Peak In Early Summer Research Articles

So-called accidental firearm fatalities in children and teenagers in Tennessee, 1961-1988.

Tennessee State medical examiner reports of firearm fatalities classified as accidents involving victims aged 19 year or less from 1961 through 1988, were reviewed to evaluate circumstantial and contributing factors. A total of 225 were analyzed. The peak age for victims was 17 years, and there were more than five times more male than female victims. In Shelby County (Memphis), the racial distribution of fatalities was approximately that of the general population. Playing with a gun was the most frequent circumstance. The person responsible for pulling the trigger was equally likely to be a friend, a family member, or the victim. Head or neck were injured in most cases. The urban mortality rate was nearly twice that of the rural rate. More than half of the deaths in urban counties occurred indoors and involved handguns, whereas in rural counties only a third were due to handguns and the location was more often outdoors. Deaths in rural counties showed a seasonal variation that corresponded with the hunting season; by contrast, a peak in early summer was noted in the urban deaths. Defective guns or guns unsafe in design caused several deaths. (Semiautomatic pistols, which can be fired after unloading the ammunition magazine, are conspicuous examples of guns unsafe in design.) An important observation of this study is that medical examiners vary considerably in their classification of accidental manner, particularly when children are involved. Furthermore, medical examiner reports need to include much more information than is currently recorded if they are to be useful in guiding public policy to reduce firearm injuries.

台湾の梅雨(Mei-Yu)期に観測されるメソスケール降水系の特徴

Mei-Yu (Baiu in Japan) is a weather and climate phenomenon in the area of Japan, Taiwan, and subtropical China where the seasonal rainfall distribution reaches a peak in late spring and early summer due to the repeated occurrence of the Mei-Yu front. From the satellite pictures, the Mei-Yu front is usually accompanied by a nearly continuous cloud band with organized mesoscale convective systems (MCSs). To the south of the Mei-Yu front, a low-level jet (LLJ) is often observed and is closely related to the formation of MCSs and heavy rainfall events. As the Mei-Yu front approaches Taiwan, the front and the accompanying MCSs and LLJ tend to be affected by the mesoscale topography of Taiwan, the Central Mountain Range (CMR). Besides, the land-sea contrast coupled with island topography produces the land-sea breeze, the mesolow, and the island circulations which are important in modulating the local precipitation.In this paper, an overview of the current understanding of the structure and dynamics of the mesoscale features observed in the Taiwan Mei-Yu season is presented. Research results in the pre-TAMEX era as well as those derived from TAMEX program are discussed for the Mei-Yu front, the LLJ, the MCSs, the mesolow, the land-sea breeze, and the island circulations.

Six years of public health surveillance of measles in France.

Data provided by the Sentinel General Practitioners (SGP) to the French Communicable Diseases Computer Network (FCDN) have been used to present the epidemiological characteristics of measles observed during a 6-year period in France. The estimated annual incidence rates per 100,000 population were 376 in 1985, 603 in 1986 and 983 in 1987, then declined during the following 3 years to 297, 258, and 263 per 100,000 population in 1988, 1989 and 1990 respectively. There is a marked seasonal change with a high early summer peak. The mean age among the cases for the 6 years of study varied from 5.4 to 6.0 years. There is an increase in the percentage of cases with a past history of measles vaccination, from 6.7% in 1985 to 12.8% in 1990. This increase may be interpreted as a consequence of a substantial increase of the vaccine coverage during the same period.

Seasonal patterns of pasture production in the Bay of Plenty and Waikato

Patterns of pasture growth were measured on 3 farms in the Bay of Plenty (BOP) and at No2 Dairy (Ruakura Agricultural Centre) in the Waikato from 1989 to 199 1. A standardised trim technique with cages and 4-weekly cutting under grazing was used. Long-term seasonal growth patterns, using a predictive pasture model, were also simulated. Simulated pasture growth from long-term climatic data shows that pasture growth rates are higher in winter, early spring and late autumn in the BOP than the Waikato. However, the actual measurements over the 2 years show that pasture growth over the latter periods is lower at the BOP sites than at the Waikato site. In the BOP the spring peak is much later than in the Waikato while an early summer peak, with higher growth rates than in the Waikato, occurred in the BOP. No such summer peak was evident in the Waikato. The difference between the two regions is caused by the large contribution of subtropical grasses to sward production in summer and autumn, The prolific summer growth of subtropical grasses may explain the low ryegrass content and low pasture production in winter. The lower than expected autumn, winter, spring production may also becaused by low clover content, possibly a result of competition from subtropical grasses and a sulphur deficiency. The apparent low amount of nitrogen fixed by clover may explain the low rates of pasture production over the cooler season. Applications of nitrogen fertiliser may substantially increase dry matter production from April to September. Keywords pasture,simulation,subtropical grasses, Paspalum, Digitaria sanguinalis, growth rates

Trombiculid Mites (Acari: Trombiculidae) and Rickettsia tsutsugamushi Isolated from Wild Rodents in a New Endemic Area of Japan

Investigations of trombiculid mites and Rickettsia tsutsugamushi in wild rodents were made in southern Gifu Prefecture where patients infected with tsutsugamushi disease recently have been found. A total of 16,396 trombiculid mites, consisting of 10 species from three genera, was collected from 170 Apodemus speciosus in two locations. Kani-Sakahogi and Kuze. Leptotrombidium scutellare (Nagayo et al.) (44.0%) was most predominant, followed by L. pallidum (Nagayo et al.) (26.9%); L. fuji (Kuwata et al.) (13.6%); and Gahrliepia saduski Womersley (14.2%). These four species constituted the bulk of the chigger mite fauna. L. scutellare was present from October to February with a remarkably high peak in November, whereas pallidum occurred from November to March with the highest peak in December. L. fuji and G. saduski showed their highest peaks in December and moderate peaks in early summer (April and May). Positive identification of Rickettsia tsutsugamushi in wild rodents from Kani-Sakahogi were found to be 50 and 58.3% in November 1985 and 1986, respectively, and 38.5% in November 1986 from Kuze. R. tsutsugamushi was isolated from chigger mites of an L. pallidum-rich group, displaying the highest titer to Karp strain. Serological investigation of rodents to R. tsutsugamushi antibodies were calculated as 41.6 and 50% positive in November 1985 and 1986 in Kani-Sakahogi, respectively, and 50% in November 1986 in Kuze. The Karp strain was dominant in specificity to antibodies. These results indicate that the surveyed areas have a high probability of occurrence of tsutsugamushi disease, and L. scutellare and L. pallidum may serve as the vectors in these areas. Particularly, we suggest that L. scutellare is the most important vector which has caused a recent outbreak of this disease in southern Gifu Prefecture.

Canopy dynamics of lianes and trees in subtropical rainforest

Canopy dynamics of lianes and trees in subtropical rainforest

甑列島産キビナゴの個体群構造

In this paper, yearly catches from 1975 to 1985, monthly catch statistics from 1984 to 1986, and biological characteristics in 1987 of the blue sprat Spratelloides gracilis (Temminck et Schlegel) were studied in Koshiki Is., southern Japan. Yearly catches ranged from about 400 to 700t, which accounted for 13-22% of total catch in Kagoshima Prefecture. Seasonal catches showed 2 fluctuations, i.e. one from spring to autumn with a peak in early summer, and the other from autumn to spring with a peak in late autumn. The former, having a higher peak, was composed exclusively of spawning adults, and the latter of immature young. Biological characteristics were different between the sexes: males are smaller in body size but larger both in coefficient of fatness and gonad index, and fewer in number than females.

Population Dynamics of Brachycorynella asparagi (Homoptera: Aphididae) on Undisturbed Asparagus in Washington State

Dynamics of the asparagus aphid, Brachycorynella asparagi (Mordvilko), were studied in two mature asparagus fields and one immature field for a minimum of two seasons. To minimize disturbance to the asparagus, no harvesting, spraying, or cultivation was done. Numbers of B. asparagi were low early in the spring and increased to a peak in late June or July or in September to early October. No midseason peak was observed. Fields with an early summer peak had a midsummer low point and usually a late summer peak. Decline of aphid numbers in the fall coincided with egg laying that started during the last week of September when day length was about 12 h. Production of winged aphids and parasitism by Diaeretiella rapae (McIntosh) were density-dependent on some plots. These mortality factors undercompensated for changes in aphid density and failed to keep aphid numbers at acceptable levels. No consistent, significant correlations between temperature or rainfall and aphid numbers were found. Egg hatch occurred shortly after the first asparagus spears emerged in the spring. Predicted time of egg hatch based on degree days was within 1 d of observed hatch. Growth of asparagus plants during a growing season had a weak, inverse relationship to aphid numbers.

Seasonal changes in abundance and spatial distribution of the soil arthropods in a Japanese cedar (Cryptomeria japonica D.Don) plantation, with special reference to collembola and acarina

AbstractSeasonal changes in abundance and distribution pattern of soil micro‐arthropods were studied in connection with a few environmental factors in a Japanese cedar (Cryptomeria japonicaD. Don) plantation. The soil arthropods were sampled from three different depths at intervals of two months for two years. Of the collected animals (total 51000–155000 m−2), Collembola (20000–76000 m−2), oribatid mites (19000–55000 m−2) and carnivorous mites (6200–21000 m−2) were the numerically dominant animal groups. Low seasonal variations in abundance indicated their seasonal stability in population levels. The trends in seasonal fluctuation were similar among these groups and between the two years, showing bimodal pattern with little peaks in early summer and winter. The pattern of seasonal fluctuation in abundance of carnivorous mites (Pd) was significantly synchronized with that in the total abundance of Collembola and oribatid mites (Pτ). Thus, the number‐ratios (Pd/Pτ) were fairly constant, ranging from 0.10 to 0.25. Seasonal changes in vertical distribution of the three animal groups showed a similar pattern for both years. The downward migrations were shown to be more affected by low temperatures in winter accompanied by snow coverage rather than by the desiccation of the surface soil in summer. All the three groups demonstrated as a whole slightly aggregated patterns of horizontal distribution throughout the two years. Temporal increases in the patchiness indices were observed from summer to autumn when the moisture content of the surface soil was low.

A long-term study of streptococcal infection experienced at an outpatient clinic--outline of patients, diagnoses and serotype of isolates

For the purpose of investigating the present condition of streptococcal infection in a typical pediatric outpatient clinic, this observance was undertaken at a private clinic in Matsuyama City, Ehime Pre., Shikoku Island.A total of 2373 cases of streptococcal infection, confirmed bacteriologically, were studied from May, 1975 to March, 1985. Results were as follows:1) Group A streptococci were identified in 96.2% of these cases; 68.1% of the patients had been diagnosed as pharyngitis and 31.2% as scarlet fever.2) Usually two epidemic peaks were observed in each year, which was measured as the period from the beginning of April to the end of the following March. One was a small peakoccuring in early summer (mainly May, June and July) and the other was a large peak occuring in winter (Oct., Nov. and Dec.). From the analysis of age distribution of the patients and serological types of group A streptococcal isolates, it seems that the typical epidemic is caused by onetype of streptococcus. The largest number of cases is seen in the winter, because of the patients' lowered resistance, andthe beginning of the school year in April exposes susceptible youngsters toinfection, resulting in a small epidemic peak in early summer.3) Prevalent serotypes of group A streptococci were types 12, 4 and 1. It was observed that the peak frequency of isolation could be found for each strain every 5 to 6 years.4) T-typable rate of group A streptococcal isolates was 99.6% and M-typable rate was 67.9%. Coincidence between T and M types was as follows; Type 3; 97.9%, Type 6; 97.7%, Type 4; 92.4%, Type 1; 91.3%, Type 12; 79.9%.5) M12 strain had a more statistically significant tendency to induce scarlet fever than did the other types of group A streptococci.6) 12.9% of the patients in this study were confirmed to be reinfected cases. It is speculatedthat this result suggests that the use of antibiotics in the early stages of infection surpressed the production of antibodies and was responsible for the later reinfection.

Seasonal variation in mental depression and its correlation with occupation.

The seasonal variation in non-psychotic depressive morbidity was examined in 806 males aged 50 years and over using a 12-item questionnaire. A significant seasonal pattern in depressivity was revealed, with its peak in early summer. There was also a significant difference in the pattern depending on occupation, the summer peak for depression being typical of the middle social classes and agricultural occupations, while the peak tended to be focused later in the year at both ends of the social scale and in occupations outside agriculture. The monthly variation in depression showed some association with length of day but not with air temperature.

Riparian Vegetation of the Northern Range, Yellowstone National Park; Classification, Succession and Environmental Relationships

For many years interest in and research concerning wetlands has lagged behind the more extensive efforts put furth in upland and aquatic ecosystems. Recent years have seen wetlands featured in several symposia (Johnson and Jones 1977; Johnson and others 1985; Ratliff 1985; Brosz and Rodgers 1986). Within the Greater Yellowstone Ecosystem and contiguous areas several studies both intensive (Norton, et al 1981; Tuhy 1981; Mattson 1982; Mutz and Queiroz 1983)and extensive (Tuhy and Jensen 1982; Youngblood, et a1 1985; Pierce and Johnson 1986) have been completed. The climate of northern Yellowstone is a hybrid between continental and inland maritime. There is a gradient in precipitation and temperature between the lowest recording station Gardiner (1616 m) and the Northeast Entrance station (2244 m). Gardiner, by virtue of its low elevation, is the warmest and driest location with only 277 mm mean annual precipitation, of which most occurs in the late spring-early summer. The Northeast Entrance, the highest reporting station in this Northern portion of the park, is the wettest (670 mm) and coldest. However, precipitation at the Northeast Entrance is more evenly distributed throughout the year with distinct peaks in early summer and mid winter. Of potentially greater importance than climate to understanding wetland composition is water chemistry. Streams originating to the east of the study area in the Absaroka Range drain predominately extrusive igneous (andesitic) rock and glacial till. Streams originating to the south of the study area drain oligotrophic tephra and rhyolitic substrates. To the west and north a mix of sedimentary and glacial till substrates are represented. Groundwater from these distinct geologic substrates, in addition to water from unique thermal features producing a complexity of groundwater environments in this "northern range".

Evidence That Filterable Phosphorus Is a Significant Atmospheric Link in the Phosphorus Cycle

Deposition of phosphorus from the atmosphere was measured weekly over 7 annual cycles in the montane region of Colorado, USA. Deposition of phosphorus consistently reached a sharp peak in early summer, near the beginning of maximum biological activity. The peak is associated with soluble phosphorus capable of passing through a filter. Pollen studies show that the peak cannot be accounted for by leaching of phosphorus from pollen, and the amounts of miscellaneous mineral and organic particulate materials are too small to account for the peak. The study thus indicates transport of filterable, water-soluble phosphorus substance, probably of biogenic origin, in large amounts over a short period of time. This transport mechanism, heretofore unsuspected, may account for significant long-distance phosphorus transport.

Experiments on Disturbance in Old‐Field Plant Communities: Impact on Species Richness and Abundance

Changes in species richness and abundance following experimental disturbance were studied in a 7th—yr old field (the “older” field) dominated by Solidago canadensis, and 2nd—yr old field (the “younger” field) dominated by Ambrosia artemisiifolia. The two fields were disturbed in late spring 1981 by clipping and removing aboveground plant biomass in experimental plots, which were compared with undisturbed control plots. Treatments represented three intensities of disturbance (low, intermediate, and high), as defined by amount of biomass removed and extent of canopy disruption. Different patterns of change in richness were observed in each field during the 1981 growing season. In the older field the number of species decreased in control plots during the summer. In disturbed plots, richness increased with intensity of disturbance, resulting in maximum richness at the highest disturbance intensity during mid— and late summer. Several species increased significantly in cover and/or frequency in plots representing intermediate and high intensity of disturbance. In the young field, species richness fluctuated in control plots, with peaks in early and late summer. In disturbed plots, richness decreased with intensity of disturbance in early summer and increased in midsummer. By late summer no difference in richness or species composition was detected between control and clipped plots. These patterns of change in richness can be explained by the different effect of treatments on the vegetation structure and by the role of the dominant species in each field. In the bi—layered older field, disturbances greatly disrupted the closed canopy of S. canadensis, thus providing resource patches (i.e., increased light, moisture) for suppressed and invading species. In the younger field, the impact of disturbance was only detectable in early and midsummer, and changes in richness were mainly related to the seasonal cycle of the dominant annual A. artemisiifolia. Results from these experiments provide insights into the mechanisms of species coexistence under natural disturbance regimes comparable to our disturbance treatments. They also indicate that the impact of disturbance on species richness depends largely on the nature of the dominants and rates of successional or seasonal change of the community.

TAPHONOMY OF PROSPECTIVE PLANT MACROFOSSILS IN A RIVER CATCHMENT ON SPITSBERGEN

SummaryRepresentation of recent plant parts in fluvial sediments and in the vegetation of a braided‐river catchment on Spitsbergen was studied quantitatively in order to provide a model for taphonomy of plant macrofossils during cold stages of the British Pleistocene. The area studied on the Adventelva is in a region with continuous permafrost and on a river that has high (nival) peak discharges in early summer, features that were also present in the British lowlands during the Pleistocene cold stages.Deposition of ‘prospective macrofossils’ in silts of channels on the Adventelva floodplain occurred mainly during the decline from the early summer peak of discharge. Surface runoff overland was much the most important process by which ‘prospective macrofossils’ reached river channels, and this accounts for them giving a surprisingly even overall representation of the abundance of similar parts in the vegetation. Taxa having ‘prospective macrofossil parts’ that were under‐represented in the deposits had parts that were: (a) very small, (b) of soft or perishable texture, (c) firmly attached to stems, (d) neither deciduous nor renewed annually, or (e) they were plants growing on the river floodplain. Taxa with parts over‐represented in the deposits were: (a) those with parts that break into numerous identifiable fragments, or (b) they were plants growing in localized areas of late snow‐lie.

Nipple-search pheromone in rabbits: dependence on season and reproductive state

By using the response of newborn pups to test for the presence of nipple-search pheromone on female rabbits, it could be shown that: 1. In non-breeding does pheromone emission follows a seasonal cycle with the peak in early summer, and this appears to be dependent on daylength. 2. At all times of year the probability of pheromone being present increases during pregnancy and decreases again during late lactation or following early removal of pups. 3. Pheromone emission is depressed following ovariectomy but can be stimulated by administration of estradiol.

Studies of hypersensitivity with mold in allergic diseases of respiratory tract (author's transl)

The significance of the mold as an allergen in the allergic diseases of the respiratory tract was studied. The air-borne mold was surveyd for the past five years. The results of the skin test performed on 4510 cases with the respiratory allergic disease were also analyzed. The allergic condition of respiratory tract was generally, divided into two types, upper respiratory type (nasal allergy) and lower respratory type (bronchial asthma). The IgE concentrations and IgE antibody levels in the sera of 20 cases of each two types were titlated with RIST and RAST. Those levels were compared between each allergen and between each disease type. The results were as follows; 1) Using the slide glass method, ten kinds of the mold spores were identified by the air-borne mold spores survey. The kinds of mold detected were changed every year. However, Al-ternaria and Epiccccum were observed abundantly every year. The amount of the spores varied seasonally and showed two peaks in early summer and fall. The spores diminished in winter remarkably. 2) The kinds of mold identified with culture plate method also changed every year. The seasonal peak of the amounts of the mold was not always similar to those with slide glass method. 3) The mold, with which the immediate reaction of the skin test was highly positive, were Candida, Aspergillus, Trichophyton, Penicillium, Cladosporium and Alternaria. And the skin test with Candida and Trichophyton showed positive delayed reaction frequently. 4) Not only IgE concentrations, but also IgE antibody levels of the sera, were higher in the lower respiratory type than in the upper respiratory type. 5) It is suggested that the sensitive organs with mold are selected with the size of the spores. And almost all kinds of the mold, except Alternaria, are considered to he more significant allergen for the allergic diseases of the lower respiratory tract (bronchial asthma) than of the upper one (nasal allergy).

Seasonal Nutrient Dynamics of Litter in a Subtropical Eucalypt Forest, North Stradbroke Island

The plant components and chemical composition of litter fall and the litter layer in a forest growing on deep, nutrient-poor sands were examined on North Stradbroke Island, south-eastern Queensland. The seasonal distribution of litter fall was examined over a 26-month period. While the total litter fall was greatest during summer months, the dominant tree species differed in their individual patterns of litter fall. Eucalyptus signata showed a single summer peak for leaf fall while E. umbra exhibited one peak in early summer and another in autumn. The possibility is discussed that these and other temporal differences are evolutionary expressions of niche differentiatibn to reduce competition between species in the ecosystem. The total litter fall averaged 640 g m-1 yr-1 and the accumulated forest floor mass totalled 2700 g m-2. Total nutrient pools and nutrient inputs in litter fall are presented. A litter half-life of 2.9 years is estimated, a figure close to the half-life of most of the nutrients in the litter. Manganese appears to be markedly concentrated in eucalypt leaves before they fall. Only sodium, potassium, copper and chloride appear to be leached easily from leaves slashed from trees and left on the forest floor. Patterns of litter production and decay in this subtropical forest fit within trends extrapolated from temperate Eucalyptus-dominated communities studied to date.

Patterns in the numbers of air-borne conidia of apple powdery mildew,Podosphaera leucotricha(Ell. and Ev.) Salm., and their relevance to control measures

Abstract Air-borne conidia of apple powdery mildew, trapped for two seasons, showed a marked seasonal periodicity. Spore concentration rose rapidly in spring (October) to reach a peak in early summer (November) then declined until the end of February. No evidence was found for a weekly periodicity of spore release. Fungicidal spray experiments in a third season demonstrated the importance of close-interval spray application during spring (October—November), the period during which apple trees show active extension growth. Such spraying was important both in reducing current season build-up of infection and in preventing the formation of overwintering sources of primary infection in buds.

VI. Wairakei, pasture and lucerne production

Abstract Pasture growth rates are presented for a hill and flatland site on pumice soils at Wairakei for a 7-year period. They were obtained from grazing trials cut by a standardised cutting method at regular intervals using a movable cage technique. The mean yield and standard error of individual samples over all years of measurement are given for standard dates at 14-day intervals. The growth pattern at each site had a spring and early summer peak, a summer depression, and a smaller but more variable peak in autumn. On the flatland site spring growth and the early autumn flush were delayed compared with the hill site. The hill site had substantially higher growth rates than the flatland site. At both sites about 8% of the annual yield was produced in winter (June, July, and August), 38% in spring, 37% in summer, and 17% in autumn. Spring, summer, and autumn growth rates were more variable on the flatland site than on the hill site, but this was reversed in winter. Seasonal growth rates and annual yields...