General Policies

Subject of this Directive

Nefeli is the data repository where researchers from Helmholtz Munich can store data obtained from their research projects for long-term reuse. Nefeli thus fulfills an important requirement at the center for FAIR-compliant handling of research data and our commitment to an open science culture.

Content

Scope

All research data created at Helmholtz Munich or in collaboration with Helmholtz Munich can be published in Nefeli. The content must not violate copyright, data protection, or confidentiality agreements. The uploader is responsible for ensuring that their content is suitable for dissemination. Nefeli must not be used to store complete datasets from other public repositories in copy. Research data from any stage of the research data lifecycle can be uploaded to Nefeli.

Eligible Users

All employees of Helmholtz Munich can register as users of Nefeli. An active user account at Helmholtz Munich is required to store research datasets in Nefeli. Authentication is done via Helmholtz AAI (Shibboleth) using your Helmholtz Munich account information.

File Formats

There are no restrictions on suitable file formats – all formats are allowed. However, the uploader should choose a format suitable for long-term reuse. Proprietary file formats that can only be read by paid programs should be avoided or at least supplemented by lossless exports in generally readable data formats. Please contact us if you need help choosing your format.

License

Depending on the confidentiality level of the data, the author must choose an access variant (open or restricted access to the data, the latter possibly with open metadata). For possible reuse of the data, a variant must be selected from the possible licenses.

Language

The preferred language for text content is English.

Size Limitations

The default limit is 100 GiB per record. These quotas can be increased upon request (contact us in SPIT).

Access to and Reuse of Data in NEFELI

File Access

Files can be defined as open, restricted, limited, or closed. Files can be accessed via the HTTPS protocol. Files marked as closed access can only be accessed by the owner. Datasets for which a restricted user group ("community") has been defined can only be accessed by members of this group. Membership in such a restricted group is administered by the group owner.

Metadata Access

Nefeli metadata is licensed under CC0. It is possible to make only the metadata of restricted datasets openly accessible. All open metadata (i.e., all metadata of open datasets as well as openly provided metadata of closed or restricted datasets) are exported via OAI-PMH and can be harvested.

Use and Reuse of Data

The reuse of research data from the Nefeli repository in other research projects is subject to the license under which the files were deposited by the authors at Helmholtz Munich in Nefeli. Data released for reuse under a CC0 or CC-SA license can be used without further inquiry. In the case of potentially derived, novel findings (such as publications, patent applications, AI foundation models), reference must be made to the data author as indicated in the Nefeli metadata.

For closed or restricted datasets whose metadata is openly viewable, reuse can be requested. This must be regulated by a data transfer agreement between the data author, represented by the Helmholtz Munich legal department, and the external research partner. The data author thus enables data access in a restricted form by the external research partner.

Embargo Period

Uploaders can specify an embargo date. Nefeli restricts access until the end of the embargo period. Files are automatically made public after the embargo period ends.

Persistence

Versioning

After a final upload of a dataset, the individual data contained therein can no longer be changed or deleted (exception see below). If an update of the dataset is to be made later, a new version must be created. This can contain all data of the previous version in addition to additional files. The metadata description must indicate how the versions differ from each other.

Integrity and Authenticity

All files are stored together with the corresponding MD5 checksum of their content. Files are automatically and regularly checked against their checksum to ensure that the file content remains constant and unchanged.

Backups and Data Security

Files are stored in a distributed NAS file system, which is locally available at Helmholtz Munich and backed up to tape twice a week (until further review).

Preservation of Metadata

Metadata is stored in a highly available PostgreSQL installation with backups twice a week (until further review).

Retention Period

Items are retained for the entire lifetime of the Nefeli data repository. Deletion is not intended (exception see below).

Succession Plans

In the event of the repository's closure, all efforts will be made to integrate all content into suitable alternative institutional and/or thematic repositories.

Removal

Revocation

Files with content that does not fall within the repository's scope will be removed, and all DOIs assigned by Nefeli will be revoked. Uploads that have already been assigned an external DOI will be invalidated. The metadata of the dataset will be updated with the external DOI.

Withdrawal

In the event that datasets deposited in Nefeli need to be withdrawn at a later date for substantive reasons, the reason for the withdrawal will be displayed on a tombstone page provided in place of the original dataset. Withdrawal is considered an extremely exceptional action. The withdrawal must be requested and fully justified by the original uploader. The DOI and URL of the original object will be retained.