bio-ontology-research-group / unit-ontology

An ontology of units of measurements

Unit Ontology: An ontology of units of measurements

The ontology is provided under a CC-BY license.

Description: An ontology of units of measurements

More information can be found at http://obofoundry.org/ontology/uo

Versions

Stable release versions

The latest version of the ontology can always be found at:

http://purl.obolibrary.org/obo/uo.owl

(note this will not show up until the request has been approved by obofoundry.org)

Editors' version

Editors of this ontology should use the edit version, src/ontology/uo-edit.owl

Contact

Please use this GitHub repository's Issue tracker to request new terms/classes or report errors or specific concerns related to the ontology.

Acknowledgements

This ontology repository was created using the Ontology Development Kit (ODK).

unit-ontology's Issues

Using unit class as an instance

We would like to use unit ontology term to represent some values in RDF format. For example, a feature of a nucleotide sequence "GC content 50%". Currently I am doing with uo:percent like;

<a Nucleotide Sequence> myOntology:gcContent [
  sio:has_unit uo:percent;
  rdf:value 50;
] .

However, uo:percent is a class of unit, not an instance. Using blank node to create an instance of the class seems redundant. Is it possible to change definitions of those terms so that we can use them as instance, too?

NTRs for clinical measurements

We would like the addition of these units to the ontology:

kilometer
milligram per deciliter
microgram per deciliter
micromole per liter

unit.obo is missing a couple of dbxref lists in the def: tag

unit.obo is missing a couple of dbxref lists in the def: tag
IDK about owl, but for obo, this is a required feature for the term definition tag (if the tag is present). At least in v1.4, but it's probably not a new requirement.
Like here:

unit-ontology/unit.obo

Line 1917 in f9ff25b

def: "An absorbed dose unit which is equal to 0.01 gray (Gy)"

NTRs - units needed in agronomic experiments

Could you please add the following units:?

• Square meter per second : unit of kinematic viscosity, specific relative angular momentum and thermal diffusivity. synonym: m2/s, m2·s−1, m2s−1.
• centimole charge per kilogram (synonym: cmolc/kg): Unit of the cation-exchange capacity. equivalent units me/100g or meq/100g
• decisiemens per metre (synonym:dS/m): https://www.naturalresources.sa.gov.au/samurraydarlingbasin/publications/measuring-salinity
• microgram per gram: A mass unit density which is equal to mass of an object in micrograms divided by the mass in grams.
• gram per kilogram: A mass unit density which is equal to mass of an object in grams divided by the mass in kilograms. g/kg
• Feet per second: A speed/velocity unit which is equal to the speed of an object traveling 1-foot distance in one second. synonym: ft/s
• Miles per hour: A speed/velocity unit which is equal to the speed of an object traveling 1-mile distance in one hour. synonym: mi/h
• gram per square meter: An area density unit which is equal to the mass of an object in grams divided by the surface area in hectares. synonym: g/m2
• Pound per hectare: An area density unit which is equal to the mass of an object in pounds divided by the surface area in hectares. synonym: lb/ha
• Bushel: A unit volume equivalent to 8 US dry gallons https://en.wikipedia.org/wiki/Bushel . synonym: bsh
• Quintal: A mass unit equivalent to 100 kilograms - synonym: q
• Square foot: An area unit which is equal to an area enclosed by a square with sides each 1 foot . synonym: ft2, sq. ft, sf.
• gram per square meter: An area density unit which is equal to the mass of an object in grams divided by the surface area in meters squared. synonym: g/m2
• gram per square foot: An area density unit which is equal to the mass of an object in grams divided by the surface area in feet squared. synonym: g/ft2
• pound per acre: An area density unit which is equal to the mass of an object in pounds divided by the surface area in acres. synonym lb/ac
• milliliter per square meter: A volume density unit? which is equal to the volume of an object in milliliters divided by the surface area in meters squared. synonym: mm/m2
• liter per hectare: A volume density unit? unit which is equal to the volume of an object in liters divided by the surface area in hectares. synonym: l/ha
• liter per acre: A volume density unit? unit which is equal to the volume of an object in liters divided by the surface area in acres. synonym: l/ac
• liter per square meter: A volume density unit? unit which is equal to the volume of an object in liters divided by the surface area in meters squared. synonym: l/m2
• liter per square foot: A volume density unit? unit which is equal to the volume of an object in liters divided by the surface area in feet squared. l/ft2
• ton per acre: An area density unit which is equal to the mass of an object in tons divided by the surface area in acres. synonym: t/ac
• pound per square foot: An area density unit which is equal to the mass of an object in pounds divided by the surface area in feet squared. synonym: lb/ft2
• bushel per acre: An area density unit which is equal to the mass of an object in bushels divided by the surface area in acres. synonym: bsh/ac
• quintal per acre: An area density unit which is equal to the mass of an object in quintals divided by the surface area in acres. synonym: q/ac
• quintal per hectare: An area density unit which is equal to the mass of an object in quintals divided by the surface area in hectares. synonym: q/ha
• ton per acre: An area density unit which is equal to the mass of an object in tons divided by the surface area in acres. t/ac
• m3/ha

@marieALaporte

Wrong IRIs used in UO

Hey! In our great OBO wide effort to fix our PURLs, I noticed the following wrong ones being used in UO:

• oboInOwl:hasExactSynonym (used as an IRI!! not shortform)
• oboInOwl:hasRelatedSynonym

Add 'µmoles per m2 per second' as an alternative label to microeinstein per square meter per second?

Hello! I work at NASA's GeneLab ingesting plant spaceflight studies into out repository. I use UO all the time and I appreciate the effort you've put into it! I'm having some trouble finding appropriate units to describe light intensity in plant growth studies. The most common unit I see used to report light intensity is µmol/m2/s, which I don't see a defined class for in Ontobee/BioPortal. I see you have microeinstein per square meter per second, which I understand is equivalent. However, the Einstein is not a unit in the SI (International System) of units, so for our repository using moles is preferred.

Would you be willing to make µmoles per m2 per second a synonym or alternative label to microeinstein per square meter per second?

Alternatively, does this already exist somewhere and I am just not seeing it?

Thank you for your help!
Kristen

NTR: psu - practical salinity units

As part of https://github.com/INCATools/biosample-analysis we are normalizing units for mixs properties like salinity

We are seeing 100s of samples with values like 26.49 PSU

https://en.wikipedia.org/wiki/Salinity#Seawater

The use of electrical conductivity measurements to estimate the ionic content of seawater led to the development of the scale called the practical salinity scale 1978 (PSS-78).[9][10] Salinities measured using PSS-78 do not have units. The suffix psu or PSU (denoting practical salinity unit) is sometimes added to PSS-78 measurement values.[11] The addition of PSU as a unit after the value is "formally incorrect and strongly discouraged

This indicates that PSU should not be added to UO. However, where should the concept live?

@pbuttigieg @wdduncan should be add docs to mixs6 that say not to use PSU?

I think you can assign @kaiiam to this

unit.obo is not loadable in OBO-Edit

Hello,

I like OBO-Edit (http://oboedit.org) because of it's showing clearly the tree-like structure of ontologies.

Unfortunately, when I try to open the unit.obo file, I get the following error message:
Load Error, line 1497 48 unrecognized parent terms:      line 1626: PATO:0000133 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1713: PATO:0001744 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 3181: PATO:0001574 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 803: PATO:0001351 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 53: PATO:0000128 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 2439: PATO:0001674 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 2693: PATO:0001682 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 731: PATO:0001709 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 3063: PATO:0001757 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 2006: PATO:0001299 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 42: PATO:0001708 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1518: PATO:0001026 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 2376: PATO:0001428 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1703: PATO:0001746 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1693: PATO:0001745 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1295: PATO:0001710 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1456: PATO:0000044 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 3034: PATO:0001521 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 2612: PATO:0001464 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo      line 1497: PATO:0001025 of file:C:/Users/mayerg97/MyUNI/Schemas/Ontologies/OBO/unit.obo
org.obo.dataadapter.DefaultOBOParser.endParse(DefaultOBOParser.java:1672)
org.obo.dataadapter.AbstractParseEngine.parse(AbstractParseEngine.java:70)
org.obo.dataadapter.OBOFileAdapter.doOperation(OBOFileAdapter.java:270)
org.bbop.dataadapter.DataAdapterOperationTask.execute(DataAdapterOperationTask.java:43)
org.bbop.util.AbstractTaskDelegate.run(AbstractTaskDelegate.java:60)
org.bbop.swing.BackgroundEventQueue$BackgroundEventThread.executeTask(BackgroundEventQueue.java:137)
org.bbop.swing.BackgroundEventQueue$BackgroundEventThread.run(BackgroundEventQueue.java:79)

This is because the PATO terms are not known, when referenced in
relationship: is_unit_of PATO:0000xyz ! ...
lines.

By adding the import line
import: http://ontologies.berkeleybop.org/pato.obo
to the header tags of unit.obo, e.g. before setting the default namespace, this error could be easily avoided.

Best regards
Gerhard Mayer

Term request fold

In an NIH funded project we are required to represent besides 'percent' also 'fold'. I suggest to add 'fold' as a subclass to 'ratio'. I suggest the following definition: "A dimensionless ratio unit which, given a pair of quantities a and b, for which b is a multiple of a, denotes b by giving the multiplier (coefficient) c for a to result in b."

OWL API throws a parser exception when trying to parse uo.owl

org.semanticweb.owlapi.rdf.rdfxml.parser.RDFParserException: [line=7751:column=57] IRI 'l/m^2' cannot be resolved against current base IRI http://purl.obolibrary.org/obo/uo.owl reason is: Illegal character in path at index 3: l/m^2

Line in question

I believe changing that line to the following would fix this:
<oboInOwl:hasExactSynonym xml:lang="en">l/m^2</oboInOwl:hasExactSynonym>

Add a CONTRIBUTING.md

It seems there are people willing to volunteer help for UO - it would be great to encourage this further

• it should be clear what file to edit
• it should be clear what best practice should be followed (e.g. do you require a definition? what is the DP for putting in symbols)
• what is the expectation on timeline for a review?
• after merge, how long until a release is made

It is standard with github to have a CONTRIBUTING.md that welcomes contributors and gives instructions

I like this guide:

https://github.com/OpenEnergyPlatform/ontology/blob/dev/CONTRIBUTING.md

Some general guidelines:

https://mozillascience.github.io/working-open-workshop/contributing/

Refactor UO using ODK

As discussed in #33 and it email correspondences with @leechuck @reality and @cmungall, UO could benefit from being restructured to a standard OBO directory structure and makefile workflow by running the ontology development kit to generate the missing files and merging them in. I will try to get to this in the next couple weeks as a pull request.

@reality I don't want to disrupt the existing groovy workflow so once I've got a branch with the new files we'll have to make sure that gets in there, perhaps as hooks in the makefile.

"Vs/cm2"

Hello,

I would like to propose a new unit term, which is used ion ion mobility spectrometry

[Term]
id: UO:0000xxx
name: volt-second per square centimeter
def: "An electrical mobility unit which is equal to one volt second per square centimeter."
synonym: "Vs/cm^2" EXACT []

Best regards,
Gerhard Mayer
PRIDE team

New term request: nanogram/microliter, ng/ul

For biological experiments, it is quite common to specify concentrations in nanogram/microliter with the synonym ng/ul. Would it be possible to add it to this ontology?

And if so, what would be the best process?

Term request teaspoon, tablespoon

We are annotating foods and wonder if units such as "teaspoon", "tablespoon", or "cup" would be in the scope of UO.

Need genetic distance measurement units

CentiMorgan (cM)

    A unit used to express distances on a genetic map. In genetic mapping, distances between markers are determined by measuring the rate of meoitic recombination between them, which increases proportionately with the distance separating them. A cM is defined as the length of an interval in which there is a 1% probability of recombination. On the average, 1 cM is roughly equivalent to 1 megabase (Mb) of DNA, although this can vary widely due to hot and cold spots of recombination. 


CentiRay (cR)

    A unit of genetic map distance defined corresponding to an interval in which there is a 1% probability of X-irradiation induced breakage. To be completely specified, the unit must be qualified by the radiation in dosage in rads (e.g. cR8000), because this determines the actual breakage probability. 

Definitions taken from http://www.ncbi.nlm.nih.gov/SCIENCE96/Glossary.html

Original issue reported on code.google.com by [email protected] on 3 Dec 2012 at 11:58

Term request: gram per square meter

Name	Value
Label	gram per square meter
Definition	An area density unit which is equal to the mass of an object in grams divided by the surface area in meters squared.
Definition source	EFO_0002898 gram per meter squared
Parent	UO_0000054 area density unit
alternative term	gram per metre squared, g/m^2, gram per square meter

Request by VEuPathDB (https://eupathdb.org/)

Request for PURL for uo-without-units-as-classes.owl

We're interested in importing uo-without-units-as-classes.owl, but cannot do so without a working PURL.

Provide URIs for units as datatypes

we are exploring a has-quantity property that links a characteristic instance to a literal of the form "NUMBER"^^UNIT_DATATYPE

here is an example:

@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix owl: <http://www.w3.org/2002/07/owl#> .
@prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> .
@prefix skos: <http://www.w3.org/2004/02/skos/core#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix COB: <http://purl.obolibrary.org/obo/COB_> .

@prefix cellular_organism: <http://purl.obolibrary.org/obo/COB_0000118> .
@prefix has-characteristic: <http://purl.obolibrary.org/obo/COB_0000512> .
@prefix has-quantity: <http://purl.obolibrary.org/obo/COB_0000511> .
@prefix characteristic: <http://purl.obolibrary.org/obo/COB_0000502> .

@prefix cm: <http://purl.obolibrary.org/obo/UO_0000015> .

@prefix : <http://example.org/> .

:Chris a cellular_organism: ;
  has-characteristic: [
     a characteristic: ;
     has-quantity: "182"^^cm:
  ] .

This leads the owlapi to induce:

#################################################################
#    Datatypes
#################################################################

###  http://purl.obolibrary.org/obo/UO_0000015
<http://purl.obolibrary.org/obo/UO_0000015> rdf:type rdfs:Datatype .

I don't know if punning class vs datatype is allowed but it's kinda weird

• should there be new URIs, e.g. http://purl.obolibrary.org/obo/UO_0000015/dt
• should this go in a new namespace altogether?
• maybe use QUDT or something instead?

OBOFoundry/COB#35

cc @jamesaoverton

Term requests for upcoming GenEpiO ontology

Hi there,

We have a number of environmental measurables in our upcoming genomic epidemiology ontology that it would be great to have UO terms for:

Under concentration unit:
micromole per kilogram ( µmol/kg , used in measure of dissolved oxygen concentration)
micromole per litre ( µmol/L , aka micromolar µM, used in measure of phosphorus, nitrite, nitrate etc. concentration)

cubic metre per second (SI derived volumetric flow rate, used in measuring stream flow)

Would this go under "Conduction unit"?
millisiemens per centimetre (used in measuring electrical conductivity of water to infer its salinity)

Under speed/velocity unit:
millimetres per day (for measuring rainfall)

Regards,
Damion

Term request: Milli mass unit (mmu)

The "Milli mass unit" is missing in the current version of the unit ontology.
This unit is often used in mass spectrometry for instance.
For a definition see: https://en.wikipedia.org/wiki/Milli_mass_unit

A synonym of this term is millidalton (mDa).

add new related synonym "MHz" to term "megaHertz (UO:0000325)"

The unit MHz can be found as full name "megaHertz (UO:0000325)" or under his relatedSynonym "mH" in UO. "mH" is however not a common abbreviation for this unit.
It would be nice if the term "megaHertz (UO:0000325)" could be supplemented by the more common unit abbreviation "MHz" via "hasRelatedSynonym".

NTR: four terms for clinical assays etc., motivated by LOINC

The PennTURBO team is creating axiomatic definitions for organismal assays. This is motivated by instantiating "lab results" in our electronic health records system, although most of the assays will be applicable to research on model organisms, too. From our weekly OBI developers discussions, it looks like the assays will be importable as an OBI module.

We're bootstrapping the process with a subset of LOINC, which describes the property that is being measured (like concentration), not the units per se. However, we would like our axioms to specify what measurement datum, as defined by the units, is expected as the output of each assay.

Here are four LOINC properties for which we haven't been able to find corresponding units in UO. Would you please add them to UO?

EDIT:
prefix : <http://purl.bioontology.org/ontology/LNC/>

BioPortal LOINC IRI	LOINC Abbrev.	LOINC Descr.	Example Assay Code	Example Assay Descr.	Relation to existing UO term?
:LP6773-8	ACnc	arbitrary units per volume	10334-1	Cancer Ag 125 [Units/volume] in Serum or Plasma	subclass of (or equivalent to?) 'unit per volume unit' obo:UO_0000177
:LP6787-8	ArVRat	aric volume rate; volume per unit time per unit	69405-9	Glomerular filtration rate/1.73 sq M.predicted [Volume Rate/Area] in Serum, Plasma or Blood	subclass of 'volumetric flow rate unit' obo:UO_0000270
:LP70220-6	LsCnc	log substance concentration	9347-6	combined acid of Gastric fluid	subclass of 'unit of molarity' obo:UO_000006
:LP6836-3	NCnc	number per volume	30412-1	Abnormal lymphocytes [#/volume] in Blood	subclass of 'concentration unit' obo:UO_0000051

UO is not parseable

 robot -vvv merge -I http://purl.obolibrary.org/obo/uo.owl -o uo.owl

Causes other ontologies importing it to fail (like MS).

Most likely culprit:

org.xml.sax.SAXParseException; systemId: http://purl.obolibrary.org/obo/uo.owl; lineNumber: 7563; columnNumber: 75; The prefix "dc" for element "dc:creator" is not bound.        org.semanticweb.owlapi.rdf.rdfxml.parser.RDFXMLParser.parse(RDFXMLParser.java:78)

But not sure if its the only one.

Term request: pounds per square inch

We Americans need this term to keep our tires inflated properly! Also sometimes chromatography pump pressure, apparently. Thanks!

[Term]
id: UO:0000xxx
name: pounds per square inch
namespace: unit.ontology
def: "A pressure unit which is equal to 6894.757 pascal." [Wikipedia:Wikipedia]
synonym: "psi" EXACT []
synonym: "lbf/in^[2]" EXACT []
is_a: UO:0000109 ! pressure unit

Wrong synonym?

I don't think this synonym is right:

unit-ontology/unit.obo

Lines 1956 to 1960 in f9ff25b

	name: milligray per day
	namespace: unit.ontology
	def: "A derived absorbed dose unit which is equal to one milligray absorbed per day."
	subset: unit_slim
	synonym: "mGy/min" EXACT []

Create version without instances/without singletons

Create version without instances/without singletons

Original issue reported on code.google.com by [email protected] on 6 Apr 2011 at 5:25

typo of UO_0000036:'year' definition

EuPathDB (http://eupathdb.org/) used UO. We found the definition of "year" contains a typo:
"A time unit which is equal to 12 months which is science is taken to be equal to 365.25 days."

should probably say: " ...which IN science..."?

Thanks!

Term request: megahertz

Dear UO,

I am aware of UO prefixes and that UO has Hertz unit, however I could see that 
megavolt was available.
The use case here is to report NMR magnet frequency which are always expressed 
in MHz. Having the term readily available would make using in an XML schema

If this is not possible, can you point to documentation on how to compose UO 
units and prefixes?

Thx

Philippe

Original issue reported on code.google.com by [email protected] on 4 Dec 2013 at 4:06

NTR: square micrometer

New term request

square micrometer
Defn: An area unit which is equal to an area enclosed by a square with sides each 1 micrometer long.
is_a: area unit UO:0000047

Add synonym cm to centimeter

http://purl.obolibrary.org/obo/UO_0000015 lacks a synonym cm

Add obofoundry topic to repo metadata

The OBO Foundry has recently created a topics page at https://github.com/topics/obofoundry. It would be great if you could add the obofoundry topic to your repository, since it's currently listed as active in the OBO Foundry. If you're not sure how to do that, follow the instructions here. The main issue for this task is at OBOFoundry/OBOFoundry.github.io#1538 in case you want some more context or to join the larger discussion.

milligram per liter and milligram per mililiter has the same equivalent class axioms

milligram per liter and milligram per mililiter has the same equivalent class axioms
This is problematic as it 1) causes failure of checks, 2) would end up meaning the same thing to a reasoner - misclassification will be a problem
Perhaps changing them to subclass_of axioms instead would fix it?

New class: kilometers per hour

Would it be possible to have a class kilometers per hour under the class speed/velocity unit http://purl.obolibrary.org/obo/UO_0000060 ?

Interest in contributing to UO/uo-idranges.owl

Hello UO team and @reality, My name is Kai Blumberg, I'm a developer for the Environment Ontology (ENVO). I'm working on a project Planet Microbe in which I am using various OBO ontologies including UO to make marine metagenomic datasets interoperable. I have about 20 terms, I'd be interested in adding to UO, (e.g., bar, decibar, atmosphere unit).

Let me know if this would be possible and how you would prefer I do so. If I should post issues, or if you might be interested in having me make pull requests or be a direct contributor.

Thanks

-Kai

Non-unique rdfs:labels ?

Some concepts do share rdfs:label values (e.g. UO_0000190 and UO_0010006). This does not seem to be a good practice (e.g. w.r.t. OBO Foundry principles https://obofoundry.org/principles/fp-012-naming-conventions.html).

Awareness of Units Summit Summer 2022

Sorry this is not an issue but a message just trying to get in touch with the developers of this project. There will be three coordinated session at ScIDataCon 2022. See this page for more info. https://codata.org/initiatives/task-groups/drum/units-summit-recap-meeting/

Stuart Chalk
DRUM Secretary
https://codata.org/initiatives/task-groups/drum/

Synonyms not present in OWL

In the OWL version of UO, I am not finding synonyms. For example, kilogram has synonym kg on OLS. But this is not given in uo.owl.

cc @cmungall

duplicated micro mole

http://purl.obolibrary.org/obo/UO_0010048 and http://purl.obolibrary.org/obo/UO_0000039 are duplicated - causing equivalent class failure in importing ontologies

REQUEST adding a new unit: meter squared per gram

I am working on a dataset that contains a unit for specific surface area (SSA) which is m^2/g (meter squared per gram)
Specific surface area (SSA) is a property of solids defined as the total surface area of a material per unit of mass, (with units of m2/kg or m2/g)
I would really appreciate it if this unit can be added to the Unit Ontology

Term request: kilograms per hectare

Hi UO, we'd like to have a class: kilograms per hectare. hectare would need to be created in the area hierarchy.

hectare =def. a unit of area equal to 10,000 square meters: equivalent to 2.471 acres.

Missing `dc` namespace.

Dear UO developers, I would like to report that a declaration of dc namespace is missing in the uo.owl.

I am trying to use UO in a project, and when running the following commands:

curl --output uo.owl --location http://purl.obolibrary.org/obo/uo.owl
robot convert --input uo.owl  --format owl --output uo.local.owl

I receive the error:

[Fatal Error] :7563:75: The prefix "dc" for element "dc:creator" is not bound.
INVALID ONTOLOGY FILE ERROR Could not load a valid ontology from file: uo.owl

Apparently, the dc namespace declaration is missing from uo.owl, because adding the following line fixes the error:

xmlns:dc="http://purl.org/dc/elements/1.1/"

Do you think this should be fixed on UO side or it is a parsing issue? Thanks a lot!

Note: robot refers to ROBOT v1.8.3, and the no-op robot convert from OWL to OWL format above just demonstrates the error.

Add synonym: kg/ha

Could you please add the abbreviation kg/ha as a synonym for http://purl.obolibrary.org/obo/UO_0000283

Introduce localisation to labels and definitions

introduce distinctions between en-us, en, en-aus etc for labels to facilitate nlp uses for regional customary units as per e.g. [#8]

minor typo for "year"

[Term]
id: UO:0000036
name: year
def: "A time unit which is equal to 12 months which is science is taken to be 
equal to 365.25 days." [Wikipedia:Wikipedia "http://www.wikipedia.org/"]
subset: unit_slim
is_a: UO:0000003 ! time unit
created_by: george gkoutos

def should read: "...which in science is taken..."

Seen Mar. 7, under 
http://obo.cvs.sourceforge.net/obo/obo/ontology/phenotype/unit.obo

Original issue reported on code.google.com by [email protected] on 7 Mar 2012 at 9:27

NTR: calorie

label: large calorie
definition: A unit of energy widely used in nutrition, equivalent to the amount of heat needed to cause one kilogram of water to rise in temperature by one degree Celsius.
definition source: https://en.wikipedia.org/wiki/Calorie
parent: energy unit
example of use: "There probably are a lot of brands out there that use the large calorie in their labels to avoid big, intimidating numbers"
synonyms: food calorie, kilocalorie, big calorie, Cal, Calorie, calorie or kcal
requestor: Damion Dooley
comment: "By convention in food science, the large calorie is commonly called calorie (with a capital C by some authors to distinguish from the smaller unit)" [Wikipedia]

Term request: picoampere

I have a Charged Aerosol Detector returning values in picoAmps. Would be nice to keep it in the native units.

[Term]
id: UO:000xxx
name: picoampere
namespace: unit.ontology
def: "An electric current unit current which is equal to one trillionth of an ampere or 10^[-12] A." [UOC:GVG]
subset: unit_slim
synonym: "pA" EXACT []
is_a: UO:0000004 ! electric current unit

Thanks!

add imperial units

as per https://en.wikipedia.org/wiki/Imperial_units , by request

amu as synonym for dalton

Wouldn't it make sense to add amu as a synonym to the dalton term?

Original issue reported on code.google.com by [email protected] on 1 Feb 2013 at 12:17

Term request: micrograms per bottle

Hi! Could we add the term microgram per bottle?