Electron-driven acid-base chemistry: proton transfer from hydrogen chloride to ammonia

In contrast to widely familiar acid-base behavior in solution, single molecules of NH3 and HCl do not react to form the ionic salt, NH+4Cl-, in isolation. We applied anion photoelectron spectroscopy and ab initio theory to investigate the interaction of an excess electron with the hydrogen-bonded complex NH3...HCl. Our results show that an excess electron induces this complex to form the ionic salt. We propose a mechanism that proceeds through a dipole-bound state to form the negative ion of ionic ammonium chloride, a species that can also be characterized as a deformed Rydberg radical, NH4, polarized by a chloride anion, Cl-.     

Influence of stocking density and type of feed on the rearing of crucian carp, <Emphasis Type="Italic">Carassius carassius</Emphasis> (L.), larvae under controlled conditions

Two experiments were conducted into the rearing of crucian carp larvae under controlled conditions in an experimental closed water system. In both cases, the rearing lasted 21 days. The first experiment concerned the initial stocking density (from 50 to 600 individuals per l), whilst the second one studied the first food offered (two types of Artemia nauplii, decapsulated Artemia cysts and three types of commercial feeds) which were applied at the moment of exogenous feeding commencement. The best results were obtained using 50 larvae per l, whilst there were no significant differences within the range 200–600 larvae per l. The application of dry feed had a negative influence on the survival and other parameters. The highest survival rate was found in the groups fed with freshly hatched Artemia naupli. The results obtained indicate that the rearing of crucian carp larvae may be successfully conducted in very high stocking densities. However, the very high sensitivity of crucian carp larvae to the type of food offered during the initial days of life should be taken into account. The data presented in this article could be very useful in crucian carp larviculture.     

Distribution and Degradation of Fresh Water Plastic Particles Along the Beaches of Lake Huron, Canada

Resistivity of plastic litter to chemical weathering, mechanical erosion, and biological degradation poses a critical environmental threat. Plastic debris has increased in abundance over the past several decades along shorelines and at sea, where organisms mistake small particles including plastic pellets as a potential food supply. These pellets have been shown to adsorb persistent organic pollutants such as PCBs, which may endanger the organism and become ingested higher in the food chain. Although several studies have been conducted to determine the amount and effects of plastics pollution in marine environments, relatively little is known concerning fresh water plastics pollution. This study represents the first detailed examination of the distribution, types, and physical and chemical degradation processes of plastic particles in a fresh water setting. In conducting field surveys along the shoreline of Lake Huron, Canada, we were able to ascertain that the total number of pellets over multiple sampling localities comprise 94% of plastic debris. The majority of the pellets were found proximal to an industrial sector along the southeastern margin of the lake and their abundance steadily decreased northward, following the dominant lake current patterns. Laboratory analyses using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy indicate predominant mechanical abrasion textures, including grooves, gauges, pits, and flakes, and less common chemical weathering features such as linear and crescentic fractures that developed from shrinkage during subaerial exposure. The predominant type of plastic, polyethylene, appears to be much more resistant to chemical weathering than polypropylene, as indicated by oxidation peaks on FTIR spectra suggesting that polypropylene degrades more readily under natural conditions on freshwater beaches.     

Assessing water-related plant traits to explain slow-wilting in soybean PI 471938

Soybean [Glycine max (L.) Merr.] genotype PI 471938 expresses a slow-wilting phenotype in the field, and the progeny of this genotype have shown to have high yield under water deficit conditions. However, the physiological basis for the slow-wilting trait in PI 471938 remains unclear, and failure to understand the causal mechanism may limit future breeding efforts. This study investigated three primary hypotheses for trait expression that could explain slow-wilting trait in PI 471938: (1) a low osmotic potential in the leaves allowing greater water retention, (2) high elastic modulus of leaves resulting in delayed development of wilting, and (3) high hydraulic conductance allowing rapid water redistribution in the plants. Experiments included three other soybean genotypes as references for the results obtained with PI 471938. Surprisingly, the results for PI 471938 did not prove to be unique as compared to the other three tested genotypes for any of the three hypotheses. These negative results indicate that a hypothesis outside the usual candidates describing plant water transport, possibly anatomical features related to specific water transport properties, is required to explain slow-wilting in PI 471938.     

GLP1 and GIP are involved in the action of synbiotics in broiler chickens

Background: In order to discover new strategies to replace antibiotics in the post-antibiotic era in meat-type chicken production, two new synbiotics were tested:(Lactobacillus salivarius IBB3154 plus galactooligosaccharide(Syn1) and Lactobacillus plantarum IBB3036 plus raffinose family oligosaccharides(Syn2).Methods: The synbiotics were administered via syringe, using a special automatic system, into the egg air chamber of Cobb 500 broiler chicks on the 12 thday of egg incubation(2 mg of prebiotics + 105 cfu bacteria per egg).Hatched roosters(total 2,400) were reared on an experimental farm, kept in pens(75 animals per pen), with free access to feed and water. After 42 d animals were slaughtered. Blood serum, pancreas, duodenum and duodenum content were collected.Results: Syn2 increased trypsin activity by 2.5-fold in the pancreas and 1.5-fold in the duodenal content. In the duodenum content, Syn2 resulted in ca 30% elevation in lipase activity and 70% reduction in amylase activity.Syn1 and Syn2 strongly decreased expression of m RNA for GLP-1 and GIP in the duodenum and for GLP-1 receptors in the pancreas. Simultaneously, concentrations of the incretins significantly diminished in the blood serum(P 0.05). The decreased expression of incretins coincides with changed activity of digestive enzymes in the pancreas and in the duodenal content. The results indicate that incretins are involved in the action of Syn1 and Syn2 or that they may even be their target. No changes were observed in key hormones regulating metabolism(insulin, glucagon, corticosterone, thyroid hormones, and leptin) or in metabolic indices(glucose,NEFA, triglycerides, cholesterol). Additionally, synbiotics did not cause significant changes in the activities of alanine and aspartate aminotransferases in broiler chickens. Simultaneously, the activity of alkaline phosphatase and gamma glutamyl transferase diminished after Syn2 and Syn1, respectively.Conclusion: The selected synbiotics may be used as in ovo additives for broiler chickens, and Syn2 seems to improve their potential digestive proteolytic and lipolytic ability. Our results suggest that synbiotics can be directly or indirectly involved in incretin secretion and reception.     

The effect of inulin supply to high‐fat diet rich in saturated fatty acids on pork quality and profile of sarcoplasmic protein in meat exudate

The aim of the study was to evaluate the influence of inulin supply to high‐fat diet rich in saturated fatty acids (SFA) on pork quality and profile of sarcoplasmic protein in drip loss. At 50 days of age, twenty cross‐bred pigs (gilts) were randomly allotted to four groups: the control (C) group fed a standard diet, and three experimental (D1, D2 and D3) groups fed a high‐fat diet rich in SFA. Moreover, pigs from the groups D2 and D3 consumed an extra inulin supply (7% of daily feed intake) from 85 to 120 days of age (for 5 weeks) and from 50 to 120 days of age (for 10 weeks) respectively. The addition of inulin to the diet reduced meaty odour and flavour significantly, improved tenderness and overall sensory quality of pork and additionally influenced ultimate pH, L* colour parameter, lactate level and protein content in meat. The diets also affected the profile of sarcoplasmic proteins. Significant effects were observed for the following enzymes—PK/PGI (pyruvate kinase/phosphoglucose isomerase) and ALD (aldolase), which are related to the intensity of post‐mortem glycolysis. Presented data indicate that long‐term inulin supply to high‐fat diet has a positive effect on technological and sensory quality as well as protein profile of pork.