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Classical conditioning experiments which employ CS-US intervals shorter than the latency of the CR, and which therefore require interspersed CS-alone test trials to assess conditioning, are open to the stimulus-sequence-change-elicited (SSCE) OR argument. The form of the SSCE argument which denies associative status to SCRs elicited by the CS-alone test trials is here termed an “empirical red herring” because: a) the argument cannot be dismissed on purely logical grounds, but requires the assessment of evidence for its examination; b) the argument enjoys empirical plausibility in the minds of the scientific community, as evidenced by published statements in both experimental articles and textbook chapters on autonomic conditioning; c) critical examination of the evidence which apparently supports the argument reveals that while the argument has provided a fascinating byway in the progress of our understanding of SCR conditioning, it is now time to bid farewell to the argument since it lacks any genuine empirical base. In the course of examining this particular argument, both the advantages and disadvantages of such arguments for scientific progress are discussed. Finally, it is emphasized that if one wants to study multiple-response phenomena in SCR conditioning, then a longer CS-US interval is clearly desirable. Our message only is that if the aim is to study SCR conditioning—defined as an increase in responding to a CS relative to some appropriate control condition(s) which is attributable to the contiguity of the CS with the UR to the US—in its most robust form, then the short-interval CS-US arrangement should not be avoided on the basis of the SSCE argument which, on examination, turns out to be an empirical red herring.

Two experiments were conducted to estimate the influence of initial cutting dates in March and April and of cutting frequencies on Guinea grass, elephant grass and star grass productivity. Increasing delay in date of first cut in the season resulted in a progressive increase in dry-matter yield. 72–81% of the tiller population at any cut were vegetative and this helped to maintain good aftermath yield for each date of first cut. Early April cuts gave the highest dry-matter yield and early March the least. Harvesting frequencies affected the sward productivity such that the annual dry matter yield increased with increasing harvesting interval from 6800 kg ha-1 for a 3-week interval to 13,000 kg ha-1 for a 10-week interval. The proportion of green leaf in the dry matter dropped from 57·7% at 3-week intervals to 32·0% at 10-week intervals. Seasonal effects showed that potential yield was reduced by a short interval between harvests early in the season but not late in the season. Species differences in quality and in the harvesting interval that gave the maximum yields were noted. These results are discussed in relation to management of the sward throughout the growing season.

Because of their known tendency to occur in the interval 2–7 days after the start of a geomagnetic storm, Pc 1 pulsations (0.2–5 Hz) are particularly well suited for a method of occurrence prediction based on the comparison of running means of a geomagnetic activity index. By comparing the running mean of a short interval (∼ 2 days) of activity data with the mean of a longer interval (∼ 5 days), it is possible to isolate the intervals of declining activity that contain a large proportion (if 66%) of Pc 1 pulsation occurrences. Assuming the real time availability of a daily activity index, predictions can be made for 3–10 days ahead of the probability of Pc 1 occurrences. The method of prediction generalizes the previous observations on the relation between Pc 1 pulsations and geomagnetic storms, and one of its important features is its ability to divide Pc 1 pulsation occurrences into a unified system of categories. It is probable that this system can be exploited to provide new information about the pulsations.

A positive integer nis called a square-full integer if p2 divides n whenever p is a prime divisor of n. For x > 1 we denote by Q(x) the number of square-full integers not exceeding x. Bateman and Grosswald [1] proved that

To investigate alternation behavior in the cockroach as an invertebrate, three T-maze experiments were conducted assessing the effects of (a) intratrial (exposure) and intertrial (exposure to test) interval, (b) brightness similarity of the alternatives and response-direction factors, and (c) an initial free-choice vs. a varying number of forced-choice exposures. Alternation was enhanced with a long exposure on Trial 1, a short interval between Trial 1 and Trial 2 (test), greater dissimilarity (or discriminability) of the arm brightnesses and more frequent forced-choice exposures to an arm prior to test. These results highlight the role of intramaze brightness cues as controlling alternation in the cockroach and accord well with a response-to-change interpretation of the phenomenon. In addition, they suggest that the alternation paradigm can be used effectively to assay short-term memory storage in neurologically simple organisms.

Repeated stimulation of division at a short interval (2–3 days) after the first division causes shortening of the prereplicative period of the mitotic cycle of hepatocytes in the regenerating rat liver to 9–10 h. Cells dividing a second time after one stimulation passed through the G1 period of the second mitotic cycle in the same length of time. It is suggested that cells with the minimal duration of the prereplicative period do not pass through a period of transformation. With an increase in the time between successive stimulations of division (to 4–5 days) the duration of stay in a resting state was increased for most hepatocytes and they lost their ability to maintain a shortened prereplicative period.

Soon after his accession to the English throne William’s two navies started combined operations against the common enemy France. The Nine Years War had broken out, and this was followed after a short interval by the War of the Spanish Succession. Combined naval operations by two allies were nothing uncommon in those days. Anglo- French fleets had fought the Dutch in no fewer than four fierce battles in 1672 and 1673. French and Dutch squadrons had cooperated against the English Navy in 1666, and much earlier in 1596 and 16252727 Anglo- Dutch fleets jointly attacked Spanish ports (1). In these examples cooperation never lasted long nor was it very close. Problems concerning the command structure were seldom satisfactorily solved. Allies regularly changed sides during the 17th century. The Glorious Revolution, however, can be treated as a turning point. England became involved in a generations-long struggle against France. The Dutch Republic under William III had already started to fight Louis XIV’s urge for expansion, more than 15 years earlier. Both countries almost became traditional allies. Right from the beginning in 1689 detailed arrangements were made for naval cooperation, long-standing ones as later developments showed.

Feral-strain fowl, bred from birds captured on North-West Island (24°S, 150°E), were compared with domestic chickens hatched and raised under similar conditions. Aspects of behaviour considered included agonistic behaviour and responses to unfamiliar environments and objects. There were many similarities between the feral and domestic fowl in behaviour, but there were also many differences between the strains. Feral cockerels showed higher levels of agonistic behaviour than domestic cockerels, under some conditions. There were differences between young feral and Leghorn-cross chickens in the “freezing” response to handling and placement in an unfamiliar cage, with the feral chickens responding more rapidly. Feral cockerels showed a greater initial avoidance of a novel object than did Black Australorp bantam cockerels, but after a short interval they spent more time near the novel object than the bantams. These results are discussed in relation to selection pressures under conditions of domestication, and on North-West Island.

The presence of radioactivity in coronary arterial thrombi was studied at necropsy by autoradiography in 12 patients with acute myocardial infarction. Seven patients had been given 125I-and five patients 131I-labeled fibrinogen. With a short interval (less than 10 hours) between onset of symptoms and injection of fibrinogen the entire thrombus was radioactive in four of five patients, whereas with longer time intervals only parts or none of the thrombus contained detectable radioactivity. The findings give further evidence that thrombus formation in acute myocardial infarction probably is a slow process and that the major part of the thrombus may form after the onset of necrosis.

— The validity and efficacy of the prognosis equation published by Saunders (1984b) is tested against previously reported longitudinal data. In a fair and random sample and over a short interval, nearly 60% of the sample was found to have a prediction error of less than 0.25 DS and, in 92%, the error involved was less than 0.5 DS. Long-term prediction was found to have a less favourable outcome but 50% were correct within an error of 0.5 DS and 90% were found to have a prediction error of less than 1 DS. The largest prediction errors occur in the medium to high myopes whose myopia progresses rapidly.

Seven patients had bilateral intraocular lens implantation performed with a short interval between procedures, using intraocular lenses of unproven design or deficient quality control All seven patients suffered severe visual impairment, some to the level of legal blindness in both eyes. Lenses with unproven design characteristics should never be implanted in both eyes of a patients. The interval between the first and second procedure, even when using lenses of proven design and quality, should be long enough to insure the long-term successful outcome of the first procedure.

Let Ψ(x, y) denote the number of positive integers ≦ x and free of prime factors > y. De Bruijn showed that the relation Ψ(x, x 1 u ) ∼ xϱ(u) holds, as x → ∞, uniformly in the range 1 ≦ u ≦ ( log x) 3 8 − ϵ . We extend this range to 1 ≦ u ≦ log x ( log log x) 5 3 + ϵ , and give a similar, but weaker estimate for the range 1 ≦ u ≦ log x (1 + ϵ) log log x . We also prove a short interval result.

Summary A battery of time perception tests evaluating the areas of filled time estimation, empty time estimation, time in abstract reasoning and short interval comparisons was administered to 30 alcoholic inpatients, 24 general psychiatric inpatients, and 17 normal controls. The tests of abstract reasoning and estimates of unfilled intervals discriminated between the alcoholic and general psychiatric group on the one hand, and the controls on the other. No significant differences between alcoholic and general psychiatric patients were found.

Quantitative changes of pituitary basophils were investigated by the method of Chalkley, together with radioimmunoassays of serum TSH, LH and FSH concentrations, in rats during the short interval after thyroidectomy (TX)(3, 6, 12 hr, 1, 3, 5 and 7 days). The irregularly shaped or elongated II-type cells (classical thyrotrophs), which are stained intensively with thionin, immediately decrease in number below the normal value (2.7±0.7%), to 0.6±0.2% at 12 hr and 0.3±0.1% at 7 days. The intermediate cells (II/III-type cells) can be easily distinguished, by their staining properties and shape, from the II-type cells and III-type cells (classical LH-gonadotrophs) during this time interval. The II/III-type cells are enlarged polygonal cells whose central area stains with PAS and whose peripheral area shows an affinity for thionin. They gradually increase in number after the first day. The total number of all kinds of the PAS-positive cells tends to rapidly increase after TX and reaches the highest value (12.3±0.8%) after as early as 12 hr. They are distinguishable as oval III-type cells stained violet and large spherical or polygonal IV-type cells stained red. However, the values returns to normal (9.7±0.5%) by 7 days. The total of all kinds of basophils (II-, II/III-, III-, III/IV- and IV-type cells), however, is not altered but remain balanced through the entire time. Serum TSH concentrations rise at 3 hr and fall thereafter, but rise again at 5 days (230.5±16.7ng/ml), the latter being equivalent to twice the normal value (122.5±8.7ng/ml). Serum FSH concentrations tend to be slightly reduced, but not profoundly, through the entire time course after TX. Serum LH concentrations quickly and conspicuously 4crease after the operation, reaching the lowest value (0.18±0.06ng/ml), equivalent to approximately 1/4 of the normal value (1.42±0.12ng/ml), within one day. It has been corroborated by the present results of cell counts and radioimmunoassays that, following TX, the II-type cells may transform morphokinetically into the III- and IV-type cells, supporting a working hypothesis as to the secretory cycle of the basophil proposed by Yoshimura et al.(1977).

Gossypium hirsutum L. cv. Lankart plants exhibited three different types of independent short interval leaf movements which were superimposed on the circadian movements. The different types were termed SIRV (short interval rhythmical vertical), SIHM (short interval horizontal movements), and SHAKE (short stroked SIRV). The 36-minute period SIRV movements occurred at higher moisture levels. The 176-minute period SIHM occurred at lower moisture levels and ceased as the stress increased. The SHAKE movements were initiated with further stresses. The SLEEP (circadian, diurnal) movements ceased with further stress. The last to cease just prior to permanent wilting were the SHAKE movements.

Different protocols based on the priming principle have been proposed so as to enable rapid tracheal intubation with vecuronium. The conditions of such an intubation have been assessed in 47 ASA I or ASA II patients, with an empty stomach, using a priming dose of 0.01 mg · kg−1, followed by a second injection of 0.1 mg · kg−1 after a short interval of 4 min. An intubation score was defined using a nerve stimulator (Relaxograph Datex), by measuring the twitch in comparison with a reference value, as well as time before intubation for four groups of patients. Good intubation scores with a twitch approaching 50 % was obtained in all and, in the same way, for a fifth group of patients, intubated in an arbitrary manner 60 s after the second dose of vecuronium. These results can be compared with those obtained by other authors using a different protocol. Nevertheless, this method does not match perfectly that of suxamethonium. Taking into account the side-effects and above all the inhalation risk existing after a priming dose, is it opportune to use this technique for the anaesthesia of a patient with a full stomach ?

Two experiments were conducted to examine the relationship between baseline response rate and the effects of omission training and extinction training in pigeons. Exp. 1 employed four omission-training groups, differentiated by the values of the reinforcement-reinforcement and/or response-reinforcement intervals, and an extinction-training group while Exp. 2 used two omission-training groups and an extinction-training group. Results indicated that baseline response rate was not related to the differential effects of omission training and extinction training and that omission-training groups with relatively short interval values reduced responding significantly faster than did extinction-training groups.

Two refrigerated (0 to −1°C) vans containing polyvinyl chloride film (PVC) wrapped OI vacuum packaged (VP) beef cuts were monitored from Richmond, Calif. to Honolulu, Hawaii. One van had a normal (ambient air) atmosphere; the other van had a modified (60% CO2, 25% O2, 15% N2) atmosphere. Neither packaging system nor van atmosphere affected (P 0.05) in appearance traits to PVC cuts in 6 of 10 comparisons of cuts in normal atmosphere vans and in only 1 of 10 comparisons of cuts in modified atmosphere vans. Use of a modified atmosphere decreased (P > 0.05) microbial growth on cuts shipped and/or stored for 7–9 days. Neither packaging method nor van atmosphere affected (P 0.05) to those wrapped with PVC film in: freedom from surface discoloration (5–9 days), overall appearance (5–9 days), bacterial counts (7–9 days), and trim losses (7–9 days). Vacuum packaged cuts which were leakers (no terminal vacuum) did not differ from those wrapped with PVC film in any appearance trait (5–9 days) but sustained increased (P >0.05) purge loss after 5–6 days of transit-storage. Short interval (5–6 days) transoceanic beef shipments can be consummated with acceptable product condition in normal atmosphere vans and wrapped in PVC film; if longer transit-storage periods (7–9 days) prior to cutting are anticipated, cuts should either be vacuum packaged or wrapped with PVC film and shipped in modified atmosphere vans.

Rats were given intermittent electric foot-shock during food-rewarded alley training. In the test phase, food and shock were given on every trial. These animals persisted in running down the alley in the test phase compared to those without prior shock experience. The effects of chlordiazepoxide (CDP) on this learned resistance to punishment were examined using a long and short interval between trials. It was found that CDP abolished the effect at a long inter-trial interval, but left it unaltered if the interval was short. The results match those found previously with an analogous effect using non-reward. It is suggested that the effects of punishment and non-reward may be mediated by a common process, and that the benzodiazepines may act on this process. This paper is dedicated to Neal E. Miller.

For many physical experiments carried out with nuclear reactors, the decisive factor is not the average output delivered over a long period of time, but rather the peak output delivered over a short period of time as required by the experiment. In such cases it appears to be most advantageous to have pulsed cycle operation of the nuclear reactor, i.e., a cycle during which the reactor output increases manyfold during a short interval of time. The advantage of work in a pulsed cycle is most apparent for a fast reactor since the lifetime of neutrons is a minimum in such a reactor in comparison with other types. This paper presents expressions for the duration of output pulses in a fast reactor, and expressions describing the time dependence of the output pulses. There are also described the possible characteristics of a pulsed fast reactor which could be used for carrying out investigations in nuclear physics.

Twenty potted plants each of Donner variety were transfered from the open to a greenhouse, in which minimum temperature was maintained higher than 10°C, at two weeks intervals from September 28 to February 2. One half of each group was kept under natural day length, while another half was exposed to longday (16 hours), and their subsequent vegetative and flowering behaviors were recorded.Petiole length and leaf area of new leaves and flower cluster length were reduced as the transfer was delayed until November 23, and thereafter, they were increased as it was delayed. This result showed that dormancy in Donner variety was deepest in late November, and was broken gradually by chilling temperature during winter in this experimental condition.Vegetative growth of the plants exposed to long day was better than that of the corresponding plants grown under natural day length (short day). The promoting effect of long day was least in the plants transfered in late November, and was significant in the plants in non-dormant condition.Runner was not formed in the plants transfered earlier than January 18 under natural day length, and earlier than January 4 under long day condition. It seemed that the plants could not form runners until their dormancy was nearly broken.A flowering period of about 60 days was followed by a second flowering period with a short interval of few flowerings in the plants under natural day length. Under long day condition, the second flowering period was observed in the plants exclusively transfered from October 26 to January 4 while it was not found in the plants transfered earlier or later than the above mentioned period. This result suggested that the plants in deep dormancy could form flower buds even under the long day condition which was known to be unfavorable to the flower bud formation.Proper time of covering plants with plastic film was discussed in relation to the forcing of Donner variety.

In numerous applications it is necessary to observe a target in flight by radar for a short interval and compute its origin or destination. The present-day techniques are mostly dependent on observation of two close points on the trajectory and the transit time of the target between the two points. A new method has been evolved to give a solution from any single point on a part of the trajectory seen by an autofollow radar and is under investigation.

At College (Fairbanks), Alaska, simple magnetic disturbances of negative bay type are closely related to a sequence of change in the type of auroral activity. General features of the relationship indicate that auroral forms are not independent of the electromotive force responsible for the intense auroral-zone currents. Following the major −ΔH disturbance, a short interval of +ΔH disturbance is observed; this cannot be explained by the existing idealized current-systems for the auroral zone.

Transient solutions of the Navier Stokes flow equations for Newtonian liquids are described for the escape of the suspending fluid trapped between two drops when a head-on collision is effected. The equations enable the effects of interfacial mobility, the rate of disc expansion, the force of impact, and both physical and interfacial property variables to be determined. Analysis of the results of Part I shows that the probability of drop coalescence per collision depends on the amount of film thinning accomplished within the time span of the contact. Complete mobility of the interfaces is essential to accomplish sufficient thinning in this short interval if coalescence is to occur.

Fourteen patients have been treated with triazol and eleven with cardiazol over a concurrent period of eight months, this system enabling a close, “day-to-day” comparison of the action of the drugs to be drawn. One patient has been given 30 fits with cardiazol, followed, after a short interval, by 24 fits with triazol, and a comparison is made between the action of the two drugs on the same patient. In three cases in the triazol series cardiac complications were encountered. In one case these were not altogether unexpected, as the patient had been confined to bed for a long time, and had been tube-fed over a period of three years and eight months. The other two had apparently healthy myocardia prior to treatment (electrocardiograms were not taken). It is suggested that triazol imposes a greater and more prolonged strain on the heart-muscle than does cardiazol. In spite of this we have come to prefer the use of azoman for most cases, and find ourselves in entire agreement with the claim of Walk and Mayer-Gross that it possesses several practical advantages over cardiazol as a convulsive agent. Certain beneficial effects, short of complete recovery, which are likely to result from convulsion therapy generally are discussed. Minor details of technique are referred to.

The measurement of the pressure produced in the “explosion-wave” in gaseous mixtures is difficult because of the rapidity of movement of the wave and the short time for which the pressure over any given area lasts. In 1894 Dixon and Cain pointed out that the pressures obtained by firing a mixture in a closed vessel did not correspond to pressures in the wave front. Following a suggestion of Mallard and Le Chatelier, they used a method in which glass tubes of known strength were fractured by the explosion-wave, it being assumed that “if a pressure is produced in a glass tube greater than it can stand, the glass will be broken although the pressure may only last for a very short interval of time.” The strength of the glass tubes was found by determining the static pressures required to break similar pieces. It was found that three lengths from the same piece of glass tubing required respectively 890, 950 and 1220 lbs. per square inch to fracture them: the accuracy of the results was therefore not very great. Dixon and Cain estimated that the pressure in the explosion-wave in C 2 N 2 + O 2 lay, probably, between 70 and 120 atmospheres and that in C 2 N 2 O + 2N 2 between 63 and 84 atmospheres. Jones and Bower cast some doubt on the pressures given by Dixon and Cain, and suggested that they were the pressures produced just after detonation had been re-established when the explosion-wave had been damped down at a junction. The pressure in the wave front of the fully established detonation wave in the mixture C 2 N 2 + O 2 was estimated by Jones and Bower to lie between 58 and 75 atmospheres.

1. Japan is a rainy country, not infrequently visited by heavy rainfalls. “Syuchugo-u” is rather a new word in Japanese with a special nuance which means rainfall characterized by its tremendous amount concentrated within a narrow limited area in a short interval of time. Such a sort of rainfall is liable to cause a terrible damage for human living and activities, hence this subject becomes one of the most urgent problem in the field of applied meteorology and climatology in Japan. In the previous studies (1967, 1968, 1970), the present author made clear the distribution and secular change of heavy rainfalls for the sixty years up to 1960. Before a full discussion in this paper, an exact definition of heavy rainfall is indispensable. In the first paper (1967), the writer adopted the occurrence number of heavy rainfalls whose daily amount exceeded 10% of the annual totals in the respective years. However, someone suggested him that this definition is too severe for the practical purposes and then it was altered to 5% of annual totals in the second paper. Notwithstanding, 5% is adequate in a case while in others 10% is more preferable according to circumstances and the . standard limit is by no means unique according to the purpose and aim of the study. For this reason, both are used in this paper as occasion demands and, for distinguishing them, those exceeding 5% of annual totals are called “heavy rainfall” and the others “extraordinarily rainfall”. At many places in Japan, the latter commonly occurred once in about twenty years while former was experienced once in about three to four years. 2. Heavy rainfall is most frequent in typhoon and Bai-u or the rainy season in early summer in Japan. For the determination of these two types, the following method is used. Taking the twenty years' record of monthly and daily rainfalls, number of heavy rainfalls that occurred in the earlier summer from May to July (A) and those from August to October (B) are reckoned. If (A) is significantly larger than (B), it is called Bai-u or earlier summer type and typhoon season or later summer type for the reversed case. A method of significant test at 20% level is applied for this judgement. For example, if (A) and (B) are 18 and 2 respectively among 20 occurrences, the difference is distinctly significant at 20% level. Generally the following frequency k is necessary for total number n to discern the significant difference between them at 20% level. _??_ When a difference between (A) and (B) is small, it is commonly insignificant and included in the mixed type. Fig. 1 shows the distribution pattern of these types. In entire Japan, the Baiuperiod type heavy rainfall spreads continuously in the western and northern part of Kyusyf and in western Chyugoku and also is scattered in limited areas in Hokuriku and Tosan (inland mountainous region from Gifu to Nagano Prefecture), while the typhoon period type develops in far wider regions. 3. Secular change of extraordinarily heavy rainfalls for the period of seventy years from 1901 to 1970 is examined. For this purpose the entire period is divided into seven equal intervals of ten years. In the next step, total sum of extraordinarily heavy rainfalls occurring at forty-one places in Japan are calculated as shown by the following series: _??_ For this time series, the secular trend is expressed by the trend index devised by E. Suzuki (1968).

1. The reaction time of Mya to light is composed of two parts. The first, a sensitization period, is an exceedingly short interval of the order of magnitude associated with photographic processes. The second is a latent period of about 1.3 seconds, during which Mya need not remain exposed to the stimulating light. 2. The process of dark adaptation in Mya is orderly. Its progress may be represented by the formation of a photosensitive substance according to the dynamics of a bimolecular reaction. See PDF for Structure 3. Photosensory equilibrium as represented by the light- and dark-adapted conditions finds a rational explanation in terms of the "stationary state" of a reversible photochemical reaction involving a photosensitive substance and its two precursors. 4. There are two corollaries to this hypothesis. The first requires that the reaction time at sensory equilibrium for a given intensity should vary inversely with the temperature; the second, that the rate of dark adaptation should vary directly with the temperature. Experiments verified both of these requirements.

1. Unfertilized Arbacia eggs, subjected to 50, 60, or 80 per cent sea water, at the same temperature, pH, and duration, swelled progressively faster with age. Swelling increased 12.2 to 39.6 per cent. 2. Permeability to water was calculated by the method of Lucké and McCutcheon. For freshly shed eggs from nine different females, permeability varied from 0.078 to 0.124, or 59 per cent. This variation was not due to differences in age nor to physiologic condition but was correlated with size of eggs. 3. About twenty eggs were tested each age to 60 hours after shedding. The permeability rate increased with age in all nine experiments. 4. The total increase ranged from 30 to 69 per cent. 5. The increase was slow but constant or almost constant during early and intermediate ages. 6. The increase began at earliest ages. 7. An increase may not be demonstrable for any short interval but is readily demonstrable for longer intervals (6 or more hours), or, from the entire curve. 8. Permeability increased faster at late ages. For special factors during late ages see text. 9. Injury by experimental procedure was not induced until ca. the 24th hour. Injury by aging was not detectable during the first 6 to 9 hours. It increased progressively between 10 and 24 hours, and very rapidly thereafter. Permeability increased at approximately the same rate during early and intermediate ages. Permeability therefore was not correlated with degree of injury. 10. The troublesome factor in the permeability equation was initial size, or Vo. Several methods were used to obtain this Vo, viz. (a) extrapolations approximating known cyclical change in size, (b) extrapolations approximating control sizes, (c) constant or average of all Vo's, (d) maximum Vo approximating control Vo's. Recalculation with these different Vo's gave approximately the same permeabilities. 11. The increase in permeability with age was substantially the same whether "approved," or other possible rates or average rates or range of rates be used as criteria of change. 12. When the data were recalculated by integrating the equation of Northrop, the increases in permeability with age were essentially the same as the increases calculated by the graphic method of Lucké.

Summary Thirteen Holstein cows at various stages of lactation and levels of production were milked at 2-hr. intervals with the aid of oxytocin. It was shown that the average daily milk production was increased and that the fat per cent in milk was reduced for the high producers (average daily production: 60.6 lb. milk) during the 2-hr. milking. Following return to twice-a-day milking, the milk production returned to normal, but there was an over-compensatory increase in fat per cent. The moderate producers among the cows (average daily production 39–43 lb. milk) did not show any significant changes in milk production, fat production, or fat per cent. It is concluded that the rate of milk secretion is not altered significantly for moderate producers on changing from twice-daily milking to 2-hr. milking for short total periods. The response of the high producers is explained on the basis of the effects of intramammary pressure on fat uptake by the mammary gland and on the rate of milk secretion.

1. Cercaria hamata swims intermittently. A short, rapid swim alternates with a relatively long period of quiet sinking.2. The duration of the period of sinking decreases with rise in temperature. Below 15° C. the cercariae exhibit jerking and lashing movements in place of swimming.3. Shadowing a dense group of cercariae results instantly in the almost simultaneous swimming of most of them. The response is partly due to the shadow stimulus and partly to the mechanical stimulus occasioned by the colliding of active individuals with quiet ones.4. Repeated shadowing at short intervals results in inhibition of swimming.5. Mechanical stimulation by touch (or a stream of water) initiates swimming instantaneously. Only a very short interval between stimuli is necessary to keep a cercaria in almost continuous locomotion. This indicates that a dual mechanism is involved in response to shadowing and to touch.6. The duration of swim in response to shadow, touch, and stimulation by a stream of water is significantly gre...

Summary In a material consisting of 167 cases of skin tuberculosis, where tuberculous disease has appeared prior to the first skin symptoms, about one-third showed a time interval between first tuberculous disease and skin tuberculosis of 5 years or less, whereas the interval was 26 years or more in one-fifth of the cases. A short interval was a little more frequent in those who had their first tuberculous disease at the age of 20 or later than among those who had it at an earlier age. These findings indicate that skin tuberculosis in the majority of cases is diagnosed considerably later after primary infection than pulmonary tuberculosis, and seems to be about in the same position with regard to the time interval as renal tuberculosis, whereas tuberculosis of the suprarenal glands mostly appears still later. Also in those cases of renal, suprarenal and cutaneous tuberculosis which are diagnosed many years after primary infection, the lesions may possibly derive from tubercle bacilli which have reached the kidneys, suprarenal glands and skin already in the first years after primary infection, through haematogenous dissemination, but which have for years not given rise to clinically detectable disease.

Although lightning flashes have been photographed which apparently have up to 40 or more component strokes, no flashes having more than 14 strokes have been observed on records of the eletrical fields of thunderstorms. The apparent discrepancy between the two methods of observation is explained by the fact that small momentary increases in the continuing current flowing to ground after some strokes, are easily mistaken for component strokes on photographs taken with slow cameras.

The following work was undertaken in connexion with a device for counting blood cells electronically, which has been developed in the Clinical Pathology Department of the Radcliffe Infirmary with financial assistance from the Medical Research Council and the Nuffield Foundation. Although the results will apply to other types of counter, it will help to fix the ideas if we consider the problem for this specific device. A large number of blood cells, contained in a shallow chamber, are scanned by a photoelectric cell. The depth of the chamber and the concentration of blood cells in solution therein allow blood cells (supposed distributed at random throughout the chamber) to overlap when viewed from above by the scanner. The field of view of the scanner at any instant is somewhat larger than the size of a blood cell, but is, nevertheless, of much the same order of magnitude. With passage of time the chamber moves underneath the photocell so that the field of view traces out a long narrow path not crossing or overlapping itself and only embracing a portion of. the whole chamber. The blood cells have no motion relative to the chamber. As each blood cell comes under the photocell it produces an electrical impulse, whose duration depends upon the size and shape and orientation of the blood cell. These impulses go to a counter, which counts them except that it will not count any impulse which is overlapped by a previous impulse. The problem is to determine the number of blood cells in the chamber from a knowledge of the recorded count and the distribution of the lengths of individual impulses. A further complication arises because it is inadvisable to count two impulses separated only by a very short interval of time, and therefore the counter itself generates some self-paralysing impulses additional to the blood-cell impulses and in a manner which is correlated with them. Until § 3, however, we shall neglect paralysis, because a proper understanding of its effects cannot be reached unless we first know how the system behaves in the absence of paralysis.

Inomata (6) has proved that the time errors in the estimation of visual length and in that of auditory intensity appeared different, and proposed a hypothesis that this might be explained by the difference of “the mode of phrasing” The purpose of our present investigation is to test this idea in a different kind of comparison, i.e. the estimation of time-duration. At first, we compared two durations which were represented by the whole space lighted (Gs:Gs) or sounded (Gh:Gh) by means of five small electric lamps or four buzzers which were placed unseen far from Os.. The durations were three in kind: short (1sec.), middle (3sec.) & long (6sec.); the intervals were two: short (1sec.) & long (3sec.). In the visual experiment (see Table 1), the time errors were negative, except in the short duration of the short interval, and in the auditory experiment (see Table 3), the time errors were negative solely in two long duration values. Next, we placed one light (a circle of 2cm in diameter) (Ks:Ks) orone buzzer 120cm before Os. (Ks:Ks). The results (see Table 1, 3) were similar to those of the first experiment. Only the absolute values were here somewhat higher.The positive values in these results may be explained by the hypothesis proposed by Inomata, that they appear inthe cases where the stimulus constellations are easy to fuse in a single “phrasing”. For, firstly, any stimulus given ina short duration may fuse easier in one Gestalt, and secondly, the visual stimuli are more independent and more difficult to fuse each other than the auditory ones.In the other experiment, i.e. whole space vs. part space (Gs:Ks, Gh:Kh; see Table 9, 10); strong part stimulus vs. weak part stimulus (see Table 12, 14), the results were similar to those of the foregoing experiments, and may be explained by the same hypothesis of “the mode of phrasing”.Then, we reversed the stimulus-interval relationship of the first “whole space experiment”; in other words, the vacant time durations were compared (see Table 5, 7). The results were different, especially in the visual experiment, where all values were proved to be positive. This means, perhaps, that the vacant times were perceived as accessory components of one larger time Gestalt, and furthermore, that the first stimuli were overestimated. It is noticeable, however, that in this experiment some Os. gave results similar to those in the first experiment, when they were expressly required to observe the vacant intervals as “figures”.Now, we turn to the effects caused by the difference of two stimuli as the “carriers” of the time durations compared. As mentioned above we compared the whole space stimulus with the part space stimuius. In the auditory experiment (see Table 19), it seems that there are no meaningful effects of the different stimuli, while in the visual experiment (see Table 16), it is manifest that the small stimuli are more greatly overestimated. This may be explained by its high “figuredness.” In the results of the other experiments concerning the difference of the intensity of stimuli (ca. 1:3), we find a paradoxical result, that in the visual experiment (see Table 17), there appears an effect of overestimation of the strong stimuli, while in the auditory experiment (see Table 21), an antagonistic effect of overestimation of the weak stimuli. It is probable that the strong visual stimuli carry higher figuredness, and the weak auditory stimuli likewise. But this is of course a mere hypothesis which must be proved by further investigation.

Analogs of models of duration discrimination are here related to the timing of discrete motor responses. The measure of interest is the variability in duration of intervals collected in short interval reproduction tasks. For data from a Morse key-tapping task, it is shown that, taken separately, neither of the models described can completely account for the relation between the mean and the variance of the interresponse intervals.

The degree of precision to be expected in judgments of glare discomfort has been investigated using a method of pair-comparisons. Previous work indicated that on nineteen occasions out of twenty, any one observer would judge the glare from an installation within 3 units of his mean judgment on the Glare Index scale. This has been confirmed by the present study, in the sense that with the same order of probability he would distinguish correctly the more (or less) glaring of two installations seen one after the other within a short interval of time, when the glare difference is of the order of 3 units on the Glare Index scale. The threshold glare difference, below which the correct choice of the more glaring installation is obtained only by chance, appears to be approximately an interval of 1 unit on the Glare Index scale.

When an afferent nerve is stimulated by two similar break-shocks at a sufficiently short interval, it has been found that the ensuing reflex response is no greater than the response to a single break-shock. The shortest interval at which the second stimulus produces an additional response has been called “the least interval for muscular summation” (Adrian and Olmsted, 1922). Different observes have found fairly comparable values for this interval in the mammalian preparation: 0·75 σ to 1·31 σ (Sherrington and Sowton, 1915); 1·2 σ to 2·4 σ (Adrian and olmsted, 1922); 1·0 σ to 2·4 σ (Forbes, Querido, Whitaker and Hurxthal, 1928). It was at first thought that the ineffectiveness of the second stimulus at intervals less that “the least interval” was due to a refractory period of the central part of the reflex arc; consequently the “least interval” was used as a measure of the duration of the absolutely refractory period of the reflex arc. Forbes (1922), however, pointed out that the duration of the “least interval” was similar to the duration of the absolutely refractory period of the afferent nerve ( cf . Sherrington, 1921, p. 257), and concluded that the ineffectiveness of the second stimulus was probably due to its inability to set up centripetal impulses in the afferent nerve, and not to a blocking of such impulses by a refractory period in some part of the central reflex pathway. Later (1928) Forbes and his co-workers suggested that the reflex response added by the second centripetal volley, when it followed the first at very short intervals, might not be due to a second discharge of those motoneourones which had already responded to the first volley. Other motoneurones might be excited by summation of the central effects of the two centripetal volleys. If that were so, “the least interval for muscular summation” would have no relation to the refractory period of the reflex pathway.

The increase in frequency of occurrence of earthquakes with decreasing magnitude is well known. In a few cases observations have shown that this relation holds for extremely small events, including those with magnitudes well below zero, and that the energy of the smaller shocks is confined largely to the higher seismic frequencies. These facts suggest that portable seismographs with ultra-high sensitivity might record a sufficient number of nearby microearthquakes in a short interval of time, say one day, so that some measure of the seismic activity of a very local area might be obtained very quickly. This idea was tested in west central Nevada where ten sites were occupied for short intervals of time. Microearthquakes were recorded at rates ranging from several per day to over two hundred per day. Generally, consistently high microseismicity was observed in areas of recent faulting. A lower level of activity, well above that of aseismic areas however, was observed at other sites in Nevada. Some indication of variation of microearthquake activity with time was obtained. Activity averaged over an interval of about ten hours usually differed by less than a factor of two from the overall mean for that site. In one case, however, swarms of events persisting for a total interval of a little more than one day were observed. The method appears very promising as a technique for monitoring current tectonic activity.

Experiments in mice on the fraction of haemopoietic stem cells in S-phase after irradiation indicated that a large fraction of the cells resting in G0 will enter S-phase after a very short interval of time. After excluding alternative explanations it must be concluded that cells in G0 have completed all preparations for going into S-phase or, in other words, that the localization of these G0 cells in relation to other phases of the cell cycle must be between G1 and S-phase.

A suite of samples of stony meteorites with a spread in Rb 87 Sr 86 ratios from about 0.02 to 3.0 has been analysed for Rb and Sr contents and Sr isotopic compositions. These whole-meteorite analyses all coincide within experimental error with a single isochron. The slope of this isochron yields an age of (4.52 ± 0.12) × 109yr using a decay constant of 1.39 × 10−11yr−1forRb87. The meteorites that form the isochron are all observed falls, and consequently are comparatively fresh (unweathered) samples. Each point on the isochron represents several analyses. On the same basis, the intercept of the isochron yields an initial Sr 87 Sr 86 ratio of 0.698 ± 0.001. This value is based on a normalization to 0.1194 of the meteoritic Sr 86 Sr 88 ratio, and is relative to a value of 0.7085 for the Sr 87 Sr 86 ratio in a standard sample of SrCO3 (Eimer and Amend, lot No. 492327) which was analysed alternately and repeatedly with the meteorite Sr samples during this investigation. It is inferred from this investigation that the source materials of the stony meteorites contained Sr whose Sr 87 Sr 86 ratio was 0.698, and that this source material was chemically differentiated into a variety of Rb-Sr systems. The close fit of the samples to a single isochron indicates that this chemical differentiation must have occurred within a relatively short interval of time, and that the individual meteorites are samples of systems that have remained closed ever since. This investigation favors a decay constant of about 1.38 × 10−11yr−1forRb87, in so far as this value is required to make the Rb-Sr age of the meteorites coincide with Patterson's (1956) Pb-isotope age for the meteorites and Earth of 4.55 × 109 years.

The latest and best determination of the quantitative relation of the two chief phases of heat production in frog's nerve is that of Bronk (1931) who found the average ratio of total to initial heat to be 11. More recently Hill (1932) has given reason to believe that even Bronk's ratio is probably too low, and in the same paper (p. 148) has suggested an alternative method of estimating it based on the principle of the steady state. the present work arose from this suggestion and has led to the discovery of the profound effect of steady activity on the “efficiency” of the recovery process. The steady state of nerve activity during continual stimulation has been discussed in a preceding paper. Its nature is such that the rate of recovery heat production at any moment corresponds to the rate of initial heat production at that moment. the total heat rate can easily be measured. The initial heat rate can be determined by omitting the stimulus for a short interval, when an analysis of the resulting defection allows an estimate of the heat which immediately drops out as a result of omitting the stimulus, i. e ., of the initial heat.

DAILY trap-nesting of fowls is one of the most costly operations of a poultry breeding plant. Any reduction in the labor required in obtaining trap-nest records would obviously reduce the costs of operation. Many short-cut methods for obtaining satisfactory egg records of hens have been proposed and a complete review of the literature was given by Olsen (1939). In his article he suggested the possibility of one-day-a-week trap-nesting of fowls. His statistical analysis shows that the individual error for some hens, if trap-nested only one day a week, would be large. When the individual error is large, accurate comparisons of families could not be made, and progeny testing would not be valid. This study, comparing the accuracy of one, two, three, four, five, and six day-a-week trap-nesting, and trap-nesting six consecutive days every other week, should aid the poultry breeder in finding a shortcut method of obtaining satisfactory information regarding . . .

Le Magnen (1959) reported evidence that eating is a response to an anticipated rather than existing nutritional deficit. However, it is the contention of this paper that the evidence was based upon a statistical artifact. The purpose of the present experiment was to obtain the anticipatory effect using a modified procedure. In both Le Magnen's experiment and the present one, one meal preceded a long interval and followed a short interval while the other meal preceded a short interval and followed a long interval. Insofar as eating is anticipatory, more should be eaten at the meal which precedes the long interval than at the meal that precedes the short one. If eating is a response to an existing deficit, then more should be eaten at the meal that precedes the short interval because this meal also follows the long intermeal interval. There was no systematic relationship between the length of the intermeal interval (either preceding or following a meal) and the amount consumed.

The extent to which exchange and reutilization processes of mineral tracers affect skeletal mineral accretion and resorption measurements was evaluated by comparing the rates of appearance and disappearance of85Sr and14C-proline-hydroxyproline in bones and teeth in growing rats for 12 days following simultaneous parenteral injection of these tracers. Expressions for the relative rates of collagen synthesis and breakdown, which unlike mineral metabolism are considered not to be complicated by exchange phenomena, were based on14C-proline conversion to14C-hydroxyproline; the specific activity of the latter was determined. Both the mineral and the collagen specific activities reflected the rates and patterns of growth of the samples assayed; rapid growth and a short interval of time between formation and resorption of tissue in themetaphyseal bone which contains the cartilagineous growth plate, slow growth and an interval of time between formation and resorption of tissue indiaphyseal bone and incisor teeth which is longer than the 12 days of the experiment. However, in metaphyseal bone the specific activity collagen/mineral ratio dropped by one half during the 4–12 day interval in contrast to diaphyseal bone and incisor teeth in which no change in this ratio was observed during this period of time. The data indicate that collagen in the metaphyseal growth zone is removed by resorption before it has become fully mineralized, and that exchange is a relatively unimportant factor in the long term kinetics of bone mineral.

Relating of air pollution concentrations to effects on agriculture is hampered by deficiencies in present methods of atmospheric analysis and by inadequate knowledge about how various factors modify the effects. Analytical methods frequently lack sufficient sensitivity or specificity to determine accurately the substances involved. Typical examples include the difficulty of distinguishing among fluoride compounds with loidely differing phytotoxic activity, the serious interference from concomitant air pollutants with the usual methods of determining ozone, and the common failure or inability to detect short interval concentration extremes which may cause acute injury. The interrelationship of pollutant concentration and length of exposure in determining plant injury is poorly understood, as are the modifying effects of environmental conditions and age of tissue. The identity of some of the phytotoxic components of the urban photochemical pollution complex is still uncertain, making it difficult to select ...