Uniform Scaling of Physical Units and the Principle of Rationality of Measurement

One of the most basic principles in science is the objectivity of measurement of physical properties. According to the special theory of relativity (STR), this ancient principle is violated for observers in relative motion since it predicts that they generally will disagree on the ratios of the lengths of two objects and also on whose clock is running slower at any given time. Both predictions stem from the Lorentz transformation (LT), which is the centerpiece of Einstein's STR. It has recently been pointed out that two of the claims of this theory are mutually contradictory; it is impossible that the rates of two clocks in motion are strictly proportional to one another (time dilation) while one of them finds that two events are simultaneous whereas the other does not (remote nonsimultaneity). This recognition proves that the LT is not a valid component of the relativistic theory of motion, including its well-known thesis that space and time are not distinct quantities. Instead, it has always been found experimentally that the rates of clocks in motion are governed by a Universal Timedilation Law (UTDL), whereby the speed of the clock relative to a specific rest system is the sole determining factor. A simple way of describing this state of affairs is to say that the standard unit of time in each rest frame is different and increases with its relative speed to the above rest system by a definite factor. The measurement process is thereby rendered to be completely objective in nature. A key goal of relativity theory is therefore to develop a quantitatively valid method for determining this factor. It will be shown that the same factor appears in the true relativistic space-time transformation and that it also plays a key role in the uniform scaling of all other physical properties

Is Packing Density Important in Stent-Assisted Coiling?

BACKGROUND: Recent reports have shown that stent-assisted coiling (SAC) is associated with lower aneurysm recanalization rates compared with conventional coiling, raising questions about the necessity of achieving high packing density (PD) in stented aneurysms. OBJECTIVE: To assess the impact of PD on follow-up obliteration rates of stented aneurysms and attempt to determine the optimal range of PD in SAC. METHODS: This is a retrospective analysis of a single, large, cerebrovascular referral center's experience over a 5-year period in SAC with the use of Neuroform and Enterprise stents. The rate of complete obliteration on follow-up angiograms was compared for 3 different PD groups: high PD (>22%), moderate PD (12–22%), and low PD (<12%). RESULTS: There were 292 stent-coiled aneurysms (36 ruptured, 256 unruptured) with available angiographic follow-up. Mean PD was 15.2%, and complete obliteration rate was 79.5% at latest follow-up. The rates of complete obliteration were significantly higher in the moderate (86.4%; OR = 2.58; P = .006) and high PD groups (85.3%; OR = 2.35; P = .037) compared with the low PD group (71.1%). However, no statistically significant difference was found between the moderate and high PD groups (OR = 0.91; P = .84). In multivariate analysis, PD was a significant predictor of complete obliteration (P = .007) along with smaller aneurysm volumes (P = .004). Ruptured (P = .002) and cavernous aneurysms (P < .001) had significantly lower obliteration rates. CONCLUSION: High obliteration rates at follow-up were observed despite modest packing of stented aneurysms. Although PD is a definite factor in SAC, moderate and high packing of stented aneurysms seems to provide equivalent angiographic obliteration rates at follow-up.

Upper Incisor Root Resorption during Stage II of the Begg Technique: Two Case Reports

Two cases exhibiting upper incisor apical root resorption when using purely tipping movements with a fixed appliance technique are reported. Possible causes of resorption are discussed, but no definite factor was apparent in these cases.

Diagnosis and Treatment of a Bleeding Diathesis Causing Hematoma of Sigmoid

Several discrepancies in the description of the coagulation data presented in the article by Schiller and others1 are apparent. A patient with "definite" Factor X deficiency of a clinically severe degree should have an abnormal prothrombin time and thromboplastin generation test. The authors report these tests to be within normal limits. Also, a platelet adhesiveness of 74% is hardly "slightly reduced" by most published normal values which range from 20 to 80%. In addition, if "A.P.T.T." means "a partial thromboplastin time," then this test should also be abnormal.

THE RÔLE OF THE SPLEEN IN IRON METABOLISM AS ELUCIDATED BY CHANGES IN THE IRON BALANCE AFTER SPLENECTOMY

We have estimated the iron balance in six dogs before and after splenectomy, in two intact dogs, and in five dogs before and after major operations other than splenectomy. In all the animals studied, considerable variation in iron balance was observed in the periods used (6 to 14 days). The intact controls had positive balances, the one followed for a year and a half having over 0.4 mg. per kilo per day, except when fasting or on an inadequate intake. The iron of urine, lost hair, dandruff, etc., which was not included in the determinations, would be far from sufficient to restore equilibrium. Of five animals subjected to major operations other than splenectomy, all of which in preoperative periods had positive balances varying between 0.423 mg. to 0.075 mg. per kilo per day, three showed a positive balance of from 0.989 mg. to 0.057 mg. and two showed negative balances of from 0.02 to 0.18 mg., the last two having anemia in the period of study while the others had none. Of the six splenectomized dogs, five showed a greater tendency to loss of iron after splenectomy (i.e., either a change from a positive to a negative balance or to an increasedly negative or lessened positive balance). This was not always apparent until some days after splenectomy and coincided approximately with the period of developing anemia. The removal of the spleen was usually found therefore to be transiently associated with increased excretion of iron. It is not possible to demonstrate, however, that the increased loss of iron is the cause of the anemia, and the matter awaits further investigation before the reason of its occurrence is made clear. An adequate iron intake in an intact animal was usually accompanied by a positive balance, though in splenectomized animals during the period of anemia it was frequently accompanied by a negative balance. Gain in weight in intact animals likewise was associated with a positive balance; but in the three instances in which gain of weight occurred during periods of anemia, after splenectomy or other operations, it was associated with a negative balance. Weight maintenance was also associated with a positive balance except in one instance of severe postsplenectomy anemia. Loss of weight was not sufficiently associated with a negative balance to make it seem a definite factor influencing the balance, per se, although about one-third of the periods of loss of weight were associated with negative balances.