Invited review: The influence of immune activation on transition cow health and performance—A critical evaluation of traditional dogmas

2021 ◽  
Author(s):  
E.A. Horst ◽  
S.K. Kvidera ◽  
L.H. Baumgard
Keyword(s):  
Immune Activation ◽  
Critical Evaluation ◽  
Transition Cow ◽  
And Performance ◽  
Cow Health

A Critical Evaluation of Automatic Bacterial Colony Counters

1979 ◽  
Vol 42 (2) ◽  
pp. 138-143 ◽  
Author(s):  
M. H. BRODSKY ◽  
B. W. CIEBIN ◽  
D. A. SCHIEMANN
Keyword(s):  
Experimental Design ◽  
Critical Evaluation ◽  
Bacterial Colony ◽  
Pasteurized Milk ◽  
Instrument Calibration ◽  
Manual Count ◽  
Milk Samples ◽  
Precision And Accuracy ◽  
And Performance ◽  
Acceptability Criterion

Four automatic colony counters (ACC), 3M Model 620 and Artek Models 480, 870 and 880, were evaluated for their precision and accuracy in counting bacterial colonies in pour-plates prepared using raw and pasteurized milk samples. The automatic colony counters were precise, labor saving devices. but not one of the ACC units approached our acceptability criterion that 90% of the ACC counts fall within ± 10% of the corresponding manual count. Some parameters of experimental design and instrument calibration which may significantly influence the response and performance of the automatic counters are discussed.

The nexus between nutrient metabolism, oxidative stress and inflammation in transition cows

2014 ◽  
Vol 54 (9) ◽  
pp. 1204 ◽  
Author(s):  
L. M. Sordillo ◽  
V. Mavangira
Keyword(s):  
Oxidative Stress ◽  
Inflammatory Responses ◽  
Metabolic Stress ◽  
Dry Period ◽  
Nutrient Metabolism ◽  
Transition Cow ◽  
Control Programs ◽  
Transition Cows ◽  
Cow Health ◽  
Global Population

Increased incidence of several economically important diseases (i.e. mastitis, metritis, displaced abomasum and ketosis) causes significant animal welfare problems and production losses in transition dairy cattle and decreases the availability of safe and nutritious food for a growing global population. A major underlying factor responsible for the development of transition cow disorders is metabolic stress, which occurs when cows fail to adapt physiologically to an increase in nutrient requirements needed for parturition and the onset of copious milk synthesis and secretion. Metabolic stress can be characterised as resulting from the combined effects of altered nutrient metabolism, dysfunctional inflammatory responses, and oxidative stress. Together, these factors form destructive feedback loops that exacerbate metabolic stress and cause health disorders in transition cows. A better understanding of how nutrition and immunology interact to influence metabolic stress will facilitate the development of control programs to improve transition cow health. The ability to detect signs of metabolic stress early enough in the dry period to implement needed management adjustments before calving will be the key to successful monitoring and intervention programs.

The new generation of L. C. columns; A critical evaluation of their systems compatibility and performance

1985 ◽  
Vol 20 (6) ◽  
pp. 335-342 ◽  
Author(s):  
Pamela J. Naish ◽  
D. P. Goulder ◽  
C. V. Perkins
Keyword(s):  
Critical Evaluation ◽  
And Performance ◽  
New Generation

scholarly journals How Can Biomechanics Improve Physical Preparation and Performance in Paralympic Athletes? A Narrative Review

Sports ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 89
Author(s):  
Jared R. Fletcher ◽  
Tessa Gallinger ◽  
Francois Prince
Keyword(s):  
Critical Evaluation ◽  
Narrative Review ◽  
Hydrodynamic Drag ◽  
Specific Training ◽  
Lower Limb Amputee ◽  
Paralympic Sport ◽  
And Performance ◽  
Training Modalities ◽  
Hand Cycling ◽  
Physical Preparation

Recent research in Paralympic biomechanics has offered opportunities for coaches, athletes, and sports practitioners to optimize training and performance, and recent systematic reviews have served to summarize the state of the evidence connecting biomechanics to Paralympic performance. This narrative review serves to provide a comprehensive and critical evaluation of the evidence related to biomechanics and Paralympic performance published since 2016. The main themes within this review focus on sport-specific body posture: the standing, sitting, and horizontal positions of current summer Paralympic sports. For standing sports, sprint and jump mechanics were assessed in athletes with cerebral palsy and in lower-limb amputee athletes using running-specific prostheses. Our findings suggest that running and jumping-specific prostheses should be ‘tuned’ to each athlete depending on specific event demands to optimize performance. Standing sports were also inclusive to athletes with visual impairments. Sitting sports comprise of athletes performing on a bike, in a wheelchair (WC), or in a boat. WC configuration is deemed an important consideration for injury prevention, mobility, and performance. Other sitting sports like hand-cycling, rowing, and canoeing/kayaking should focus on specific sitting positions (e.g., arm-crank position, grip, or seat configuration) and ways to reduce aero/hydrodynamic drag. Para-swimming practitioners should consider athlete-specific impairments, including asymmetrical anthropometrics, on the swim-start and free-swim velocities, with special considerations for drag factors. Taken together, we provide practitioners working in Paralympic sport with specific considerations on disability and event-specific training modalities and equipment configurations to optimize performance from a biomechanical perspective.

scholarly journals Evaluating the Effects of Rumenocentesis on Health and Performance in Dairy Cows

2010 ◽  
Vol 79 (3) ◽  
pp. 459-468 ◽  
Author(s):  
Matteo Gianesella ◽  
Massimo Morgante ◽  
Calogero Stelletta ◽  
Licia Ravarotto ◽  
Elisabetta Giudice ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Skin Temperature ◽  
Milk Yield ◽  
Diagnostic Techniques ◽  
Blood Cell Count ◽  
Physiological Variables ◽  
Ruminal Acidosis ◽  
Superficial Skin ◽  
And Performance ◽  
Cow Health

The objective of this study was to evaluate the effects of the rumenocentesis procedure on dairy cows by determining selected metabolic and physiological variables representing the health status. Two groups of 6 cows either underwent rumenocentesis (GA) or sham (GB) procedures. Superficial skin temperature of the rumenocentesis area was measured using infrared thermography before the procedure (-1 h), immediately after (0 h), and at 48 h, 96 h, and 20 days following rumenocentesis. Blood samples were collected at all times, except for immediately after the procedure (0 h), and selected immunologic response variables were determined. Milk yield and rectal temperatures were measured daily. Rumenocentesis did not influence the white blood cell count, haptoglobin or total protein concentrations. Electrophoretic protein fractions were not different between GA and GB treatments. Milk yield and rectal temperature were not affected by rumenocentesis. Skin temperature of the rumenocentesis region in GA group cows increased by 1.0 °C immediately after rumenocentesis and returned to baseline after 48 h where it remained constantly until the end of the study; similar to observation in GB group cows. Results of this study would suggest minimal adverse effects on cow health and production when performing rumenocentesis for the diagnosis of subacute ruminal acidosis. Additional more intensive studies addressing animal welfare issues relative to the diagnostic techniques are needed.

scholarly journals Synthesis and Performance of Photocatalysts for Photocatalytic Hydrogen Production: Future Perspectives

Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1505
Author(s):  
Salvador Escobedo ◽  
Hugo de de Lasa
Keyword(s):  
Hydrogen Production ◽  
Energy Production ◽  
State Of The Art ◽  
Agricultural Waste ◽  
Critical Evaluation ◽  
Electron Hole ◽  
Organic Species ◽  
Photocatalytic Reactors ◽  
And Performance

Photocatalysis for “green” hydrogen production is a technology of increasing importance that has been studied using both TiO2–based and heterojunction composite-based semiconductors. Different irradiation sources and reactor units can be considered for the enhancement of photocatalysis. Current approaches also consider the use of electron/hole scavengers, organic species, such as ethanol, that are “available” in agricultural waste, in communities around the world. Alternatively, organic pollutants present in wastewaters can be used as organic scavengers, reducing health and environmental concerns for plants, animals, and humans. Thus, photocatalysis may help reduce the carbon footprint of energy production by generating H2, a friendly energy carrier, and by minimizing water contamination. This review discusses the most up-to-date and important information on photocatalysis for hydrogen production, providing a critical evaluation of: (1) The synthesis and characterization of semiconductor materials; (2) The design of photocatalytic reactors; (3) The reaction engineering of photocatalysis; (4) Photocatalysis energy efficiencies; and (5) The future opportunities for photocatalysis using artificial intelligence. Overall, this review describes the state-of-the-art of TiO2–based and heterojunction composite-based semiconductors that produce H2 from aqueous systems, demonstrating the viability of photocatalysis for “green” hydrogen production.

scholarly journals 332 Young Scholar Presentation: regulation of immune signaling by extracellular vesicles

2019 ◽  
Vol 97 (Supplement_2) ◽  
pp. 132-133
Author(s):  
Caroline M Ylioja ◽  
Laman K Mamedova ◽  
Barry J Bradford
Keyword(s):  
Extracellular Vesicles ◽  
Immune Suppression ◽  
Immune Cells ◽  
The Body ◽  
Metabolic Dysfunction ◽  
Mediated Communication ◽  
Transition Cow ◽  
Cow Health ◽  
And Function ◽  
High Degree

Abstract Exosomes and other extracellular vesicles traffic a variety of protein and nucleic acid cargo throughout the body. Immune cells especially utilize these vesicles for communication, and they are being studied in clinical settings for their potential to act as disease markers, but also to serve as drug delivery systems. In animal science, a large part of the research around exosomes has centered around their presence in milk, as well as their bioavailability and potential impact for the neonate and for humans; milk-derived exosomes are enriched with immune-related proteins and microRNA that may relate to maternal health, mammary function, or neonate development. We sequenced miRNA isolated from colostrum of dairy cows predicted to feature either moderate or high degree of immune suppression, but found minimal differences (2 differentially expressed miRNA of 343 miRNA analyzed) between the two groups. Immune suppression exhibited during early lactation may also be related to altered exosome-mediated communication between immune cells. We studied the ability of bovine exosomes to alter immune responses of primary bovine monocyte-derived macrophages and found that exosomes alone or in combination with LPS were able to stimulate cytokine production to a greater extent than LPS alone. The ability of exosomes to transport cytokine, bioactive lipid, and regulatory RNA cargo suggests potential involvement in transition cow health. Altered exosome content and function have been associated with uterine infection, mastitis, and metabolic dysfunction; future studies with exosome signaling may help clarify the complexities of transition cow immune function and point to strategies to support immunity.

Effects of body condition and diet in late gestation on the subsequent health and performance of dairy cows

2007 ◽  
Vol 47 (5) ◽  
pp. 495 ◽  
Author(s):  
C. R. Stockdale
Keyword(s):  
Dairy Cows ◽  
Body Condition ◽  
Serum Calcium ◽  
Late Gestation ◽  
Urine Ph ◽  
Grazed Pasture ◽  
Milk Fever ◽  
And Performance ◽  
Cow Health ◽  
Subclinical Hypocalcaemia

The objective of the experiment reported here was to compare the effects of a total mixed ration (TMR) with a pasture hay diet on the healthy transition from late gestation to early lactation of dairy cows with different body condition scores [BCS; 4.2 (thin) and 5.8 (fat) units on an 8-point scale]. It was hypothesised that providing the dietary cation-anion differences (DCAD) of the two diets were similar, more clinical and subclinical hypocalcaemia would be recorded in fat cows than in thin cows, and that this would not be affected by type of diet. The design of the experiment included 72 cows in a 2 × 2 factorial (two BCS × two types of diet fed for the 4 weeks before expected calving date) where cows were fed individually indoors before calving, and grazed pasture and fed concentrates after calving. The calculated DCAD of the two diets were similar (22.1 v. 18.4 meq/100 g DM for the hay and TMR diets) as were the precalving urine pH levels (7.73 and 7.74) of the cows. Intakes of hay and TMR during late gestation were on average 8.8 and 9.3 kg DM/cow.day, respectively, but the patterns of intake varied, with hay intake declining over the 3 weeks before calving and that of TMR remaining relatively constant until just before parturition. Cows fed hay had higher (P < 0.05) non-esterified fatty acid (0.90 v. 0.64 mmol/L), β-hydroxybutyrate (0.61 v. 0.43 mmol/L) and calcium (2.50 v. 2.24 mmol/L) concentrations, and lower (P < 0.05) glucose (3.03 v. 3.21 mmol/L) concentrations, than the cows fed the TMR before calving. Immediately after calving, most of these differences had disappeared. Average blood serum calcium concentrations within 12 h of calving were similar (P > 0.05) in cows fed each diet (1.94 and 1.79 mmol/L for hay and TMR, respectively). At calving, concentrations of serum calcium and urea were greater (P < 0.05) in the thin cows than the fat cows. Only fat cows had clinical hypocalcaemia (serum calcium concentrations <1.40 mmol/L) or needed to be treated for milk fever either at calving or in the week following calving, whereas there tended to be more thin cows with subclinical hypocalcaemia (serum calcium concentrations of 1.40–2.00 mmol/L). Subclinical ketosis (serum β-hydroxybutyrate concentrations of 1.00–3.00 mmol/L) was more prevalent in fat cows than in thin cows; otherwise health disorders were evenly spread across treatments. In the first 5 weeks of lactation, there were no significant (P > 0.05) effects of late gestation diet on any aspect of production. In contrast, there were positive (P < 0.05) effects of BCS on milk yield and concentrations of fat and protein in milk. The hypothesis concerning the amount and severity of hypocalcaemia in fat cows was only partially supported by the results, but type of diet had no effects on cow health or subsequent production.

Competence and performance in language acquisition

1996 ◽  
Vol 19 (4) ◽  
pp. 730-731
Author(s):  
Mark Hale
Keyword(s):  
Language Acquisition ◽  
Language Change ◽  
Critical Evaluation ◽  
L2 Acquisition ◽  
And Performance ◽  
L1 Acquisition

AbstractThe implications of Epstein et al.'s critical evaluation of much of the existing literature on L2-acquisition extends far beyond the domain they discuss. I argue that similar methodological clarification is urgently needed in analyses of the role of UG in L1-acquisition, as well as in discussions in such seemingly “distant” areas as the study of language change.

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