Evidence for magnetospheric effects on the sodium atmosphere of mercury

Monochromatic images of Mercury at the sodium D(2) emission line showed excess sodium emission in localized regions at high northern and southern latitudes and day-to-day global variations in the distribution of sodium emission. These phenomena support the suggestion that magnetospheric effects could be the cause. Sputtering of surface minerals could produce sodium vapor in polar regions during magnetic substorms, when magnetospheric ions directly impact the surface. Another important process may be the transport of sodium ions along magnetic field lines toward polar regions, where they impact directly on the surface of Mercury and are neutralized to regenerate neutral sodium atoms. Day-to-day variations in planetary sodium distributions could result from changing solar activity, which can change the magnetosphere in time scales of a few hours. Observations of the sodium exosphere may provide a tool for remote monitoring of the magnetosphere of Mercury.     

Reticular stimulation and chlorpromazine: an animal model for schizophrenic overarousal

It has been postulated that certain schizophrenic patients are in a state of continual central excitation and that improvement in these patients after treatment with chlorpromazine is a result of the action of the drug in reducing this excitation. A model was developed to test this postulated state of central excitation. Rats were electrically stimulated in the mesencephalic reticular formation while performing a simple attention task. Stimulation or treatment with chlorpromazine impaired the performance of the animals; however, the two treatments together resulted in performance indistinguishable from that seen after injections of saline alone.     

Retrograde amnesia gradients: effects of direct cortical stimulation

Electrical stimulation was delivered bilaterally to either the anterior or posterior cortex in rats from 0.1 second to 4 hours after a single training trial on an inhibitory avoidance task. As indicated by a retention test given 24 hours later, the length of the retrograde amnesia gradients ranged from 5 seconds to 240 minutes, depending on the brain region stimulated and the intensity of the stimulating current. The stimulation intensity that was threshold for amnesia varied directly with the length of the interval between training and treatment.     

Lateral hypothalamic stimulation: inhibition of aversive effects by feeding, drinking, and gnawing

The opportunity to engage in feeding, drinking, and gnawing behavior facilitated by localized hypothalamic stimulation can delay the onset of the aversive effects of the stimulation and may completely suppress them. This suggests that the aversive effects of the stimulation are due to the excessive of the stimulation are due to the exessive arousal of a drive.     

Helpers: effects of experimental removal on reproductive success

Experimental removal of helpers from a communal bird population decreased the reproductive success of the reduced units. By controlling for variables that are potentially correlated with both reproductive success and unit size, this experiment establishes that helpers-contribute significantly to their indirect fitness.     

Microwave hearing: evidence for thermoacoustic auditory stimulation by pulsed microwaves

Acoustic transients can be thermally generated in water by pulsed microwave energy. The peak pressure level of these transients, measured within the audible frequency band as a function of the microwave pulse parameters, is adequate to explain the "clicks" heard by people exposed to microwave radiation.     

Navigation of single homing pigeons: airplane observations by radio tracking

Navigation of homing pigeons was investigated by tracking their homeward flights from a light airplane. Released on successive days from a single training point 35 miles (56 kilometers) from home, individual pigeons, each carrying a transmitter, were repeatedly tracked back to theirloft. No two tracks covered the same ground for even short distances, yet all tracks were within 10 miles of a straight line. Results from further releases north and south of the training point suggest that pigeons often use three methods in sequence to find home: compass orientation, bi-coordinate navigation, and orientation by familiar landmarks.     

Particle capture by a pacific brittle star: experimental test of the aerosol suspension feeding model

Ophiopholis aculeata, a suspension feeding brittle star, is capable of removing artificial particles from seawater by some mechanism or mechanisms other than sieving; the animal can capture a finite proportion of particles in all size classes available from at least 30 to 360 micrometers in diameter. A marked shift in the size distribution of particles caught by the animal toward larger particle sizes agrees with predictions derived from aerosol filtration theory. Adhesion of particles to the tube feet is strongly dependent on the presence of fixed charged groups on the surface of the particles.     

液氮充注气调保鲜环境数学模型

为了掌握液氮充注气调过程中保鲜厢体内氧气浓度、温度的变化规律,建立液氮充注气调保鲜环境的数学模型,对氧气浓度、温度随时间变化过程进行了详细的理论推导,得出相应的计算式。在试验厢体上进行的验证试验表明:计算结果与试验结果基本吻合,为液氮充注气调系统的优化设计和控制策略提供了理论依据。     

Immunotherapy of cancer: an experimental model in syngeneic guinea pigs

Successful treatment of a solid tumor was accomplished by repeated intradermal injection of living tumor cells.     

Early experience effects upon cortical dendrites: a proposed model for development

We studied the effects of environmental stimulation on the development of rat cortical pyramidal cell synaptic loci (dendritic spines) and the number of such cells staining by the rapid Golgi technique. Stimulation three to five times a day from the day of birth increased the number of spines per micrometer in 8-day-old animals and increased the number of neurons stanining at 8 to 16 days of age. This effect of afferent input upon development of the dendritic spine may represent the neuroanatomical basis for the influence of early experience on subsequent behavior. The number of neurons staining by the rapid Golgi technique appears to be related to those that are functionally involved at the time of tissue preparation.     

Pompe's disease: detection of heterozygotes by lymphocyte stimulation

A technique has been developed for the detection of inborn errors by multiple enzyme analysis of lymphocytes stimulated by phytohemagglutinin. Its practicality has been demonstrated in Pompe's disease in which there is a deficiency of acid alpha-1,4-glucosidase (E.C.3.2.1.20).     

Lateral hypothalamic stimulation in satiated rats: the rewarding effects of self-induced drinking

It is well known that thirsty rats will press a lever for water. The purpose of the present experiment was to demonstrate that, when water is freely available, nonthirsty rats will press a lever for thirst. Three satiated rats, bearing permanently implanted electrodes, were trained to press a lever which caused stimulation to be applied to an area of the lateral hypothalamus which induces thirst. The animals were tested with and without water available. Two of the rats pressed the lever to induce thirst only when water was available. Thus, thirst-inducing stimulation was not rewarding by itself, but only in combination with drinking.     

Venus: ionosphere and atmosphere as measured by dual-frequency radio occultation of mariner v

Venus has daytime and nighttime ionospheres at the positions probed by radio occulation. The main layers are thin by terrestrial standards, with the nighttime peak concentration of electrons being about two orders of magnitude below that of the daytime peak. Above the nighttime peak were several scale-height regimes extending to a radius of at least 7500, and probably to 9700, kilometers from the center of Venus. Helium and hydrogen at plasma temperatures of 600 degrees to 1100 degrees K seem indicated in the regimes from 6300 to 7500 kilometers, with cooler molecular ions in lower regions. Above the daytime peak a sharp plasmapause was discovered, marking a sudden transition from appreciable ionization concentrations near Venus to the tenuous conditions of the solar wind. This may be indicative of a kind of interaction of the magnetized solar wind with a planetary body that differs from the two different kinds of interaction characterized by Earth and by Moon. For Venus and probably for Mars, the magnetic field of the solar wind may pile up in front of the conducting ionosphere, form an induced magnetosphere that ends at the plasmapause, above which any ionosphere that tends to form is swept away by the shocked solar wind that flows between the stand-off bow-shock and the magnetopause. The neutral atmosphere was also probed and a surface reflection may have been detected, but the data have not yet been studied in detail. Results are consistent with a super-refractive atmosphere, as expected from Soviet measurements near the surface. Thus, two unusual features of Venus can be described in terms of a light trap in the lower atmosphere, and a magnetic trap in the conducting ionosphere.     

四氯化碳致鸡肝脏和肾脏损伤实验动物模型的建立

给试验鸡人工灌服亲肝毒物四氯化碳（CCl4）,检测血清中的丙氨酸氨基转移酶（ALT）、门冬氨酸氨基转移酶（AST）活性的改变,观察肝脏和肾脏病理组织学变化,以建立肝脏和肾脏损伤的实验动物模型。试验结果显示,CCl4对鸡肝脏的损伤呈现出毒性累加效应,CCl4对鸡肝脏的损伤和致血清中转氨酶活性升高需要一定的作用时间和较高的攻毒剂量,而且随着投药剂量的增加,试验鸡血清中ALT的活性呈现出升高的趋势。试验鸡灌服CCl4后引起的肝细胞急性变性呈现出以典型的水泡变性为特征的病理变化。     

不同试验条件下生孢梭菌孢子生长预测方程的建立

    应用响应曲面模型(RSM)方法研究不同温度、pH值、NaCl浓度对生孢梭菌孢子生长的影响.不同试验条件下生孢梭菌孢子的生长曲线应用Baranyi生长模型进行拟合,生长曲线参数生长率(GR)和迟滞期(LT)应用RSM方法建立生孢梭菌孢子的生长预测方程.从另外随机选择试验组合对建立的方程进行验证,并通过计算预测标准差(SEP)、平方根误差(RMSE)、准确性因子(Af)和偏差因子(Bf)对建立的生长预测方程进行数学检验.结果表明,温度、pH值和NaCl浓度对生孢梭菌孢子生长影响显著,应用RSM方法建立的生长预测方程能够较好的模拟生孢梭菌孢子在不同试验条件下的生长状况,对食品中蛋白水解型肉毒梭菌的生长和控制具有参考意义.     

Movement disorders of aged rats: reversal by dopamine receptor stimulation

When placed in a tank of water, aged rats (24 to 27 months old) showed marked impairments in swimming. Compared with young adult rats (3 to 4 months old), the older animals moved their limbs less vigorously and were less successful in keeping their heads above water. The young, but not old, rats maintained a position nearly horizontal to the water surface and planed across it. These movement dysfunctions of aged rats resemble those seen in young adult animals that have sustained injury to brain dopamine-containing neurons. The swimming impairments of the aged rats were reversed by the dopamine receptor stimulant apomorphine and by the biosynthetic precursor of dopamine, L-dopa. Thus, age-related alterations in brain dopaminergic systems may be responsible for some of the movement disturbances associated with senescence.