The results of this study demonstrate that even when high quality DNA from fresh blood extractions is available, difficulties in establishing the correct organellar mtDNA sequence may be encountered.
However, due to the small number of studies available, difficulties in the data preparation process (i.e. statistics required for calculating effect measures were missing in two articles), and high heterogeneity among studies, we considered a quantitative synthesis of data inappropriate for the current review.
With the assumption that only closed-loop data in normal condition are available, difficulty arises due to the facts that little a priori knowledge is known about closed-loop sensor fault propagation and the open-loop process model may not be identifiable.
However, distributed hydrological model applications are partly limited due to the requirement of large amount of spatial data which are not always available and difficulties in obtaining such data.
This warning is valid, but it is equally important to consider the relative merits of multiple analysis options given the data available, the difficulties in collecting the data, and the objective of the study.
So far, the use of these cells is burdened by ethical considerations as well as by practical problems: the lack of available embryos, difficulties with the generation of immunocompatible cells, and the risk of uncontrolled malignant proliferation of residual undifferentiated cells.
The causes of the high case fatality are multifactorial but include the high toxicity of locally available poisons, difficulties in transporting patients across long distances to hospital, the paucity of health care workers compared with the large numbers of patients, and the lack of facilities, antidotes, and training for the management of pesticide-poisoned patients [ 2, 4].
However, the use of these cells is hampered by ethical considerations as well as by practical issues, such as the lack of available embryos, difficulties with the generation of immunocompatible cells, and the risk of teratomas formed via proliferation of residual undifferentiated cells.
As more diagnostic tests become available, the difficulty of weighing these factors only grows [ 36].
Root canal treatment was finished in one to three visits according to pathological status, time available, the difficulty of the case and patient cooperation.
Hence, it is important to ensure that an adequate dose of induction agent is administered initially, and that further doses are available should difficulty with intubation be encountered.
