Shingle sawyers are exposed to noise predominantly from the left side. This study examined the asymmetry in hearing loss among shingle sawyers and its possible relation to the difference in noise exposure to the two ears. The results suggest that the lateral difference in noise exposure in industry, even in the obvious case of a shingle sawyer, is small. The resulting asymmetrical noise-induced hearing loss is also relatively small. Therefore, significant asymmetry in hearing loss in this type of occupation should be viewed with caution. Special tests and medical examination should be undertaken to determine if there are other contributing factors.
There were at least four waves of bow and arrow use in northern North America. These occurred at 12000, 4500, 2400, and after about 1300 years ago. But to understand the role of the bow and arrow in the north, one must begin in the eighteenth century, when the Russians first arrived in the Aleutian Islands. At that time, the Aleut were using both the atlatl and dart and the bow and arrow (Fig. ). This is significant for two particular and important reasons. First, there are few historic cases in which both technologies were used concurrently; second, the bow and arrow in the Aleutian Islands were used almost exclusively in warfare. The atlatl was a critical technology because the bow and arrow are useless for hunting sea mammals. One cannot launch an arrow from a kayak because it is too unstable and requires that both hands remain on a paddle. To use an atlatl, it is necessary only to stabilize the kayak with a paddle on one side and launch the atlatl dart with the opposite hand. The Aleut on the Alaska Peninsula did indeed use the bow and arrow to hunt caribou there. However, in the 1,400 km of the Aleutian Islands, there are no terrestrial mammals except humans and the bow was reserved almost exclusively for conflicts among them. The most significant event in the history of the bow and arrow is not its early introduction, but rather the Asian War Complex 1300 years ago, when the recurve and backed bows first entered the region, altering regional and hemispheric political dynamics forever. [Figure: see text].
The Danish National Patient Register, Landspatientregistret (LPR), is a register of all hospital discharges and outpatient treatments in Denmark.
It is increasingly used in research so it is important to understand to what extent this can be used as an accurate source of information. Virtually all patients in Denmark with multiple sclerosis (MS) are reported to the Combined MS Registry (DMSR), so this was used as the standard which the LPR was compared against.
All residents of Denmark are assigned a unique Civil Register (CPR) number; this was used to compare data between registers. The LPR completeness was estimated by the proportion of cases from the DMSR that could be retrieved from the LPR. The LPR validity was estimated by the proportion of cases, listed in the LPR and DMSR, in whom the MS diagnosis could be confirmed as definite/probable/possible by the DMSR.
We found that 86.9% of those who were DMSR listed with an approved MS diagnosis were also listed in the LPR with a MS diagnosis. The diagnosis was valid in 96.3% of patients listed in the LPR when compared against the DMSR.
The low completeness reduces the usefulness of the LPR in epidemiological MS research, in particular incidence studies. The study also found that the completeness of the LPR could be increased to 92.8% by including LPR records from other departments in addition, but this reduced the validity of the LPR to 95.1%. However, these results cannot uncritically be applied to registration of other diseases in the LPR.
The prevalence of tinnitus was studied in a large population of noise-exposed workers. It was found that 6.6% had tinnitus which was more than momentary. Results of two other studies were compared. Factors possibly relating to the prevalence of tinnitus were studied. The single most important factor found to be related to tinnitus is hearing level. The higher the hearing level, the faster the rate of increase in the prevalence of tinnitus. Other factors such as sex, age, laterality, smoking and shooting do not seem to have a significant, direct relationship with tinnitus, but they are related to the prevalence of tinnitus indirectly through the influence they have on hearing loss.
Several studies in the literature suggest that poor health is related to hearing loss. One hundred subjects claiming occupational hearing loss were chosen randomly for this study. Information was obtained on employment, noise exposure, medical history, family history, and use of cigarettes, alcohol, and medication. Physical examination audiometric tests, and biological tests were carried out. Computer analysis of the data with chi-square test did not show conclusively that noise-induced hearing loss is related to poor health, indicated by abnormal biological or physical findings, or both. There were, however, some indications that the presence of cardiovascular risk factors may influence hearing loss.
The paper considers the status of the wrongful life action particularly in the light of the recent acceptance of such actions in continental Europe. It is considered that the hurdle of causation is still not adequately overcome in these cases and, in a search for an answer to the difficulty, the author re-examines the Canadian case of Cherry v Borsman. This case was originally thought of as one of wrongful life associated with a negligently performed abortion and the paper attempts to overcome the problems of causation by comparing and contrasting the roles of the genetic counsellor and the abortionist. While the attempt is by no means wholly successful, it also serves to draw attention to some significant differences between wrongful life actions based on physical and mental disability in the neonate.