Amino acid composition of edible parts of three-year-old experimental scaly crossbreds of common carp (Cyprinus carpio, Linnaeus 1758)

The aim of this study was to compare the amino acid (AA) composition of edible parts of three experimental groups of carp, i.e. a pure line of Přerov scaly carp (PS), a hybrid line of Přerov scaly carp and Northern mirror carp (PS × M72), and a hybrid line of Přerov scaly carp and Ropsha scaly carp (PS × ROP), with the quality of the edible parts of control hybrids of Hungarian and Northern mirror carp (M2 × M72) in harvest size (K₃). A comparison between the controls (M2 × M72) and experimental carp (PS, PS × M72, PS × ROP) showed that their muscle tissues contained the same amounts of 10 AA [essential amino acids (EAA): Thr, Val, Leu, Phe, Lys, His; non‐essential amino acids (NEAA): Asp, Gly, Ala, Tyr] of the 16 AA determined. Glu, Asp, Lys and Leu were the AA with the highest muscle concentrations. The total EAA_sum and NEAA_sum contents in the fastest‐growing PS × ROP hybrid, in spite of specific differences found (P<0.05: Arg, Met; P<0.01: Pro), were practically identical to those found in the control group of M2 × M72 mirror carp. PS × ROP hybrid female and male muscle tissues differed (P<0.05) only in Met and Ala levels. Hard roes of experimental female carp (PS, PS × M72, PS × ROP) contained the largest quantities of Glu and Val, and that of control female carp (M2 × M72) the largest quantities of Glu and Gly. Hard roes of PS × ROP hybrids contained the largest quantities (P<0.01) of EAA_sum (52.44±0.19%). Compared with hard roes, soft roes from all groups of carp contained more EAA_sum (PS × ROP: 55.03±0.26%). The two most abundant AA in soft roes were Lys and Arg. The most abundant AA in the hepatopancreas in all carp groups were Glu, Asp, Leu and Arg. Hepatopancreas EAA_sum levels in experimental carp (PS, PS × M72, PS × ROP) were significantly (P<0.05) lower than those in controls (M2 × M72).     

Evaluation of growth and dressing out parameters of experimental scaly crossbreds in 3-year-old common carp (Cyprinus carpio, Linnaeus 1758)

Performance tests of the Pr?erov Scaly Carp (PS), two crossbreds (PS × M72 and PS × ROP) and an internal control group (M2 × M72) were designed to assess their production and dressing out parameters at harvest size for their potential commercial utilization. The fastest growth rate (standard length (SL): 405±21.91 mm, P<0.01) and the highest final live weight (FLW: 2015.70±323.92 g, P<0.01) were recorded in the PS × ROP hybrid. The SL values in this group of carp were 12.5%, 19.12% and 11.57% higher (P<0.01) than those at M2 × M72, PS and PS × M72, respectively, and the FLW values were 21.57%, 62.83% and 24.37% higher (P<0.01) compared with M2 × M72, PS and PS × M72 hybrids respectively. Growth rate parameters of PS × M72 hybrid and control group M2 × M72 were practically identical. The lowest growth rate potential and FLW were recorded in the PS group (P<0.01). The highest (P<0.01) dressing out parameters were found in the control group of mirror carp M2 × M72 with a dressing percentage of 65.64±2.11%. There were practically no differences in this parameter between scaly carp groups (PS: 61.79±2.82%, PS × M72: 61.51±1.72%, PS × ROP: 63.60±1.96%). This study shows evidence for faster somatic growth and bigger final weight in the hybrid line PS × ROP of 3‐year‐old common carp compared with the pure line PS and the crossbreed PS × M72.     

Analysis of growth, weight and relevant indices of diploid and triploid population of tench Tinca tinca (Linnaeus 1758)

This study determined biometric and weight parameters and relevant indices of diploid and triploid tench. Altogether, 137 siblings of tench were studied. The effect of ploidy level appeared in significantly better growth of triploids (P<0.001) as to biometric [total length (TL), standard length (SL), body height (BH), body width (BW)] and weight [fish weight (FW), carcass weight (CW)] parameters of T₃ of both sexes and of T₃₊ females. The effect of ploidy level also appeared as significantly higher dressing percentage (DP; P<0.001) of triploid T₃ females compared with other groups, significantly higher gonad weight (GW) and gonadosomatic index (GSI; P<0.001) of diploid T₃ females, as well as GSI and hepatosomatic index of diploid T₃₊ females. The effect of sex appeared in significantly higher (P<0.001) biometric (TL, SL, BH, BW) and weight (FW, CW) parameters of T₃ females of both ploidy levels, as well as of triploid T₃₊ females. The effect of sex also appeared as significantly higher DP (P<0.001) of males in diploid T₃ fish, as well as of males of both ploidy levels in T₃₊ fish and significantly higher GW and GSI (P<0.001) of females in diploid T₃ fish, as well as of females of both ploidy levels in T₃₊ fish. This study shows evidence for faster somatic growth and bigger final weight of triploid populations of tench compared with diploids in both age categories T₃ and T₃₊.     

采后UV-B照射保持贮藏番茄果实感官品质及抗氧化能力的研究

对绿熟期的番茄果实采用不同剂量(10、20、40、80 kJ.m-2)的UV-B进行照射后,在温度34℃、相对湿度95%的环境中避光贮藏34 d。结果表明,在4个处理中,以20、40 kJ.m-2剂量的UV-B照射处理贮藏效果最好,有效地保持了果实硬度,并延缓了果实的转色时间。此外,20、40 kJ.m-2的UV-B照射处理还可促进果实总酚及黄酮成分的积累,从而增强果实在贮藏过程中的抗氧化能力,但UV-B照射处理却降低了果实中抗坏血酸的含量。10 kJ.m-2的UV-B照射处理同样具有类似效果,但作用程度较小。较高的照射剂量80 kJ.m-2尽管促进了果实番茄红素的积累,但同时也给果实质地、颜色及抗氧化功能方面带来了不利影响。因此,用于保持番茄果实感官品质及抗氧化能力的最佳UV-B照射剂量为20 kJ.m-2或40 kJ.m-2。UV-B照射作为一种非化学手段可以有效保持番茄采后感官品质并提高其抗氧化能力。     

Litter decomposition along a primary post-mining chronosequence

Biology and Fertility of Soils - The aim of this study was to describe the decomposition of litter along a successive series of sites developed at a post-mining overburden deposit over 12, 21 and...     

The influence of plant residues on soil aggregation and carbon content: A meta-analysis

Background

Soil aggregation and organic carbon (OC) content are important indicators of soil quality that can be improved with plant residue amendments. The extent of the effects of plant residue amendments on soil aggregation and OC content across different plant residue and soil types is not fully understood.

Aim

In this meta-analysis, we evaluated the effects of plant residue amendments on soil aggregation and OC content for different plant residues (fresh, charred) and soil types varying in clay content, initial OC content, and pH.

Methods

Our meta-analysis included 50 published studies (total of 299 paired observations). We estimated the response ratios of mean weight diameter (MWD) and separate aggregate size classes, total soil OC (TSC), and aggregate-associated OC. We also considered the effect of experimental factors (study duration, residue type, residue amount, initial soil OC, clay content, and pH).

Results

The benefit of plant residue amendment on soil aggregation was larger in soils with initially low OC content and neutral pH. Initial soil OC content and pH were more important than soil clay content for OC storage in soil aggregates. Both fresh and charred plant residue amendments were effective in forming aggregates, whereas charred residues were more effective in increasing TSC. We found only a weak positive relationship between the response ratio of TSC and MWD indicating that other factors besides soil aggregation contributed to the increase in soil C storage.

Conclusions

While plant residue amendments can enhance soil aggregation and TSC, these effects are likely governed by the type of plant residue and soil properties such as the initial soil pH and OC content.     

Determination of Toxicity of Spoil Substrates After Brown Coal Mining Using a Laboratory Reproduction Test with Enchytraeus crypticus (Oligochaeta)

Laboratory-reared cultures of Enchytraeus crypticus were used in a reproduction toxicity test to evaluate the toxicity of 46 spoil substrates collected in four brown coal mining areas in the Czech Republic and Germany. A set of substrate parameters (pH, conductivity, Na, Ca, K, Al, Fe, loss of ignition and polyphenol contents) were measured for each spoil and correlated with spoil toxicity for E. crypticus. Toxicity increased with decreasing pH and increasing Al, Fe content. Spoil with a pH below 3 did not support the survival of E. crypticus. However, some alkaline spoils with high conductivity and ion concentration were also toxic. Toxicity was positively correlated with the loss of ignition and polyphenol content. The results indicate that the toxicity of post-mining spoil substrates have multiple origins. Most frequently the toxicity of post-mining substrates corresponds with low pH and consequent toxicity of Al and Fe. However some substrates may be toxic due to high ion concentrations. The potential role of fossil organic matter (namely polyphenols) in toxicity of post-mining substrates requires further research.     

Measurement of in situ Phosphorus Availability in Acidified Soils using Iron-Infused Resin

A hybrid anion resin was tested for in situ phosphorus (P) availability measurement in soils of two stands recovering from acidification and having different P-sorption characteristics. The phosphate (P-PO₄) sorption capacity of the resin (before saturation) was 48 µmol g^?1. Sorption and elution were tested under P-PO₄ concentrations common in acidic soils (0–0.42 mmol l^?1) either with or without the presence of sulfate (0.2 mmol l^?1). The efficiency of P-PO₄ sorption was independent of the sulfate and was 100 ± 0.2% (n = 56, ± SD). The P-PO₄ recovery stabilized after six elution steps (each: 50 ml of 0.5 M sodium hydroxide, resin/solution 5:1). The efficiency of P-PO₄ recovery was 80 ± 7% and was used to evaluate field measurements. We determined the amount of P-PO₄ in the field using resin bags in three consecutive years. The results indicate that bioavailable P is negatively related to the soil ability to retain P.     

Alterations in plasma antioxidants during reperfusion of the ischemic small intestine in rats

The aim of this study was to evaluate the contribution of three plasma antioxidants (albumin, uric acid, SH groups) to the plasma total peroxyl radical-trapping antioxidant capacity (TRAP) in 2 and 4 h of intestinal reperfusion in rats. TRAP increased significantly both after 2 and 4 h of reperfusion. Neither albumin nor SH groups contributed significantly to this increase. TRAP was strongly influenced by the increase in uric acid concentration and also probably by the cell destruction caused by oxidative stress. Since the TRAP increase was accompanied by an increase in the level of thiobarbituric acid reactive substances (TBARS, a marker of lipid peroxidation), we can conclude that even such a large increase in TRAP is not sufficient to prevent the progression of lipid peroxidation and oxidative stress.     

Simultaneous subchronic exposure to selenium and diazinon as possible risk factor for osteoporosis in adult male rats

Background

Osteoporosis and its main health outcome, fragility fractures, are large and escalating health problems. Skeletal damage may be the critical result of low-level prolonged exposure to several xenobiotics in the general population, but the mechanisms of their adverse effects are not clearly understood. The current study was aimed to investigate the possible ability of simultaneous subchronic peroral administration of selenium (Se) and diazinon (DZN) to induce changes in bone of adult male rats.In our study, twenty 1-month-old male Wistar rats were randomly divided into two experimental groups. In the first group, young males were exposed to 5 mg Na₂SeO₃/L and 40 mg of DZN/L in drinking water, for 90 days. Ten 1-month-old males without Se and DZN intoxication served as a control group. At the end of the experiment, macroscopic and microscopic structures of the femurs were analysed using analytical scales, sliding instrument, and polarized light microscopy.

Results

The body weight, femoral length and cortical bone thickness were significantly decreased in rats simultaneously exposed to Se and DZN (P < 0.05). These rats also displayed different microstructure in the middle part of the compact bone where vascular canals expanded into central area of substantia compacta. The canals occurred only near endosteal surfaces in rats from the control group. Additionally, a smaller number of primary and secondary osteons, as well as a few resorption lacunae were observed near endosteal surfaces in rats simultaneously administered to Se and DZN. The resorption lacunae as typical structures of bone resorption manifestation are connected with an early stage of osteoporosis. Histomorphometric analysis revealed that area, perimeter, maximum and minimum diameters of primary osteons’ vascular canals were significantly increased (P < 0.05) in the Se-DZN-exposed rats. On the other hand, all measured variables of Haversian canals and secondary osteons were considerable reduced (P < 0.05) in these rats.

Conclusions

Simultaneous subchronic peroral exposure to Se and DZN induces changes in macroscopic and microscopic structures of the femurs in adult male rats, and also it can be considered as possible risk factor for osteoporosis. The current study contributes to the knowledge on damaging impact of several xenobiotics on the bone.