Questions: How have the historical frequency and severity of natural disturbances in primary Picea abies forests varied at the forest stand and landscape level during recent centuries? Is there a relationship between physiographic attributes and historical patterns of disturbance severity in this system? Location: Primary P. abies forests of the Eastern Carpathian Mountains, Romania; a region thought to hold the largest concentration of primary P. abies forests in Europe's temperate zone.Methods: We used dendrochronological methods applied to many plots over a large area (132 plots representing six stands in two landscapes), thereby providing information at both stand and landscape levels. Evidence of past canopy disturbance was derived from two patterns of radial growth: (1) abrupt, sustained increases in growth (releases) and (2) rapid early growth rates (gap recruitment). These methods were augmented with non-metric multidimensional scaling to facilitate the interpretation of factors influencing past disturbance.Results: Of the two growth pattern criteria used to assess past disturbance, gap recruitment was the most common, representing 80% of disturbance evidence overall. Disturbance severities varied over the landscape, including stand-replacing events, as well as low-and intermediate-severity disturbances. More than half of the study plots experienced extreme-severity disturbances at the plot level, although they were not always synchronized across stands and landscapes. Plots indicating high-severity disturbances were often spatially clustered (indicating disturbances up to 20 ha), while this tendency was less clear for lowand moderate-severity disturbances. Physiographic attributes such as altitude and land form were only weakly correlated with disturbance severity. Historical documents suggest windstorms as the primary disturbance agent, while the role of bark beetles (Ips typographus) remains unclear. Conclusions:The historical disturbance regime revealed in this multi-scale study is characterized by considerable spatial and temporal heterogeneity, which could be seen among plots within stands, among stands within landscapes and between the two landscapes. When the disturbance regime was evaluated at these larger scales, the entire range of disturbance severity was revealed within this landscape.
Arachidonic acid (AA) content, long-chain n-3 polyunsaturated fatty acid (PUFA) equivalent [LCE; calculated as 0.15 x linolenic acid (LA) + eicosapentaenoic acid (EPA) + docosahexaenoic acid (DHA)], and PUFA n-6/PUFA n-3 ratio were determined in meat [breast meat (BM), thigh meat (TM), and fillets (F), respectively] within four sets of chickens, five sets of turkeys, one set of common carp, and four sets of rainbow trout, fed either commercial diet or diets with manipulated PUFA n-3 and PUFA n-6 contents. AA content was within the range of 20 mg/100 g (F of rainbow trout fed the diet with linseed oil, LO) to 138 mg/100 g (TM of chickens fed restrictively the diet based on maize to the age of 90 days). AA content in BM of turkeys fed the diet with LO or fish oil (FO) did not differ (P > 0.05) from that of rainbow trout F. LCE was in the range of 16 mg/100 g (BM of turkeys fed a commercial feed mixture) to 681 mg/100 g (F of rainbow trout fed a commercial feed mixture). With regard to BM, only turkeys fed the diet with LO deposited more (P < 0.01) LCE (71 mg/100 g) as compared to all other poultry sets except turkeys fed the diet with FO (123 mg/100 g). Apart from all fish samples, also both BM and TM of turkeys fed the diet with either LO or FO met the recommended value of the PUFA n-6/PUFA n-3 ratio (<4). AA content in the tissue increased significantly (P < 0.001) with increasing dietary LA in both all chicken tissues and all turkey tissues, which is contrary to the suggested strong metabolic regulation of the AA formation. When all tissues within all animal species were taken as a one set, both AA percentage and EPA + DHA percentage in the tissue (Y, %) decreased (P < 0.001) with increasing fat content in the tissue (X, %), according to the equation Y = 4.7 - 0.54X (R (2) = 0.41) and Y = 6.0 - 0.33X (R (2) = 0.35), respectively. AA content in chicken BM, chicken TM, and turkey BM, respectively, decreased linearly (P < 0.01) with increasing live weight reached at the slaughter age.
An experiment was conducted to determine the response of broiler chickens to guanidinoacetic acid (GAA) added to diets with diff erent energy levels during fattening to 35 days of age. Ross 308 male chicks were allotted to 10 treatments, each consisting of six replicates of 140 birds/pen. Five maize-soyabean meal isonitrogenous diets with decreasing AME n levels (100, 99, 98, 97 and 96% of requirement) with or without supplements of 0.6 g/kg CreAMINO® containing a minimum of 96% GAA were formulated. The criteria of response were feed intake, body weight gains, feed conversion ratio and carcass, breast meat, leg meat and abdominal fat yields. Supplementation of broiler diets with 0.06% GAA resulted in a signifi cant (P < 0.05) decrease in voluntary feed intake. With decreasing AME n level, voluntary feed intake and consequently protein and amino acid intakes increased which was manifested by improved growth performance (P < 0.01). GAA supplements signifi cantly (P < 0.001) improved feed conversion ratio and effi ciency of AME n utilization and signifi cantly (P < 0.01) increased breast meat yield. With decreasing AME n level, the eff ects of GAA supplementation tended to diminish.
Effects of 1, 3, 5 or 7% of linseed oil in the diet on the content of fatty acids in breast and thigh meat were studied in broiler chickens. Oils made either of seeds of the linseed cultivar Atalante (A) with a high content of α-linolenic acid or of the cultivar Lola (L) with a predominating content of linoleic acid were fed from 25 to 40 days of age. When feeding A, the contents of all n-3 polyunsaturated fatty acids (PUFA), including eicosatrienoic acid, were significantly higher, those of n-6 PUFA were lower, and the ratio of n-6/n-3 PUFA was narrower (P < 0.001) than when L was fed. The narrowest n-6 to n-3 PUFA ratio was observed at the content 36 g of α-linolenic acid (58 g A) per kg of the diet while the widest one at 2 g of α-linolenic acid (70 g L) per kg of the diet. When using L, the increasing level of linoleic acid in feed was associated with significantly increasing levels of all n-6 PUFA in meat. The content of all n-3 PUFA increased after the application of oil A, but the dependence for eicosapentaenoic acid in thigh meat was expressed significantly more precisely by the second degree parabola with the maximum at the level of 37 mg of α-linolenic acid and for clupanodonic and docosahexaenoic acids by parabolas with maxima at the level of α-linolenic acid in the diet 41 g and 30 g for breast meat and 35 g and 27 g for thigh meat, respectively. By means of the inclusion of linseed oil with a high content of α-linolenic acid in the feed mixture it would be possible to produce poultry meat with a high content of n-3 PUFA as a functional food.
Total cholesterol content in 24 fillets (F) of males and females of common carp, 35 samples of male chicken breast meat (BM) and thigh meat (TM), and 48 samples of male turkey BM and TM, respectively, was determined by high-performance liquid chromatography after total lipid (TL) extraction using n-hexane/2-propanol mixture. Cholesterol content in male carp fillets (77.6 mg/100 g) was higher (P < 0.001) in comparison with females (69.4 mg/100 g). Irrespective of the sex differences, cholesterol content increased (P < 0.01) in the sequence chicken BM (53.0 mg/100 g) = turkey BM (53.0) < turkey TM (61.5) < carp F (73.5) < chicken TM (82.9 mg/100 g). Cholesterol content in chicken TM decreased (P < 0.05) with increasing live weight reached at the age of 43 days, but did not change (P > 0.05) in other tested tissues. Cholesterol concentration in TL of all five tested tissues within three animal species decreased sharply (P < 0.001) with increasing TL content reached in a given tissue at the fixed age. It follows from the results of the study that a two hundred gram portion of carp F and chicken TM without skin represents 49 and 55% of the upper limit of daily cholesterol intake, respectively.
Analysis is made of nonlinear underwater apparatus with account being taken of the real properties of the medium. A comparison is given of the experimental and theoretical data over the spatial distributions, frequencies, amplitudes, and phase characteristics of parametric transmitters and receivers. For convenience of engineering calculations, nomograms are presented that allow choice of parameters for nonlinear arrays. Features of construction are given, and the basic characteristics of both Soviet and foreign parametric arrays are described.For scientific investigations, parametric arrays have been designed for tank and test stations, precision sonar, fish detection, underwater sonar for shelf zones, transfer of broadband information in underwater sound channels, parametric Doppler sonar and acoustic recorders, geolocation, cartography through a water layer, etc. The book not only gives the theory underlying these developments, but it also gives design criteria that can be used in the design of other types of underwater parametric arrays as well as data taken from such systems. It is a thorough discussion of the subject. Although individual authors wrote specific chapters
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