Partitioning of starter bacteria and added exogenous enzyme activities between curd and whey during Cheddar cheese manufacture

peer-reviewedPartitioning of starter bacteria and enzyme activities was investigated at different stages of Cheddar cheese manufacture using three exogenous commercial enzyme preparations added to milk or at salting. The enzyme preparations used were: Accelase AM317, Accelase AHC50, Accelerzyme CPG. Flow cytometric analysis indicated that AHC50 or AM317 consisted of permeabilised or dead cells and contained a range of enzyme activities. The CPG preparation contained only carboxypeptidase activity. Approximately 90% of starter bacteria cells partitioned with the curd at whey drainage. However, key enzyme activities partitioned with the bulk whey in the range of 22%–90%. An increased level of enzyme partitioning with the curd was observed for AHC50 which was added at salting, indicating that the mode of addition influenced partitioning. These findings suggest that further scope exists to optimise both bacterial and exogenous enzyme incorporation into cheese curd to accelerate ripening.Department of Agriculture, Food and the Marin

Cyclic AMP-vepenvent protein kinase phosphorylates residues in the C-terminal domain of the cardiac L-type calcium channel α1 subunit

AbstractThe molecular basis of the regulation of cardiac L-type calcium channel activity by cAMP-vepenvent protein kinase (cA-PK) remains unclear. Direct cA-PK-vepenvent phosphorylation of the bovine ventricular α1 subunit in vitro has been vemonstrated in microsomal membranes, vetergent extracts and partially purified (+)-[3H]PN 200-100 receptor preparations. Two 32P-labelled phosphopeptives, herived from cyanogen bromive cleavage, of 4.7 and 9.5 kDa were immunoprecipitated specifically by site-directed antibodies against the rabbit cardiac α1 subunit amino acid sequences 1602–1616 and 1681–1694, respectively, consistent with phosphorylation at the cA-PK consensus sites at Ser1627 and Ser1700. No phosphopeptive products consistent with phosphorylation at three other C-terminal cA-PK consensus phosphorylation sites (Ser1575, Ser1848 and Ser1928) were iventified using similar procedures suggesting that these sites are poor substrates for this kinase. Ser1627 and Ser1700 may represent sites of cA-PK phosphorylation involved in the physiological regulation of cardiac L-type calcium channel function

Anatomical and molecular properties of long descending propriospinal neurons in mice

Long descending propriospinal neurons (LDPNs) are interneurons that form direct connections between cervical and lumbar spinal circuits. LDPNs are involved in interlimb coordination and are important mediators of functional recovery after spinal cord injury (SCI). Much of what we know about LDPNs comes from a range of species, however, the increased use of transgenic mouse lines to better define neuronal populations calls for a more complete characterisation of LDPNs in mice. In this study, we examined the cell body location, inhibitory neurotransmitter phenotype, developmental provenance, morphology and synaptic inputs of mouse LDPNs throughout the cervical and upper thoracic spinal cord. LDPNs were retrogradely labelled from the lumbar spinal cord to map cell body locations throughout the cervical and upper thoracic segments. Ipsilateral LDPNs were distributed throughout the dorsal, intermediate and ventral grey matter as well as the lateral spinal nucleus and lateral cervical nucleus. In contrast, contralateral LDPNs were more densely concentrated in the ventromedial grey matter. Retrograde labelling in GlyT2GFP and GAD67GFP mice showed the majority of inhibitory LDPNs project either ipsilaterally or adjacent to the midline. Additionally, we used several transgenic mouse lines to define the developmental provenance of LDPNs and found that V2b positive neurons form a subset of ipsilaterally projecting LDPNs. Finally, a population of Neurobiotin (NB) labelled LDPNs were assessed in detail to examine morphology and plot the spatial distribution of contacts from a variety of neurochemically distinct axon terminals. These results provide important baseline data in mice for future work on their role in locomotion and recovery from SCI

Contextual advantages and certification for maximum confidence discrimination

One of the most fundamental results in quantum information theory is that no measurement can perfectly discriminate between non-orthogonal quantum states. In this work, we investigate quantum advantages for discrimination tasks over noncontextual theories by considering a maximum confidence measurement that unifies different strategies of quantum state discrimination, including minimum-error and unambiguous discrimination. We first show that maximum confidence discrimination, as well as unambiguous discrimination, contains contextual advantages. We then consider a semi-device independent scenario of certifying maximum confidence measurement. The scenario naturally contains undetected events, making it a natural setting to explore maximum confidence measurements. We show that the certified maximum confidence in quantum theory also contains contextual advantages. Our results establish how the advantages of quantum theory over a classical model may appear in a realistic scenario of a discrimination task

Product Distribution in the Low Temperature Conventional Pyrolysis of Nigerian Corn Stalks.

In view of the global energy crises and the ongoing renewable energy studies, clear understanding of the product distribution in the pyrolysis of lignocellulose from different corn plant components is required. Unextracted lignocellulose from the dry corn stalks was pyrolysed at 200oC and 250oC for 30 minutes, 60 minutes, 90 minutes and 120 minutes, respectively in an in house reactor. Liquid (bio-oil), gaseous and solid (bio-char) products were obtained. Their volumes and masses were determined. The volumes of the liquid and gaseous products produced increased with retention time and temperature while the masses of the solid products decreased with retention time and temperature. The pyrolysed corn stalks produced 17.93% bio-oil, 43.33% bio-char and 38.74% gases. The reaction order and rate constants were determined. The reaction was found to be first order. The bio-oil compounds that were detected by GCMS were identified from the MS library and characterized into: acids, ester, alcohol, phenol, alkane, multicomponent compounds and miscellaneous oxygenates. The bio-oils samples obtained were shown to be comparable with those produced by other processes

How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals

We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax–solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005–0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax–solvent–PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) < ϕ* < 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate species likely to be effective PPDs for particular wax systems

Patient Perspective on the Value of Genetic Counselling for Familial Pancreas Cancer

<p>Abstract</p> <p>Purpose</p> <p>To assess patient views regarding the value of genetic counselling for familial pancreas cancer in the absence of predictive genetic testing.</p> <p>Patients and methods</p> <p>At-risk adults with three or more relatives with pancreas cancer received genetic counselling prior to research screening via endoscopic ultrasound. Questionnaires were mailed after the visit to assess perceived value of the counselling session.</p> <p>Results</p> <p>Ninety-three percent of respondents felt genetic counselling for pancreas cancer was helpful despite the lack of a causative gene, while only 7% felt that it should not be offered until such a gene is discovered. Over half of respondents believed the pancreas cancer in their family was caused by a gene mutation, and 42% thought they had inherited the mutation. The average perceived lifetime risk of developing pancreas cancer was 51%, and 87% of respondents would ultimately seek predictive genetic testing. When more information is gained, 89% would be interested in another genetic counselling session, and 82% would recommend current genetic counselling for pancreas cancer to a friend or relative with a family history of the disease.</p> <p>Conclusion</p> <p>Despite the lack of an identified major causative gene for pancreas cancer, respondents found genetic counselling for this malignancy to be helpful. These patients perceive their personal cancer risk to be high, and would seek predictive genetic testing if it were available. Referral for genetic counselling should be offered to appropriate individuals.</p