The phrase "a major effort has" is correct and usable in written English.
It can be used to indicate that a significant amount of work or resources has been dedicated to a particular task or project.
Example: "A major effort has been made to improve the infrastructure in the community over the past year."
Alternatives: "a significant effort has" or "a considerable effort has".
A major effort has been made to determine the role of stem cell transplantation in adult MDS patients, currently the only curative option available for them.
To achieve the best structural model improvement using vibration test data, a major effort has been made to identify poor modelling regions as a guideline for subsequent model updating.
In particular, a major effort has been placed on providing a service for managing persistent data and the experience using a commercial ODBMS (Objectivity/DB) is therefore described in detail.
A major effort has been devoted to optimizing the computation speed using state-of-the-art algorithms for the time-consuming parts of the calculations implemented in the core of the program using the C programming language.
A major effort has been to develop or enhance imaging modalities including light sheet microscopy, fluorescence correlation spectroscopy and microfluidics for confocal imaging of living seedlings.
A major effort has been put into adapting containment actions: "Identifying and Isolating Other Infected Hosts" Study the profile of the infected host and compare it to other worker nodes' profiles, in order to identify compromised hosts.
Movielink, the industry's first major effort, has met limited success so far.
As a result, major efforts have been directed to identify small molecule inhibitors against APE1/Ref-1 activities.
In that vein, a major effort this year has been the development of CASE's new online learning series, beginning with the 9-module Smart Impact Capital to address common pitfalls of impact entrepreneurs seeking investment capital.
Since 1949 major efforts have been made in planting trees for shelter, timber, and other uses.
Until now, major efforts had been financed and directed by the Italian Government.
