PROPERTIES OF THE DEAMINASES IN BLOOD AND TISSUES Methods. Water extracts of tissues ground with pure quartz sand (Merck's) were used throughout unless otherwise stated. The efficiency of extraction with water and saline extracts etc. is commented on below. For the ammonia and other estimations the procedure described in the previous paper [Conway & Cooke, 1939] was used.

II. THE NORMAL CONTENT OF NH3 IN CIRCULATING BLOOD Methods Experimental. The blood either from an arm vein in the resting human subject, or from the carotid in the anaesthetized rabbit (ether anaesthesia) or from the severed neck vessels in the fowl has been investigated. The method of collecting the blood has been already described [Conway, 1935] the same procedure being adopted, using a carotid cannula in the rabbit. Revised method. Analytical. The method of suspended absorption [Conway, 1935] with the special micro-diffusion "unit" [Conway & Byrne, 1933] has been used, but revised in certain points. The essential differences of the revised method consist first in standardizing the whole procedure with each series of determinations by means of a duplicate control on standard ammonium sulphate solutions. When this is done with the same glassware, all corrections for this and the alkali as well as temperature effects on the absorption rate are eliminated. Also it is recognized that the emission rate of NH3 from a blood-carbonate mixture is not quite the same as from a water-carbonate mixture. The previous conclusion in this respect [Conway, 1935] was based on a few recoveries under conditions not quite ideal for the comparison, though it was pointed out that a small difference was unimportant. A very large number of such recoveries of comparatively high NH3 quantities (to avoid appreciable fluctuations of the blood NH3 throughout the procedure) has since been carried out. The NH3 formed by the alkali in addition to the preformed NH3 in blood has also been carefully studied. It has been found to be strictly linear with the time over a few hours. No essential difference from the previous conclusions has been found, but a temperature factor has been included which, however, for the short absorption periods is scarcely significant. In Table I are incorporated the necessary details for the revised method. The allowances for the alkali action on the blood have been calculated with the help of the formula previously given [Conway, 1935] and correspond with the experimental findings. Calculation of the blood ammonia using the revised method. This is shown by an example. Example 1. (All titrations carried out in duplicate, the control solution containing 2,ug./ml. NH3-N.) Titration of "blank" unit ...

Abstract:The invasive woodwasp Sirex noctilio (Hymenoptera: Siricidae) is established in east-central North America. A replicated case study testing the effectiveness of silvicultural treatments for reducing the number of S. noctilio attacked trees in a stand was conducted in New York, USA. Silvicultural treatments reduced S. noctilio attacked trees by approximately 75% over the course of the study. There was no tree growth response to silvicultural treatments in the four years after thinning, but targeted removal of weakened trees removed potential S. noctilio habitat from treated stands. Two spectral vegetation indices were used to determine tree health in each treatment and potentially provide guidance for detection efforts. Silvicultural treatment significantly influenced the Red Edge Inflection Point, a strong indicator of chlorophyll content, and the Moisture Stress Index, a reflectance measurement sensitive to changes in foliar leaf water content, with the greatest differences occurring between control and treated blocks. Vegetation indices showed promise as a tool for aiding in stand prioritization for S. noctilio surveys or management activities.

A nonnative woodwasp of Eurasian origin, Sirex noctilio F., was detected recently in Oswego, New York, infesting Scots, red, and white pine. S. noctilio has caused periodic widespread losses of pine timber resources in several Southern Hemisphere countries and may cause significant damage in pure even-aged stands and overstocked plantations in North America. However, stand management and biological control programs have successfully managed S. noctilio populations in other countries and similar programs are being developed for North America. Until the primary biological control agent, Beddingia siricidicola, a parasitic nematode, is established in North America, forest owners will have to rely solely on silvicultural treatments to reduce the susceptibility of at-risk pine stands to S. noctilio attack. Silvicultural treatments including precommercial thinning, promoting optimal growing conditions for pines on a given site, reducing numbers of susceptible hosts, and consistent monitoring of stands are suggested activities to help protect pine stands from invasion by S. noctilio.

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