Urinary felinine excretion in intact male cats is increased by dietary cystine

Felinine is a branched-chain sulfur amino acid present in the urine of certain Felidae, including domestic cats. The objective of the present study was to determine if additional cystine and/or dietary N would increase felinine and N-acetylfelinine excretion by intact male cats fed a low-protein (LP) diet. Feeding five adult intact male cats an LP diet (18·8% of metabolisable energy (ME) as protein) v. a high-protein diet (38·6% of ME as protein) resulted in a trend (P¼0·08) for decreased urinary felinine and no change in N-acetylfelinine excretion. In a 23 d study, when the LP diet was supplemented with L-cystine at 9·3 g/kg DM, urinary felinine:creatinine ratio showed a linear two-fold (121 %) increase (P,0·01) from 0·24 (SEM 0·05) to 0·53 (SEM 0·13) after 10 d. Subsequent feeding of the LP diet resulted in a decrease in felinine excretion to base levels. Plasma gglutamylfelinylglycine concentrations were consistent with the excretion of felinine. Supplementation of the LP diet with L-cystine (9·3 g/kg DM), dispensable amino acids and arginine to a second group (n 5) also resulted in a significant (P,0·01) but smaller (þ72 %) increase in the daily felinine:creatinine ratio (0·25 (SEM 0·04) to 0·43 (SEM 0·05)). The degree of felinine N-acetylation within groups was unaffected by dietary addition and withdrawal of amino acids. The results indicate that felinine synthesis is regulated by cystine availability, and that arginine may be physiologically important in decreasing felinine biosynthesis in intact male cats

Fermentation of animal components in strict carnivores: a comparative study with cheetah fecal inoculum

The natural diet of felids contains highly digestible animal tissues but also fractions resistant to small intestinal digestion, which enter the large intestine where they may be fermented by the resident microbial population. Little information exists on the microbial degradability of animal tissues in the large intestine of felids consuming a natural diet. This study aimed to rank animal substrates in their microbial degradability by means of an in vitro study using captive cheetahs fed a strict carnivorous diet as fecal donors. Fresh cheetah fecal samples were collected, pooled, and incubated with various raw animal substrates (chicken cartilage, collagen, glucosamine-chondroitin, glucosamine, rabbit bone, rabbit hair, and rabbit skin; 4 replicates per substrate) for cumulative gas production measurement in a batch culture technique. Negative (cellulose) and positive (casein and fructo-oligosaccharides; FOS) controls were incorporated in the study. Additionally, after 72 h of incubation, short-chain fatty acids (SCFA), including branched-chain fatty acids (BCFA), and ammonia concentrations were determined for each substrate. Glucosamine and glucosamine-chondroitin yielded the greatest OM cumulative gas volume (OMCV) among animal substrates (P < 0.05), whereas total SCFA production was greatest for collagen (P < 0.05). Collagen induced an acetate production comparable to FOS and a markedly high acetate-to-propionate ratio (8.41:1) compared to all other substrates (1.67:1 to 2.97:1)

The conduction pathway of potassium channels is water free under physiological conditions.

Ion conduction through potassium channels is a fundamental process of life. On the basis of crystallographic data, it was originally proposed that potassium ions and water molecules are transported through the selectivity filter in an alternating arrangement, suggesting a "water-mediated" knock-on mechanism. Later on, this view was challenged by results from molecular dynamics simulations that revealed a "direct" knock-on mechanism where ions are in direct contact. Using solid-state nuclear magnetic resonance techniques tailored to characterize the interaction between water molecules and the ion channel, we show here that the selectivity filter of a potassium channel is free of water under physiological conditions. Our results are fully consistent with the direct knock-on mechanism of ion conduction but contradict the previously proposed water-mediated knock-on mechanism

When images work faster than words: The integration of content-based image retrieval with the Northumbria Watermark Archive

Information on the manufacture, history, provenance, identification, care and conservation of paper-based artwork/objects is disparate and not always readily available. The Northumbria Watermark Archive will incorporate such material into a database, which will be made freely available on the Internet providing an invaluable resource for conservation, research and education. The efficiency of a database is highly dependant on its search mechanism. Text based mechanisms are frequently ineffective when a range of descriptive terminologies might be used i.e. when describing images or translating from foreign languages. In such cases a Content Based Image Retrieval (CBIR) system can be more effective. Watermarks provide paper with unique visual identification characteristics and have been used to provide a point of entry to the archive that is more efficient and effective than a text based search mechanism. The research carried out has the potential to be applied to any numerically large collection of images with distinctive features of colour, shape or texture i.e. coins, architectural features, picture frame profiles, hallmarks, Japanese artists stamps etc. Although the establishment of an electronic archive incorporating a CBIR system can undoubtedly improve access to large collections of images and related data, the development is rarely trouble free. This paper discusses some of the issues that must be considered i.e. collaboration between disciplines; project management; copying and digitising objects; content based image retrieval; the Northumbria Watermark Archive; the use of standardised terminology within a database as well as copyright issues

Projected free energies for polydisperse phase equilibria

A `polydisperse' system has an infinite number of conserved densities. We give a rational procedure for projecting its infinite-dimensional free energy surface onto a subspace comprising a finite number of linear combinations of densities (`moments'), in which the phase behavior is then found as usual. If the excess free energy of the system depends only on the moments used, exact cloud, shadow and spinodal curves result; two- and multi-phase regions are approximate, but refinable indefinitely by adding extra moments. The approach is computationally robust and gives new geometrical insights into the thermodynamics of polydispersity.Comment: 4 pages, REVTeX, uses multicol.sty and epsf.sty, 1 postscript figure include

The importance of genetic parenthood for infertile men and women

STUDY QUESTION: Do men and women beginning to attend a fertility clinic prefer genetic over non-genetic parenthood? SUMMARY ANSWER: Nearly, all infertile men and women prefer genetic parenthood. WHAT IS KNOWN ALREADY: Clinicians assume that all infertile couples prefer genetic parenthood over non-genetic parenthood and, therefore, consider treatments with donor gametes an option of last resort. Previous studies of the desire for parenthood identified 30 motivations for genetic parenthood, and 51 motivations for which having a genetically related child is not strictly necessary but might be deemed required. The exact strength of the preference of infertile men and women for genetic parenthood remains unclear, as does the importance of the various motivations. STUDY DESIGN, SIZE, DURATION: A questionnaire was developed based on a literature review. It was assessed by professionals and pilot tested among patients. The coded paper-pencil questionnaire was disseminated among both partners of 201 heterosexual infertile couples after their first consultation at one of two Belgian fertility clinics between October 2015 and May 2016. PARTICIPANTS/MATERIALS, SETTING, METHODS: The survey addressed: (i) the preference for genetic parenthood for themselves and for their partner, (ii) the importance of 30 motivations for genetic parenthood and (iii) the importance of 51 other motivations for parenthood and whether these motivations require being the genetic parent of their child to be fulfilled. To simplify presentation of the results, all 81 motivations were grouped into reliable categories of motivations using psychometric analyses. MAIN RESULTS AND THE ROLE OF CHANCE: The survey was completed by 104 women and 91 men (response rate: 49%). Almost all respondents (98%) favored genetic over non-genetic parenthood for both their partner and themselves. One-third of the respondents stated they only wanted to parent their own genetically related child. Achieving genetic parenthood for their partner was considered significantly more important than achieving genetic parenthood for themselves. Within couples, men had a stronger preference for genetic parenthood (P = 0.004), but this was not significant after correction for educational level, which was significantly associated with the preference of both men and women. The 30 motivations for becoming a genetic parent clustered into 11 categories of which 'to experience a natural process' was deemed most important. The 51 motivations for becoming a parent for which having a genetically related child is not strictly necessary clustered into 14 categories of which 'to contribute to a child's well-being' and 'to experience the love of a child' were most important. Respondents deemed they would need to be the genetic parent of their child to fulfill nearly all their motivations for parenthood. LIMITATIONS REASONS FOR CAUTION: We included couples that visited the fertility clinic for the first time, and the preference for genetic parenthood might change throughout a fertility treatment trajectory. Moreover, what prospective parents expect to be important for their future well-being might not really define parents' well-being. WIDER IMPLICATIONS OF THE FINDINGS: The presumed preference of couples for genetic parenthood was confirmed. Resistance against using donor gametes is more likely among lower educated individuals. Researching whether non-genetic parents actually feel they cannot fulfill the 51 motivations for parenthood, could be a basis for developing patient informatio

Sensitivity of native and introduced fish species to changes in flow velocity of European rivers

Item does not contain fulltex