Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lightning”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 775 records · Page 43Linked to original sources
PubMed2005

A study of the trace gas columns of O3, NO2 and HCHO over Africa in September 1997.

Retrievals of trace gas columns from the measurements of backscattered radiation by GOME (Global Ozone Monitoring Experiment) show that enhanced tropospheric columns of ozone (O3), nitrogen dioxide (NO2) and formaldehyde (HCHO), over the African continent occur frequently. This study focuses on the behaviour of trace gases over Africa in September 1997, a period impacted by the strongest known El Niño phase of the ENSO. It investigates our qualitative and quantitative understanding of the retrieved tropospheric trace gas column densities. The emissions of NOx and volatile organic compounds (VOC) from biomass burning, biogenic sources and lightning and their photochemical transformation have been investigated. By performing a trajectory analysis, the transport of air masses from the different emission regions was analysed and the potential atmospheric spatial distribution determined. BRemen's Atmospheric PHOtochemical model (BRAPHO) was applied to compute the chemistry along a large number of trajectories. From these results, tropospheric column amounts of O3, NO2 and HCHO were derived. Tropospheric trace gas columns retrieved from GOME measurements and those calculated are in reasonable agreement. Their general spatial extent was similar in the lower troposphere but the modeled trace gas columns in the upper troposphere were located south of the retrieved columns. We attribute this behaviour to uncertainties in the ERA-40 meteorological data in the upper troposphere. The significance of biomass burning and of biogenic emissions with respect to HCHO columns over Africa was investigated. The analysis reveals that the total amounts of HCHO generated over Africa during September 1997 as a result of biomass burning and biogenic emissions are similar. However the HCHO from biogenic sources has the highest specific columns and these are located close to their source. In comparison the HCHO from biomass burning is predicted to be produced and transported over a much wider area. Overall all the emission processes mix together to produce the plume of O3.

Africa↗
PubMed2003

Novel excitatory Conus peptides define a new conotoxin superfamily.

A new class of Conus peptides, the I-superfamily of conotoxins, has been characterized using biochemical, electrophysiological and molecular genetic methods. Peptides in this superfamily have a novel pattern of eight Cys residues. Five peptides that elicited excitatory symptomatology, r11a, r11b, r11c, r11d and r11e, were purified from Conus radiatus venom; four were tested on amphibian peripheral axons and shown to elicit repetitive action potentials, consistent with being members of the 'lightning-strike cabal' of toxins that effect instant immobilization of fish prey. A parallel analysis of Conus cDNA clones revealed a new class of conotoxin genes that was particularly enriched (with 18 identified paralogues) in a Conus radiatus venom duct library; several C. radiatus clones encoded the excitatory peptides directly characterized from venom. The remarkable diversity of related I-superfamily peptides within a single Conus species is unprecedented. When combined with the excitatory effects observed on peripheral circuitry, this unexpected diversity suggests a corresponding molecular complexity of the targeted signaling components in peripheral axons; the I-conotoxin superfamily should provide a rich lode of pharmacological tools for dissecting and understanding these. Thus, the I-superfamily conotoxins promise to provide a significant new technology platform for dissecting the molecular components of axons.

Action Potentials↗
PubMed2001

Contribution of the MHC class II antigens to the etiology of infantile spasm in Mexican Mestizos.

PURPOSE: Infantile spasms (ISs) are age-dependant epileptic seizures, which may be flexor, extensor, lightning or nods, or mixed. The aim of this study was the analysis of genetic factors within the human leukocyte antigen (HLA) complex associated with ISs. METHODS: Sixty-five patients diagnosed according to the established international criteria were compared with 229 healthy individuals; all of them were Mexican Mestizos. Five families were also analyzed (seven affected and five healthy sibs); HLA class I and class II antigens were typed using the standard microlymphocytotoxicity methods. RESULTS: The findings showed female gender preference (2:1). Two thirds were symptomatic, and prevalent seizures were of mixed type (67%). A strong association with HLA-DR17 was detected in the IS group (pc < 0.01; OR = 3.6; EF = 0.20). DR17 was also found increased in the symptomatic patients (p = 0.009; OR = 3.16) and in those with other types of seizures (p = 0.001; OR = 2.0). Conversely, HLA-DQ6 was significantly decreased (pc < 0.002; PF = 0.37) in the total and in the symptomatic groups (p < 0.01). Haplotype linkage was not confirmed in the families; however, those with more than one affected sib shared at least one haplotype. CONCLUSIONS: These findings suggest the contribution of DR locus to the susceptibility and the participation of DQ region in the resistance to IS. Severity seems also to be influenced by HLA-DR17, and therefore class II typing may be a helpful tool for disease prognosis.

Adult↗
PubMed2001

[Differential diagnosis of visual aura in migraine and epilepsy].

Visual phenomena like lightnings, disturbed contours of objects, or skotoma, can be due to ophthalmological diseases, but can also occur as symptoms generated by the central nervous system ("aura") in migraine or epilepsy. A subsequent hemicrania is considered as a hallmark of migraine, but in many cases does not allow for a certain distinction from postictal headaches in patients with focal epilepsy. A detailed analysis of the aura does, however, provide sufficient information for classifying the disorder as an aura in migraine or as a simple partial epileptic seizure in most cases. The higher degree of differentiation of visual phenomena including colour, movement, and complex visual phenomena, is characteristic of the activation of neuronal circuits during an epileptic aura. The higher speed of transsynaptic propagation of epileptic discharges and postictal inactivation causes a more rapid time-course of the epileptic aura as compared to a migraine aura resulting from a depolarization spreading by diffusion. Clinically, the diagnosis of epilepsy is supported by additional positive motor phenomena or by a transition into a complex partial seizure, e. g. when epileptic activity spreads into a temporal lobe. Secondarily generalized seizures, however, may also occur in patients with migraine. Interictal and ictal EEG recordings can be important to prove an epileptic origin, but their sensitivity is low if ictal discharges remain limited to a small brain area. In rare cases, measurements of ictal cerebral perfusion can contribute to the differential diagnosis.

Brain↗
PubMed1985

[Opsoclonus and myoclonus syndrome. Clinical and electronystagmography findings with course studies].

This review is based on the clinical experience with 7 patients and a total of 171 additional cases described in literature. Clinical features are presented of this "benign" cerebellar encephalopathy, which occurs preferably in association with viral infections, neuroblastomas or rarely carcinomas. Numerous descriptions of single cases stress a heterogeneous variety of other diseases which possibly may cause this syndrome. Special emphasis is put on the electronystagmographic documentation of eye movements with follow up of the spontaneous recovery over several years. The eye movement characteristics of opsoclonus allow for a clear differentiation from other forms of acquired ocular oscillations, such as ocular flutter, ocular dysmetria, square wave jerks, macro-saccadicoscillations, lightning eye movements, pendular nystagmus, obliquus superior myokymia and voluntary nystagmus. Differential diagnosis of the underlying diseases is particularly dependent on the age of onset. Histopathological findings as well as the hitherto suggested immunologic pathogenesis, therapeutic regimen and the prognosis are discussed critically on the basis of the literature.

Adolescent↗
PubMed1997

The cloud-ionosphere discharge: a newly observed thunderstorm phenomenon.

This paper deals with a luminous electric discharge that forms in the mesospheric region between thundercloud tops and the ionosphere at 90-km altitude. These cloud-ionosphere discharges (CIs), following visual reports dating back to the 19th century, were finally imaged by a low-light TV camera as part of the "SKYFLASH" program at the University of Minnesota in 1989. Many observations were made by various groups in the period 1993-1996. The characteristics of CIs are that they have a wide range of sizes from a few kilometers up to 50 km horizontally; they extend from 40 km to nearly 90 km vertically, with an intense region near 60-70 km and streamers extending down toward cloud tops; the CIs are partly or entirely composed of vertical luminous filaments of kilometer size. The predominate color is red. The TV images show that the CIs usually have a duration less than one TV field (16.7 ms), but higher-speed photometric measurements show that they last about 3 ms, and are delayed 3 ms after an initiating cloud-ground lightning stroke; 95% of these initiating strokes are found to be "positive"-i.e., carry positive charges from clouds to ground. The preference for positive initiating strokes is not understood. Theories of the formation of CIs are briefly reviewed.

Journal Article↗
PubMed1999

Association of a missense change in the D2 dopamine receptor with myoclonus dystonia.

Hereditary autosomal dominant myoclonus dystonia (MD) is a movement disorder characterized by involuntary lightning jerks and dystonic movements and postures alleviated by alcohol. Although various large families with MD have been described, no positive linkage has been found to a chromosomal location. We report a family with eight members with MD. Linkage analysis identified a 23-centimorgan region on chromosome 11q23 that cosegregates with the disease state (maximum multipoint logarithm of odds score = 2.96 at D11S897). This region contains an excellent candidate gene for involvement in the etiology of MD, the D2 dopamine receptor (DRD2) gene. Neurotransmission mediated by DRD2 is known to have a key role in the control of movement and also has been implicated in reward and reinforcement mechanisms and psychiatric disorders. Sequencing of the coding region of DRD2 indicated that all affected and obligate carriers were heterozygous for a Val154Ile change in exon 3 of the protein, which is highly conserved across species. This change was found neither in other unaffected members of the pedigree nor in 250 control chromosomes. Our finding provides evidence for the involvement of DRD2 in a disorder of the central nervous system and should lead to further insight into the function of the dopaminergic system in dystonia and other movement and mood disorders.

Adolescent↗
PubMed2002

Solution NMR characterization of an unusual distal H-bond network in the active site of the cyanide-inhibited, human heme oxygenase complex of the symmetric substrate, 2,4-dimethyldeuterohemin.

The presence of variable static hemin orientational disorder about the alpha-gamma-meso axis in the substrate complexes of mammalian heme oxygenase, together with the incomplete averaging of a second, dynamic disorder, for each hemin orientation, has led to NMR spectra with severe spectral overlap and loss of key two-dimensional correlations that seriously interfere with structural characterization in solution. We demonstrate that the symmetric substrate, 2,4-dimethyldeuterohemin, yields a single solution species for which the dynamic disorder is sufficiently rapid to allow effective and informative (1)H NMR structural characterization. A much more extensive, effective, and definitive NMR characterization of the cyanide-inhibited, symmetric heme complex of human heme oxygenase shows that the active site structure, with some minor differences, is essentially the same as that for the native protohemin in solution and crystal. A unique distal network that involves particularly strong hydrogen bonds, as well as inter-aromatic contacts, is described that is proposed to stabilize the position of the catalytically critical distal helix Asp-140 carboxylate (Liu, Y., Koenigs Lightning, L., Huang, H., Moënne-Loccoz, P., Schuller, D. J., Poulos, T. L., Loehr, T. M., and Ortiz de Montellano, P. R. (2000) J. Biol. Chem. 275, 34501-34507). The potential role of this network in placing a water molecule to stabilize the hydroperoxy species and as a template for the condensation of the distal helix upon substrate binding are discussed.

Binding Sites↗
PubMedDate not supplied

The 1987 forest fire disaster in California: assessment of emergency room visits.

During a 5-d period that commenced on August 30, 1987, dry lightning strikes ignited more than 1,500 fires that destroyed in excess of 600,000 acres of California forests. To evaluate the public health impact of the smoke on the general population, all hospital emergency rooms located in the six counties most severely affected by smoke or fire were surveyed. Selected hospital information was abstracted for a 2 1/2-wk period during the fires and during two reference periods. During the period of major forest fire activity, visits of persons with asthma and chronic obstructive pulmonary disease increased in number (observed/expected ratios of 1.4 and 1.3, respectively), as did visits of persons with sinusitis, upper respiratory infections, and laryngitis. A few patients with acute respiratory or eye irritation also visited the emergency rooms. Even recognizing the limited sensitivity of emergency room surveys, the overall public health impact was relatively modest. The increased respiratory morbidity detected in this survey, however, supports the notion that persons with pre-existing respiratory disease represent a sensitive subpopulation, who should be targeted for purposes of public health intervention when exposure to forest fire smoke is likely.

Air Pollutants↗
PubMedDate not supplied

The early atmosphere: a new picture.

Over the last several years, many of the fundamental ideas concerning the composition and chemical evolution of the Earth's early atmosphere have changed. While many aspects of this subject are clouded--either uncertain or unknown, a new picture is emerging. We are just beginning to understand how astronomical, geochemical, and atmospheric processes each contributed to the development of the gaseous envelope around the third planet from the sun some 4.6 billion years ago and how that envelope chemically evolved over the history of our planet. Simple compounds in that gaseous envelope, energized by atmospheric lightning and/or solar ultraviolet radiation, formed molecules of increasing complexity that eventually evolved into the first living systems on our planet. This process is called "chemical evolution" and immediately preceded biological evolution; once life developed and evolved, it began to alter the chemical composition of the atmosphere that provided the very essence of its creation. Photosynthetic organisms which have the ability to biochemically transform carbon dioxide and water to carbohydrates, which they use for food, produce large amounts of molecular oxygen (O2) as a by-product of the reaction. Atmospheric oxygen photochemically formed ozone, which absorbs ultraviolet radiation from the sun and shields the Earth's surface from this biologically lethal radiation. Once atmospheric ozone levels increased sufficiently, life could leave the safety of the oceans and go ashore for the first time. Throughout the history of our planet, there has been strong interaction between life and the atmosphere. Understanding our cosmic roots is particularly relevant as we embark on a search for life outside the Earth. At this very moment, several radio telescopes around the world are searching for extraterrestrial intelligence (SETI).

Atmosphere↗
PubMed2003

Risperidone treatment of motor restlessness following anoxic brain injury.

PRIMARY OBJECTIVE: This paper examined the use of an atypical neuroleptic medication, risperidone, in reducing the excessive motor activity of an adolescent with an anoxic brain injury following cardiac arrest from a lightning strike. Lower extremity restlessness caused the patient to develop skin breakdown and interfered with healing of existing burns. RESEARCH DESIGN: Single-blind, placebo-controlled single-subject experimental design. EXPERIMENTAL INTERVENTION: Escalating doses of risperidone up to 1 mg and in combination with methylphenidate (10 mg) and amantidine (100 mg). MAIN OUTCOMES AND RESULTS: The patient demonstrated a reduction in restlessness in response to the use of risperidone, which permitted wound healing. The addition of methlphenidate to risperidone led to a slight increase in attention to task. CONCLUSIONS: The use of the atypical neuroleptic medication, risperidone, may be considered as part of the armamentarium available to physicians treating restlessness in severe brain injuries.

Adolescent↗
PubMed2006

Magnetism, iron minerals, and life on Mars.

A short critical review is provided on two questions linking magnetism and possible early life on Mars: (1) Did Mars have an Earth-like internal magnetic field, and, if so, during which period and was it a requisite for life? (2) Is there a connection between iron minerals in the martian regolith and life? We also discuss the possible astrobiological implications of magnetic measurements at the surface of Mars using two proposed instruments. A magnetic remanence device based on magnetic field measurements can be used to identify Noachian age rocks and lightning impacts. A contact magnetic susceptibility probe can be used to investigate weathering rinds on martian rocks and identify meteorites among the small regolith rocks. Both materials are considered possible specific niches for microorganisms and, thus, potential astrobiological targets. Experimental results on analogues are presented to support the suitability of such in situ measurements.

Exobiology↗
PubMed2002

Backspatter on the firearm and hand in experimental close-range gunshots to the head.

The deposition of backspatter on the firearm or person shooting can greatly assist the reconstruction of shooting incidents. Backspatter was investigated in experimental transverse gunshots (9-mm Luger) to the heads of calves (n = 9) from shooting distances of 0 to 10 cm. The firearms were examined with a magnifying glass; the surgical gloves and the right sleeve worn by the person shooting were examined with a stereomicroscope. On the firearms, backspatter of blood was found in five of the nine cases, and one or both gloves showed bloodspatter deposits in six and the right sleeves in four cases. Most droplets were 1 to 3 mm and circular or elongated. In addition, a fine spray of tiny blood deposits was present on the firearm and textiles in four cases. The distribution of the droplets on the firearms varied: the areas included regions shielded by prominent parts, and the droplets were predominantly located on the extensor side of the fingers and the radial aspect of the hands and sleeves. Backspatter of tiny bone fragments was recovered from the firearm and sleeve in only one case, but tissue (bone, fat, muscle, skin) was present on the ground in front of the entrance wound in seven cases. A careful investigation, including appropriate lightning and magnification, is necessary for reliable statements concerning the absence of backspatter or the extent of backspatter present.

Animals↗
PubMed1983

The evaluation and management of electrical injuries.

It is essential for the critical care physician to understand the ramifications of electrical injuries, as these patients are frequently seen in the ICU. Being able to anticipate possible complications may be ultimately life-preserving. A collaborative effort between the surgeon, critical care physician, and ICU staff ensures premium care for this injured patient. Educational efforts for the public regarding precautions in the avoidance of electrical and lightning injuries will help prevent many of these accidents.

Critical Care↗
PubMed2002

Electrical injuries.

Electrical injury is a relatively infrequent but potentially devastating form of multisystem injury with high morbidity and mortality. Most electrical injuries in adults occur in the work-place, whereas children are exposed primarily at home. In nature, electrical injury occurs due to lightning, which also carries the highest mortality. The severity of the injury depends on the intensity of the electrical current (determined by the voltage of the source and the resistance of the victim), the pathway it follows through the victim's body, and the duration of the contact with the source of the current. Immediate death may occur either from current-induced ventricular fibrillation or asystole or from respiratory arrest secondary to paralysis of the central respiratory control system or due to paralysis of the respiratory muscles. Presence of severe burns (common in high-voltage electrical injury), myocardial necrosis, the level of central nervous system injury, and the secondary multiple system organ failure determine the subsequent morbidity and long-term prognosis. There is no specific therapy for electrical injury, and the management is symptomatic. Although advances in the intensive care unit, and especially in burn care, have improved the outcome, prevention remains the best way to minimize the prevalence and severity of electrical injury.

Adult↗
PubMed2004

Probiotics for mother and child.

For the survival of humankind, nothing can be as important as the health of a mother and a child. As the world's population grows to more than 6 billion, it might seem ridiculous to suggest that any real threat exists to the human species. Diseases have long ravaged populations, as have wars, poverty, and malnutrition. Life today is no different with new and emerging diseases such as SARS and Mad Cow Disease leaving a trail of concern around the planet. All that being said, the AIDS crisis is threatening humans like no other. In countries such as Botswana, close to half the population of pregnant women is infected. Of great concern, the disease is now prevalent among women and teenage girls, threatening not only their lives but those of their offspring. Efforts to control this spread are quite abysmal, albeit well intentioned. Likewise, the death of a child every 15 seconds from diarrheal disease is not being addressed with the same vigor as SARS, even though the risk of dying from the latter for most people is similar to being struck by lightning. In the end, it is the economy and politics that dictate health spending. Image and perception are everything. While deaths mount among women and children from AIDS and other infections, the potential to intervene with a low-risk natural concept of probiotics seemed all too distant. As evidence mounts of the attributes of certain probiotic strains to treat diarrhea and reduce the risk of urogenital and other diseases, the developing world has failed to embrace it, support its evaluation and implementation, and take it to where it is needed the most. In this review, the case for and against probiotics for urogenital and intestinal infections is presented based on current literature. The story is far from complete, but the potential for improving the health of the mother and child is significant. United Nations and World Health Organization guidelines have now been developed to vanquish the unproved marketing hype products that have given probiotics a bad name. It is now up to science to deliver the remedies, and to society to make sure that only proven products reach the marketplace and the people in most need.

Female↗
PubMed2004

Varied clinical presentations of Vibrio vulnificus infections: a report of four unusual cases and review of the literature.

Vibrio vulnificus is a Gram-negative, motile, curved bacillus of the family Vibrionaceae that is a rare cause of gastroenteritis, septicemia, and wound infections in humans. V. vulnificus is halophilic, flourishes in warm temperatures, and is part of the bacterial flora of the marine environment. The location of our health care setting, on the Gulf of Mexico, has given us the opportunity to observe a wide variety of clinical presentations of infections caused by this organism. In the first case, a 27-year-old man struck by lightning while windsurfing was found pulseless in the water and was resuscitated. The patient subsequently developed cardiac arrhythmias, respiratory failure, and necrotizing fasciitis, blood cultures yielded V. vulnificus. After antibiotic therapy and several fasciotomies, the patient recovered. The second case was that of a 43-year-old Asian man employed as an oyster shucker who presented with complaints of redness, tearing, and photophobia of the right eye. The diagnosis of corneal ulcer secondary to V. vulnificus was made after culture of the right eye revealed the organism. The third case involved a 46-year-old man who presented with complaints of abdominal pain, nausea, chills, and bullous lesions on the lower extremities. He developed disseminated intravascular coagulation, and cultures of the lesions on his lower extremities showed V. vulnificus. Initially, the patient denied any exposure to raw seafood or seawater, but he eventually remembered eating raw oysters 3 days before his illness. The fourth case is that of a 32-year-old, human immunodeficiency virus-positive, hepatitis C-positive woman with cirrhosis who presented with productive cough, chills, fever, and red spots on her extremities and buttocks. Blood cultures revealed V. vulnificus and the patient was treated with antibiotics and improved clinically. These four cases illustrate the wide range of clinical presentations associated with this organism.

Adult↗
PubMed1999

Is integer arithmetic fundamental to mental processing?: the mind's secret arithmetic.

Unlike the ability to acquire our native language, we struggle to learn multiplication and division. It may then come as a surprise that the mental machinery for performing lightning-fast integer arithmetic calculations could be within us all even though it cannot be readily accessed, nor do we have any idea of its primary function. We are led to this provocative hypothesis by analysing the extraordinary skills of autistic savants. In our view such individuals have privileged access to lower levels of information not normally available through introspection.

Art↗