Radio Emission Reveals Inner Meter-Scale Structure of Negative Lightning Leader Steps.

We use the Low Frequency Array (LOFAR) to probe the dynamics of the stepping process of negatively charged plasma channels (negative leaders) in a lightning discharge. We observe that at each step of a leader, multiple pulses of vhf (30-80 MHz) radiation are emitted in short-duration bursts (<10 µs). This is evidence for streamer formation during corona flashes that occur with each leader step, which has not been observed before in natural lightning and it could help explain x-ray emission from lightning leaders, as x rays from laboratory leaders tend to be associated with corona flashes. Surprisingly, we find that the stepping length is very similar to what was observed near the ground, however with a stepping time that is considerably larger, which as yet is not understood. These results will help to improve lightning propagation models, and eventually lightning protection models.

How the alternating degeneracy in rotational Raman spectra of CO2 and C2H2 reveals the vibrational temperature.

The contribution of higher vibrational levels to the rotational spectrum of linear polyatomic molecules with a center of symmetry (CO2 and C2H2) is assessed. An apparent nuclear degeneracy is analytically formulated by vibrational averaging and compared to numerical averaging over vibrational levels. It enables inferring the vibrational temperature of the bending and asymmetric stretching modes from the ratio of even to odd peaks in the rotational Raman spectrum. The contribution from higher vibrational levels is already observable at room temperature as g˜e/o=0.96/0.04 for CO2 and g˜e/o=1.16/2.84 for C2H2. The use of the apparent degeneracy to account for higher vibrational levels is demonstrated on spectra measured for a CO2 microwave plasma in the temperature range of 300-3500 K, and shown to be valid up to 1500 K.

[Anxiety and depression caused by side effects of drugs]. / Trevoga i depressiia, vyzvannye pobochnym deistviem lekarstv.

The word "drug" in accordance with the definition given by the WHO means "any substance that, when taken into the living organisms, may modify one or more of its functions". This thus covers a wider field than the word "medicine" or "medicament". There are many substances which are capable of provoking anxiety and are very frequently consumed. According to recent publications the use and abuse of alcohol, cigarettes, heroin, cocaine, marihuana, and drugs such as sedatives (neuroleptics), caffeine, minor tranquilisers and other may provoke acute and chronic anxiety and depression. When confronted with anxiety states or depressive states, it is absolutely essential not to overlook the possibility that they may have been induced by a medicament or a drug which the patient has been using.

Depression--a diagnosis sometimes missed and sometimes mistaken.

A short description of the clinical picture of the major depression is given. Different forms of missed diagnosis in depression are discussed. Beside somatic symptomatology there are behavioural disturbances and disorders of a psychopathological type. Attention is paid to sexuality, anxiety and compulsion. The depression as a mistaken diagnosis is considered in relationship with endocrinopathy and with pharmacotherapy. In this respect reference is made to Cushing's disease, psychotropic drugs and oral contraceptives.

PIP: Following a brief presentation of the clinical picture of major depression, attention is directed to different forms of missed diagnosis. The clinical picture of major depression is characterized by marked uniformity and includes 2 highly typical disturbances: pronounced diurnal fluctuations and early or very early awakening. Other central features include a feeling of hopelessness, the disappearance of all prospects for the future, and feelings of guilt sometimes assuming absurd proportions. In addition, there are many other accompanying manifestations. Yet, despite this, it is not easy to recognize depression, particularly since the patient's gloomy and dejected mood often occupies the background of the picture. Cross-cultural psychiatric studies reveal that in non-Western cultures expression often mainfests itself in the form of a wide variety of somatic complaints, including pain. The term "masked depression" has come into common use to describe what are cases where, in the presence of predominantly physical signs and symptoms, an underlying depressive state goes unrecognized. This applies particularly to syndromes of which headache and pains in the chest, abdomen, and limbs are prominent features. It is unclear as to what extent somatic manifestations of depression are on the increase in the Western world. Yet, clearly, many patients deny that they suffer from depression and cling firmly to their physical complaints. Although depression may lurk behind a series of poorly defined physical complaints, essential characteristics of genuine depression emerge upon further diagnostic exploration. Secondary accompaiments to depression include periodic abuse of alcohol or medicines and disturbances affecting sexual behavior. In the elderly, the differential diagnosis of dementia and depression may give rise to confusion. Anxiety emerges as a frequent accompanying manifestation in depressive patients, yet all anxious patients do not suffer with depression. Additionally, many manifestations of anxiety and depression closely resemble one another, adding to the confusion. There is limited awareness of phobic and compulsive phenomena as manifestations of depression. These phenomena may disappear in response to treatment for the depression and are by no means always related to a premorbid compulsive personality structure. The issue of the application of the term "depression" to conditions that most likely are not depressive are considered from the standpoints of endocrinopathy and of pharmacology. The problem posed by depressive syndromes occurring in oral contraceptive (OC) users is more complex. When the progesterone content is high in relation to the estrogen component, the patient may sometimes suffer from loss of libido and loss of pleasure in sex or life in general. These changes respond favorably to a change in the type of OC.