Early Stage Of Eruption Research Articles

Fluoride Varnishes for Preventing Occlusal Dental Caries: A Review.

Dental caries are most likely to occur on occlusal surfaces from the early eruptive stages of the tooth. In children, about 80% to 90% of dental caries are occlusal caries. Different preventive modalities are used to prevent occlusal caries. One of the methods used for occlusal caries prevention is fluoride varnish. A vast number of clinical trials have evaluated several types of sealant material and fluoride varnish to assess their ability to prevent occlusal caries in both primary and permanent dentition. The purpose of the current study was to provide an updated overview of the development, composition, mechanism of action, application, and safety of fluoride varnish, as well as its effect on occlusal caries prevention. This review of recently published studies on fluoride varnish and its effect on occlusal caries prevention shows that in children at moderate to high risk of caries, fluoride varnishes prevent occlusal caries. Both resin-based fissure sealants and fluoride varnish are effective for occlusal caries prevention for first-permanent molars. However, it was not possible to identify which one has the best effect. It is recommend that fluoride varnish is applied for children at high risk of caries two to four times per year.

Facies architecture of a subaqueous volcano–sedimentary succession on Bogda Mountains, NW China—Evidence of extension in Late Carboniferous

A Late Carboniferous volcano–sedimentary complex outcrops on the southwestern flank of the Bogda Mountains, NW China. The volcanic architecture, spatial relationships, and emplacement mechanisms of the lithofacies were studied in detail, providing a lithofacies context for previously published structural and geochemical studies and constraining the reconstruction of palaeo‐environments. Four distinct volcano–sedimentary facies are identified in the Qijiagou Formation: close‐packed pillow basalts, pillow basalts with interstitial sediments, hyaloclastites, and peperites. Textural features of the lithofacies, especially hyaloclastites and peperites, provide clear evidence for in situ fragmentation of lava flows, co‐volcanic sedimentation of limestone, and intimate interaction between lava, water, and sediments. They demonstrate autochthonous, subaqueous origin of the succession. Discovery of peperites and stratigraphic transitions of the related lithofacies indicate a progressively deepening subaqueous environment, resembling a volcanic evolution from early stage of eruption at a shallower level to increasingly subsiding basin with increasing eruption frequency of basaltic lava at greater water depth. Vesicularity of basalts, ambient pressure, and peperitic features indicate eruption depth at between 1,500 and 2,500 m. The deep extensional basin in the Baiyanggou area was coeval with bimodal volcanism, uplift, and granite intrusion along strike in the region, all indicating continental collision and post‐collisional extension. The substantial depth of the Baiyanggou Basin indicates that it may have been a back‐arc or even a residual oceanic basin.

Family characteristics on self-reported toothache among Indonesian children aged 12–14 years

Abstract Objective Toothache was reported as a reason for school absenteeism, sleeping difficulties, loss of appetite, and seeking dental treatment among children. These represented some impacts of dental problems on health, quality of life, and socioeconomic problems. The aims of this study were to describe the prevalence of toothache among 12–14-year-old children in Indonesia and their family characteristics and to analyze the associations of family characteristics on the toothache. Methods We analyzed the data from the Indonesian Family Life Survey 5 in 2014–2015. A total of 2,377 children aged 12–14 years were included in this survey. This age is the early stage of eruption of all permanent teeth. Children were asked about their experience on toothache in the last 4 weeks as a dependent variable. The independent variables were the family socioeconomic characteristics including father's and mother's highest educational level, family income, and the number of children in the family. A logistic regression was applied to analyze the relationship of family characteristics with toothache experience of children. Results Toothache experience was reported from 13.9% of the respondents. Descriptive statistics showed that higher percentages of toothache were experienced by male children and children from family with lower parental education and economic position as well as from bigger family. However, logistic regression showed that only the number of children in the family had a statistically positive association with self-reported toothache of the children. Children living in the family with more than four children were more likely reported toothache than living in the family with one or two children (P=0.012; odds ratio [OR]=1.53). Children living with more siblings may experience less attention from their parents on oral health hygiene. Poor oral health habits could result in dental pain. Conclusions Descriptive statistics showed that a higher percentage of toothache was experienced by children from lower socioeconomic families, although the only significant association was the number of children in the family.

Study on the element geochemical charactersitics of the Shazi large-sized anatase ore deposit in Qinglong, Guizhou Province

The Shazi anatase ore deposit in Qinglong, Guizhou Province, is a large-sized anatase deposit that has been recently explored. The characteristics of major oxides in the ore are similar to those of modern laterite weathering crust and laterite in the laterite-type gold deposits in the western part of Guizhou Province. Studies on the REE characteristics of basalts and anatase ores in the study region showed that both of them do have extremely strong affinities. There are two groups of trace elements in the ores, i.e., Au-Ag-As-Sb-Hg-Tl association and Sc-TiO2-Cu-Fe-Mn association, reflecting that the formation of anatase ore is related to the formation of siliceous claystone at the early stage of eruption of the Emeishan basaltic magma. The siliceous claystones are the major country rocks for the formation of laterite-type gold ores and anatase ores. In the region anatase ores are rich in Sc and the basalts enriched in Fe, Mn, Ti and Sc are the material source of metallogenesis.

Diamonds in lavas of the Tolbachik fissure eruption in Kamchatka

Diamond crystals 0.05–0.2 mm (rarely up to 0.7 mm) in size were found in lavas of the Tolbachik fissure eruption (TFE, Kamchatka, 2012–2013). The TFE basaltic lavas with diamonds in the pores are similar in chemical composition to the lavas of the Great Tolbachik Fissure Eruption (GTFE, Kamchatka, 1975–1976); however, the basalts of the new eruption contain slightly more SiO2 and higher Fe relative to those of GTFE. Basalts of both eruptions are close in trace element composition. The diamonds were identified using electron microscopy and X-ray diffraction. The crystals, as a rule, represent a combination of cubes and octahedrons, with rare rhombododecahedrons. The TFE diamond has a typical cubic cell with a cube edge a = 3.574 A and belongs to the spatial group of Fd-3m. The X-ray diffraction pattern of some grains contain reflexes with fractional indices, which indicate the twinning of the diamond along the plane {111}, which is confirmed by crystal morphological analysis. The TFE diamond was formed at the early stage of eruption with typical intense gaseous-pyroclastic jets to a height of 250 m and more. The finding of diamonds in fresh products of basaltic eruption of an active volcano may be considered as evidence of its magmatic source. Such numerous (hundreds) diamond grains in lavas of the active volcano were found for the first time in the world.

Fallout and distribution of volcanic ash over Argentina following the May 2008 explosive eruption of Chaitén, Chile

The major explosive eruption of Chaitén volcano, Chile, in May 2008 provided a rare opportunity to track the long‐range dispersal and deposition of fine volcanic ash. The eruption followed ∼10,000 years of quiescence, was the largest explosive eruption globally since Hudson, Chile, in 1991, and was the first explosive rhyolitic eruption since Novarupta, Alaska, in 1912. Field examination of distal ashfall indicates that ∼1.6 × 1011 kg of ash (dense rock equivalent volume of ∼0.07 km3) was deposited over ∼2 × 105 km2 of Argentina during the first week of eruption. The minimum eruption magnitude, estimated from the mass of the tephra deposit, is 4.2. Several discrete ashfall units are identifiable from their distribution and grain size characteristics, with more energetic phases showing a bimodal size distribution and evidence of cloud aggregation processes. Ash chemistry was uniform throughout the early stages of eruption and is consistent with magma storage prior to eruption at depths of 3–6 km. Deposition of ash over a continental region allowed the tracking of eruption development and demonstrates the potential complexity of tephra dispersal from a single eruption, which in this case comprised several phases over a week‐long period of intense activity.

Special Issue on Volcanic Disasters

The volcanic disasters are quite variable depending on the nature of the volcanic eruptions, the degrees of land-use surrounding the volcanic areas and preparedness against the eruptions. In order to mitigate the volcanic disasters, therefore, multidisciplinary approach is required. The International Volcanic Conference, ``Cities on Volcanoes 5," held in Shimabara Japan on the November 19-23, 2007 encouraged a wide range of people who are engaged in the volcanic disaster mitigation to gather to discuss topics related to volcanic eruptions and their hazards. The aim of this conference was to evaluate and improve mitigation measures, emergency management, and all required to successfully confront volcanic crises in densely populated area and to recover from any devastation. As the main topics discussed during the conference is quite adequate for the aim of this journal, this special issue tried to include papers read at the conference as many as possible. For the mitigation of the volcanic disasters, several different approaches should be included. Volcano monitoring through observation is the basis for most eruption forecasts and other measures for volcanic disaster mitigation. Impacts on human health and sustainability in volcanic areas in the fields of air and water pollution are also important issues to be included in the management of volcanic hazards. The practical lessons learned through the case histories of actual events should be shared to prepare for and respond to volcano crises that may affect communities. Hiroaki Takahashi proposes a method to estimate the real-time eruption magnitude that might be utilized to judge the duration of eruption in the early stage of eruption. Yoshikazu Kikawada et al. summarize arsenic pollution of rivers originated from the Kusatsu volcanic region. Tsuneomi Kagiyama and Yuichi Morita discuss the strategy to understand the preparing process of caldera forming eruption as a first step to assess the risk of gigantic eruption. Hiroshi Ikeya describes the prevention works executed by the central and local governments during and after the Mt. Unzen 1990-1995 eruption. Harry J. R. Keys summarizes the aspects of risk assessment and mitigation for a dome-break lahar that was predicted in 1995 and actually occurred on 18 March 2007 at Ruapehu volcano. Yoichi Nakamura et al. describe the mitigation systems on volcanic disasters in Japan emphasizing the importance of preparing hazard maps. We know the topics covered by this special issue do not represent the wide-ranging aspect of the conference, but include some significant portion. We hope that this special issue will be utilized to share the lessons learned through the practical trial to mitigate the actual disasters during the volcanic crisis.

Basanite glaciovolcanism at Llangorse mountain, northern British Columbia, Canada

The Llangorse volcanic field is located in northwest British Columbia, Canada, and comprises erosional remnants of Miocene to Holocene volcanic edifices, lava flows or dykes. The focus of this study is a single overthickened, 100-m-thick-valley-filling lava flow that is Middle-Pleistocene in age and located immediately south of Llangorse Mountain. The lava flow is basanitic in composition and contains mantle-derived peridotite xeno- liths. The lava directly overlies a sequence of poorly sorted, crudely bedded volcaniclastic debris-flow sediments. The debris flow deposits contain a diverse suite of clast types, including angular clasts of basanite lava, blocks of peridotite coated by basanite, and rounded boulders of granodiorite. Many of the basanite clasts have been palagonitized. The presence and abundance of clasts of vesicular to scoriaceous, palagonitized basanite and peridotite suggest that the debris flows are syngenetic to the overlying lava flow and sampled the same volcanic vent during the early stages of eruption. They may represent lahars or outburst floods related to melting of a snow pack or ice cap during the eruption. The debris flows were water-saturated when deposited. The rapid subse- quent emplacement of a thick basanite flow over the sediments heated pore fluids to at least 80-100°C causing in-situ palagonitization of glassy basanite clasts within the sediments. The over-thickened nature of the Llangorse Mountain lavas suggests ponding of the lava against a down-stream barrier. The distribution of similar-aged glaciovolcanic features in the cordillera suggests the possibility that the barrier was a lower-elevation, valley- wide ice-sheet.

Early pulpal involvement in an unusual case of dens in dente. Case report

Dens in dente (dens invaginatus, tooth within a tooth, dilated composite odontome) is an abnormal tooth form which occurs most frequently in the permanent maxillary lateral incisor region. Dens in dente may occur, however, in any tooth in the dental arch, although these other forms are comparatively rare. It may appear within both the coronal part of the tooth and the root, although coronal forms are more common. In this paper, a case of extreme dens in dente with pulpal involvement at an early stage of eruption is presented.

Evolution of the Quaternary melitite-nephelinite Herchenberg volcano (East Eifel)

The Quaternary Herchenberg composite tephra cone (East Eifel, FR Germany) with an original bulk volume of 1.17·107 m3 (DRE of 8.2·106 m3) and dimensions of ca. 900·600·90 m (length·width·height) erupted in three main stages: (a) Initial eruptions along a NW-trending, 500-m-long fissure were dominantly Vulcanian in the northwest and Strombolian in the southeast. Removal of the unstable, underlying 20-m-thick Tertiary clays resulted in major collapse and repeated lateral caving of the crater. The northwestern Lower Cone 1 (LC1) was constructed by alternating Vulcanian and Strombolian eruptions. (b) Cone-building, mainly Strombolian eruptions resulted in two major scoria cones beginning initially in the northwest (Cone 1) and terminating in the southeast (Cones 2 and 3) following a period of simultaneous activity of cones 1 and 2. Lapilli deposits are subdivided by thin phreatomagmatic marker beds rich in Tertiary clays in the early stages and Devonian clasts in the later stages. Three dikes intruded radially into the flanks of cone 1. (c) The eruption and deposition of fine-grained uppermost layers (phreatomagmatic tuffs, accretionary lapilli, and Strombolian fallout lapilli) presumably from the northwestern center (cone 1) terminated the activity of Herchenberg volcano. The Herchenberg volcano is distinguished from most Strombolian scoria cones in the Eifel by (1) small volume of agglutinates in central craters, (2) scarcity of scoria bomb breccias, (3) well-bedded tephra deposits even in the proximal facies, (4) moderate fragmentation of tephra (small proportions of both ash and coarse lapilli/bomb-size fraction), (5) abundance of dense ellipsoidal juvenile lapilli, and (6) characteristic depositional cycles in the early eruptive stages beginning with laterally emplaced, fine-grained, xenolith-rich tephra and ending with fallout scoria lapilli. Herchenberg tephra is distinguished from maar deposits by (1) paucity of xenoliths, (2) higher depositional temperatures, (3) coarser grain size and thicker bedding, (4) absence of glassy quenched clasts except in the initial stages and late phreatomagmatic marker beds, and (5) predominance of Strombolian, cone-building activity. The characteristics of Herchenberg deposits are interpreted as due to a high proportion of magmatic volatiles (dominantly CO2) relative to low-viscosity magma during most of the eruptive activity.

Dental replacement resorption after bone grafting to the alveolar cleft.

In a review of 100 consecutively performed bone grafts to the alveolar cleft, replacement resorption was found in 7 teeth adjacent to the cleft. Damage to the periodontal tissues during surgery is considered to be the main cause of this complication: granulation tissue from the bone graft may have some influence. Treatment of the affected teeth eventually includes extraction or surgical removal. To minimize the risk for this complication, we suggest that bone grafting should be done when the canine (or lateral incisor) is in an early stage of eruption and that orthodontic uprighting of the medial incisor should be done after surgery.

The formation of the vasculature of free gingiva in deciduous teeth of cats and dogs.

Vital microscopy, silicone rubber perfusion and histologic techniques were applied in a study of the development of the gingival vascular morphology in cats and dogs, during and following eruption of the deciduous canines and molars. It was found that vascular and histological events associated with the organisation of the capillaries in crestal gingiva predominated during the early stages of eruption. Vascular remodelling during the later stages of tooth eruption occurred in apical gingiva and was associated with apparent degeneration and loss of some vessels. A regular vascular network, comparable to that described by Hock and Nuki (1971), was found in all gingival specimens examined prior to the onset of clinical gingivitis.

Treatment of early measles with parental whole blood: Effect on clinical course and pulmonary complications in young children

Summary The etiological agent of measles is presumably a filtrable virus. The subsequent complications are presumably due to the presence of pathogenic bacteria. In an attempt to reduce the incidence of pulmonary complications and thus lower the mortality in children, sixtysix children under three years of age were injected subcutaneously with from 20 c.c. to 40 c.c. of adult blood during the pre-eruptive or early eruptive stages of measles. There was very little difference in the severity of the measles or in the incidence of pulmonary involvement, when these sixty-six children were compared with 758 children in the same age group who did not receive blood injections.

THE ETIOLOGY OF MEASLES

It is generally accepted as a proved fact that the contagium of measles is present in the blood stream during the late preeruptive and early eruptive stages of the disease. This was first conclusively demonstrated by Hektoen,1who produced clinical measles in two adults by injecting them with ascites broth which had been inoculated with blood from a measles patient. Experiments with monkeys2have confirmed the correctness of this view. The epidemiologic evidence indicates with great probability that the contagium is present in the throat and nasal secretions just before the fastigium and at the height of the eruption, disappearing or becoming noninfectious with the fading of the rash. While both of these facts have been apparent for some time, and attempts to cultivate the specific organism from the blood and throat secretions had been made, little had been accomplished until Tunnicliff,3in 1917, isolated a green,

STUDIES ON MEASLES

By the intratracheal injection into monkeys of unfiltered nasopharyngeal washings from cases of measles in the preeruptive and early eruptive stages of the disease a relatively constant group of symptoms was induced which closely resemble those of measles in man. Of seven monkeys inoculated intratracheally with unfiltered nasopharyngeal washings from seven cases of measles, five developed the symptoms. The same group of symptoms was induced in one monkey by inoculation of the mucous membrane of the nose and mouth with unfiltered nasopharyngeal washings from a case of measles. In these experiments a variety of organisms, largely saprophytic inhabitants of the nasopharynx and mouth, were present in the material inoculated. There is sufficient evidence, however, that these organisms were in no way responsible for the reaction, since the same group of symptoms was induced in two monkeys by the intratracheal injection of nasopharyngeal washings from three cases of measles after the washings had been freed from ordinary organisms of the mouth flora by filtration through Berkefeld N filters. The characteristic group of symptoms which follows the inoculation of monkeys with the nasopharyngeal washings from patients with measles has been. successfully carried through six passages by intratracheal injection of saline emulsions of the skin and buccal mucous membranes of monkeys killed from 2 to 6 days after the onset of the reaction. From the fourth passage monkey the reaction was also successfully induced in three monkeys by means of citrated whole blood injected intravenously. This experiment showed the blood to be capable of inciting the reaction from at least the 7th to 13th days after intratracheal inoculation of the donor monkey, but incapable of inducing it from the 2nd to 4th days. Cultures of the blood showed no growth. The group of symptoms induced has been constant and definite in character. After an incubation period of 6 to 10 days the animal becomes listless and drowsy, the conjunctivae become injected, and small, discrete, hyperemic macules appear on the labial mucous membrane. These spots increase in number and may eventually coalesce in the course of 2 to 4 days to form a diffuse, red, granular rash. This rash is usually limited to the labial mucous membrane but may extend to the inside of the cheeks. The individual macules may or may not show the minute bluish white center characteristic of Koplik spots. From one to several days after onset an eruption of small, discrete, red maculopapules appears on the skin, usually coming out first on the face. The rash progressively increases in the number and size of the individual lesions and may in the course of 2 to 3 days extend to the skin of the neck, shoulders, upper arms, chest, abdomen, and thighs. It is constant in character but varies considerably in extent in different animals. By the time the exanthem is fully developed, the rash on the mucous membranes has begun to fade and soon disappears. The exanthem in turn progressively fades, sometimes with a branny desquamation, sometimes without. There may be moderate pigmentation. By the 6th to the 10th day after onset all symptoms have disappeared and the animal again appears well. Coincident with this group of symptoms there is a constant and definite reduction in the total leucocyte count, frequently constituting a true leucopenia. Other symptoms of irregular occurrence are photophobia, diarrhea, and fever. Symptoms of rhinitis and bronchitis have not been noted. Histological sections of the lesions of the skin show an exudative and proliferative lesion about the capillaries of the corium in which endothelial leucocytes are the predominating cells. Mitotic cells are not infrequently present in these areas. The endothelial leucocytes may be seen migrating toward and occasionally invading the epithelial layers of the hair follicles, sebaceous glands, and epidermis. In places the epithelial cells appear edematous and vacuolated, and there is evidence of minute vesicle formation. The lesions of the labial mucous membrane are similar in character. Minute vesicle formation in the epithelium is more frequent and the vesicles occasionally assume a more pustular appearance. Similar lesions are found in histological sections of the tongue. Cultures of the blood made both during the incubation period and during the course of the reaction in a variety of media, aerobic and anaerobic, have consistently shown no growth. The close similarity of the symptoms and pathological lesions of the reaction to the symptoms and pathological lesions of measles, the successful transmission of the reaction from monkey to monkey, and the elimination of ordinary bacteria as a possible source of error in the interpretation of the results, warrant the belief that the reaction is caused by the inciting organism of measles.

Agglutination in Measles

In a previous article1 I have described a small, gram-positive diplococcus, which was isolated in anaerobic cultures from the blood of measles patients, during the pre-eruptive and early eruptive stages of the disease. Similar diplococci were also isolated from the throat, nose, eye, and in one instance from the ear. During the acute stage of measles, I found that the serum showed a diminished opsonic power for this organism,2 followed by a marked increase as the symptoms subsided and the rash began to fade. This increase in opsonins occurred generally on the third or fourth day after the appearance of the eruption and was specific for the measles diplococcus. The serum of measles patients gave slight complement fixation for the diplococcus,3 at the time corresponding to the height of the opsonic reaction. Measles serum was found also to agglutinate this diplococcus, but when first isolated the organism often agglutinated so much spontaneously that no satisfactory experiments could be made. Later, when studying the serum of rabbits immunized with diplococci isolated from measles, it was found3 that strains about one year old grew diffusely in dextrose broth and did not agglutinate spontaneously, but were agglutinated distinctly by immune rabbit serum. Hence it seemed worth while to study again agglutination reactions in measles. The new experiments were made at Camp Meade, Md. The serum of 10 measles patients was examined, generally daily, for agglutinins by the macroscopic method. A strain, isolated from the blood of a measles patient a few hours before the appearance of the eruption, was used in the experiments. Another blood strain isolated at the same time of the disease, was also tested from time to time and found to correspond closely in its agglutinative reaction. The diplococci were transplanted from human blood agar to dextrose (29fc) broth and incubated 24 hours. The mixtures of diluted serum and broth culture