Fluxes of Cu,Zn, Pb,Cd, Cr,and Ni in temperate forest ecosystems

The literature on the fluxes of six heavy metals in temperate forest ecosystems is reviewed. Special attention is given to wet and dry deposition and internal flux, to metal budgets for ecosystems and soils, to concentrations in aqueous compartments of the ecosystem and to speciation in soil solutions. Metal fluxes are discussed in relation to pollution load, soil type, tree species and land use. The mobility of Cu and Pb is strongly dependent on the solubility of organic matter. These metals are commonly accumulated in forest soils. Zinc, Cd and Ni are greatly influenced by soil acidity and are often lost in considerable amounts from acidified soils. Chromium is often at balance in forest ecosystems. Implications for metal solubility and budgets in forest soils are discussed in connection with an increase in soil acidification.     

Biological control of cereal seed-borne diseases by seed bacterization with greenhouse-selected bacteria

About 400 bacterial strains, isolated from roots of wild and cultivated plants, were screened for effects against diseases caused by Drechslera teres and/or Microdochium nivale in greenhouse tests and against common bunt caused by Tilletia caries in field tests. Four of the strains showed good biocontrol activity <70% disease reduction) against D. teres and T. caries both in screenings and field tests. One Pseudomonas isolate, MA 342, strongly and reliably suppressed both D. teres and T. caries in the field, while effects against M. nivale were weaker. The effects could not be enhanced by varying pre-application or seed application procedures. This isolate could be stored as a suspension in a refrigerator, frozen or applied to seeds for at least one month without loosing its disease controlling ability.     

Chronic toxicity of fenoxycarb to the midge Chironomus riparius after exposure in sediments of different composition

Background, aim, and scope  

Fenoxycarb is an insect growth regulator widely used to control a variety of pests. As a juvenile hormone analogue, it interacts with the natural hormones involved in insect development, inhibiting metamorphosis to the adult stage. Adverse effects of fenoxycarb on non-target organisms have been repeatedly observed and its rapid dissipation from water to the organic fraction of the sediment is known. The aim of this work was to investigate the impact of fenoxycarb on the development of sediment-dwelling larvae of the midge Chironomus riparius after exposure to spiked sediment.     

The fibrillar orientation in the S2-layer of wood fibres as determined by X-ray diffraction analysis

Summary It is the fibrillar orientation in the S2-layer which to a great extent determines the mechanical properties of the wood fibre, with regard both to strength and stiffness and to swelling properties. Measurements of the average fibril angle of fibres are not however easy and the results differ between the methods used. In order to evaluate in more detail how the fibril angle varies in spruce wood, an X-ray method based on diffraction from the 040-plane was developed. By comparison with microscopic examination it is concluded that reliable results relating to the fibrillar orientation in the S2-layer are obtained with the X-ray technique. It is shown that the fibril angle of mature wood is rather constant with regard to both age of the annual ring and its position in the height of the tree. The fibril angle of the earlywood is found to be only slightly higher than that of latewood fibres. It is also shown that compression wood may be easily identified by virtue of the fact that its fibril angle is much higher than that of normal mature wood.The authors thank Ms Ulla Jonsson for the microscopic measurements and Dr Anthony Bristow for the linguistic revision     

Economic utility of 3D remote sensing data for estimation of site index in Nordic commercial forest inventories: a comparison of airborne laser scanning,digital aerial photogrammetry and conventional practices

ABSTRACT

Forest productivity is a crucial variable in forest planning, usually expressed as site index (SI). In Nordic commercial forest inventories, SI is commonly estimated by a combination of aerial image interpretation, field assessment and information obtained from previous inventories. Airborne laser scanning (ALS) and digital aerial photogrammetry (DAP) data can alternatively be used for SI estimation, however the economic utilities of the inventory methods have not been compared. We compared seven methods of SI estimation in a cost-plus-loss analysis, by which we added the expected economic losses due to sub-optimal treatment decisions to the inventory costs. The methods comprised direct and indirect estimation from combinations of ALS, DAP and stand register data, and manual interpretation from aerial imagery supported by field assessment and information from previous inventories (conventional practices). The choice of method had great impact on both the accuracy and the economic value of the produced estimates. Direct methods using bitemporal ALS and DAP data gave the best accuracy and the smallest total cost. DAP was a suitable and low-cost data source for SI estimation. Estimation from single-date ALS and DAP data and age obtained from the stand register provided practical alternatives when applied to even-aged stands.     

Salmonella isolated from individual reptiles and environmental samples from terraria in private households in Sweden

Background

This study investigates Salmonella spp. isolated from privately kept reptiles and from environmental samples such as bedding materials or water from the floor of the enclosures (terraria). It also compares isolation of Salmonella using Modified Semisolid Rappaport-Vassiliadis (MSRV) medium or selective enrichment in Rappaport-Vassiliadis-Soya (RVS) pepton broth. Cloacal swabs or swabs from the cloacal area were collected from 63 individual reptiles belonging to 14 households. All reptiles were from different terraria and from 62 of these, environmental samples were also collected. Sampling were done by the reptile owners according to written instructions and sent by mail immediately after sampling. All but three samples were analyzed within 24 h after collection. Colonies suspected for Salmonella were tested for agglutination and serotyped using the White-Kauffmann-Le Minor scheme. The relative sensitivity (se) and specificity (sp) for MSRV compared with RVS, and the agreement coefficient kappa (κ) were calculated.

Results

Salmonella was isolated from 50/63 (80%) terraria, either from the reptiles (31/63; 49%) or from bedding material (39/62; 63%). The most common subspecies was Salmonella enterica subspecies enterica followed by S. enterica subspecies diarizonae. In reptiles, the most common S. enterica subspecies enterica serovars were Java (n = 4) and Fluntern (n = 4), compared with the serovars Tennessee (n = 10) and Fluntern (n = 10) in the environmental samples. The exact same set of Salmonella subspecies and serovars were not isolated from the individual reptiles and the environmental samples from any of the households. Isolation using MSRV yielded more Salmonella isolates 61/113 (54%) than enrichment in RVS 57/125 (46%). The se was 97.9% (95% Confidence Interval 93.9-100), the sp 78.5% (95% CI 68.5-88.5) and the κ 0.74, indicating substantial agreement between the tests.

Conclusions

Salmonella can be expected to be present in environments where reptiles are kept. This constitutes public health risks and should be considered during handling of the reptiles and during cleaning and disposal of bedding. A combination of different culturing techniques may be used to increase the isolation rate.     

Senile cardiac amyloidosis in the dog

Thirty-two cases of senile cardiac amyloidosis from a routine necropsy material of 594 dogs were studied. The age of the affected dogs ranged from 10 to 16 years. Amyloid was observed in the intramural arteries and arterioles, predominantly in the ventricular myocardium. The vessels were often obturated with amyloid, and myocardial necroses and fibroses were common consequences of the vascular lesions. In three cases amyloid deposits were also observed in the main subepicardial coronary arteries. In contrast to man, only slight interstitial amyloid degeneration was found in four of the dogs observed. Amyloid in the mitral valves, tricuspid valves and aortic cusps was observed in six, two and three cases respectively. It was concluded that the distribution of senile cardiac amyloidosis in the heart of the dog differs considerably from that in man.     

Effect of Maize Tempering on Throughput and Product Yields

Scientifically researched 2‐ and 3‐stage tempering procedures and the commercially practiced 1‐stage procedure were compared for throughput and corn dry‐milling product yields at pilot‐scale (30‐kg lots) operation. The throughput and product yields were influenced by the temper procedure and the tailgate weight distance. For most corn dry‐milling products, yields corresponding to 2‐ or 3‐stage tempering procedures could be equaled or surpassed using the 1‐stage tempering procedure at specific temper durations. In general, yields from the 2‐stage and 3‐stage procedures were comparable to the yields from the 1‐stage procedure at temper durations of 30–40 and 50–60 min, respectively. An increase in the tailgate weight distance improved the product yields for temper durations <30 min but reduced the yields for longer temper durations. An increase in temper duration ≤50 min resulted in a reduction in throughput but an improvement in flaking grit yield. The temper duration and tailgate weight distance could be suitably adjusted for obtaining the desired output.     

Effect of Hybrid and Physical Properties of Individual Popcorn Kernels on Expansion Volume

The relationships between expansion volume and physical properties of three varieties of popcorn kernels were investigated on a single kernel basis. Physical properties studied were kernel size, kernel sphericity, and kernel density. Methods of measuring densities and popped volumes of individual popcorn kernels were developed. Popcorn kernels were separated into seven kernel sizes by screening with round‐hole sieves. Thirty kernels from each of three kernel sizes (4.76 < D < 5.16, 5.56 < D < 5.95, 6.35 < D < 6.75 mm) of three popcorn varieties were individually measured for sphericity, density, and popped volume. Density and sphericity measures of popcorn kernels showed little variability. Variety, kernel sphericity, and kernel density had minor effects on expansion volume. Kernel size had no effect. There were no strong linear relationships (R² = 0.28) among expansion volume and physical properties of the three varieties of popcorn kernels. The variety with the highest mean density and the highest mean sphericity showed a tendency of producing higher mean expansion volumes.     

The effect of a single prolonged milking interval on inflammatory parameters, milk composition and yield in dairy cows

A technical stop in automatic milking systems may result in a severely prolonged milking interval (PMI) with subsequent impact on milk somatic cell count (SCC). This study investigated the inflammatory reaction, milk composition and yield during SCC peak observed in composite milk after exposing cows to a single PMI of 24h. At the first milking after the PMI, a sharply increased proportion of milk polymorphonuclear leukocytes (PMN) but marginally increased SCC were observed. The peak in SCC was not seen until morning milking day 2 after the PMI, notably, concomitantly with a decreased PMN proportion. An increase in blood lactose, milk bovine serum albumin and serum amyloid A (SAA) and a drop in milk alpha lactalbumin (ALA) were seen concomitantly with the peak in PMN. All parameters mentioned, had returned to base line after day 2. The changes in SCC and SAA had the longest duration. Lactate dehydrogenase in afternoon milk was decreased during the whole study as was also afternoon milk yield. Interleukin-1β could not be detected in milk at any time. SAA and ALA, respectively, may influence chemotaxis and the changed concentrations observed after the PMI might have contributed to the increased migration of PMN to milk.