However, while viruses are effective, they can introduce problems like toxicity, immune and inflammatory responses, and gene control and targeting issues.

However, other methods exploit natural forms of gene transfer, such as the ability of Agrobacterium to transfer genetic material to plants, or the ability of lentiviruses to transfer genes to animal cells.

However, this has proven more difficult than modifying bacteria, primarily because of the problems involved in carrying large sections of DNA and delivering them to the correct site on the gene.

However, mutations of the dystrophin gene and nutritional defects ( with no genetics history ) at the prenatal stage are also possible in about 33 % of people affected by DMD.

However, many endogenous retroviruses play important roles in host biology, such as control of gene transcription, cell fusion during placental development in the course of the germination of an embryo, and resistance to exogenous retroviral infection.

However these drugs can quickly become ineffective due to the fact that the gene sequences that code for the protease and the reverse transcriptase quickly mutate.

However, such an approach can be methodologically problematic, as a statistical correlation could be due to circularity if the measurement of gene frequency indirectly uses the same measurements that describe the strategy.

However, not all polyploids are reproductively isolated from their parental plants, and gene flow may still occur for example through triploid hybrid x diploid matings that produce tetraploids, or matings between meiotically unreduced gametes from diploids and gametes from tetraploids ( see also hybrid speciation ).

However, 2006 research shows that jumping of a gene from one chromosome to another can contribute to the birth of new species.

However, scientists have silenced the gene that produces the toxin, making it a potential food crop.

However, physical barriers to gene exchange ( such as the Himalayan mountain range ) might have enabled Cannabis gene pools to diverge before the onset of human intervention, resulting in speciation.

However, other changes such as Transgenesis introduce DNA into an organism that is not available in the species ' gene pool.

However, there are cases in which testes can develop in the absence of an SRY gene ( see sex reversal ).

However, there is some evidence to suggest that there could have been transitions between ZW and XY, such as in Xiphophorus maculatus, which have both ZW and XY systems in the same population, despite the fact that ZW and XY have different gene locations.

However, when an extra DAX1 gene is placed on the X, the result is a female, despite the existence of SRY.

However, homologues to the avian DMRT1 gene on platypus sex chromosomes X3 and X5 suggest that it is possible the sex-determining gene for the platypus is the same one that is involved in bird sex-determination.

However, killing another male's cubs, upon the takeover, allows for the new selected gene complement of the incoming alpha male to prevail over the previous male.

However, in 1997, Dr Matalon's employer, the Miami Children's Hospital, patented the gene and started claiming royalties on the genetic test, forcing the Canavan Foundation to withdraw their testing.

However, a study published in the journal Cell in 2010, based on gene expression profiles, reported strong affinities between the cerebral cortex and the mushroom bodies of ragworms.

However, the frequency of recombination is actually not the same for all gene combinations.

However a different genetic symbol ( hr ) is given to the Sphynx gene and it is more likely that these are different genes interacting with each other.

However, a hypothetical gene that prompts behaviour which enhances the fitness of relatives but lowers that of the individual displaying the behavior, may nonetheless increase in frequency, because relatives often carry the same gene.

However, no diagram of her brain patterns, no early I.Q. tests recorded certain essential facts about Helva that Central must eventually learn.

However, by identifying clusters of observable properties that are associated with core examples of clitics on the one hand, and core examples of affixes on the other, one can pick out a battery of tests that provide an empirical foundation for a clitic / affix distinction.

However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.

However, after doing some screen tests and storyboards, Toho figured Jet Jaguar would not be able to carry the film on his own, either in screen appearance or marketing value, so they shut the project down during pre-production.

However, laboratory tests on fire ants have shown that grits are an ineffective pesticide.

However, he failed to reach fifty in the next two tests and four ODIs as both series were drawn.

However, in tests conducted on rhesus monkeys, the analgesic potency of hydrocodone was actually found to be higher than that of morphine.

However, in the case of Griggs v. Duke Power Co. in 1971, for the purpose of minimizing employment practices that disparately impacted racial minorities, the U. S. Supreme Court banned the use of IQ tests in employment, except when linked to job performance via a Job analysis.

However, IQ tests may well be biased when used in other situations.

However, it has been challenged as to whether the measurement of job performance is usually done through pencil / paper tests, job skills tests, on-site hands-on tests, off-site hands-on tests, high-fidelity simulations, symbolic simulations, task ratings and global ratings.

However, when the new test subjects take the older tests, in almost every case their average scores are significantly above 100.

However, if failures occur mostly on weekends, many uniform-distribution tests such as K-S would miss this, since weekends are spread throughout the year.

However, on tests with a heterogeneous distribution of point values — i. e. different questions are worth different point values — it is more difficult to provide choices.

However, like methadone, buprenorphine produces similar cognitive dehabilitation in multiple areas of mental function in both memory and timed choice task tests, which may persist after cessation of substitution treatment.

However, the issue is not finally settled, for each of these experimental tests has left open at least one loophole by which it is possible to question the validity of the results.

* However, aquarium tests showed:

However, Hammer worked primarily on the incandescent electric lamp and was put in charge of tests and records on that device.

However, DNA tests on Dunbar's son and nephew revealed the two were not related, thus establishing that the boy found in 1912 was not Bobby Dunbar, whose real fate remains unknown.

However, there are recordings with substantial low frequency content that most conventional loudspeakers are ill-equipped to handle without the help of a subwoofer, especially at high playback levels, such as music for pipe organs with 32 ' bass pipes ( 16 Hz ), very large bass drums on symphony orchestra recordings and electronic music with extremely low synth bass parts, such as bass tests or bass songs.

" However, if additional evidence is available, from theory and / or from experiment ( such as density dependence ), there is no obstacle to incisive tests of the Arrhenius law.

" However, Ertl's most recent tests show that subroutine threading is faster than direct threading in 15 out of 25 test cases.