text stringlengths 31 999 | source stringclasses 5 values |
|---|---|
Neutron backscattering is one of several inelastic neutron scattering techniques. Backscattering from monochromator and analyzer crystals is used to achieve an energy resolution in the order of μeV. Neutron backscattering experiments are performed to study atomic or molecular motion on a nanosecond time scale | https://huggingface.co/datasets/fmars/wiki_stem |
Neutron spectroscopy is a spectroscopic method of measuring atomic and magnetic motions by measuring the kinetic energy of emitted neutrons. The measured neutrons may be emitted directly (for example, by nuclear reactions), or they may scatter off cold matter before reaching the detector. Inelastic neutron scattering observes the change in the energy of the neutron as it scatters from a sample and can be used to probe a wide variety of different physical phenomena such as the motions of atoms (diffusional or hopping), the rotational modes of molecules, sound modes and molecular vibrations, recoil in quantum fluids, magnetic and quantum excitations or even electronic transitions | https://huggingface.co/datasets/fmars/wiki_stem |
Noise-immune cavity-enhanced optical-heterodyne molecular spectroscopy (NICE-OHMS) is an ultra-sensitive laser-based absorption technique that utilizes laser light to assess the concentration or the amount of a species in gas phase by absorption spectrometry (AS).
Principles
The NICE-OHMS technique combines cavity enhanced absorption spectrometry (CEAS) for prolonged interaction length with the sample with frequency modulation (fm) spectrometry FMS for reduction of 1/f noise. By choosing the fm-modulation frequency equal to the free spectral range (FSR) of the cavity, all components of the spectral fm-triplet are transmitted through the cavity in an identical manner | https://huggingface.co/datasets/fmars/wiki_stem |
A normal mode of a dynamical system is a pattern of motion in which all parts of the system move sinusoidally with the same frequency and with a fixed phase relation. The free motion described by the normal modes takes place at fixed frequencies. These fixed frequencies of the normal modes of a system are known as its natural frequencies or resonant frequencies | https://huggingface.co/datasets/fmars/wiki_stem |
Nuclear spectroscopy is a superordinate concept of methods that uses properties of a nucleus to probe material properties. By emission or absorption of radiation from the nucleus information of the local structure is obtained, as an interaction of an atom with its closest neighbours. Or a radiation spectrum of the nucleus is detected | https://huggingface.co/datasets/fmars/wiki_stem |
In molecular biology, quantitation of nucleic acids is commonly performed to determine the average concentrations of DNA or RNA present in a mixture, as well as their purity. Reactions that use nucleic acids often require particular amounts and purity for optimum performance. To date, there are two main approaches used by scientists to quantitate, or establish the concentration, of nucleic acids (such as DNA or RNA) in a solution | https://huggingface.co/datasets/fmars/wiki_stem |
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc. An opaque object is neither transparent (allowing all light to pass through) nor translucent (allowing some light to pass through) | https://huggingface.co/datasets/fmars/wiki_stem |
Operando spectroscopy is an analytical methodology wherein the spectroscopic characterization of materials undergoing reaction is coupled simultaneously with measurement of catalytic activity and selectivity. The primary concern of this methodology is to establish structure-reactivity/selectivity relationships of catalysts and thereby yield information about mechanisms. Other uses include those in engineering improvements to existing catalytic materials and processes and in developing new ones | https://huggingface.co/datasets/fmars/wiki_stem |
In physics, optical depth or optical thickness is the natural logarithm of the ratio of incident to transmitted radiant power through a material.
Thus, the larger the optical depth, the smaller the amount of transmitted radiant power through the material.
Spectral optical depth or spectral optical thickness is the natural logarithm of the ratio of incident to transmitted spectral radiant power through a material | https://huggingface.co/datasets/fmars/wiki_stem |
Genetic testing, also known as DNA testing, is used to identify changes in DNA sequence or chromosome structure. Genetic testing can also include measuring the results of genetic changes, such as RNA analysis as an output of gene expression, or through biochemical analysis to measure specific protein output. In a medical setting, genetic testing can be used to diagnose or rule out suspected genetic disorders, predict risks for specific conditions, or gain information that can be used to customize medical treatments based on an individual's genetic makeup | https://huggingface.co/datasets/fmars/wiki_stem |
Genotyping is the process of determining differences in the genetic make-up (genotype) of an individual by examining the individual's DNA sequence using biological assays and comparing it to another individual's sequence or a reference sequence. It reveals the alleles an individual has inherited from their parents. Traditionally genotyping is the use of DNA sequences to define biological populations by use of molecular tools | https://huggingface.co/datasets/fmars/wiki_stem |
In genetics, haplotype estimation (also known as "phasing") refers to the process of statistical estimation of haplotypes from genotype data. The most common situation arises when genotypes are collected at a set of polymorphic sites from a group of individuals. For example in human genetics, genome-wide association studies collect genotypes in thousands of individuals at between 200,000-5,000,000 SNPs using microarrays | https://huggingface.co/datasets/fmars/wiki_stem |
Hin recombinase is a 21kD protein composed of 198 amino acids that is found in the bacteria Salmonella. Hin belongs to the serine recombinase family (B2) of DNA invertases in which it relies on the active site serine to initiate DNA cleavage and recombination. The related protein, gamma-delta resolvase shares high similarity to Hin, of which much structural work has been done, including structures bound to DNA and reaction intermediates | https://huggingface.co/datasets/fmars/wiki_stem |
iCLIP (individual-nucleotide resolution CrossLinking and ImmunoPrecipitation) is a variant of the original CLIP method used for identifying protein-RNA interactions, which uses UV light to covalently bind proteins and RNA molecules to identify RNA binding sites of proteins. This crosslinking step has generally less background than standard RNA immunoprecipitation (RIP) protocols, because the covalent bond formed by UV light allows RNA to be fragmented, followed by stringent purification, and this also enables CLIP to identify the positions of protein-RNA interactions. As with all CLIP methods, iCLIP allows for a very stringent purification of the linked protein-RNA complexes by stringent washing during immunoprecipitation followed by SDS-PAGE and transfer to nitrocellulose | https://huggingface.co/datasets/fmars/wiki_stem |
In situ hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA, RNA or modified nucleic acids strand (i. e. , probe) to localize a specific DNA or RNA sequence in a portion or section of tissue (in situ) or if the tissue is small enough (e | https://huggingface.co/datasets/fmars/wiki_stem |
Iterons are directly repeated DNA sequences which play an important role in regulation of plasmid copy number in bacterial cells. It is one among the three negative regulatory elements found in plasmids which control its copy number. The others include antisense RNAs and ctRNAs | https://huggingface.co/datasets/fmars/wiki_stem |
Enterobacteria phage λ (lambda phage, coliphage λ, officially Escherichia virus Lambda) is a bacterial virus, or bacteriophage, that infects the bacterial species Escherichia coli (E. coli). It was discovered by Esther Lederberg in 1950 | https://huggingface.co/datasets/fmars/wiki_stem |
Loop-mediated isothermal amplification (LAMP) is a single-tube technique for the amplification of DNA and a low-cost alternative to detect certain diseases. Reverse transcription loop-mediated isothermal amplification (RT-LAMP) combines LAMP with a reverse transcription step to allow the detection of RNA.
LAMP is an isothermal nucleic acid amplification technique | https://huggingface.co/datasets/fmars/wiki_stem |
Methylthioninium chloride, commonly called methylene blue, is a salt used as a dye and as a medication. As a medication, it is mainly used to treat methemoglobinemia by converting/chemically reducing the ferric iron in hemoglobin to ferrous iron. Specifically, it is used to treat methemoglobin levels that are greater than 30% or in which there are symptoms despite oxygen therapy | https://huggingface.co/datasets/fmars/wiki_stem |
Minimum information about a microarray experiment (MIAME) is a standard created by the FGED Society for reporting microarray experiments. MIAME is intended to specify all the information necessary to interpret the results of the experiment unambiguously and to potentially reproduce the experiment. While the standard defines the content required for compliant reports, it does not specify the format in which this data should be presented | https://huggingface.co/datasets/fmars/wiki_stem |
Molecular cloning is a set of experimental methods in molecular biology that are used to assemble recombinant DNA molecules and to direct their replication within host organisms. The use of the word cloning refers to the fact that the method involves the replication of one molecule to produce a population of cells with identical DNA molecules. Molecular cloning generally uses DNA sequences from two different organisms: the species that is the source of the DNA to be cloned, and the species that will serve as the living host for replication of the recombinant DNA | https://huggingface.co/datasets/fmars/wiki_stem |
A molecular-weight size marker, also referred to as a protein ladder, DNA ladder, or RNA ladder, is a set of standards that are used to identify the approximate size of a molecule run on a gel during electrophoresis, using the principle that molecular weight is inversely proportional to migration rate through a gel matrix. Therefore, when used in gel electrophoresis, markers effectively provide a logarithmic scale by which to estimate the size of the other fragments (providing the fragment sizes of the marker are known).
Protein, DNA, and RNA markers with pre-determined fragment sizes and concentrations are commercially available | https://huggingface.co/datasets/fmars/wiki_stem |
A Morpholino, also known as a Morpholino oligomer and as a phosphorodiamidate Morpholino oligomer (PMO), is a type of oligomer molecule (colloquially, an oligo) used in molecular biology to modify gene expression. Its molecular structure contains DNA bases attached to a backbone of methylenemorpholine rings linked through phosphorodiamidate groups. Morpholinos block access of other molecules to small (~25 base) specific sequences of the base-pairing surfaces of ribonucleic acid (RNA) | https://huggingface.co/datasets/fmars/wiki_stem |
A multiple cloning site (MCS), also called a polylinker, is a short segment of DNA which contains many (up to ~20) restriction sites - a standard feature of engineered plasmids. Restriction sites within an MCS are typically unique, occurring only once within a given plasmid. The purpose of an MCS in a plasmid is to allow a piece of DNA to be inserted into that region | https://huggingface.co/datasets/fmars/wiki_stem |
Nick translation (or head translation), developed in 1977 by Peter Rigby and Paul Berg, is a tagging technique in molecular biology in which DNA Polymerase I is used to replace some of the nucleotides of a DNA sequence with their labeled analogues, creating a tagged DNA sequence which can be used as a probe in fluorescent in situ hybridization (FISH) or blotting techniques. It can also be used for radiolabeling. This process is called nick translation because the DNA to be processed is treated with DNAase to produce single-stranded "nicks" | https://huggingface.co/datasets/fmars/wiki_stem |
A nuclear run-on assay is conducted to identify the genes that are being transcribed at a certain time point. Approximately one million cell nuclei are isolated and incubated with labeled nucleotides, and genes in the process of being transcribed are detected by hybridization of extracted RNA to gene specific probes on a blot. Garcia-Martinez et al | https://huggingface.co/datasets/fmars/wiki_stem |
In molecular biology, hybridization (or hybridisation) is a phenomenon in which single-stranded deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) molecules anneal to complementary DNA or RNA. Though a double-stranded DNA sequence is generally stable under physiological conditions, changing these conditions in the laboratory (generally by raising the surrounding temperature) will cause the molecules to separate into single strands. These strands are complementary to each other but may also be complementary to other sequences present in their surroundings | https://huggingface.co/datasets/fmars/wiki_stem |
A nucleic acid test (NAT) is a technique used to detect a particular nucleic acid sequence and thus usually to detect and identify a particular species or subspecies of organism, often a virus or bacterium that acts as a pathogen in blood, tissue, urine, etc. NATs differ from other tests in that they detect genetic materials (RNA or DNA) rather than antigens or antibodies. Detection of genetic materials allows an early diagnosis of a disease because the detection of antigens and/or antibodies requires time for them to start appearing in the bloodstream | https://huggingface.co/datasets/fmars/wiki_stem |
Oligonucleotide synthesis is the chemical synthesis of relatively short fragments of nucleic acids with defined chemical structure (sequence). The technique is extremely useful in current laboratory practice because it provides a rapid and inexpensive access to custom-made oligonucleotides of the desired sequence. Whereas enzymes synthesize DNA and RNA only in a 5' to 3' direction, chemical oligonucleotide synthesis does not have this limitation, although it is most often carried out in the opposite, 3' to 5' direction | https://huggingface.co/datasets/fmars/wiki_stem |
DNA paternity testing is the use of DNA profiles to determine whether an individual is the biological parent of another individual. Paternity testing can be especially important when the rights and duties of the father are in issue and a child's paternity is in doubt. Tests can also determine the likelihood of someone being a biological grandparent | https://huggingface.co/datasets/fmars/wiki_stem |
A plasmid preparation is a method of DNA extraction and purification for plasmid DNA, it is an important step in many molecular biology experiments and is essential for the successful use of plasmids in research and biotechnology. Many methods have been developed to purify plasmid DNA from bacteria. During the purification procedure, the plasmid DNA is often separated from contaminating proteins and genomic DNA | https://huggingface.co/datasets/fmars/wiki_stem |
Polony sequencing is an inexpensive but highly accurate multiplex sequencing technique that can be used to “read” millions of immobilized DNA sequences in parallel. This technique was first developed by Dr. George Church's group at Harvard Medical School | https://huggingface.co/datasets/fmars/wiki_stem |
Pulsed field gel electrophoresis is a technique used for the separation of large DNA molecules by applying to a gel matrix an electric field that periodically changes direction. Pulsed-field gel electrophoresis (PFGE) is a method used to separate large segments of DNA using an alternating and cross field. In a uniform magnetic field, components larger than 50kb move through the gel in a zigzag pattern, allowing for more effective separation of DNA molecules | https://huggingface.co/datasets/fmars/wiki_stem |
Rapid amplification of cDNA ends (RACE) is a technique used in molecular biology to obtain the full length sequence of an RNA transcript found within a cell. RACE results in the production of a cDNA copy of the RNA sequence of interest, produced through reverse transcription, followed by PCR amplification of the cDNA copies (see RT-PCR). The amplified cDNA copies are then sequenced and, if long enough, should map to a unique genomic region | https://huggingface.co/datasets/fmars/wiki_stem |
Recombinant DNA (rDNA) molecules are DNA molecules formed by laboratory methods of genetic recombination (such as molecular cloning) that bring together genetic material from multiple sources, creating sequences that would not otherwise be found in the genome.
Recombinant DNA is the general name for a piece of DNA that has been created by combining two or more fragments from different sources. Recombinant DNA is possible because DNA molecules from all organisms share the same chemical structure, differing only in the nucleotide sequence | https://huggingface.co/datasets/fmars/wiki_stem |
RMCE (recombinase-mediated cassette exchange) is a procedure in reverse genetics allowing the systematic, repeated modification of higher eukaryotic genomes by targeted integration, based on the features of site-specific recombination processes (SSRs). For RMCE, this is achieved by the clean exchange of a preexisting gene cassette for an analogous cassette carrying the "gene of interest" (GOI).
The genetic modification of mammalian cells is a standard procedure for the production of correctly modified proteins with pharmaceutical relevance | https://huggingface.co/datasets/fmars/wiki_stem |
In molecular biology, a reporter gene (often simply reporter) is a gene that researchers attach to a regulatory sequence of another gene of interest in bacteria, cell culture, animals or plants. Such genes are called reporters because the characteristics they confer on organisms expressing them are easily identified and measured, or because they are selectable markers. Reporter genes are often used as an indication of whether a certain gene has been taken up by or expressed in the cell or organism population | https://huggingface.co/datasets/fmars/wiki_stem |
A restriction digest is a procedure used in molecular biology to prepare DNA for analysis or other processing. It is sometimes termed DNA fragmentation, though this term is used for other procedures as well. In a restriction digest, DNA molecules are cleaved at specific restriction sites of 4-12 nucleotides in length by use of restriction enzymes which recognize these sequences | https://huggingface.co/datasets/fmars/wiki_stem |
Restriction sites, or restriction recognition sites, are located on a DNA molecule containing specific (4-8 base pairs in length) sequences of nucleotides, which are recognized by restriction enzymes. These are generally palindromic sequences (because restriction enzymes usually bind as homodimers), and a particular restriction enzyme may cut the sequence between two nucleotides within its recognition site, or somewhere nearby.
Function
For example, the common restriction enzyme EcoRI recognizes the palindromic sequence GAATTC and cuts between the G and the A on both the top and bottom strands | https://huggingface.co/datasets/fmars/wiki_stem |
Ribonucleoprotein Networks Analyzed by Mutational Profiling (RNP-MaP) is a strategy for probing RNA-protein networks and protein binding sites at a nucleotide resolution. Information about RNP assembly and function can facilitate a better understanding of biological mechanisms. RNP-MaP uses NHS-diazirine (SDA), a hetero-bifunctional crosslinker, to freeze RNA-bound proteins in place | https://huggingface.co/datasets/fmars/wiki_stem |
Ribotyping is a molecular technique for bacterial identification and characterization that uses information from rRNA-based phylogenetic analyses. It is a rapid and specific method widely used in clinical diagnostics and analysis of microbial communities in food, water, and beverages. All bacteria have ribosomal genes, but the exact sequence is unique to each species, serving as a genetic fingerprint | https://huggingface.co/datasets/fmars/wiki_stem |
RNA extraction is the purification of RNA from biological samples. This procedure is complicated by the ubiquitous presence of ribonuclease enzymes in cells and tissues, which can rapidly degrade RNA. Several methods are used in molecular biology to isolate RNA from samples, the most common of these is guanidinium thiocyanate-phenol-chloroform extraction | https://huggingface.co/datasets/fmars/wiki_stem |
RIP-chip (RNA immunoprecipitation chip) is a molecular biology technique which combines RNA immunoprecipitation with a microarray. The purpose of this technique is to identify which RNA sequences interact with a particular RNA binding protein of interest in vivo. It can also be used to determine relative levels of gene expression, to identify subsets of RNAs which may be co-regulated, or to identify RNAs that may have related functions | https://huggingface.co/datasets/fmars/wiki_stem |
Site saturation mutagenesis (SSM), or simply site saturation, is a random mutagenesis technique used in protein engineering, in which a single codon or set of codons is substituted with all possible amino acids at the position. There are many variants of the site saturation technique, from paired site saturation (saturating two positions in every mutant in the library) to scanning site saturation (performing a site saturation at every site in the protein, resulting in a library of size [20 x (number of residues in the protein)] that contains every possible point mutant of the protein).
Method
Saturation mutagenesis is commonly achieved by site-directed mutagenesis PCR with a randomised codon in the primers (e | https://huggingface.co/datasets/fmars/wiki_stem |
A selectable marker is a gene introduced into a cell, especially a bacterium or to cells in culture, that confers a trait suitable for artificial selection. They are a type of reporter gene used in laboratory microbiology, molecular biology, and genetic engineering to indicate the success of a transfection or other procedure meant to introduce foreign DNA into a cell. Selectable markers are often antibiotic resistance genes (An antibiotic resistance marker is a gene that produces a protein that provides cells expressing this protein with resistance to an antibiotic | https://huggingface.co/datasets/fmars/wiki_stem |
Single-base extension (SBE) is a method for determining the identity of a nucleotide base at a specific position along a nucleic acid. The method is used to identify a single-nucleotide polymorphism (SNP).
In the method, an oligonucleotide primer hybridizes to a complementary region along the nucleic acid to form a duplex, with the primer’s terminal 3’-end directly adjacent to the nucleotide base to be identified | https://huggingface.co/datasets/fmars/wiki_stem |
Site-directed mutagenesis is a molecular biology method that is used to make specific and intentional mutating changes to the DNA sequence of a gene and any gene products. Also called site-specific mutagenesis or oligonucleotide-directed mutagenesis, it is used for investigating the structure and biological activity of DNA, RNA, and protein molecules, and for protein engineering.
Site-directed mutagenesis is one of the most important laboratory techniques for creating DNA libraries by introducing mutations into DNA sequences | https://huggingface.co/datasets/fmars/wiki_stem |
Site-specific recombination, also known as conservative site-specific recombination, is a type of genetic recombination in which DNA strand exchange takes place between segments possessing at least a certain degree of sequence homology. Enzymes known as site-specific recombinases (SSRs) perform rearrangements of DNA segments by recognizing and binding to short, specific DNA sequences (sites), at which they cleave the DNA backbone, exchange the two DNA helices involved, and rejoin the DNA strands. In some cases the presence of a recombinase enzyme and the recombination sites is sufficient for the reaction to proceed; in other systems a number of accessory proteins and/or accessory sites are required | https://huggingface.co/datasets/fmars/wiki_stem |
SNV calling from NGS data is any of a range of methods for identifying the existence of single nucleotide variants (SNVs) from the results of next generation sequencing (NGS) experiments. These are computational techniques, and are in contrast to special experimental methods based on known population-wide single nucleotide polymorphisms (see SNP genotyping). Due to the increasing abundance of NGS data, these techniques are becoming increasingly popular for performing SNP genotyping, with a wide variety of algorithms designed for specific experimental designs and applications | https://huggingface.co/datasets/fmars/wiki_stem |
DNA ends refer to the properties of the ends of linear DNA molecules, which in molecular biology are described as "sticky" or "blunt" based on the shape of the complementary strands at the terminus. In sticky ends, one strand is longer than the other (typically by at least a few nucleotides), such that the longer strand has bases which are left unpaired. In blunt ends, both strands are of equal length – i | https://huggingface.co/datasets/fmars/wiki_stem |
TILLING (Targeting Induced Local Lesions in Genomes) is a method in molecular biology that allows directed identification of mutations in a specific gene. TILLING was introduced in 2000, using the model plant Arabidopsis thaliana, and expanded on into other uses and methodologies by a small group of scientists including Luca Comai. TILLING has since been used as a reverse genetics method in other organisms such as zebrafish, maize, wheat, rice, soybean, tomato and lettuce | https://huggingface.co/datasets/fmars/wiki_stem |
In genetic engineering, transposon tagging is a process where transposons (transposable elements) are amplified inside a biological cell by a tagging technique. Transposon tagging has been used with several species to isolate genes. Even without knowing the nature of the specific genes, the process can still be used | https://huggingface.co/datasets/fmars/wiki_stem |
TSE or Tris/Saline/EDTA, is a buffer solution containing a mixture of Tris base, Sodium chloride and EDTA.
In molecular biology, TSE buffers are often used in procedures involving nucleic acids. Tris-acid solutions are effective buffers for slightly basic conditions, which keep DNA deprotonated and soluble in water | https://huggingface.co/datasets/fmars/wiki_stem |
An agar plate is a Petri dish that contains a growth medium solidified with agar, used to culture microorganisms. Sometimes selective compounds are added to influence growth, such as antibiotics. Individual microorganisms placed on the plate will grow into individual colonies, each a clone genetically identical to the individual ancestor organism (except for the low, unavoidable rate of mutation) | https://huggingface.co/datasets/fmars/wiki_stem |
Piston-driven air displacement pipettes are a type of micropipette, which are tools to handle volumes of liquid in the microliter scale. They are more commonly used in biology and biochemistry, and less commonly in chemistry; the equipment is susceptible to damage from many organic solvents.
Operation
These pipettes operate by piston-driven air displacement | https://huggingface.co/datasets/fmars/wiki_stem |
Ampliphox (stylized "ampliPHOX") is a colorimetric detection technology created as a research tool for the analysis of low-density microarrays using colorimetric detection. It combines a reagent kit and a benchtop instrument for detection for low-density (<2500 spots) microarray applications and is produced by InDevR, Inc. The ampliphox provides equivalent analytical sensitivity to fluorescence by using colorimetric readout | https://huggingface.co/datasets/fmars/wiki_stem |
Autoclave tape is an adhesive tape used in autoclaving (heating under high pressure with steam to sterilise) to indicate whether a specific temperature has been reached. Autoclave tape works by changing color after exposure to temperatures commonly used in sterilization processes, typically 121°C in a steam autoclave.
Small strips of the tape are applied to the items before they are placed into the autoclave | https://huggingface.co/datasets/fmars/wiki_stem |
A biosafety cabinet (BSC)—also called a biological safety cabinet or microbiological safety cabinet—is an enclosed, ventilated laboratory workspace for safely working with materials contaminated with (or potentially contaminated with) pathogens requiring a defined biosafety level. Several different types of BSC exist, differentiated by the degree of biocontainment they provide. BSCs first became commercially available in 1950 | https://huggingface.co/datasets/fmars/wiki_stem |
A Chamberland filter, also known as a Pasteur–Chamberland filter, is a porcelain water filter invented by Charles Chamberland in 1884.
It was developed after Henry Doulton's ceramic water filter of 1827. It is similar to the Berkefeld filter in principle | https://huggingface.co/datasets/fmars/wiki_stem |
Gas-pak is a method used in the production of an anaerobic environment. It is used to culture bacteria which die or fail to grow in the presence of oxygen (anaerobes).
These are commercially available, disposable sachets containing a dry powder or pellets, which, when mixed with water and kept in an appropriately sized airtight jar, produce an atmosphere free of elemental oxygen gas (O2) | https://huggingface.co/datasets/fmars/wiki_stem |
Hot air ovens are electrical devices which use dry heat to sterilize. They were originally developed by Louis Pasteur. Generally, they use a thermostat to control the temperature | https://huggingface.co/datasets/fmars/wiki_stem |
An incubator is a device used to grow and maintain microbiological cultures or cell cultures. The incubator maintains optimal temperature, humidity and other conditions such as the CO2 and oxygen content of the atmosphere inside. Incubators are essential for much experimental work in cell biology, microbiology and molecular biology and are used to culture both bacterial and eukaryotic cells | https://huggingface.co/datasets/fmars/wiki_stem |
An inoculation needle is a laboratory equipment used in the field of microbiology to transfer and inoculate living microorganisms. It is one of the most commonly implicated biological laboratory tools and can be disposable or re-usable. A standard reusable inoculation needle is made from nichrome or platinum wire affixed to a metallic handle | https://huggingface.co/datasets/fmars/wiki_stem |
A water bath is laboratory equipment made from a container filled with heated water. It is used to incubate samples in water at a constant temperature over a long period of time. Most water baths have a digital or an analogue interface to allow users to set a desired temperature, but some water baths have their temperature controlled by a current passing through a reader | https://huggingface.co/datasets/fmars/wiki_stem |
In microbiology, McFarland standards are used as a reference to adjust the turbidity of bacterial suspensions so that the number of bacteria will be within a given range to standardize microbial testing. An example of such testing is antibiotic susceptibility testing by measurement of minimum inhibitory concentration which is routinely used in medical microbiology and research. If a suspension used is too heavy or too dilute, an erroneous result (either falsely resistant or falsely susceptible) for any given antimicrobial agent could occur | https://huggingface.co/datasets/fmars/wiki_stem |
A nasopharyngeal swab is a device used for collecting a sample of nasal secretions from the back of the nose and throat. The sample is then analyzed for the presence of organisms or other clinical markers for disease. This diagnostic method is commonly used in suspected cases of whooping cough, diphtheria, influenza, and various types of diseases caused by the coronavirus family of viruses, including SARS, MERS, and COVID-19 | https://huggingface.co/datasets/fmars/wiki_stem |
A nitrogen fixation package is a piece of research equipment for studying nitrogen fixation in plants. One product of this kind, the Q-Box NF1LP made by Qubit Systems, operates by measuring the hydrogen (H2) given off in the nitrogen-fixing chemical reaction enabled by nitrogenase enzymes.
Principle of operation
Nitrogen is produced by bacteria, which have an endo-symbiotic relationship with the legume host | https://huggingface.co/datasets/fmars/wiki_stem |
Out of autoclave composite manufacturing is an alternative to the traditional high pressure autoclave (industrial) curing process commonly used by the aerospace manufacturers for manufacturing composite material. Out of autoclave (OOA) is a process that achieves the same quality as an autoclave but through a different process. OOA curing achieves the desired fiber content and elimination of voids by placing the layup within a closed mold and applying vacuum, pressure, and heat by means other than an autoclave | https://huggingface.co/datasets/fmars/wiki_stem |
The phase-change incubator is a low-cost, low-maintenance incubator that tests for microorganisms in water supplies. It uses small balls containing a chemical compound that, when heated and then kept insulated, will stay at 37 °C (approx. 99 °F) for 24 hours | https://huggingface.co/datasets/fmars/wiki_stem |
Photoactivatable probes, or caged probes, are cellular players (proteins, nucleic acids, small molecules) that can be triggered by a flash of light. They are used in biological research to study processes in cells. The basic principle is to bring a photoactivatable agent (e | https://huggingface.co/datasets/fmars/wiki_stem |
A pipette (sometimes spelled as pipet) is a laboratory tool commonly used in chemistry, biology and medicine to transport a measured volume of liquid, often as a media dispenser. Pipettes come in several designs for various purposes with differing levels of accuracy and precision, from single piece glass pipettes to more complex adjustable or electronic pipettes. Many pipette types work by creating a partial vacuum above the liquid-holding chamber and selectively releasing this vacuum to draw up and dispense liquid | https://huggingface.co/datasets/fmars/wiki_stem |
A pipette stand is a holder designed to provide safe and convenient storage for manual and electronic pipettes. In particular, the stands for electronic pipettes can recharge the battery of the pipettes, typically by means of charging pins or connectors.
The design of the pipette stand can be:
wall mount holder
linear stand
carousel standThe main purpose of the use of pipette stand is to reduce the cross contamination risk between pipettes or from benchtop to your pipettes | https://huggingface.co/datasets/fmars/wiki_stem |
A policeman is a hand-held flexible natural-rubber or plastic scraper. The common type of it is attached to a glass rod and used in chemical laboratories to transfer residues of precipitate or solid on glass surfaces when performing gravimetric analysis. This equipment works well under gentle, delicate and precise requirement | https://huggingface.co/datasets/fmars/wiki_stem |
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture medium under controlled laboratory conditions. Microbial cultures are foundational and basic diagnostic methods used as research tools in molecular biology.
The term culture can also refer to the microorganisms being grown | https://huggingface.co/datasets/fmars/wiki_stem |
The analytical profile index or API is a classification of bacteria based on biochemical tests, allowing fast identification. This system is developed for the quick identification of clinically relevant bacteria. Because of this, only known bacteria can be identified | https://huggingface.co/datasets/fmars/wiki_stem |
Antibiotic sensitivity testing or antibiotic susceptibility testing is the measurement of the susceptibility of bacteria to antibiotics. It is used because bacteria may have resistance to some antibiotics. Sensitivity testing results can allow a clinician to change the choice of antibiotics from empiric therapy, which is when an antibiotic is selected based on clinical suspicion about the site of an infection and common causative bacteria, to directed therapy, in which the choice of antibiotic is based on knowledge of the organism and its sensitivities | https://huggingface.co/datasets/fmars/wiki_stem |
Asepsis is the state of being free from disease-causing micro-organisms (such as pathogenic bacteria, viruses, pathogenic fungi, and parasites). There are two categories of asepsis: medical and surgical. The modern day notion of asepsis is derived from the older antiseptic techniques, a shift initiated by different individuals in the 19th century who introduced practices such as the sterilizing of surgical tools and the wearing of surgical gloves during operations | https://huggingface.co/datasets/fmars/wiki_stem |
Underwater acoustics or hydroacoustics is the study of the propagation of sound in water and the interaction of the mechanical waves that constitute sound with the water, its contents and its boundaries. The water may be in the ocean, a lake, a river or a tank. Typical frequencies associated with underwater acoustics are between 10 Hz and 1 MHz | https://huggingface.co/datasets/fmars/wiki_stem |
The Hyperspectral Imager for the Coastal Ocean (HICO) was a hyperspectral earth observation sensor that operated on the International Space Station (ISS) from 2009 to 2014. HICO collected hyperspectral satellite imagery of the earth's surface from the ISS. HICO was a pathfinder or proof-of-concept mission for hyperspectral imaging of the oceans, particularly for optically complex coastal waters | https://huggingface.co/datasets/fmars/wiki_stem |
Isoline retrieval is a remote sensing inverse method that retrieves one or more isolines of a trace atmospheric constituent or variable. When used to validate another contour, it is the most accurate method possible for the task. When used to retrieve a whole field, it is a general, nonlinear inverse method and a robust estimator | https://huggingface.co/datasets/fmars/wiki_stem |
Leaf area index (LAI) is a dimensionless quantity that characterizes plant canopies. It is defined as the one-sided green leaf area per unit ground surface area (LAI = leaf area / ground area, m2 / m2) in broadleaf canopies. In conifers, three definitions for LAI have been used:
Half of the total needle surface area per unit ground surface area
Projected (or one-sided, in accordance the definition for broadleaf canopies) needle area per unit ground area
Total needle surface area per unit ground area The definition “half the total leaf area” pertains to biological processes, such as gas exchange, whereas the definition “projected leaf area” was disregarded because the projection of a given area in one direction may differ in another direction when leaves are not flat, thick, or 3D-shaped | https://huggingface.co/datasets/fmars/wiki_stem |
In science, the concept of a macroscope is the antithesis of the microscope, namely a method, technique or system appropriate to the study of very large objects or very complex processes, for example the Earth and its contents, or conceptually, the Universe. Obviously, a single system or instrument does not presently exist that could fulfil this function, however its concept may be approached by some current or future combination of existing observational systems. The term "macroscope" has also been applied to a method or compendium which can view some more specific aspect of global scientific phenomena in its entirety, such as all plant life, specific ecological processes, or all life on earth | https://huggingface.co/datasets/fmars/wiki_stem |
A maximum-value composite procedure (or MVC) is a procedure used in satellite imaging, which is applied to vegetation studies. It requires that a series of multi-temporal geo-referenced satellite data be processed into NDVI images. On a pixel-by-pixel basis, each NDVI value is examined, and only the highest value is retained for each pixel location | https://huggingface.co/datasets/fmars/wiki_stem |
METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is a computer model developed by the University of Idaho, that uses Landsat satellite data to compute and map evapotranspiration (ET). METRIC calculates ET as a residual of the surface energy balance, where ET is estimated by keeping account of total net short wave and long wave radiation at the vegetation or soil surface, the amount of heat conducted into soil, and the amount of heat convected into the air above the surface. The difference in these three terms represents the amount of energy absorbed during the conversion of liquid water to vapor, which is ET | https://huggingface.co/datasets/fmars/wiki_stem |
The moment distance index (MDI) is a shape-based metric or shape index that can be used to analyze spectral reflectance curves and waveform LiDAR, proposed by Salas and Henebry in 2014. In the case of spectral data, the shape of the reflectance curve should unmask fine points of the spectra usually not considered by existing band-specific indices. It has been used to identify spectral regions for chlorophyll and carotenoids, detect greenhouses using WorldView-2, Landsat, and Sentinel-2 satellite data, identify greenhouse crops, compute canopy heights, estimate green vegetation fraction, and optimize Fourier-transform infrared (FTIR) scans for soil spectroscopy | https://huggingface.co/datasets/fmars/wiki_stem |
The normalized difference vegetation index (NDVI) is a widely-used metric for quantifying the health and density of vegetation using sensor data. It is calculated from spectrometric data at two specific bands: red and near-infrared. The spectrometric data is usually sourced from remote sensors, such as satellites | https://huggingface.co/datasets/fmars/wiki_stem |
An orthophoto, orthophotograph, orthoimage or orthoimagery is an aerial photograph or satellite imagery geometrically corrected ("orthorectified") such that the scale is uniform: the photo or image follows a given map projection. Unlike an uncorrected aerial photograph, an orthophoto can be used to measure true distances, because it is an accurate representation of the Earth's surface, having been adjusted for topographic relief, lens distortion, and camera tilt.
Orthophotographs are commonly used in geographic information systems (GIS) as a "map accurate" background image | https://huggingface.co/datasets/fmars/wiki_stem |
Radiometric calibration is a general term used in science and technology for any set of calibration techniques in support of the measurement of electromagnetic radiation and atomic particle radiation. These can be for instance, in the field of radiometry or the measurement of ionising radiation radiated from a source.
Ionising radiation
Ionising radiation is non-visible and requires the use of ionisation detectors such as the Geiger Muller counter or ion chamber for its detection and measurement | https://huggingface.co/datasets/fmars/wiki_stem |
Red edge refers to the region of rapid change in reflectance of vegetation in the near infrared range of the electromagnetic spectrum. Chlorophyll contained in vegetation absorbs most of the light in the visible part of the spectrum but becomes almost transparent at wavelengths greater than 700 nm. The cellular structure of the vegetation then causes this infrared light to be reflected because each cell acts something like an elementary corner reflector | https://huggingface.co/datasets/fmars/wiki_stem |
Mobile mapping is the process of collecting geospatial data from a mobile vehicle, typically fitted with a range of GNSS, photographic, radar, laser, LiDAR or any number of remote sensing systems. Such systems are composed of an integrated array of time synchronised navigation sensors and imaging sensors mounted on a mobile platform. The primary output from such systems include GIS data, digital maps, and georeferenced images and video | https://huggingface.co/datasets/fmars/wiki_stem |
Remote sensing in oceanography is a widely used observational technique which enables researchers to acquire data of a location without physically measuring at that location. Remote sensing in oceanography mostly refers to measuring properties of the ocean surface with sensors on satellites or planes, which compose an image of captured electromagnetic radiation. A remote sensing instrument can either receive radiation from the earth’s surface (passive), whether reflected from the sun or emitted, or send out radiation to the surface and catch the reflection (active) | https://huggingface.co/datasets/fmars/wiki_stem |
Sea ice concentration is a useful variable for climate
scientists and nautical navigators. It is defined as the area of
sea ice relative to the total at a given point in the ocean.
This article will deal primarily with its determination from remote sensing measurements | https://huggingface.co/datasets/fmars/wiki_stem |
With increased interest in sea ice and its effects on the global climate, efficient methods are required to monitor both its extent and exchange processes. Satellite-mounted, microwave radiometers, such SSMI, AMSR and AMSU, are an ideal tool for the task because they can see through cloud cover, and they have frequent, global coverage. A passive microwave instrument detects objects through emitted radiation since different substance have different emission spectra | https://huggingface.co/datasets/fmars/wiki_stem |
Sea ice thickness spatial extent, and open water within sea ice packs can vary rapidly in response to weather and climate. Sea ice concentration are measured by satellites, with the Special Sensor Microwave Imager / Sounder (SSMIS), and the European Space Agency's Cryosat-2 satellite to map the thickness and shape of the Earth's polar ice cover. The sea ice volume is calculated with the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS), which blends satellite-observed data, such as sea ice concentrations into model calculations to estimate sea ice thickness and volume | https://huggingface.co/datasets/fmars/wiki_stem |
The Surface Energy Balance Algorithm for Land (SEBAL) uses the '''surface''' energy balance to estimate aspects of the hydrological cycle. SEBAL maps evapotranspiration, biomass growth, water deficit and soil moisture. Its main creator is Prof | https://huggingface.co/datasets/fmars/wiki_stem |
Snapshot hyperspectral imaging is a method for capturing hyperspectral images during a single integration time of a detector array. No scanning is involved with this method, in contrast to push broom and whisk broom scanning techniques. The lack of moving parts means that motion artifacts should be avoided | https://huggingface.co/datasets/fmars/wiki_stem |
Empirically derived NDVI products have been shown to be unstable, varying with soil colour, soil moisture, and saturation effects from high density vegetation. In an attempt to improve NDVI, Huete developed a vegetation index that accounted for the differential red and near-infrared extinction through the vegetation canopy. The index is a transformation technique that minimizes soil brightness influences from spectral vegetation indices involving red and near-infrared (NIR) wavelengths | https://huggingface.co/datasets/fmars/wiki_stem |
Spatio-spectral scanning is one of four techniques for hyperspectral imaging, the other three being spatial scanning, spectral scanning and non-scanning, or snapshot hyperspectral imaging.
The technique was designed to put into practice the concept of 'tilted sampling' of the hyperspectral data cube, which had been deemed difficult to achieve. Spatio-spectral scanning yields a series of thin, diagonal slices of the data cube | https://huggingface.co/datasets/fmars/wiki_stem |
Tasseled cap transformation is a method to transform the spectral information of satellite data into spectral indicators. This index is used especially in the analysis of vegetation (phenological stages).
Background
In 1976, the Tasseled Cap Index was published by R | https://huggingface.co/datasets/fmars/wiki_stem |
Thermal infrared spectroscopy (TIR spectroscopy) is the subset of infrared spectroscopy that deals with radiation emitted in the infrared part of the electromagnetic spectrum. The emitted infrared radiation, though similar to blackbody radiation, is different in that the radiation is banded at characteristic vibrations in the material. The method measures the thermal infrared radiation emitted (as opposed to being transmitted or reflected) from a volume or surface | https://huggingface.co/datasets/fmars/wiki_stem |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.