Differences In Biochemical Composition Research Articles

Comparative biochemical composition of wild and farm origin grayling (Thymallus thymallus) eggs

In this study, the biochemical composition of wild and farm origin grayling eggs was compared, first, to evaluate the composition of fatty acids and protein content in grayling eggs for the first time, and second, to discover differences in biochemical composition between wild and farm origin eggs which is affected by broodstock feed. Farm origin grayling females were fed commercial trout starter feed, while wild origin females were feeding on food present in their natural environment. Fatty acid composition, protein content and colour were determined. Based on a principle component analysis (PCA) of the biochemical profile, farm and wild origin grayling eggs were clearly separated. Wild origin grayling eggs contained higher amount of SFA, but lower MUFA and PUFA than farm origin eggs. A considerable difference between wild and farm origin grayling eggs was observed also in essential fatty acids: C22:6 n-3 (DHA), C20:5 n-3 (EPA) and C20:4 n-6 (ARA), resulting in higher EPA/ARA and DHA/EPA ratio in farm origin eggs compared to wild origin eggs. Wild origin grayling eggs were characterised by higher protein content and were more intensely red-coloured than farm origin eggs, which were almost colourless. It could be concluded that the biochemical composition of farm origin eggs significantly differs from wild origin grayling eggs, which might have an influence on the embryonic development and hatching success of farm origin grayling. Therefore, the diet that has the greatest effect on egg composition needs to be optimised to meet the needs of the grayling broodstock and to improve the breeding efficiency of farm raised graylings.

A Multi-Fluorophore Staining Scheme for Identification and Quantification of Vomocytosis.

Vomocytosis is a process by which fungal pathogens, for instance, Cryptococcus neoformans (CN), escape from the digestive phagolysosome of phagocytic cells after ingestion. Interestingly, this expulsion leaves both the pathogen and phagocyte unharmed, and is believed to be an important mechanism by which CNs disseminate throughout infected hosts. This phenomenon was discovered in 2006, and research to date has relied almost entirely on quantification via manual counting of vomocytosis events in time-lapse microscopy videos. This archaic method has the significant disadvantages of requiring excessive labor in manual analysis, limited throughput capabilities, and low accuracy due to subjectivity. Here, we present an alternative method to measure vomocytosis rates using a multi-fluorophore reporter system comprised of two in situ staining steps during infection and a flow cytometry readout. This approach overcomes the limitations of conventional time lapse microscopy methods, with key advantages of high throughput capability, simple procedural steps, and accurate objective readouts. This study rigorously characterizes this vomocytosis reporter system in CN-infected MΦ and DC cultures via fluorescence microscopy, confocal microscopy, and flow cytometry. Here, this fluorescent tool is used to observe differences in expulsion rates after phagosome-modifying drug treatments and additionally utilized to distinguish differences in biochemical compositions among fluorescence-activated cell sorted fungal populations via Raman spectroscopy. Furthermore, this reporter scheme is demonstrated to be adaptable for use in measuring potential biomaterial particle expulsion events. Ultimately, the fluorescent reporter system presented here provides a universal tool for vomocytosis rate measurement of phagocytosed material. This facile approach opens the door to previously unfeasible types of vomocytosis-related studies such as high throughput treatment mechanistic screening and downstream characterization of expelled material.

Growth and photosynthetic performance of Nostoc linckia (formerly N. calcicola) cells grown in BG11 and BG110 media

The biotechnological potential of Nostoc linckia as a biofertilizer and source of bioactive compounds makes it important to study its growth physiology and productivity. Since nitrogen is a fundamental component of N. linckia biomass, we compared the growth and biochemical composition of cultures grown in BG11 (i.e., in the presence of nitrate) and BG110 (in the absence of nitrate). Cultures grown in BG11 accumulated more cell biomass reaching a dry weight of 1.65 ± 0.06 g L–1, compared to 0.92 ± 0.01 g L–1 in BG110 after 240 h of culture. Biomass productivity was higher in culture grown in BG11 medium (average 317 ± 38 mg L–1 day–1) compared to that attained in BG110 (average 262 ± 37 mg L–1 day–1). The chlorophyll content of cells grown in BG11 increased continuously up to (39.0 ± 1.3 mg L–1), while in BG110 it increased much more slowly (13.6 ± 0.8 mg L–1). Biomass grown in BG11 had higher protein and phycobilin contents. However, despite the differences in biochemical composition and pigment concentration, between BG11 and BG110 cultures, both their net photosynthetic rates and maximum quantum yields of the photosystem II resulted in similar.Graphical

A Proof-of-Principle Study of Non-invasive Identification of Peanut Genotypes and Nematode Resistance Using Raman Spectroscopy.

Identification of peanut cultivars for distinct phenotypic or genotypic traits whether using visual characterization or laboratory analysis requires substantial expertise, time, and resources. A less subjective and more precise method is needed for identification of peanut germplasm throughout the value chain. In this proof-of-principle study, the accuracy of Raman spectroscopy (RS), a non-invasive, non-destructive technique, in peanut phenotyping and identification is explored. We show that RS can be used for highly accurate peanut phenotyping via surface scans of peanut leaves and the resulting chemometric analysis: On average 94% accuracy in identification of peanut cultivars and breeding lines was achieved. Our results also suggest that RS can be used for highly accurate determination of nematode resistance and susceptibility of those breeding lines and cultivars. Specifically, nematode-resistant peanut cultivars can be identified with 92% accuracy, whereas susceptible breeding lines were identified with 81% accuracy. Finally, RS revealed substantial differences in biochemical composition between resistant and susceptible peanut cultivars. We found that resistant cultivars exhibit substantially higher carotenoid content compared to the susceptible breeding lines. The results of this study show that RS can be used for quick, accurate, and non-invasive identification of genotype, nematode resistance, and nutrient content. Armed with this knowledge, the peanut industry can utilize Raman spectroscopy for expedited breeding to increase yields, nutrition, and maintaining purity levels of cultivars following release.

Tea Bag Index to Assess Carbon Decomposition Rate in Cranberry Agroecosystems

In cranberry production systems, stands are covered by 1–5 cm of sand every 2–5 years to stimulate plant growth, resulting in alternate layers of sand and litter in soil upper layers. However, almost intact twigs and leaves remain in subsurface layers, indicating a slow decomposition rate. The Tea Bag Index (TBI) provides an internationally standardized methodology to compare litter decomposition rates (k) and stabilization (S) among terrestrial ecosystems. However, TBI parameters may be altered by time-dependent changes in the contact between litter and their immediate environment. The aims of this study were to determine the TBI of cranberry agroecosystems and compare it to the TBI of other terrestrial ecosystems. Litters were standardized green tea, standardized rooibos tea, and cranberry residues collected on the plantation floor. Litter decomposition was monitored during two consecutive years. Added N did not affect TBI parameters (k and S) due to possible N leaching and strong acidic soil condition. Decomposition rates (k) averaged (mean ± SD) 9.7 × 10−3 day−1 ± 1.6 × 10−3 for green tea, 3.3 × 10−3 day−1 ± 0.8 × 10−5 for rooibos tea, and 0.4 × 10−3 day−1 ± 0.86 × 10−3 for cranberry residues due to large differences in biochemical composition and tissue structure. The TBI decomposition rate (k) was 0.006 day−1 ± 0.002 in the low range among terrestrial ecosystems, and the stabilization factor (S) was 0.28 ± 0.08, indicating high potential for carbon accumulation in cranberry agroecosystems. Decomposition rates of tea litters were reduced by fractal coefficients of 0.6 for green tea and 0.4 for rooibos tea, indicating protection mechanisms building up with time in the tea bags. While the computation of the TBI stabilization factor may be biased because the green tea was not fully decomposed, fractal kinetics could be used as additional index to compare agroecosystems.

Metabonomics of white adipose tissue and brown adipose tissue in Tupaia belangeri during cold acclimation

In the present study, liquid chromatography-mass spectrometer (LC-MS) was used to perform untargeted metabolomics analysis of white adipose tissue (WAT) and brown adipose tissue (BAT) in Tupaia belangeri during cold acclimation. Differences in biochemical composition between WAT and BAT were compared. Clarifying how the two adipose tissues respond to the lower temperature in terms of metabolomics, which elucidate the metabolic process and energy homeostasis regulation mechanism in T. belangeri. The results showed that there were 34, 59 and 20 differential metabolites in the WAT, BAT and WAT compared with BAT, respectively. WAT and BAT had significant differences in various metabolic pathways such as sugar metabolism, amino acid metabolism, lipid metabolism, and nucleotide metabolism, which were closely related to the different biological roles of the two tissues. Increasing the concentrations of intermediate products of tricarboxylic acid (TCA) cycle, pyruvic acid, and phosphoenolpyruvic acid (PEP) in WAT and increasing the metabolites in TCA cycle, glyoxylate and dicarboxylate metabolism pathways in BAT, likely to increase the thermogenic capacity in T. belangeri in response to cold stress. There were more differential metabolic pathways in BAT during cold acclimation than that of in WAT. Moreover, compared to WAT, BAT responds to cold stress by adjusting the concentration of nucleotide metabolites.

Effect of detergent type on the performance of liver decellularized extracellular matrix-based bio-inks

Decellularized extracellular matrix-based bio-inks (dECM bio-inks) for bioprinting technology have recently gained attention owing to their excellent ability to confer tissue-specific functions and 3D-printing capability. Although decellularization has led to a major advancement in bio-ink development, the effects of detergent type, the most important factor in decellularization, are still unclear. In this study, the effects of various detergent types on bio-ink performance were investigated. Porcine liver-derived dECM bio-inks prepared using widely used detergents, including sodium dodecyl sulfate (SDS), sodium deoxycholate (SDC), Triton X-100 (TX), and TX with ammonium hydroxide (TXA), were characterized in detail. SDS and SDC severely damaged glycosaminoglycan and elastin proteins, TX showed the lowest rate of decellularization, and TXA-based dECM bio-ink possessed the highest ECM content among all bio-inks. Differences in biochemical composition directly affected bio-ink performance, with TXA-dECM bio-ink showing the best performance with respect to gelation kinetics, intermolecular bonding, mechanical properties, and 2D/3D printability. More importantly, cytocompatibility tests using primary mouse hepatocytes also showed that the TXA-dECM bio-ink improved albumin secretion and cytochrome P450 activity by approximately 2.12- and 1.67-fold, respectively, compared with the observed values for other bio-inks. Our results indicate that the detergent type has a great influence on dECM damage and that the higher the dECM content, the better the performance of the bio-ink for 3D bioprinting.

Biochemical composition of scab-immune apple fruits varieties (Malus domestica B.) as a valuable component of healthy dietary

The article presents an analysis of the biochemical composition of apple varieties (Malus domestica B.) with immunity to scab. Domestic and foreign apple varieties are used as research objects. Variability in fruits in the content of ascorbic acid (AA), soluble solids (SDS), P-active compounds, and titratable acids was noted. The high content of AA is noted in Uspenskoe, Skala, Bylina, Flagman, Yubilyar apple varieties. Long-term studies have revealed intervarietal differences in biochemical composition and variation of this trait over the years in apples. Varieties with valuable biochemical composition and immunity to scab can be used in organic food production, as well as in further breeding work to improve the quality of fruits.

Impact of the European bark beetle Ips typographus on biochemical and growth properties of wood and needles in Siberian spruce Picea obovata

Abstract European spruce bark beetle Ips typographus is an important driver of ecological processes in spruce stands, with severe effects on forestry economies. To prevent bark beetle outbreaks, early detection of infestations is a crucial step in forest management. It is expected that bark beetle infestation modifies biochemical composition of wood and needles, alters physiological responses in the early stage of infestation, which results in the reduction of tree growth and ultimately a tree death. Therefore, we studied the differences in biochemical composition of wood, content of photosynthesis-related pigments, shoot morphology, and growth between the healthy Siberian spruce trees (Picea obovata) and trees which were infested by I. typographus. The study was performed in five experimental plots established in the south of the Udmurt Republic in the European part of the Russian Federation. Three infested and three non-infested trees were chosen on each plot. Our results showed no significant effect of bark beetle infestation on the content of main structural components of wood – holocellulose (cellulose and hemicellulose) and lignin. On the other hand, we found differences in the content of extractive substances in the wood. Specifically, we found a higher tannin content in the non-infested trees. The content of photosynthesis-related pigments differed between the non-infested and infested trees as well. Unexpectedly, bark beetle infestation caused the overproduction of both pigment types rather than their degradation. Moreover, we observed that a higher amount of total extractive substances positively affected the incremental growth, whereas tannins supported the growth of shoots and needles.

Patients with Type 2 Diabetes Exhibit a More Mineralized Deep Cartilage Layer Compared with Nondiabetic Controls: A Pilot Study.

To assess differences in biochemical composition of the deep cartilage layer in subjects with type 2 diabetes mellitus (T2DM) and nondiabetic controls using UTE (ultra-short echo time) T2* mapping and to investigate the association of vascular health and UTE T2* measurements. Ten subjects with T2DM matched for age, sex, and body mass index with 10 nondiabetic controls. A 3D UTE sequence with 6 echo times was acquired using 3T magnetic resonance imaging of the knee. For UTE T2* analysis, the deep cartilage layer was segmented and analyzed in 5 compartments (patella, medial, and lateral femur and tibia). The ankle brachial index (ABI) was obtained in all subjects. Linear regression analyses were used to assess associations of T2DM and UTE T2* relaxation times and the associations of ABI measurements and UTE measurements. Compared with nondiabetic controls, T2DM subjects had significantly lower mean T2*-UTE in the patella (mean difference 4.87 ms; 95% confidence interval [CI] 1.09-8.65; P = 0.015), the lateral tibia (mean difference 2.26 ms; 95% CI 0.06-4.45; P = 0.045), and the lateral femur (mean difference 4.96 ms; 95% CI 0.19-9.73; P = 0.043). Independent of diabetic status, subjects with higher ABI values, indicating better vascular health, had higher T2*-UTE of the patella (coefficient 15.2; 95% CI 3.3-21.4; P = 0.017), the medial tibia (coefficient 9.8; 95% CI 1.0-18.6; P = 0.031), and the lateral femur (coefficient 18.8; 95% CI 3.3-34.3; P = 0.021). T2*-UTE measurements of the deep cartilage layer were consistently lower in subjects with T2DM and in subjects with impaired vascular health, likely indicating increased mineralization of this layer.

Different biochemical composition and nutritional value attribute to salinity and rearing period in male and female mud crab Scylla paramamosain

Crabs show major differences in biochemical composition and nutritional value responding to various culture environments, growth stages and even sexes. In the present study, juvenile mud crab Scylla paramamosain (0.026 ± 0.010 g) were cultured at two earthen ponds with the respective salinity level of 25‰ and 5‰ for four months. The proximate composition, amino acid content and fatty acid profile in edible parts (muscle and hepatopancreas) of male and female crabs reared at different salinities and two rearing periods (three-month stage: 60–120 g and four-month stage: 150–300 g) were investigated and compared. Crabs at high salinity had significantly lower moisture contents in muscle and hepatopancreas, but had higher protein contents in muscle and higher ratio of n-3/n-6 highly unsaturated fatty acids (PUFA) in both edible parts, regardless of gender and rearing period. Additionally, significant differences in biochemical composition and nutritional value were also found between male and female crabs. For example, the contents of crude protein and most amino acids were higher in muscle and hepatopancreas of females, whereas males contained higher n-3 PUFA contents in both edible parts. Further, the contents of delicious amino acids (DAA) and essential amino acids (EAA) in muscle and the crude lipid content in hepatopancreas exhibited a higher trend at three-month stage than that at four-month stage. The results suggested that S. paramamosain reared at high salinity had better nutritional value than that at low salinity, while female and male crabs possess their respective advantages in terms of different nutritional composition. In addition, crabs had a better nutritional quality at three-month stage, even though they were at a smaller size.

Diagnosis of cervical squamous cell carcinoma and cervical adenocarcinoma based on Raman spectroscopy and support vector machine.

In this report, we collected the Raman spectrum of cervical adenocarcinoma and cervical squamous cell carcinoma tissues by a micro-Raman spectroscopy system. We analysed, compared and summarized the characteristics and differences of the normalized mean Raman spectra of the two tissues and pointed out the major differences in the biochemical composition between the two tissues. The PCA-SVM model that was used to distinguish the two types of cervical cancer tissues was established. The accuracy of the model in differentiating cervical adenocarcinoma from cervical squamous cell carcinoma was 93.125%. The results of this study indicate that Raman spectroscopy of cervical adenocarcinoma and cervical squamous cell carcinoma tissue in combination with SVM (support vector analysis) and PCA (principal component analysis) can be useful for the classification of cervical adenocarcinoma and cervical squamous cell carcinoma tissues and for the exploration of the differences in biochemical compositions between the two types of cervical tissue. This study lays a foundation to further study Raman spectroscopy as a clinical diagnostic method for cervical cancer.

Induced Ripening Agents and Their Effect on Fruit Quality of Banana

Ripening is a genetically programmed highly coordinated irreversible phenomenon which includes many biochemical changes including tissue softening, pigment changes, aroma and flavour volatile production, reduction in astringency, and many others. Banana is one of mostly consumed fruit crops in the world. Since banana is a climactic fruit, induced ripening is essential in commercial scale banana cultivation and distribution to assure good flavour, texture, and uniform peel colour. Ethylene gas, acetylene gas liberated from calcium carbide, and ethephon are some of the commercial ripening agents used successfully in the trade and they have been widely studied for their effectiveness on initiating and accelerating the ripening process and their effect on fruit quality and health related issues. Lauryl alcohol was also shown as a ripening agent for bananas. Most studies suggest that there is no difference in biochemical composition and sensory quality in bananas treated with chemicals that induce ripening from naturally ripened bananas. However volatile profiles of artificially ripened bananas were shown to be considerably different from naturally ripened bananas in some studies. This review discusses induced ripening agents and their effect on fruit quality of bananas.

Raman and Fourier transform infrared spectroscopy application to the Puno and Titicaca cvs. of quinoa seed microstructure and perisperm characterization

The aim of this study was to investigate the quinoa fruit and seed microstructure, as well as to determine the qualitative composition of quinoa whole seed spatial localisation of food reserves in cultivars Puno and Titicaca using two complementary spectroscopic techniques (Fourier Transform infrared and Raman). The analyses of the seeds also included measurements of the crude proteins and starch contents. The experiment was carried out during the 2016 growing season in rain-fed conditions in the north of Serbia. The analysis of the scores of the principal components based on the Raman spectra revealed two groups in both seed parts (cotyledons and perisperm). The analysis of the loadings highlighted the spectrum region that contributed to the differentiation, e.g. the band at 472 cm−1 was related to the amylopectin content in the perisperm region. As for the cotyledons, the spectral range from 1100 to 1650 cm−1 was responsible for genotype differences and it included both the most important bands derived from Amide I, II and quinoa protein with globoid crystals composed of phytin. IR analysis, similar to the analyses of the crude proteins and starch contents in the seeds, failed to reveal any differences in biochemical composition between two analyzed genotypes.

Rapid identification of Paracoccidioides lutzii and P. Brasiliensis using Fourier Transform Infrared spectroscopy

The inhalation of the fungus Paracoccidioides brasiliensis (P. brasiliensis, Pb03 and Pb18) causes the Parcoccidioidomycosis. Initially, only P. brasiliensis was thought to be responsible for it. Later the researchers found out that another pathogen: Paracoccidioides lutzii (P. lutzii, Pb01) may also cause the disease. Clinical manifestation and treatment differ based on the causative agent, making it important to identify them correctly. Therefore, this study focusses on distinguishing P. brasiliensis from P. lutzii using Fourier Transform Infrared (FTIR) spectroscopy - a rapid, highly specific and sensitive technique that can identify biochemical composition with minimal sample preparation. We acquired thirty spectra each from pure cultures of P. lutzii, and P. brasiliensis. The FTIR spectra showed the difference in biochemical composition, the major differences being in the polysaccharide and proteins vibrations. Principal Component Linear Discriminant Analysis (PC-LDA) could distinguish the species. We acquired nearly 10 spectra per sample in triplicates, resulting around 30 spectra per group. The analysis of spectra indicates biochemical difference. Multivariate analysis is important to identify spectral differences in specific chosen spectra regions where we can take biological or vibration information. PC-LDA could distinguish Pb01 (P. lutzii) with 96% efficiency and Pb03/Pb18 (P.brasiliensis) with 100% efficiency. Thus, FTIR may contribute to clinical diagnosis of this highly prevalent Latin American disease.

Ultra-Performance Liquid Chromatography-High-Resolution Mass Spectrometry and Direct Infusion-High-Resolution Mass Spectrometry for Combined Exploratory and Targeted Metabolic Profiling of Human Urine.

The application of metabolic phenotyping to epidemiological studies involving thousands of biofluid samples presents a challenge for the selection of analytical platforms that meet the requirements of high-throughput precision analysis and cost-effectiveness. Here direct infusion–nanoelectrospray (DI–nESI) was compared with an ultra-performance liquid chromatography (UPLC)–high-resolution mass spectrometry (HRMS) method for metabolic profiling of an exemplary set of 132 human urine samples from a large epidemiological cohort. Both methods were developed and optimized to allow the simultaneous collection of high-resolution urinary metabolic profiles and quantitative data for a selected panel of 35 metabolites. The total run time for measuring the sample set in both polarities by UPLC–HRMS was 5 days compared with 9 h by DI–nESI–HRMS. To compare the classification ability of the two MS methods, we performed exploratory analysis of the full-scan HRMS profiles to detect sex-related differences in biochemical composition. Although metabolite identification is less specific in DI–nESI–HRMS, the significant features responsible for discrimination between sexes were mostly the same in both MS-based platforms. Using the quantitative data, we showed that 10 metabolites have strong correlation (Pearson’s r > 0.9 and Passing–Bablok regression slope of 0.8–1.3) and good agreement assessed by Bland–Altman plots between UPLC–HRMS and DI–nESI–HRMS and thus can be measured using a cheaper and less sample- and time-consuming method. A further twenty metabolites showed acceptable correlation between the two methods with only five metabolites showing weak correlation (Pearson’s r < 0.4) and poor agreement due to the overestimation of the results by DI–nESI–HRMS.

PO-224 Fourier transform infrared spectroscopy-based detection of hypoxia-induced biomolecular changes in different cancer cell lines

IntroductionOur previous studies have shown that under hypoxic stress human colorectal and breast cancer cells produce higher amounts of lipids compared to that under normoxic environment. The aim of this study was to estimate hypoxia induced cell metabolic response via the biochemical composition in prostate and lung cancer cells by using Fourier transform infrared spectroscopy (FTIR).Material and methodsLung cancer cell lines NCI-H69, COR-L23 and prostate cancer cell line PC3, and primary prostate cancer culture NFI-56 were seed in serum-free medium in density 1 × 106 per well in triplicates in 6-well plates and incubated for 48 in normoxic and hypoxic (5% CO2, 1% O2 and 94% N2) conditions. Cells were washed and snap frozen within 5 min after incubation. Hypoxic response in cells was verified by HIF1α expression in Western blot analysis. FTIR spectra of cancer cells were registered using HTS-XT microplate reader coupled with Vertex 70 (Bruker), and recorded in the frequency range of 4000–600 cm−1, with the spectral resolution of 4 cm−1 and 64 scans. Quantitative analysis of cell macromolecular composition was done as in (Grube et al. 2002). As characteristic absorption bands were used 1080 cm−1 for carbohydrates, 1250 cm−1 for nucleic acids, 1550 cm−1 for proteins and 2930 cm−1 for lipids.Results and discussionsResults showed differences in biochemical composition of prostate and lung cancer cells even under normoxic growth conditions. The carbohydrate content in NCI-H69 cells was 8.16% of dry weight (dw), in PC3 cells – 11.60% dw. The lipid content in NCI-H69 cells was 10.91% dw, but in PC3%–13.58% dw. The hypoxia induced metabolic response of prostate and lung cancer cells was more pronounced as an increase of lipid content – e.g., the lipid content in hypoxic cells of NCI-H69 was 13.29% dw, but in PC3%–15.91% dw. Thus, hypoxia induced lipid increase in lung cancer cells was for 22% but in prostate cancer cells for 17% compared to that in normoxic cells. These results are in line with our previous results and thus might represent universal mechanism and the observed total lipid content increase due to hypoxia could have a potential value for further studies of cancer cell lipid metabolism.ConclusionThe results of this study showed that under oxygen stress – starvation (hypoxia) the metabolism of lipids was much more affected than that of proteins, nucleic acids or carbohydrates suggesting that regulation of lipid synthesis can possibly provide advantages for cancer cell survival in extreme growth conditions.

The Temporomandibular Joint of the Domestic Dog (Canis lupus familiaris) in Health and Disease

This study aimed to characterize the histological, biomechanical and biochemical properties of the temporomandibular joint (TMJ) of the domestic dog in health and disease. In addition, we sought to identify structure-function relationships and to characterize TMJ degenerative lesions that may be found naturally in this species. TMJs (n=20) from fresh cadaver heads (n=10) of domestic dogs were examined macroscopically and microscopicallyand by cone-beam computed tomography. The TMJ discs were evaluated for their mechanical and biochemical properties. If TMJ arthritic changes were found, pathological characteristics weredescribed and compared with healthy joints. Five (50%) dogs demonstrated macroscopically normal fibrocartilaginous articular surfaces and fibrous discs and five (50%) dogs exhibited degenerative changes that were observed either in the articular surfaces or the discs. In the articulating surfaces, these changes included erosions, conformational changes and osteophytes. In the discs, degenerative changes were represented by full-thickness perforations. Histologically, pathological specimens demonstrated fibrillations with or without erosions, subchondral bone defects and subchondral bone sclerosis. Significant anisotropy in the TMJ discs was evident on histology and tensile mechanical testing. Specifically, the discs were significantly stiffer and stronger in the rostrocaudal direction compared with the mediolateral direction. No significant differences were detected in compressive properties of different disc regions. Biochemical analyses showed high collagen content and low glycosaminoglycan (GAG) content. No significant differences in biochemical composition, apart from GAG, were detected among the disc regions. GAG concentration was significantly higher in the central region as compared with the caudal (posterior) region. The TMJ of the domestic dog exhibits similarities, but also differences, compared with other mammals with regards to structure-function relationships. The TMJ articular surfaces and the disc exhibit degenerative changes as seen in other species, including perforation of the disc as seen in man. The degenerative changes had greater effects on the mechanical properties compared with the biochemical properties of the TMJ components. Translational motion of the TMJ does occur in dogs, but is limited.

Effect of nutritional status and concentration of Nannochloropsis gaditana as enrichment diet for the marine rotifer Brachionus sp

The development of strategies to improve the quality and to optimize the costs of rotifer production for fish larval feeding, particularly those related to microalgal supply, are highly desirable. In the present work, three different rations (80,000, 130,000 or 200,000 cells rotifer−1) of Nannochloropsis gaditana were assessed as enrichment diets for the marine rotifer Brachionus sp. The microalga was cultured in semi-continuous regime with two different daily renewal rates, 10% and 40%, which provided nutrient-depleted or nutrient-sufficient conditions respectively and resulted in strong differences in biochemical composition. Protein and arachidonic acid (ARA) content were twice higher and eicosapentaenoic acid (EPA) was three times higher in N. gaditana from nutrient-sufficient cultures. After 24-h enrichment, rotifers fed N. gaditana cultured in nutrient-sufficient conditions showed higher dry weight, as well as higher contents of protein, lipids and carbohydrates. Total polyunsaturated fatty acids (PUFAs) and ARA contents increased >50%, whereas EPA content doubled in rotifers fed N. gaditana from nutrient-sufficient conditions. As for feed ration, the increase from 80,000 to 130,000 cells individual−1 enhanced the accumulation of protein, lipids, carbohydrates, total PUFAs, ARA and EPA, but a further increase to 200,000 cells individual−1 only enhanced the accumulation of lipid content. Our results show that the nutritional quality of microalgae, rather than concentration, is the most important factor influencing biomass productivity and biochemical composition of rotifer cultures. Since microalgal biomass is in general a limited resource for aquaculture, the improvement of its nutritional value through the optimization of culture conditions should be considered as an adequate and cost-efficient strategy to produce high-quality live feed.

Biochemical determinants of litter quality in 15 species of Sphagnum

Background and aimsSphagnum mosses are ecosystem engineers that create and maintain boreal peatlands. With unique biochemistry, waterlogging and acidifying capacities, they build up meters-thick layers of peat, reducing competition and impeding decomposition. We quantify within-genus differences in biochemical composition to make inferences about decay rates, related to hummock–hollow and fen–bog gradients and to phylogeny.MethodsWe sampled litter from 15 Sphagnum species, abundant over the whole northern hemisphere. We used regression and Principal Components Analysis (PCA) to evaluate general relationships between litter quality parameters and decay rates measured under laboratory and field conditions.ResultsBoth concentrations of the polysaccharide sphagnan and the soluble phenolics were positively correlated with intrinsic decay resistance, however, so were the previously understudied lignin-like phenolics. More resistant litter had more of all the important metabolites; consequently, PC1 scores were related to lab mass loss (R2 = 0.57). There was no such relationship with field mass loss, which is also affected by the environment. PCA also revealed that metabolites clearly group Sphagnum sections (subgenera).ConclusionsWe suggest that the commonly stated growth-decomposition trade-off is largely due to litter quality. We show a strong phylogenetic control on Sphagnum metabolites, but their effects on decay are affected by nutrient availability in the habitat.