OZONE DAMAGE AND SEMIMATURE-TISSUE NEEDLE BLIGHT OF EASTERN WHITE PINE

1967 ◽  
Vol 45 (11) ◽  
pp. 2047-2061 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Urban Areas ◽  
Average Concentration ◽  
Atmospheric Ozone ◽  
White Pine ◽  
Eastern White Pine ◽  
Naturally Occurring ◽  
Apparent Relationship ◽  
Coulometric Method ◽  
High Concentrations ◽  
Needle Blight

Investigations were conducted in forests remote from large urban areas to determine whether there was any cause and effect relationship between naturally occurring atmospheric ozone (O3) and semimature-tissue needle blight (SNB) of eastern white pine (Pinus strobus). The daily average concentration of atmospheric ozone, relative to cracking by rubber test strips, was determined for three seasons and no apparent relationship was found between excessive rubber cracking and the occurrence of outbreaks of SNB on susceptible white pines. The repeated application of vitamin C, a reducing agent, to newly developing needles of susceptible white pines, did not prevent the appearance of the symptoms of SNB or retard subsequent symptom development. In fumigation experiments with artificially produced ozone, concentrations of over 0.60 p.p.m., as measured by the manual potassium iodide method, or 0.40 p.p.m. by the coulometric method, were required to produce severe markings on the new needles of the white pine under study. Foliage on material derived from trees non-susceptible to SNB was more responsive to these high concentrations of ozone and exhibited more uniform damage than foliage derived from trees susceptible to SNB. The macroscopic and microscopic symptoms of damage caused by excess ozone were dissimilar from the typical symptoms of SNB. The results of these investigations indicate that naturally occurring atmospheric ozone in stands of eastern white pine is not an incitant of SNB.

The annual occurrence and effects of semimature-tissue needle blight on white pine

1971 ◽  
Vol 49 (3) ◽  
pp. 423-435
Author(s):  
S. N. Linzon
Keyword(s):  
Adverse Effects ◽  
Similar Pattern ◽  
Pinus Strobus ◽  
Premature Death ◽  
White Pine ◽  
Eastern White Pine ◽  
Foliar Symptoms ◽  
Needle Blight

The occurrence of semimature-tissue needle blight (SNB) on eastern white pine (pinus strobus L.) was closely followed for 7 years, 1957 to 1963. White pines susceptible to SNB displayed recurrent foliar symptoms in some years. Annual fluctuations in the incidence of SNB occurred in a similar pattern on widely separated sample plots in a localized area. Major outbreaks of SNB were infrequent and were often found to occur during a continuous sunny period following a period of excess rainfall. The adverse effects of the disease on foliage were reflected in reduced growth in other parts of affected trees and in premature death of perennially blighted trees.

HISTOLOGICAL STUDIES OF SYMPTOMS IN SEMIMATURE-TISSUE NEEDLE BLIGHT OF EASTERN WHITE PINE

1967 ◽  
Vol 45 (1) ◽  
pp. 133-143 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Pinus Strobus ◽  
Pine Needles ◽  
The Other ◽  
White Pine ◽  
Eastern White Pine ◽  
Histological Studies ◽  
Endodermal Cells ◽  
Needle Blight

The incipient symptoms of needle blight of eastern white pine (Pinus strobus L.) appear only in semimature tissues of current year needles, and the orange-red lesions then spread acropetally throughout adjacent, more mature, tissues. Semimature tissue of white pine needles is characterized by the start of the suberization of the radial and transverse walls of the endodermal cells. The first cells to break down in blighted semimature tissue occur in the mesophyll region of one of the ventral faces of the needle. Mesophyll necrosis spreads laterally to the other ventral face and finally to the dorsal face of the needle, before proceeding distally through mature tissue. Anatomical differences exist between needles collected from susceptible and non-susceptible white pines.

scholarly journals Microplastic Contamination in the Human Gastrointestinal Tract and Daily Consumables Associated with an Indonesian Farming Community

2021 ◽  
Vol 13 (22) ◽  
pp. 12840
Author(s):  
Anjar Tri Wibowo ◽  
Husna Nugrahapraja ◽  
Ruri Agung Wahyuono ◽  
Izzatul Islami ◽  
Muhammad Husain Haekal ◽  
...  
Keyword(s):  
Urban Areas ◽  
Average Concentration ◽  
Plastic Waste ◽  
Human Consumption ◽  
Freshwater Organisms ◽  
Farming Community ◽  
Indonesian Population ◽  
Soybean Cake ◽  
High Concentrations ◽  
Study Participants

Plastic is one of the most abundant pollutants in the environment. As a result of natural physical processes, large plastic waste is degraded into microsized particles (<5 mm) called microplastics. Because of their size, abundance, and durability, microplastics are widely distributed in the environment, contaminating food and water intended for human consumption. The extent of microplastic contamination in the human body is still unclear because there are few studies concerning microplastic contamination in human specimens and, in most studies, data were collected from city dwellers. Despite having the fourth largest population and being the fourth largest plastic waste producer in the world and second largest plastic polluter in the ocean, there are currently no data with respect to microplastic exposure for the Indonesian population. Several studies have reported on microplastic contamination in seafood and freshwater organisms from Indonesia, and it is likely that microplastics have contaminated the gastrointestinal tracts of Indonesians. Using Raman spectroscopy, we detected microplastic contamination in 7 out of 11 analyzed stool samples collected from a farming community in the highland village of Pacet, East Java, Indonesia. Polypropylene (PP) was the most abundant and prevalent type of microplastic observed, and it was found in four of the positive samples with an average concentration of 10.19 microgram per gram of feces (µg/g). Microplastics were also detected at high concentrations in tempeh (soybean cake, a staple protein source for Indonesians), table salts, and toothpaste, which were regularly consumed and used by the study participants. PP was particularly high in table salts (2.6 µg/g) and toothpaste (15.42 µg/g), suggesting that these products might contribute to the gastrointestinal contamination in the studied population. This pilot study indicated microplastic contamination in the rural Indonesian population and in their daily consumables, demonstrating the far-reaching extent of microplastic pollution beyond urban areas.

FIELD GRAFTING WITH HEALTHY AND NEEDLE-BLIGHTED EASTERN WHITE PINE TREES AND THE EXPRESSION OF DISEASE SYMPTOMS

1961 ◽  
Vol 39 (6) ◽  
pp. 1287-1292 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Pinus Strobus ◽  
White Pine ◽  
Stages Of Development ◽  
Eastern White Pine ◽  
Disease Symptoms ◽  
Pine Trees ◽  
Root Grafts ◽  
The Individual ◽  
Needle Blight ◽  
Made In

Healthy and needle-blighted eastern white pine trees (Pinus strobus L.) were intergrafted in the forest using bottle and cleft crown graft techniques. The grafts were made in four combinations of diseased and healthy scions and stock branches and at three different stages of development of the graft components. High percentages of successful grafts were obtained when the partner combinations included healthy scions and when the grafting was done in early May with active top growth just beginning in both scions and stock. Fewer grafts survived when diseased scions were employed and when the field grafting was carried out with dormant-collected scions or with scions and stock both possessing advanced new growth.Each grafted partner retained its original identity. Needle-blight symptoms appeared simultaneously on diseased scions and their mother trees, while the healthy stock trees remained unaffected. Conversely, healthy scions and their mother trees were unaffected while the diseased stock trees displayed the needle-blight symptoms on their foliage. No disease symptoms were transmitted by stem grafting. A search revealed that perennially needle-blighted trees were joined to neighboring healthy trees by natural root grafts, and that there was no visible communication of the disease symptoms. Additional evidence has been presented to show that needle blight is nonparasitic in etiology and that susceptibility to needle breakdown is inherent in the individual.

Etiological studies on needle fungi associated with semimature-tissue needle blight of eastern white pine

1968 ◽  
Vol 46 (12) ◽  
pp. 1565-1574 ◽  
Author(s):  
S. N. Linzon
Keyword(s):  
Bordeaux Mixture ◽  
Growing Season ◽  
Morphological Development ◽  
White Pine ◽  
Eastern White Pine ◽  
Saprophytic Fungi ◽  
Disease Symptoms ◽  
First Occurrence ◽  
Spore Trapping ◽  
Needle Blight

The results of etiological studies on semimature-tissue needle blight (SNB) of eastern white pine (Pinus strobus L.) deny any role to needle fungi as the primary cause. No mycelium was found in newly blighted semimature tissue by either cultural or histological methods. Mycelia of several saprophytic fungi were isolated from the blighted portions of current year needles about 2 weeks after the onset of SNB, and fruit-bodies of different organisms were found to occur both in the interior and on the exterior of blighted needles about 4 weeks after the first occurrence of disease symptoms. The fruit-bodies of two Ascomycetes, Cenangium acuum Peck & Cooke and Hypoderma desmazierii Duby (= Lophodermium brachysporum (Rostrup) Tub.), were found on the necrotic terminals of attached 1-year-old needles which had been blighted in the previous year. The morphological development of apothecia of C. acuum was studied. Hysterothecia of Lophodermium spp. (L. pinastri (Schrad. ex Fr.) Chev. and L. nitens Darker) occurred ubiquitously on fallen white pine needles. Aerial spore trapping snowed that ascospores of C. acuum were abundant, those of Lophodermium spp. were prevalent, and those of H. desmazierii were practically non-existent in the area investigated. There was little coincidence between the occurrence of SNB outbreaks and peak populations of air-borne ascospores of these fungi. Ascospore suspensions and needles bearing fructifications of C. acuum and Lophodermium spp. were used to inoculate the newly developing needles of SNB-susceptible and non-susceptible field trees and potted seedlings, but the typical symptoms of SNB did not develop as a result of these inoculations. Two fungicides, captan and Bordeaux mixture, were applied to SNB-susceptible and non-susceptible field trees throughout the growing season, but neither fungicide prevented the symptoms of SNB from appearing on the new needles of susceptible trees at the same time as they appeared on untreated susceptible trees in the area. The fungicidal sprays, however, did prevent saprophytic fungi from invading blighted portions of the needles. It is concluded from this investigation that SNB is not a disease of fungal origin.

scholarly journals Desensitization Contributes to the Synaptic Response of Gain-of-Function Mutants of the Muscle Nicotinic Receptor

2006 ◽  
Vol 128 (5) ◽  
pp. 615-627 ◽  
Author(s):  
Sergio Elenes ◽  
Ying Ni ◽  
Gisela D. Cymes ◽  
Claudio Grosman
Keyword(s):  
Nicotinic Receptor ◽  
Dissociation Rate ◽  
Gain Of Function ◽  
Naturally Occurring ◽  
Channel Opening ◽  
Speed Up ◽  
High Concentrations ◽  
Dissociation Rate Constants ◽  
Kinetics Of ◽  
Peak Value

Although the muscle nicotinic receptor (AChR) desensitizes almost completely in the steady presence of high concentrations of acetylcholine (ACh), it is well established that AChRs do not accumulate in desensitized states under normal physiological conditions of neurotransmitter release and clearance. Quantitative considerations in the framework of plausible kinetic schemes, however, lead us to predict that mutations that speed up channel opening, slow down channel closure, and/or slow down the dissociation of neurotransmitter (i.e., gain-of-function mutations) increase the extent to which AChRs desensitize upon ACh removal. In this paper, we confirm this prediction by applying high-frequency trains of brief (∼1 ms) ACh pulses to outside-out membrane patches expressing either lab-engineered or naturally occurring (disease-causing) gain-of-function mutants. Entry into desensitization was evident in our experiments as a frequency-dependent depression in the peak value of succesive macroscopic current responses, in a manner that is remarkably consistent with the theoretical expectation. We conclude that the comparatively small depression of the macroscopic currents observed upon repetitive stimulation of the wild-type AChR is due, not to desensitization being exceedingly slow but, rather, to the particular balance between gating, entry into desensitization, and ACh dissociation rate constants. Disruption of this fine balance by, for example, mutations can lead to enhanced desensitization even if the kinetics of entry into, and recovery from, desensitization themselves are not affected. It follows that accounting for the (usually overlooked) desensitization phenomenon is essential for the correct interpretation of mutagenesis-driven structure–function relationships and for the understanding of pathological synaptic transmission at the vertebrate neuromuscular junction.

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