This review focuses on the mechanisms responsible for some the achromatic aspects of meat colour (paleness or darkness) due to light scatter from structures within the tissue. Recent investigations ...have highlighted the role of three key mechanisms contributing to variations in the lightness of meat: (1) Variations in the myofilament lattice spacing, and the resultant changes in myofibril diameter and muscle fibre diameter. A 20% increase in lightness (L* value) between muscles with ultimate pH of 6.1 versus 5.4 is accompanied by a 17% change in muscle fibre diameter. (2) Variations in sarcomere length, if these are associated with changes in myofilament and myofiber diameter, (3) Variations in sarcoplasmic protein distribution, including whether these are bound or precipitated onto the myofilaments, as demonstrated by an increase of 1.24 in the ratio of X-ray diffraction intensities from mass centered on the thin filaments versus thick filaments in dark (pH 6.15) versus light (pH 5.47) muscles. For clarity, the discussion of these mechanisms is principally in relation to pH and temperature at rigor (5 °C–35 °C), although the possibility of contributions from numerous other factors is acknowledged.
•Non-pigment contributions to meat colour are reviewed.•Variations in light scatter causes variations in paleness or darkness in meat.•Mechanisms controlling the spacing between myofilaments and myofibrils principally contribute to light scatter.•Changes in the state and distribution of sarcoplasmic proteins also contribute to changes in light scatter.
Meat color is important for consumer acceptability, with excessively dark meat often associated with consumer rejection. It is determined chromatically by pigment content (measured by hue and chroma) ...and achromatically by scattering of light by the microstructure (measured by lightness), the latter of which has received minimal research focus. This review discusses the individual components of the meat microstructure that cause differences in achromatic contributions to color. Differences in achromatic light scattering between light and dark extremes of meat color are most likely explained by structural attributes within the muscle cell. These differences are proposed to arise from variations in (a) transverse shrinkage of the structural lattice of the myofilaments, myofibrils, and muscles fibers, (b) longitudinal shrinkage of the sarcomere, and (c) different protein composition of the surrounding medium (sarcoplasm and extracellular space). These are discussed at a mechanistic level, in relation to six parameters of the muscle cell: (a) protein surface charge altering the myofilament spacing, (b) protein solubility, (c) sarcoplasmic protein binding to myofilaments and myofibrils, (d) integrity of the cytoskeleton and cell adhesion proteins, (e) sarcomere integrity and myofibrillar proteins, and (f) myosin denaturation and rigor bond modification. New data are presented to support the proposed role of structural elements in muscle causing achromatic light scattering and their contribution to the surface color of meat. In addition, the relationships between lightness and water holding capacity and pH are explored and the economic impact of dark meat for the meat industry is discussed.
The sensory attributes and flavor chemistry of grilled beef striploins (M. longissimus lumborum, n = 42) varying widely in marbling from commercial production types typical for Southern Australia ...were extensively characterized. Striploins from Angus grass-fed yearlings (5.2–9.9% intramuscular fat), Angus grain-finished steers (10.2–14.9%), and Wagyu grass-fed heifers (7.8–17.5%) were evaluated. Inherent differences between samples from grass- and grain-fed Angus cattle were minimal when the intramuscular fat content was above ∼5%. After adjusting for intramuscular fat, Wagyu samples had more intense flavor and higher tenderness and juiciness compared to Angus grass-fed samples. Grilled beef flavor, dairy fat, and sweetness increased with the marbling level, and sourness and astringency decreased. Tenderness and juiciness increased with the marbling level and were correlated with Warner–Bratzler peak force measurements. Trained panel sensory differences in flavor corresponded with increases in aroma volatiles and changes in nonvolatile flavor compounds. Unsaturated fatty acids with potential health benefits (vaccenic, oleic, and rumenic acids) increased with the level of marbling.
Arbitrary microbiological limits or noticeable organoleptic decline are mainly used to define the shelf life of vacuum packaged chilled beef (VPCB). Excellent temperature control is critical to ...enable a long shelf life. The robustness of export supply chains was tested by sending Australian VPCB (striploins) to three Chinese destinations and a CONTROL (Brisbane, Australia) treatment (~−1 °C). Data loggers monitored temperature during storage and meat biochemistry (pH, color, weep), aerobic plate counts, lactic acid bacteria, total volatile basic nitrogen (TVB-N) and sensory changes were measured 84, 98, 120 and 140 days postslaughter. Temperature was generally well maintained and sensory scores were not indicative of spoilage. Microbial counts did not increase from 84 to 140 days, however TVB-N increased with time and was a better predictor of sensory attributes. TVB-N was below the limit of 15 mg/100 g in all CONTROL samples but most Chinese samples exceeded this value. This study demonstrated that extended shelf life is feasible with excellent temperature control.
Background
Healthcare is not without risk. Despite two decades of policy focus and improvement efforts, the global incidence of harm remains stubbornly persistent, with estimates suggesting that 10% ...of hospital patients are affected by adverse events.
Methods
We explore how current investigative responses can compound the harm for all those affected—patients, families, health professionals and organizations—by neglecting to appreciate and respond to the human impacts. We suggest that the risk of compounded harm may be reduced when investigations respond to the need for healing alongside system learning, with the former having been consistently neglected.
Discussion
We argue that incident responses must be conceived within a relational as well as a regulatory framework, and that this—a restorative approach—has the potential to radically shift the focus, conduct and outcomes of investigative processes.
Conclusion
The identification of the preconditions and mechanisms that enable the success of restorative approaches in global health systems and legal contexts is required if their demonstrated potential is to be realized on a larger scale. The policy must be co‐created by all those who will be affected by reforms and be guided by restorative principles.
Patient or Public Contribution
This viewpoint represents an international collaboration between a clinician academic, safety scientist and harmed patient and family members. The paper incorporates key findings and definitions from New Zealand's restorative response to surgical mesh harm, which was co‐designed with patient advocates, academics and clinicians.
Abstract RR Lyrae stars (RRLs) are excellent tracers of stellar populations for old, metal-poor components in the the Milky Way and the Local Group. Their luminosities have a metallicity dependence, ...but determining spectroscopic Fe/H metallicities for RRLs, especially at distances outside the solar neighborhood, is challenging. Using 40 RRLs with metallicities derived from both Fe( ii ) and Fe( i ) abundances, we verify the calibration between the Fe/H of RRLs from the calcium triplet. Our calibration is applied to all RRLs with Gaia Radial Velocity Spectrometer (RVS) spectra in Gaia DR3 and to 80 stars in the inner Galaxy from the BRAVA-RR survey. The coadded Gaia RVS RRL spectra provide RRL metallicities with an uncertainty of 0.25 dex, which is a factor of two improvement over the Gaia photometric RRL metallicities. Within our Galactic bulge RRL sample, we find a dominant fraction with low energies without a prominent rotating component. Due to the large fraction of such stars, we interpret these stars as belonging to the in situ metal-poor Galactic bulge component, although we cannot rule out that a fraction of these belong to an ancient accretion event such as Kraken/Heracles.
Wolman disease is a rare, lysosomal storage disorder in which biallelic variants in the LIPA gene result in reduced or complete lack of lysosomal acid lipase. The accumulation of the substrates; ...cholesterol esters and triglycerides, significantly impacts cellular function. Untreated patients die within the first 12 months of life. Clinically, patients present severely malnourished, with diarrhoea and hepatosplenomegaly, many have an inflammatory phenotype, including with hemophagocytic lymphohistiocytosis (HLH). Hematopoietic stem cell transplant (HCT) had been historically the only treatment available but has a high procedure-related mortality because of disease progression and disease-associated morbidities. More recently, enzyme replacement therapy (ERT) with dietary substrate reduction (DSR) has significantly improved patient survival. However, ERT is life long, expensive and its utility is limited by anti-drug antibodies (ADA) and the need for central venous access.
We describe five Wolman disease patients diagnosed in infancy that were treated at Royal Manchester Children's Hospital receiving ERT with DSR then HCT-multimodal therapy. In 3/5 an initial response to ERT was attenuated by ADA with associated clinical and laboratory features of deterioration. 1/5 developed anaphylaxis to ERT and the other patient died post HCT with ongoing HLH. All patients received allogeneic HCT. 4/5 patients are alive, and both disease phenotype and laboratory parameters are improved compared to when they were on ERT alone. The gastrointestinal symptoms are particularly improved after HCT, with reduced diarrhoea and vomiting. This allows gradual structured normalisation of diet with improved tolerance of dietary fat. Histologically there are reduced cholesterol clefts, fewer foamy macrophages and an improved villous structure. Disease biomarkers also show improvement with ERT, immunotherapy and HCT. Three patients have mixed chimerism after HCT, indicating a likely engraftment-defect in this condition.
We describe combined ERT, DSR and HCT, multimodal treatment for Wolman disease. ERT and DSR stabilises the sick infant and reduces the formerly described prohibitively high, transplant-associated mortality in this condition. HCT abrogates the problems of ERT, namely attenuating ADA, the need for continuing venous access, and continuing high cost drug treatment. HCT also brings improved efficacy, particularly evident in improved gastrointestinal function and histology. Multimodal therapy should be considered a new paradigm of treatment for Wolman disease patients where there is an attenuated response to ERT, and for all patients where there is a well-matched transplant donor, in order to improve long term gut function, tolerance of a normal diet and quality of life.
Secondary Transfer Effects of Intergroup Contact Tausch, Nicole; Hewstone, Miles; Kenworthy, Jared B ...
Journal of personality and social psychology,
08/2010, Letnik:
99, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Although intergroup contact is one of the most prominent interventions to reduce prejudice, the generalization of contact effects is still a contentious issue. This research further examined the ...rarely studied
secondary transfer effect
(STE;
Pettigrew, 2009
), by which contact with a primary outgroup reduces prejudice toward secondary groups that are not directly involved in the contact. Across 3 cross-sectional studies conducted in Cyprus (
N
= 1,653), Northern Ireland (
N
= 1,973), and Texas (
N
= 275) and 1 longitudinal study conducted in Northern Ireland (
N
= 411), the present research sought to systematically rule out alternative accounts of the STE and to investigate 2 potential mediating mechanisms (ingroup reappraisal and attitude generalization). Results indicated that, consistent with the STE, contact with a primary outgroup predicts attitudes toward secondary outgroups, over and above contact with the secondary outgroup, socially desirable responding, and prior attitudes. Mediation analyses found strong evidence for attitude generalization but only limited evidence for ingroup reappraisal as an underlying process. Two out of 3 tests of a reverse model, where contact with the secondary outgroup predicts attitudes toward the primary outgroup, provide further evidence for an indirect effect through attitude generalization. Theoretical and practical implications of these results are discussed, and directions for future research are identified.
We investigated whether protocols allowing high efficiency electrotransformation of other lactic acid bacteria were applicable to five strains of Lactobacillus casei (12A, 32G, A2-362, ATCC 334 and ...BL23). Addition of 1% glycine or 0.9 M NaCl during cell growth, limitation of the growth of the cell cultures to OD600 0.6–0.8, pre-electroporation treatment of cells with water or with a lithium acetate (100 mM)/dithiothreitol (10 mM) solution and optimization of electroporation conditions all improved transformation efficiencies. However, the five strains varied in their responses to these treatments. Transformation efficiencies of 106 colony forming units μg−1 pTRKH2 DNA and higher were obtained with three strains which is sufficient for construction of chromosomal gene knock-outs and gene replacements.
This work describes a combined approach for raising the transformation efficiency of this species that may be of use for genetically modifying other Lactobacilli.
This study explored transient inactivation of the gene encoding the DNA mismatch repair enzyme MutS as a tool for adaptive evolution of
MutS deletion derivatives of
12A and ATCC 334 were constructed ...and subjected to a 100-day adaptive evolution process to increase lactic acid resistance at low pH. Wild-type parental strains were also subjected to this treatment. At the end of the process, the Δ
lesion was repaired in representative
12A and ATCC 334 Δ
mutant isolates. Growth studies in broth at pH 4.0 (titrated with lactic acid) showed that all four adapted strains grew more rapidly, to higher cell densities, and produced significantly more lactic acid than untreated wild-type cells. However, the adapted Δ
derivative mutants showed the greatest increases in growth and lactic acid production. Further characterization of the
12A-adapted Δ
derivative revealed that it had a significantly smaller cell volume, a rougher cell surface, and significantly better survival at pH 2.5 than parental
12A. Genome sequence analysis confirmed that transient
inactivation decreased DNA replication fidelity in both
strains, and it identified genetic changes that might contribute to the lactic acid-resistant phenotypes of adapted cells. Targeted inactivation of three genes that had acquired nonsense mutations in the adapted
12A Δ
mutant derivative showed that NADH dehydrogenase (
), phosphate transport ATP-binding protein PstB (
), and two-component signal transduction system (TCS) quorum-sensing histidine protein kinase (
) genes act in combination to increase lactic acid resistance in
12A.
Adaptive evolution has been applied to microorganisms to increase industrially desirable phenotypes, including acid resistance. We developed a method to increase the adaptability of
12A and ATCC 334 through transient inactivation of the DNA mismatch repair enzyme MutS. Here, we show this method was effective in increasing the resistance of
to lactic acid at low pH. Additionally, we identified three genes that contribute to increased acid resistance in
12A. These results provide valuable insight on methods to enhance an organism's fitness to complex phenotypes through adaptive evolution and targeted gene inactivation.
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