displayed in . Freshly ablated tarsi of different walking legs from spiders anaesthetized with carbon dioxide were shaved at their dorsal side and mounted on a Plexiglas slide with bees wax. Tarsi were positioned in the wax so that the median surface of the setal array of the claw tuft was parallel to the Plexiglas slide. Those samples were attached with double sided adhesive tape to the distal cantilever of a load cell force transducer with 10 g force range (World Precision Instruments Inc., Sarasota, FL, USA). A second force transducer of the same type was attached to a micromanipulator (DC3001R with controller MS314, World Precision Instruments Inc., Sarasota, FL, USA) and placed perpendicularly to the first one. A clean glass cover slip was mounted on the lateral edge of the cantilever. Thus, normal force and friction force could be recorded simultaneously. Force curves were recorded with AcqKnowledge 3.7.0 software (Biopac Systems Ltd, Goleta, CA, USA). A laterally installed stereo microscope was used to monitor the sample movements and the proper contact formation between the claw tuft and smooth substrate.Experiments were performed at an environmental temperature of 20–23°C and a relative humidity of 20–25%. The cover slip was brought into contact with the claw tuft and loaded until normal force reached about 7 mN. Then it was horizontally moved for 3 s with the constant velocity of 200 μm·s in the proximal (simulating leg pushing) and distal (simulating leg pulling) direction, and the friction forces, resisting these movements, was recorded. Proximal and distal sliding experiments were done in a randomized order.Similar force measurements were repeated with the same but air dried samples after two days. Additionally, pro- and retrolateral shearing experiments were performed in the pro- and retrolateral lobes of the claw tuft on an air dried anterior leg tarsus. For this purpose, the leg sample was positioned in the way that the surface of respective lobe was oriented parallelly to the surface of the glass cover slip.Force data were obtained by respective processing of the recorded time-force curves. We have taken into account values recorded after two seconds after shear movement was started, to ensure that the contact between the pad and substrate was formed and friction forces have reached plateau. Friction coefficient μ was calculated as the quotient between friction and normal force. Data were statistically compared with R software package (version 2.13.2, ).Contact behaviour between tuft pad and glass substrate was visualized with an inverted light microscope (Axio Observer.A1, Carl Zeiss Microscopy GmbH, Göttingen, Germany). In the RICM mode, the light source is positioned in a way that light is reflected at the interface of direct (real) contact between the glass slide and the object. Zones of direct contact appear as dark spots on the bright background. Similar visualisation techniques were previously used in studies of attachment of cells and frogs.A cleaned glass cover slip was mounted on the stage and viewed at ×200–630 (oil immersion) magnification. The air dried claw tuft was glued onto a sample holder and positioned with the ventral side onto the cover slip. The stage was then manually moved vertically and laterally and the behaviour of spatulae in contact with glass was recorded with a high speed video camera (Photron Fastcam SA1.1, VKT Video Kommunikation GmbH, Pfullingen, Germany) at 500–1000 frames per second.
2021 06 25
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Discovery of a Female Cat with Testicles Among Weirdest Pet Claims
Discovery of a Female Cat with Testicles Among Weirdest Pet Claims
A North Shore pet owner got the shock of her life to learn her female cat also had testicles. Along with the discovery of a hermaphrodite cat, other owners have been left perplexed after discovering their pets had consumed anything from a roll of dental floss, compact mirror, blanket, sewing needle to a chicken skewer. These discoveries were among the weirdest PetCare claims received by Southern Cross last year. Lisa Newlands adopted her domestic long haired cat Cameo in 2014 with the reassurance she had been spayed. But at the end of last year, Newlands became suspicious about whether it the standard neutering had worked when her usually feisty cat started befriending a stray male. After Cameo became really sick with a high temperature and stopped eating for the second time in two months, an ultrasound revealed she had a large mass in her stomach area. The ginger cat underwent surgery and for the first time in her vet's 13 year career, she discovered two cancerous testicles in the female feline. Cancerous testicles emit oestrogen, which was why the tom cat was hanging around. "The vet was just bamboozled. She had never seen anything like this in her entire career," Newlands said. Cameo's total vet bill was $2531, but Newlands said fortunately $2013 was covered by pet insurance. Newlands estimated Cameo had racked up almost $10,000 in vet bills since she had owned her because she was notorious for getting in fights with other cats and was grateful most of it had been covered by her pet insurance. Another pet owner also claimed on a hefty $8000 vet bill after their german shepherd cut its leg on a metal shoe rack as it tried to escape from two cats. The traumatic incident resulted in the dog having to undergo two surgeries and receive post operative care. In another case, a labrador retriever went under the knife to remove pieces of a blanket it had eaten from its stomach at a cost of $6000. Another owner commented that they were amazed that the chicken skewer eaten by their miniature poodle came out whole after being endoscopically removed. And a hungry beagle's desire to snaffle up a tasty fruit cake also backfired on it after the raisins caused it to have renal failure. The wee beagle had it's kidneys flushed at the vet. But the list of weird claims gets crazier after a french bulldog ate a whole roll dental floss it had found in a visitor's bag and a Shetland sheepdog had to be treated for munching on dish cloths on two separate occasions. The mischievous mutt managed to escape surgery and was given drugs to help it either poo or vomit the rags out. And it wasn't just playful pooches causing their owners angst, a domestic long haired cat also required surgery to remove a sewing needle it had swallowed and devon rex cat had 46 hair ties surgically removed from its stomach. Both treatments cost their owners more than $2000 each. Southern Cross Pet Insurance general manager Anthony McPhail said everyday, unexpected accidents could end up costing pet owners a lot of money at the veterinary clinic. McPhail said while most of the claims processed were for typical illnesses and routine checks, the ones where pets had managed to eat something they shouldn't have still surprised them. He said the stories could be amusing, but still caused quite a lot of stress to the pet and both its owner and their wallet. "We recommend owners prepare for those unexpected veterinary visits by either setting some money aside or considering pet insurance," McPhail said.
2021 07 27
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Citing Privacy Concerns, U.S. Panel Urges End to Secret DNA Testing
Citing Privacy Concerns, U.S. Panel Urges End to Secret DNA Testing
NEW YORK (Reuters) - They're called discreet DNA samples, and the Elk Grove, California, genetic-testing company easyDNA says it can handle many kinds, from toothpicks to tampons. Blood stains from bandages and tampons? Ship them in a paper envelope for paternity, ancestry or health testing. EasyDNA also welcomes cigarette butts (two to four), dental floss ("do not touch the floss with your fingers"), razor clippings, gum, toothpicks, licked stamps and used tissues if the more standard cheek swab or tube of saliva isn't obtainable. If the availability of such services seems like an invitation to mischief or worse - imagine a discarded tissue from a prospective employee being tested to determine whether she's at risk for an expensive disease, for instance - the Presidential Commission for the Study of Bioethical Issues agrees. On Thursday it released a report on privacy concerns triggered by the advent of whole genome sequencing, determining someone's complete DNA make-up. Although sequencing "holds enormous promise for human health and medicine," commission chairwoman Amy Gutmann told reporters on Wednesday, there is a "potential for misuse of this very personal data." "In many states someone can pick up your discarded coffee cup and send it for (DNA) testing," said Gutmann, who is the president of the University of Pennsylvania. "It's not a fantasy to think about how, without baseline privacy protection, people could use this in a way that would be really detrimental," such as by denying someone with a gene that raises their risk of Alzheimer's disease long-term care insurance, or to jack up life insurance premiums for someone with an elevated genetic risk of a deadly cancer that strikes people in middle age. "Those who are willing to share some of the most intimate information about themselves for the sake of medical progress should be assured appropriate confidentiality, for example, about any discovered genetic variations that link to increased likelihood of certain diseases, such as Alzheimer's, diabetes, heart disease and schizophrenia," Gutmann said. The commission took on the issue because whole genome sequencing is poised to become part of mainstream medical care, especially by personalizing medical treatments based on a patient's DNA. That has been driven in large part by dramatic cost reductions, from $2.5 billion per genome in the Human Genome Project of the 1990s and early 2000s to $1,000 soon. Several companies, including Illumina Inc. and Life Technology's Ion Torrent division, sell machines that can sequence a genome for a few hundred dollars, but that does not include the analysis to figure out what the string of 3 billion DNA "letters" means. A three-year-old federal law prohibits discrimination in employment or health insurance based on someone's genetic information but does not address other potential misuses of the data. Without such privacy protection, said Gutmann, people may be reluctant to participate in genetic studies that do whole genome sequencing, for fear their genetic data will not be secure and could be used against them. Recommendations from such panels are not binding but have been used as the basis for policy and legislation. One scenario the panel offers is a "contentious spouse" secretly having a DNA sample sequenced and using it in a custody battle "as evidence of unfitness to parent," perhaps because the DNA showed a genetic risk for mental illness or alcoholism. There are no federal laws against that. Or, the panel said, DNA information might be posted in a social networking site "by a malicious stranger or acquaintance," possibly hurting someone's "chance of finding a spouse, achieving standing in a community, or pursuing a desired career path." The bioethics panel recommends a dozen forms of privacy protection, including that "surreptitious commercial testing" be banned: No gene sequencing or other genetic testing should be permitted without consent from the person the DNA came from, it said. About 25 states currently allow such DNA testing. Critics of the lack of genetic privacy thought greater urgency was needed. "The report lays out a lot of important best practices and does endorse further state and federal regulations, but it doesn't offer a timeline," said Jeremy Gruber, president of the Council for Responsible Genetics, a private group that monitors genetic issues. "What will inevitably happen is whole genome sequencing will enter greater use and we won't have proper regulations to insure privacy." A bill introduced in California, home to many DNA testing companies, by state Senator Alex Padilla would ban surreptitious testing, requiring written authorization from the person the genetic sample was taken from. It is not clear how many labs are willing to analyze DNA without that authorization. In practice, well-known genetic testing companies such as privately held 23andMe test only saliva samples that are too large to acquire surreptitiously, such as from a drinking glass or licked stamp. "A person would really know that they are spitting into a tube," said 23andMe spokeswoman Jane Rubinstein. The full report from the presidential commission is at www.bioethics.gov.
2021 07 28
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How to Cut Corn Off the Cob Easily, Quickly, & Safely
How to Cut Corn Off the Cob Easily, Quickly, & Safely
We've all been there: we're enjoying a nice cob of corn, happily covering our face in butter and salt, when suddenly we realize that there's a thread of corn silk stuck in our teeth. We try to dislodge it with our tongue; no luck. We pick around with our fingers; still no luck. That silk is staying there until you return home to your toothbrush and dental floss. And if you think that corn silk is bad for most people, try having braces!Cutting the kernels off corn on the cob not only helps this problem, but also makes corn a lot easier to cook with.There is a problem, of course. I'd like to think I have above-average knife skills, and yet I'm completely scared to try and cut kernels off corn on the cob. There's no way to balance the oblong cob, and you have to cut straight down. To add insult to injury, the kernels corn go flying everywhere; it's nearly impossible to cut them in a neat and orderly manner. But worry not: there are some surprisingly easy (and safe!) ways to quickly and neatly cut corn off the cob.Use a Bundt or Angel Food Cake PanI only recently found out about this (big thanks to Saveur's amazing video channel), but it's now one of my favorite food hacks. Place one end of the cob in the middle of the pan, which will keep the corn stable while you cut down. Then, as you cut the ears off of the cob, they'll collect in the pan instead of scattering everywhere.Construct a Makeshift Bundt Cake PanIf you don't have a bundt or angel food cake pan, you can make your own version. Start with a cake pan, pie dish, or shallow bowl. Then add any stable item that can hold one end of the corn, such as a narrow cup or a shot glass. (My personal favorite is a toilet paper cardboard tube, but please be careful if you try this: these tubes are remarkably flimsy, so if you apply too much pressure they will collapse while you're cutting.) Then proceed just as you would with a bundt or angel food cake pan, until you have a bowl of perfectly cut corn.Cut the Corn in HalfThis is the quickest way to get the kernels off of the cob, but you want to avoid it unless you have a nice knife and are comfortable using it. Start by cutting the corn in half, which is harder than it looks: the core of the cob is extremely hard, and the corn will want to roll while you're trying to cut. So above all, be careful!Now that the corn is in half, each piece has a flat side, making it easier and safer to balance the cob while you cut it. And with each piece half the size of a full cob of corn, there's less mess when you cut the ears off.Then again, if you're hell-bent on keeping the corn on the cob, but still want to get rid of the strings of silk, you can always microwave it.Get More Food-Cutting HacksSometimes unflavored dental floss is better at cutting certain foods than your knife-seriously! And if cutting tomatoes befuddles you, be sure to read our indispensable guide on how to do it right. As for mangoes, turns out you need to bring a drinking glass in order to cut them the right way.
2021 07 28
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How to Make Jewelry From Seeds
How to Make Jewelry From Seeds
Using natural objects to decorate the human body has been practiced for thousands of years. In this day and age, going green with your jewelry can be fashionable in more ways than one. Grow and dry your own seeds, or find them at grocery stores, garden centers or in your backyard. Making jewelry can help satisfy your creative nature, and if you create patterns and designs that appeal to other people, you could market your jewelry and add some green to your pocketbook by utilizing simple materials provided by Mother Nature.Dried seedsCotton cloth1-inch-thick boardDrill1/16-inch drill bitSmall pliersTape measureScissorsRed marker penNeedlePlain dental flossMasking tapePrepare your seeds by sorting through them to eliminate debris and remove broken or misshapen seeds. Wash any seeds that are dirty, and dry them thoroughly. Rub the seeds with a cotton cloth to make them shine.Place a 1-inch-thick board on your work area, and place a seed on the board. Hold the seed securely with pliers. Drill a hole in the seed with a cordless drill with a 1/16-inch drill bit. so this with all your necklace seeds. Drill holes in all your seeds.Measure 32 inches of dental floss with the tape measure, and cut the floss, using scissors. Use a red marker to mark a spot 2 inches from one end of the dental floss. Mark that spot with a red marker. Mark a spot 2 inches from the other end of the dental floss. Wrap a small piece of masking tape around that end.Thread the end of your dental floss through the tiny opening at the top of your self-threading needle, above the eye. Pull the floss through the eye of your needle until you reach the spot marked with masking tape.Thread one seed at a time onto the floss by pushing the needle through the hole you've drilled in the seed. Pull the first seed to the spot marked with the masking tape. Keep adding seeds until you've filled the length of floss between the red mark and masking tape.Remove the masking tape from the end of the floss, and knot the ends of floss together securely. Clip the loose ends of floss close to the knot with scissors to finish your necklace.Drill holes in the center of each seed or at a point that will allow the seed to be threaded so it will lie at the angle of your choosing. Thread all of one kind of seed onto your floss, or alternate seeds of different shapes and sizes. Store pieces of finished jewelry in tightly covered glass jars.Use caution when using a drill. Place seed jewelry in a deep freeze for a couple of weeks, at least once a year, to kill any insects that may infest the seeds. Never eat seeds that you use to make jewelry.
2021 07 28
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