Note: This page contains sample records for the topic cow physiological adaptations from Science.gov.
While these samples are representative of the content of Science.gov,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of Science.gov
to obtain the most current and comprehensive results.
Last update: August 15, 2014.
1

Addition of Sodium Bicarbonate to Rations of Postpartum Dairy Cows: Physiological and Metabolic Effects1  

Microsoft Academic Search

Sodium bicarbonate was added to complete mixed rations to characterize physiological, metabolic, and ruminal changes immediately postpartum when dairy cows are switched abruptly from a low energy ration prepartum to a high energy ration postpartum. Twelve Holstein cows were paired and assigned randomly to either a control or buffered ration containing .8% sodium bicarbonate. Ra- tions consisted of 50% corn

L. H. Kilmer; L. D. Muller; T. J. Snyder

1981-01-01

2

Characterisation of physiological and immunological responses in beef cows to abrupt weaning and subsequent housing  

Microsoft Academic Search

BACKGROUND: Weaning involves the permanent separation of the calf from the dam and has been shown to be stressful for both. The objectives of this study were to characterise the effect of i) abrupt weaning and ii) subsequent housing on the extended physiological and immunological responses of beef cows. At weaning (day (d) 0, mean age of calf (s.d.) 212

Eilish M Lynch; Bernadette Earley; Mark McGee; Sean Doyle

2010-01-01

3

Individual differences in behavioral and physiological responsiveness of primiparous dairy cows to machine milking  

Microsoft Academic Search

An experiment was performed in primiparous dairy cows (n = 23) to examine consistency of individual differences in reactivity to milking, and correlations between measures of behavior, physiology, and milk ejection. Responsiveness to milking was monitored during the first machine milking, on d 2 of lactation, and during milkings on d 4 and 130 of lactation. Measurements included kicking and

Reenen van C. G; Werf van der J. T. N; R. M. Bruckmaier; H. Hopster; B. Engel; J. P. T. M. Noordhuizen; H. J. Blokhuis

2002-01-01

4

Adaptive dynamics for physiologically structured population models.  

PubMed

We develop a systematic toolbox for analyzing the adaptive dynamics of multidimensional traits in physiologically structured population models with point equilibria (sensu Dieckmann et al. in Theor. Popul. Biol. 63:309-338, 2003). Firstly, we show how the canonical equation of adaptive dynamics (Dieckmann and Law in J. Math. Biol. 34:579-612, 1996), an approximation for the rate of evolutionary change in characters under directional selection, can be extended so as to apply to general physiologically structured population models with multiple birth states. Secondly, we show that the invasion fitness function (up to and including second order terms, in the distances of the trait vectors to the singularity) for a community of N coexisting types near an evolutionarily singular point has a rational form, which is model-independent in the following sense: the form depends on the strategies of the residents and the invader, and on the second order partial derivatives of the one-resident fitness function at the singular point. This normal form holds for Lotka-Volterra models as well as for physiologically structured population models with multiple birth states, in discrete as well as continuous time and can thus be considered universal for the evolutionary dynamics in the neighbourhood of singular points. Only in the case of one-dimensional trait spaces or when N = 1 can the normal form be reduced to a Taylor polynomial. Lastly we show, in the form of a stylized recipe, how these results can be combined into a systematic approach for the analysis of the (large) class of evolutionary models that satisfy the above restrictions. PMID:17943289

Durinx, Michel; Metz, J A J Hans; Meszéna, Géza

2008-05-01

5

Resistance Training: Physiological Responses and Adaptations (Part 3 of 4).  

ERIC Educational Resources Information Center

The physiological responses and adaptations which occur as a result of resistance training, such as cardiovascular responses, serum lipid count, body composition, and neural adaptations are discussed. Changes in the endocrine system are also described. (JL)

Fleck, Steven J.; Kraemer, William J.

1988-01-01

6

Effects of the level of feed intake and ergot contaminated concentrate on ruminal fermentation and on physiological parameters in cows  

Microsoft Academic Search

The aim of the present study was to examine the effects of ergot contaminated feed concentrate at differing levels of feed\\u000a intake on ruminal fermentation, and on various physiological parameters of dairy cows. Twelve double fistulated (in the rumen\\u000a and the proximal duodenum) Holstein Friesian cows were fed either a control diet (on a dry matter (DM) base: 60% maize

B. Schumann; P. Lebzien; K.-H. Ueberschär; J. Spilke; M. Höltershinken; S. Dänicke

2008-01-01

7

Effect of rumen-protected choline and methionine on physiological and metabolic disorders and reproductive indices of dairy cows.  

PubMed

The objective of this study was to investigate the effect of feeding different levels of ruminally protected methionine and choline on the incidence of physiological and metabolic disorders, production, and some of the reproductive indices of Holstein dairy cows. Forty Holstein dairy cows in their first and second lactation were used from 4-week pre-partum through 20-week post-partum and randomly assigned to receive one of the following treatments: 18 g/day of rumen-protected methionine (RPM), 60 g/day of rumen-protected choline (RPC), 18 g/day of RPM + 60 g/day of RPC, and neither supplement (control). The treatments significantly affected services per conception and open days of lactating dairy cows (p < 0.05), but did not affect significantly on days to first oestrus and number of pregnant cows. RPM + RPC-fed cows had the lowest open days, days to first oestrus and services per conception compared with other groups. The effect of treatments was significant on the incidence of metabolic and physiological problems except for foot/leg problems. Cows fed RPM+RPC had the lowest health problems compared with other groups (p < 0.05). Results indicate that the supplementation of RPM and RPC can improve reproductive performance and health status of dairy cows. PMID:20455967

Ardalan, M; Rezayazdi, K; Dehghan-Banadaky, M

2010-12-01

8

Complexity and network dynamics in physiological adaptation: an integrated view.  

PubMed

Living organisms constantly interact with their surroundings and sustain internal stability against perturbations. This dynamic process follows three fundamental strategies (restore, explore, and abandon) articulated in historical concepts of physiological adaptation such as homeostasis, allostasis, and the general adaptation syndrome. These strategies correspond to elementary forms of behavior (ordered, chaotic, and static) in complex adaptive systems and invite a network-based analysis of the operational characteristics, allowing us to propose an integrated framework of physiological adaptation from a complex network perspective. Applicability of this concept is illustrated by analyzing molecular and cellular mechanisms of adaptation in response to the pervasive challenge of obesity, a chronic condition resulting from sustained nutrient excess that prompts chaotic exploration for system stability associated with tradeoffs and a risk of adverse outcomes such as diabetes, cardiovascular disease, and cancer. Deconstruction of this complexity holds the promise of gaining novel insights into physiological adaptation in health and disease. PMID:24751342

Baffy, György; Loscalzo, Joseph

2014-05-28

9

[Physiology and physiopathology of postnatal pulmonary adaptation. 1: Physiology].  

PubMed

The aim of the review consists of the help to understand the complex physiological mechanisms of the onset of breathing and the regulation of the respiration during the early newborn period. The lungs of the newborn contain nearly no alveoli. Postnatal formation of alveoli enlarges the gas exchange surface until the 20th year of life, the lung volume increases by a factor of 27. Immediately postnatal the aeration of the lungs is performed by several deep inspirations with breath hold and following crying. The fetal lung liquid is resorbed via both, lymph and blood vessels. Stability of the functional residual capacity is reached very rapidly. The inflation augmenting reflex and sighing support effectively this process. The significant importance of the surfactant for the successful begin of air breathing is described. Onset of respiration is combined with the decrease of the pulmonary arterial resistance and the remarkable increase of the pulmonary blood flow. The hypoxic response in the newborn is biphasic. An initial short hyperventilation is regularly followed by ventilatory depression. Neurophysiological causes are evident. Hyperventilation by inhalation of gas mixtures with higher CO2 concentrations is low, at least in preterm infants. The causes are believed to ly in the limitation of the efficiency of the respiratory muscles. Peripheral chemoreceptors in the glomus caroticum and in the bronchial mucosa, stretch receptors in the bronchial muscles, and muscle spindles in the intercostal muscles are functioning in newborns as well as in preterm infants. PMID:1945451

Schwartze, H

1991-01-01

10

Physiologic adaptations of the tubuloglomerular feedback system  

Microsoft Academic Search

The maintenance of volume homeostasis is sufficiently important to mammalian terrestrial life that a large amount of evolutionary energy has been expended in the development of multiple control systems, each involved in regulating the volume and composition of internal body fluids. The kidney, which participates in most of these systems, has evolved physiologic attributes which enhance the efficiency of volume

Roland C Blantz; Scott C Thomson; Orjan W Peterson; Francis B Gabbai

1990-01-01

11

Physiological Self-Regulation and Adaptive Automation  

NASA Technical Reports Server (NTRS)

Adaptive automation has been proposed as a solution to current problems of human-automation interaction. Past research has shown the potential of this advanced form of automation to enhance pilot engagement and lower cognitive workload. However, there have been concerns voiced regarding issues, such as automation surprises, associated with the use of adaptive automation. This study examined the use of psychophysiological self-regulation training with adaptive automation that may help pilots deal with these problems through the enhancement of cognitive resource management skills. Eighteen participants were assigned to 3 groups (self-regulation training, false feedback, and control) and performed resource management, monitoring, and tracking tasks from the Multiple Attribute Task Battery. The tracking task was cycled between 3 levels of task difficulty (automatic, adaptive aiding, manual) on the basis of the electroencephalogram-derived engagement index. The other two tasks remained in automatic mode that had a single automation failure. Those participants who had received self-regulation training performed significantly better and reported lower National Aeronautics and Space Administration Task Load Index scores than participants in the false feedback and control groups. The theoretical and practical implications of these results for adaptive automation are discussed.

Prinzell, Lawrence J.; Pope, Alan T.; Freeman, Frederick G.

2007-01-01

12

Physiological adaptation - Crew health in space  

NASA Technical Reports Server (NTRS)

The experiments planned for the Spacelab Life Sciences-1 (SLS-1) Shuttle mission, which is dedicated to investigating biomedical issues pertinent to the man's presence in space, are discussed. The areas of research will include human and animal experiments concerned with the cardiovascular system, the vestibular apparatus, and metabolic experiments related to renal endocrine function, hematology, immune system, and muscle and bone/calcium metabolism, with particular attention given to the physiological complications resulting from short-duration space flight and subsequent return to the 1-G environment. The hardware systems to be used on the SLS-1 mission represent prototypes of systems to be developed for the medical and research facilities of the Space Station. The results of the experiments will be used to address issues related to long-duration space flight required for the Space Station and interplanetary travels.

Brand, Susan

1988-01-01

13

Physiological and genetical adaptation to temperature in fish populations  

Microsoft Academic Search

The physiological and genetical adaptation of fishes to environmental temperatures has been studied by analyzing data concerning: (i) the oxygen binding properties of haemoglobin recorded during growth experiments on Atlantic cod, and (ii) the primary structure of haemoglobin (Hb) and lactate dehydrogenase (LDH) of several fish species living in polar and temperate areas. The results on the oxygen binding properties

A. Colosimo; A. Giuliani; F. Maranghi; O. Brix; S. Thorkildsen; T. Fischer; R. Knust; H. O. Poertner

2003-01-01

14

Predicting animal ? 18 O: Accounting for diet and physiological adaptation  

Microsoft Academic Search

Theoretical predictions and measured isotope variations indicate that diet and physiological adaptation have a significant impact on animals ?18O and cannot be ignored. A generalized model is therefore developed for the prediction of animal body water and phosphate ?18O to incorporate these factors quantitatively. Application of the model reproduces most published compositions and compositional trends for mammals and birds. A

Matthew J. Kohn

1996-01-01

15

Applying additive logistic regression to data derived from sensors monitoring behavioral and physiological characteristics of dairy cows to detect lameness.  

PubMed

The hypothesis was that sensors currently available on farm that monitor behavioral and physiological characteristics have potential for the detection of lameness in dairy cows. This was tested by applying additive logistic regression to variables derived from sensor data. Data were collected between November 2010 and June 2012 on 5 commercial pasture-based dairy farms. Sensor data from weigh scales (liveweight), pedometers (activity), and milk meters (milking order, unadjusted and adjusted milk yield in the first 2 min of milking, total milk yield, and milking duration) were collected at every milking from 4,904 cows. Lameness events were recorded by farmers who were trained in detecting lameness before the study commenced. A total of 318 lameness events affecting 292 cows were available for statistical analyses. For each lameness event, the lame cow's sensor data for a time period of 14 d before observation date were randomly matched by farm and date to 10 healthy cows (i.e., cows that were not lame and had no other health event recorded for the matched time period). Sensor data relating to the 14-d time periods were used for developing univariable (using one source of sensor data) and multivariable (using multiple sources of sensor data) models. Model development involved the use of additive logistic regression by applying the LogitBoost algorithm with a regression tree as base learner. The model's output was a probability estimate for lameness, given the sensor data collected during the 14-d time period. Models were validated using leave-one-farm-out cross-validation and, as a result of this validation, each cow in the data set (318 lame and 3,180 nonlame cows) received a probability estimate for lameness. Based on the area under the curve (AUC), results indicated that univariable models had low predictive potential, with the highest AUC values found for liveweight (AUC=0.66), activity (AUC=0.60), and milking order (AUC=0.65). Combining these 3 sensors improved AUC to 0.74. Detection performance of this combined model varied between farms but it consistently and significantly outperformed univariable models across farms at a fixed specificity of 80%. Still, detection performance was not high enough to be implemented in practice on large, pasture-based dairy farms. Future research may improve performance by developing variables based on sensor data of liveweight, activity, and milking order, but that better describe changes in sensor data patterns when cows go lame. PMID:24011945

Kamphuis, C; Frank, E; Burke, J K; Verkerk, G A; Jago, J G

2013-11-01

16

Functional genomics of physiological plasticity and local adaptation in killifish.  

PubMed

Evolutionary solutions to the physiological challenges of life in highly variable habitats can span the continuum from evolution of a cosmopolitan plastic phenotype to the evolution of locally adapted phenotypes. Killifish (Fundulus sp.) have evolved both highly plastic and locally adapted phenotypes within different selective contexts, providing a comparative system in which to explore the genomic underpinnings of physiological plasticity and adaptive variation. Importantly, extensive variation exists among populations and species for tolerance to a variety of stressors, and we exploit this variation in comparative studies to yield insights into the genomic basis of evolved phenotypic variation. Notably, species of Fundulus occupy the continuum of osmotic habitats from freshwater to marine and populations within Fundulus heteroclitus span far greater variation in pollution tolerance than across all species of fish. Here, we explore how transcriptome regulation underpins extreme physiological plasticity on osmotic shock and how genomic and transcriptomic variation is associated with locally evolved pollution tolerance. We show that F. heteroclitus quickly acclimate to extreme osmotic shock by mounting a dramatic rapid transcriptomic response including an early crisis control phase followed by a tissue remodeling phase involving many regulatory pathways. We also show that convergent evolution of locally adapted pollution tolerance involves complex patterns of gene expression and genome sequence variation, which is confounded with body-weight dependence for some genes. Similarly, exploiting the natural phenotypic variation associated with other established and emerging model organisms is likely to greatly accelerate the pace of discovery of the genomic basis of phenotypic variation. PMID:20581107

Whitehead, Andrew; Galvez, Fernando; Zhang, Shujun; Williams, Larissa M; Oleksiak, Marjorie F

2011-01-01

17

COMPARISON OF BEHAVIORAL AND PHYSIOLOGICAL RESPONSE TO ELECTRIC SHOCK IN LACTATING DAIRY COWS  

Microsoft Academic Search

Summary: A series of experiments were performed to measure behavioral and blood cortisol concentration responses of cows exposed to current applied from front to rear hooves. Increased activity level was not a consistent indicator of response to current, whereas a startle response (flinch) was a consistent and repeatable indicator. Cows responded at lower current levels to the 1-front to 2-rear

Douglas J. Reinemann; Steven D. LeMire; Morten Dam Rasmusssen; Milo C. Wiltbank; Lewis G. Sheffield

18

Hormonal profiles, physiological parameters, and productive and reproductive performances of Girolando cows in the state of Ceará-Brazil  

NASA Astrophysics Data System (ADS)

This study compared two breed groups of Girolando (½ Holstein ½ Gyr vs. ¾ Holstein ¼ Gyr) through analysis of physiological, productive, and reproductive parameters to determine the group best suited to rearing in a semiarid tropical climate. The experiment was conducted at the Companhia de Alimentos do Nordeste (CIALNE) farm, in the municipality of Umirim, State of Ceará, Brazil. Eighty cows were used in a 2 × 2 factorial study; 40 of each breed group were kept under an extensive system during the wet season and an intensive system during the dry season. The collection of physiological data and blood samples were obtained in the afternoon after milking. Rectal temperature (RT), surface temperature (ST), and respiratory rate (RR) were obtained for each cow after milking. Blood samples were obtained by tail vein puncture and were determined triiodothyronine (T3) and thyroxine (T4) and cortisol. The environmental parameters obtained were relative humidity (RH) and air temperature (AT), and from these, a temperature and humidity index (THI) was calculated. Pregnancy diagnosis (PD) was determined by ultrasonography 30 days after artificial insemination (AI). The milk production of each cow was recorded with automated milkings in the farm. The variables were expressed as mean and standard error, evaluated by ANOVA at 5 % probability using the Proc GLM of SAS. Chi-square test at 5 % probability was applied to data of pregnancy rate (PR) and the number of AI's to obtain pregnancy. It can be concluded that the breed group ½ Holstein ½ Gyr is most suited for farming under conditions of thermal stress.

da Costa, Antônio Nélson Lima; Feitosa, José Valmir; Júnior, Péricles Afonso Montezuma; de Souza, Priscila Teixeira; de Araújo, Airton Alencar

2014-05-01

19

Energy and lipid metabolism gene expression of D18 embryos in dairy cows is related to dam physiological status.  

PubMed

We analyzed the change in gene expression related to dam physiological status in day (D)18 embryos from growing heifers (GH), early lactating cows (ELC), and late lactating cows (LLC). Dam energy metabolism was characterized by measurement of circulating concentrations of insulin, glucose, IGF-1, nonesterified fatty acids, ?-hydroxybutyrate, and urea before embryo flush. The metabolic parameters were related to differential gene expression in the extraembryonic tissues by correlation analysis. Embryo development estimated by measuring the length of the conceptuses and the proportion of expected D18 gastrulating stages was not different between the three groups of females. However, embryo metabolism was greatly affected by dam physiological status when we compared GH with ELC and GH with LLC but to a lesser extent when ELC was compared with LLC. Genes involved in glucose, pyruvate, and acetate utilization were upregulated in GH vs. ELC conceptuses (e.g., SLC2A1, PC, ACSS2, ACSS3). This was also true for the pentose pathway ( PGD, TKT), which is involved in synthesis of ribose precursors of RNA and DNA. The pathways involved in lipid synthesis were also upregulated in GH vs. ELC. Despite similar morphological development, the molecular characteristics of the heifers' embryos were consistently different from those of the cows. Most of these differences were strongly related to metabolic/hormone patterns before insemination and during conceptus free-life. Many biosynthetic pathways appeared to be more active in heifer embryos than in cow embryos, and consequently they seemed to be healthier, and this may be more conducive to continue development. PMID:24220328

Valour, D; Degrelle, S A; Ponter, A A; Giraud-Delville, C; Campion, E; Guyader-Joly, C; Richard, C; Constant, F; Humblot, P; Ponsart, C; Hue, I; Grimard, B

2014-01-15

20

Nutrition and human physiological adaptations to space flight  

NASA Technical Reports Server (NTRS)

Space flight provides a model for the study of healthy individuals undergoing unique stresses. This review focuses on how physiological adaptations to weightlessness may affect nutrient and food requirements in space. These adaptations include reductions in body water and plasma volume, which affect the renal and cardiovascular systems and thereby fluid and electrolyte requirements. Changes in muscle mass and function may affect requirements for energy, protein and amino acids. Changes in bone mass lead to increased urinary calcium concentrations, which may increase the risk of forming renal stones. Space motion sickness may influence putative changes in gastro-intestinal-hepatic function; neurosensory alterations may affect smell and taste. Some or all of these effects may be ameliorated through the use of specially designed dietary countermeasures.

Lane, H. W.; LeBlanc, A. D.; Putcha, L.; Whitson, P. A.

1993-01-01

21

Physiological and genetical adaptation to temperature in fish populations  

NASA Astrophysics Data System (ADS)

The physiological and genetical adaptation of fishes to environmental temperatures has been studied by analyzing data concerning: (i) the oxygen binding properties of haemoglobin recorded during growth experiments on Atlantic cod, and (ii) the primary structure of haemoglobin (Hb) and lactate dehydrogenase (LDH) of several fish species living in polar and temperate areas. The results on the oxygen binding properties of cod's haemoglobin indicate that for this species a temperature of around 12°C is the most favourable one, irrespective of the haemoglobin genotype, and are in line with recent evidence challenging the existence of significant evolutionary differences between cod stocks in North Atlantic. The primary structures of both Hb and LDH from species living under temperate environments show a higher variability as compared to that from polar species, although the difference in the recurrent patterns of hydrophobicity between the two areas is much larger for Hb. These results highlight the dominant role of physiological and genetical factors in shaping the adaptation to temperature at the individual and at the species level, respectively.

Colosimo, A.; Giuliani, A.; Maranghi, F.; Brix, O.; Thorkildsen, S.; Fischer, T.; Knust, R.; Poertner, H. O.

2003-11-01

22

Physiologically responsive, mechanically adaptive bio-nanocomposites for biomedical applications.  

PubMed

We report mechanically adaptive bionanocomposites based on poly(vinyl alcohol) (PVOH) and cellulose nanocrystals (CNCs), whose mechanical properties change significantly upon exposure to simulated physiological conditions. These nanocomposites were made using CNCs derived from tunicates (t-CNCs) and cotton (c-CNCs) to explore how aspect ratio, surface charge density, and filler content influence the mechanical properties. Dynamic mechanical analysis data reveal a significant enhancement of the tensile storage modulus (E') upon introduction of CNCs, which scaled with the CNC type and content. For example, in the dry, glassy state at 25 °C, E' increased up to 23% (for c-CNCs) and 88% (for t-CNCs) compared to the neat polymer. Exposing the materials to simulated physiological conditions caused a drastic softening of the materials, from 9.0 GPa to 1 MPa for c-CNCs and from 13.7 GPa to 160 MPa for t-CNCs. The data show that the swelling characteristics of the nanocomposites and the extent of mechanical switching could be influenced via the amount and type of CNCs and also the processing conditions. The high stiffness in the dry state and the ability to tailor the mechanical contrast via composition and processing makes the new materials particularly useful as basis for adaptive biomedical implants. PMID:23379302

Jorfi, Mehdi; Roberts, Matthew N; Foster, E Johan; Weder, Christoph

2013-02-01

23

Adaptations of Glucose and Long-Chain Fatty Acid Metabolism in Liver of Dairy Cows during the Periparturient Period  

Microsoft Academic Search

Tremendous metabolic and endocrine adjustments must be made as dairy cows move from late gestation to early lacta- tion. Requirements for glucose and metabolizable energy in- crease two- to threefold from 21 d before to 21 d after parturi- tion. The liver must adapt quickly to provide the increased glucose needed to support high milk production, and to proc- ess

James K. Drackley; Thomas R. Overton; G. Neil Douglas

2001-01-01

24

Metabolic and production profiles of dairy cows in response to decreased nutrient density to increase physiological imbalance at different stages of lactation.  

PubMed

Physiological imbalance (PI) is a situation in which physiological parameters deviate from the normal, and cows consequently have an increased risk of developing production diseases and reduced production or reproduction. Our objectives were to (1) determine the effect of stage of lactation and milk yield on metabolic and production responses of cows during a nutrient restriction period to experimentally increase PI; (2) identify major metabolites that relate to degree of PI; and (3) identify potential biomarkers in milk for on-farm detection of PI throughout lactation. Forty-seven Holstein cows in early [n=14; 49±22 d in milk (DIM); parity=1.6±0.5], mid (n=15; 159±39 DIM; parity=1.5±0.5), and late (n=18; 273±3 DIM; parity=1.3±0.5) lactation were used. Prior to restriction, all cows were fed the same total mixed ration ad libitum. All cows were then nutrient restricted for 4 d by supplementing the ration with 60% wheat straw to induce PI. After restriction, cows returned to full feed. Daily milk yield was recorded and composite milk samples were analyzed for fat, protein, lactose, citrate, somatic cells, uric acid, alkaline phosphatase, ?-hydroxybutyrate (BHBA), and milk urea nitrogen. Blood was collected daily and analyzed for metabolites: nonesterified fatty acids (NEFA), BHBA, glucose, plasma urea nitrogen, and insulin. The revised quantitative insulin sensitivity check index (RQUICKI) was calculated for each cow. Liver biopsies collected before and during restriction were analyzed for triglycerides, glycogen, phospholipids, glucose, and total lipid content. A generalized linear mixed model was used to determine the effect of stage of lactation on responses during restriction. Regression analyses were used to examine the effect of pre-restriction levels on changes during restriction. Similar decreases in milk yield among groups indicate that the capacity of individual responses is dependent on milk yield but the coping strategies used are dependent on stage of lactation. Milk yield was a better predictor of feed intake than DIM. Plasma glucose decreased for all cows, and cows in early lactation had increased plasma BHBA, whereas cows in later lactation had increased NEFA during restriction. Milk citrate had the greatest increase (58%) during restriction for all cows. Results reported here identified metabolites (i.e., glucose, NEFA, BHBA, cholesterol) as predictors of PI and identified milk citrate as a promising biomarker for PI on farm. PMID:22541465

Bjerre-Harpøth, V; Friggens, N C; Thorup, V M; Larsen, T; Damgaard, B M; Ingvartsen, K L; Moyes, K M

2012-05-01

25

Physiologically responsive, mechanically adaptive polymer optical fibers for optogenetics.  

PubMed

The capability to deliver light to specific locations within the brain using optogenetic tools has opened up new possibilities in the field of neural interfacing. In this context, optical fibers are commonly inserted into the brain to activate or mute neurons using photosensitive proteins. While chronic optogenetic stimulation studies are just beginning to emerge, knowledge gathered in connection with electrophysiological implants suggests that the mechanical mismatch of conventional optical fibers and the cortical tissue may be a significant contributor to neuroinflammatory response. Here, we present the design and fabrication of physiologically responsive, mechanically adaptive optical fibers made of poly(vinyl alcohol) (PVA) that may mitigate this problem. Produced by a one-step wet-spinning process, the fibers display a tensile storage modulus E' of ?7000??MPa in the dry state at 25°C and can thus readily be inserted into cortical tissue. Exposure to water causes a drastic reduction of E' to ?35??MPa on account of modest swelling with the water. The optical properties at 470 and 590 were comparable with losses of 0.7±0.04??dB/cm at 470 nm and 0.6±0.1??dB/cm at 590 nm in the dry state and 1.1±0.1??dB/cm at 470 nm and 0.9±0.3??dB/cm at 590 nm in the wet state. The dry end of a partially switched fiber with a length of 10 cm was coupled with a light-emitting diode with an output of 10.1 mW to deliver light with a power density of >500??mW/cm2 from the wet end, which is more than sufficient to stimulate neurons in vivo. Thus, even without a low-refractive index cladding, the physiologically responsive, mechanically adaptive optical fibers presented here appear to be a very useful new tool for future optogenetic studies. PMID:24978225

Jorfi, Mehdi; Voirin, Guy; Foster, E Johan; Weder, Christoph

2014-05-15

26

Hibernating without oxygen: physiological adaptations of the painted turtle  

PubMed Central

Many freshwater turtles in temperate climates may experience winter periods trapped under ice unable to breathe, in anoxic mud, or in water depleted of O2. To survive, these animals must not only retain function while anoxic, but they must do so for extended periods of time. Two general physiological adaptive responses appear to underlie this capacity for long-term survival. The first is a coordinated depression of metabolic processes within the cells, both the glycolytic pathway that produces ATP and the cellular processes, such as ion pumping, that consume ATP. As a result, both the rate of substrate depletion and the rate of lactic acid production are slowed greatly. The second is an exploitation of the extensive buffering capacity of the turtle's shell and skeleton to neutralize the large amount of lactic acid that eventually accumulates. Two separate shell mechanisms are involved: release of carbonate buffers from the shell and uptake of lactic acid into the shell where it is buffered and sequestered. Together, the metabolic and buffering mechanisms permit animals to survive for 3–4 months at 3 °C with no O2 and with circulating lactate levels of 150 mmol l?1 or more.

Jackson, Donald C

2002-01-01

27

Short communication: Glucose infusion into early postpartum cows defines an upper physiological set point for blood glucose and causes rapid and reversible changes in blood hormones and metabolites.  

PubMed

Low blood glucose concentrations after calving are associated with infertility in postpartum dairy cows perhaps because glucose is a master regulator of hormones and metabolites that control reproductive processes. The hypothesis was that low blood glucose postpartum is caused by inadequate glucose entry rate relative to whole-body demand as opposed to the alternative possibility that postpartum cows have a lower regulatory set point for blood glucose. Eight early postpartum (10 to 25 d) dairy cows (5 Holstein and 3 Guernsey) were jugular catheterized. During the first 24 h, cows were infused with physiological saline at 83.3 mL/h. After 24 h, the infusion solution was switched to 50% dextrose that was infused at a rate of 41.7 mL/h (total daily glucose dose=500 g). On d 3 and d 4, the rate of glucose infusion was increased to 83.3 mL/h (daily dose=1,000 g) and 125 mL/h (daily dose=1,500 g), respectively. On d 5, physiological saline was infused at 83.3 mL/h. Blood was sampled hourly through a second jugular catheter (contralateral side) and analyzed for glucose, nonesterified fatty acids, ?-hydroxybutyrate, insulin-like growth factor 1, and insulin. Blood glucose concentrations on d 1 (saline infusion) averaged 53.4±1.7 mg/dL. Blood glucose concentrations increased on d 2 when cows were infused with 500 g/d and increased further on d 3 when cows were infused with 1,000g of glucose/d. Increasing the infusion rate to 1,500 g/d on d 4 did not cause a further increase in blood glucose concentrations. Based on a segmented regression analysis, the upper physiological set point for blood glucose was 72.1 mg/dL. Both insulin and insulin-like growth factor 1 concentrations increased in response to glucose infusion and decreased when cows were infused with saline on d 5. Serum nonesterified fatty acids and ?-hydroxybutyrate concentrations decreased in response to glucose infusion and rebounded upward on d 5 (saline infusion). In conclusion, early postpartum cows had circulating blood glucose concentrations that were well below the upper set point defined in this study (72.1 mg/dL). Infusing approximately 1,000 g of glucose daily increased blood glucose to the physiological set point and rapidly changed the hormonal and metabolic profile that typifies postpartum cows. The inability of the early postpartum cow to achieve an adequate entry rate for glucose relative to whole-body demand is a possible mechanism that links postpartum physiology and nutrition to reproduction in dairy cows. PMID:23810589

Lucy, M C; Escalante, R C; Keisler, D H; Lamberson, W R; Mathew, D J

2013-09-01

28

Resistance Training: Physiological Responses and Adaptations (Part 2 of 4).  

ERIC Educational Resources Information Center

Resistance training causes a variety of physiological reactions, including changes in muscle size, connective tissue size, and bone mineral content. This article summarizes data from a variety of studies and research. (JL)

Fleck, Stephen J.; Kraerner, William J.

1988-01-01

29

Effects of acclimation to human interaction on performance, temperament, physiological responses, and pregnancy rates of Brahman-crossbred cows  

Microsoft Academic Search

The objective of this study was to eval- uate, over 2 consecutive years, the effects of acclimation to human interaction on performance, temperament, plasma concentrations of hormones and metabolites, and pregnancy rates of Brahman-crossbred cows. A to- tal of 160 Braford and 235 Brahman × British cows were assigned to the 2-yr study. Approximately 45 d after weaning (August 2006)

R. F. Cooke; J. D. Arthington; D. B. Araujo; G. C. Lamb

2009-01-01

30

Physiological and cellular adaptations of zebu cattle to thermal stress  

Microsoft Academic Search

During their separate evolution from Bos taurus, zebu cattle (Bos indicus) have acquired genes that confer thermotolerance at the physiological and cellular levels. Cattle from zebu breeds are better able to regulate body temperature in response to heat stress than are cattle from a variety of B. taurus breeds of European origin. Moreover, exposure to elevated temperature has less deleterious

P. J. Hansen

2004-01-01

31

PHYSIOLOGICAL INTERVENTIONS IN BREEDING FOR ADAPTATION TO ABIOTIC STRESS  

Microsoft Academic Search

The physiological-trait-based breeding approach has merit over breeding for yield per se because it increases the probability of crosses resulting in additive gene action. While considerable investment in germplasm characterization is required, conceptual models of crop genotypes can be employed as research tools to quantify likely genetic gains associated with specific trait or in defining traits that may have generic

M. P. REYNOLDS; R. M. TRETHOWAN

32

Human Adaptation to Space: Space Physiology and Countermeasures  

NASA Technical Reports Server (NTRS)

This viewgraph presentation reviews human physiological responses to spaceflight, and the countermeasures taken to prevent adverse effects of manned space flight. The topics include: 1) Human Spaceflight Experience; 2) Human Response to Spaceflight; 3) ISS Expeditions 1-16; 4) Countermeasure; and 5) Biomedical Data;

Fogarty, Jennifer

2009-01-01

33

The effect of administering ketoprofen on the physiology and behavior of dairy cows following surgery to correct a left displaced abomasum.  

PubMed

Surgical correction of left displaced abomasum (LDA) is common in lactating dairy cattle. Despite the growing acceptance that abdominal surgery is painful, few cows are administered analgesia following LDA surgery. The objective of this research was to examine the effect of administering a label dose of ketoprofen on physiological and behavioral indicators of pain in dairy cattle. Holstein cows were enrolled in a field study following LDA surgery. Surgery was performed using the standing right flank (RF) approach or the paramedian (PARA) approach. Using a triple-blind randomized trial, each animal was assigned to receive either 3mg of ketoprofen/kg of body weight or saline (the equivalent volume) by intramuscular injection immediately following surgery and 24h postoperatively. Physiological parameters (heart rate, respiration rate, and rumen motility), blood ?-hydroxybutyrate (BHBA) levels, and an assessment of cow attitude were measured on the day of surgery, and at 2 follow-up visits (visit 1=3 ± 0.9 d and visit 2=9 ± 1.2 d postsurgery; n=175). Milk production and culling were recorded for all cows enrolled in the study. Producers assessed their cows' attitudes and appetites daily for the first 3 d following surgery. A subset of cows (n=37) were fitted on the day of surgery with a 3-axis accelerometer on the hind leg to assess lying behavior. Continuous and binary outcome data were analyzed using multivariable mixed linear and mixed logistic models, respectively, with cow modeled as a random effect. Ketoprofen did not alter the physiological measures, BHBA levels, or behavioral outcomes measured. Cows subjected to RF surgery had longer lying times [model coefficient ?=228.9 min; 95% confidence interval (CI): 122.2 to 335.6] in the first 3 d following surgery, and lower heart rates (?=-9.4 beats/min; 95% CI: -12 to -6.9 beats/min) at the follow-up visits, compared with animals that underwent PARA surgery. Regardless of surgical procedure, BHBA decreased from surgery day to visit 1 (?=-1.9 mmol/L; 95% CI: -2.1 to -1.7) and visit 2 (?=-2.0 mmol/L; 95% CI: -0.2.2 to -1.8). Producer reports indicated that animals that received ketoprofen were more likely to begin eating when provided fresh feed during the first 3 d following surgery compared with those that received saline (odds ratio=4.8; 95% CI: 0.97 to 23.8). These results indicate that PARA surgery may be more painful relative to lying down than the RF approach. The apparent differences in appetite or attitude in cows that received ketoprofen reported by producers warrant further investigation. PMID:23332850

Newby, Nathalie C; Pearl, David L; LeBlanc, Stephen J; Leslie, Ken E; von Keyserlingk, Marina A G; Duffield, Todd F

2013-03-01

34

Stress physiology in fish : central regulation and organismal adaptions  

Microsoft Academic Search

The main goal of this thesis was to investigate the central regulation of the stress 428042response and consequent organismal adaptations in the common carp, Cyprinus carpio. In chapter 2 the control by CRH of ACTH release from the pituitary PD is investigated. It further describes the immunohistochemical distribution of ACTH, N-Ac beta-endorphin and non-acetylated beta-endorphin in the hypothalamus pituitary system.

Juriaan Rogier Metz

2006-01-01

35

Physiological adaptations and activity recorded at a polar base.  

PubMed

Physiological parameters and activity were recorded monthly on 19 men wintering at a polar base. A comparison was made between those in their first Antarctic winter (Group A, n = 13) and those in their second consecutive Antarctic winter (Group B, n = 6). Group A were more active (p less than 0.001) and spent more time outside (p less than 0.001) during the summer months than during the darker and colder winter period. Combined data showed no correlation between total activity and meteorological conditions, but a clear (p less than 0.001) negative correlation with time spent outside and wind speed. In the first part of the year group A became fitter (as shown by a lower heart rate at a VO2 1.51 min-1), increased basal oxygen uptake under standard conditions and put on body and fat mass. These changes were not demonstrated in group B living and working under identical conditions. Lean body mass of both groups rose throughout the year (A, p less than 0.001; B, p less than 0.05). These data suggested that the changes in physiological parameters in group A were in response to the life style and activity of a polar base, rather than to the Antarctic climate per se. PMID:4065123

Parker, R H

1985-01-01

36

[Physiological mechanisms of cardiovascular adaptation to orthostatism. Role of the sympathetic nervous system and pharmacological implications].  

PubMed

The main physiological adaptative systems occurring during orthostatism are discussed. The nervous mechanisms and especially baroreceptor pathways allow a rapid adaptation to the new hemodynamic conditions whereas hormones (mainly vasopressin) are involved later. The role of baroreflex and cardiocirculatory mechanisms is explained by the description of adaptative mechanisms in giraffe, an animal with its brain so far above the ground. The changes in adrenoceptor receptivity and the adaptative homeostatic mechanisms of the autonomic nervous system during orthostatism in human are discussed. Their characterization might allow to propose new pharmacological approaches for the treatment of orthostatic hypotension. PMID:7817354

Montastruc, J L; Senard, J M; Verwaerde, P; Montastruc, P

1994-01-01

37

Phenotyping for drought adaptation in wheat using physiological traits.  

PubMed

Wheat (Triticum spp) is one of the first domesticated food crops. It represents the first source of calories (after rice) and an important source of proteins in developing countries. As a result of the Green Revolution, wheat yield sharply increased due to the use of improved varieties, irrigation, pesticides, and fertilizers. The rate of increase in world wheat production, however, slowed after 1980, except in China, India, and Pakistan. Being adapted to a wide range of moisture conditions, wheat is grown on more land area worldwide than any other crop, including in drought prone areas. In these marginal rain-fed environments where at least 60 m ha of wheat is grown, amount and distribution of rainfall are the predominant factors influencing yield variability. Intensive work has been carried out in the area of drought adaptation over the last decades. Breeding strategies for drought tolerance improvement include: definition of the target environment, choice and characterization of the testing environment, water stress management and characterization, and use of phenotyping traits with high heritability. The use of integrative traits, facilitated by the development and application of new technologies (thermal imaging, spectral reflectance, stable isotopes) is facilitating high throughput phenotyping and indirect selection, consequently favoring yield improvement in drought prone environments. PMID:23181021

Monneveux, Philippe; Jing, Ruilian; Misra, Satish C

2012-01-01

38

[Mechanisms of natural variability at adaptation of human physiological systems to conditions of space flight].  

PubMed

This article analyzes the physiological data using the principle of invariant relationships, to reveal the mechanisms of adaptive variability. It was used physical-chemical, biochemical, and hormonal blood parameters of cosmonauts who have committed short-term and long space flights. These results suggest that application of the methods of fractal geometry to quantitative estimates of homeostasis allows to allocate the processes depending on the increase/decrease of adaptive variability and fix the state of stability or instability of certain physiological regulatory subsystems, due to mobility and to reduce the level of stability which remains stable internal structure of relationships throughout the body. PMID:22679800

Larina, I M; Nosovski?, A M; Grigor'ev, A I

2012-01-01

39

Right heart adaptation to pulmonary arterial hypertension: physiology and pathobiology.  

PubMed

Survival in patients with pulmonary arterial hypertension (PAH) is closely related to right ventricular (RV) function. Although pulmonary load is an important determinant of RV systolic function in PAH, there remains a significant variability in RV adaptation to pulmonary hypertension. In this report, the authors discuss the emerging concepts of right heart pathobiology in PAH. More specifically, the discussion focuses on the following questions. 1) How is right heart failure syndrome best defined? 2) What are the underlying molecular mechanisms of the failing right ventricle in PAH? 3) How are RV contractility and function and their prognostic implications best assessed? 4) What is the role of targeted RV therapy? Throughout the report, the authors highlight differences between right and left heart failure and outline key areas of future investigation. PMID:24355638

Vonk-Noordegraaf, Anton; Haddad, François; Chin, Kelly M; Forfia, Paul R; Kawut, Steven M; Lumens, Joost; Naeije, Robert; Newman, John; Oudiz, Ronald J; Provencher, Steve; Torbicki, Adam; Voelkel, Norbert F; Hassoun, Paul M

2013-12-24

40

A field study of the behavioral and physiological effects of varying amounts of shade for lactating cows at pasture.  

PubMed

Shade reduces the negative effects of heat load, but little is known about how much is required for efficient cooling in commercial settings. The effect of the amount of shade on 8 Holstein-Friesian herds was studied for 2 consecutive summers (mean temperature: 23°C) on 6 commercial, pasture-based dairy farms. Farms varied in the amount of natural shade provided (range: 0 to 15.6m(2) shade/cow). Time spent in shade, near water, eating, ruminating, lying, and standing were recorded between 1000 and 1530h in 31 shaded and 11 unshaded paddocks using 20-min instantaneous scan observations of 15 focal cows/herd. Respiration rate and panting score (0 to 4.5) was recorded for focal animals once per hour. The total numbers of cows in shade, near water, and with panting scores ?2 were recorded every 30min. Cows without shade spent 4% more time lying than cows with shade (standard error of the difference, SED=1.9%). A larger proportion of the herd had panting scores ?2 when no shade was available (6 vs. 2% of the herd, SED=1.2%), and respiration rates were higher by 8 breaths/min in cows without shade (SED=4.7 breaths/min). Under the conditions tested, the maximum proportion of the herd that was observed using the shade increased by 3.1% for every 1-m(2) increase in shade size [standard error (SE)=1.51%], and all cows were first seen simultaneously using shade when 2m(2)/cow was provided. For every 1-m(2) increase in shade, 0.3% fewer cows had panting score ?2 (SE=0.12%). We observed no significant relationships between the amount of shade available and any other variables. Although additional work is required to make specific recommendations, these results indicate that providing more shade allowed a higher proportion of animals to use this resource and reduced respiratory signs of heat load. PMID:24731637

Schütz, K E; Cox, N R; Tucker, C B

2014-06-01

41

Physiological and performance adaptations to high-intensity interval training.  

PubMed

High-intensity interval training (HIIT) refers to exercise that is characterized by relatively short bursts of vigorous activity, interspersed by periods of rest or low-intensity exercise for recovery. In untrained and recreationally active individuals, short-term HIIT is a potent stimulus to induce physiological remodeling similar to traditional endurance training despite a markedly lower total exercise volume and training time commitment. As little as six sessions of 'all-out' HIIT over 14 days, totaling ?15 min of intense cycle exercise within total training time commitment of ?2.5 h, is sufficient to enhance exercise capacity and improve skeletal muscle oxidative capacity. From an athletic standpoint, HIIT is also an effective strategy to improve performance when supplemented into the already high training volumes of well-trained endurance athletes, although the underlying mechanisms are likely different compared to less trained subjects. Most studies in this regard have examined the effect of replacing a portion (typically ?15-25%) of base/normal training with HIIT (usually 2-3 sessions per week for 4-8 weeks). It has been proposed that a polarized approach to training, in which ?75% of total training volume be performed at low intensities, with 10-15% performed at very high intensities may be the optimal training intensity distribution for elite athletes who compete in intense endurance events. PMID:23899754

Gibala, Martin J; Jones, Andrew M

2013-01-01

42

Involvement of skeletal muscle protein, glycogen, and fat metabolism in the adaptation on early lactation of dairy cows.  

PubMed

During early lactation, high-yielding dairy cows cannot consume enough feed to meet nutrient requirements. As a consequence, animals drop into negative energy balance and mobilize body reserves including muscle protein and glycogen for milk production, direct oxidation, and hepatic gluconeogenesis. To examine which muscle metabolic processes contribute to the adaptation during early lactation, six German Holstein cows were blood sampled and muscle biopsied throughout the periparturient period. From pregnancy to lactation, the free plasma amino acid pattern imbalanced and plasma glucose decreased. Several muscle amino acids, as well as total muscle protein, fat, and glycogen, and the expression of glucose transporter-4 were reduced within the first 4 weeks of lactation. The 2-DE and MALDI-TOF-MS analysis identified 43 differentially expressed muscle protein spots throughout the periparturient period. In early lactation, expression of cytoskeletal proteins and enzymes involved in glycogen synthesis and in the TCA cycle was decreased, whereas proteins related to glycolysis, fatty acid degradation, lactate, and ATP production were increased. On the basis of these results, we propose a model in which the muscle breakdown in early lactation provides substrates for milk production by a decoupled Cori cycle favoring hepatic gluconeogenesis and by interfering with feed intake signaling. PMID:21774562

Kuhla, Björn; Nürnberg, Gerd; Albrecht, Dirk; Görs, Solvig; Hammon, Harald M; Metges, Cornelia C

2011-09-01

43

Adaptation to Altitude as a Vehicle for Experiential Learning of Physiology by University Undergraduates  

ERIC Educational Resources Information Center

In this article, an experiential learning activity is described in which 19 university undergraduates made experimental observations on each other to explore physiological adaptations to high altitude. Following 2 wk of didactic sessions and baseline data collection at sea level, the group ascended to a research station at 12,500-ft elevation.…

Weigle, David S.; Buben, Amelia; Burke, Caitlin C.; Carroll, Nels D.; Cook, Brett M.; Davis, Benjamin S.; Dubowitz, Gerald; Fisher, Rian E.; Freeman, Timothy C.; Gibbons, Stephen M.; Hansen, Hale A.; Heys, Kimberly A.; Hopkins, Brittany; Jordan, Brittany L.; McElwain, Katherine L.; Powell, Frank L.; Reinhart, Katherine E.; Robbins, Charles D.; Summers, Cameron C.; Walker, Jennifer D.; Weber, Steven S.; Weinheimer, Caroline J.

2007-01-01

44

PHYCAA+: an optimized, adaptive procedure for measuring and controlling physiological noise in BOLD fMRI.  

PubMed

The presence of physiological noise in functional MRI can greatly limit the sensitivity and accuracy of BOLD signal measurements, and produce significant false positives. There are two main types of physiological confounds: (1) high-variance signal in non-neuronal tissues of the brain including vascular tracts, sinuses and ventricles, and (2) physiological noise components which extend into gray matter tissue. These physiological effects may also be partially coupled with stimuli (and thus the BOLD response). To address these issues, we have developed PHYCAA+, a significantly improved version of the PHYCAA algorithm (Churchill et al., 2011) that (1) down-weights the variance of voxels in probable non-neuronal tissue, and (2) identifies the multivariate physiological noise subspace in gray matter that is linked to non-neuronal tissue. This model estimates physiological noise directly from EPI data, without requiring external measures of heartbeat and respiration, or manual selection of physiological components. The PHYCAA+ model significantly improves the prediction accuracy and reproducibility of single-subject analyses, compared to PHYCAA and a number of commonly-used physiological correction algorithms. Individual subject denoising with PHYCAA+ is independently validated by showing that it consistently increased between-subject activation overlap, and minimized false-positive signal in non gray-matter loci. The results are demonstrated for both block and fast single-event task designs, applied to standard univariate and adaptive multivariate analysis models. PMID:23727534

Churchill, Nathan W; Strother, Stephen C

2013-11-15

45

Effects of Dietary Sodium Bicarbonate and Calcium Chloride on Physiological Responses of Lactating Dairy Cows in Hot Weather  

Microsoft Academic Search

Twenty-four lactating cows were as- signed randomly to three treatments to evaluate responses to large differences of dietary sodium and chloride. Treatments were corn-cottonseed meal-corn silage based complete rations with either: 1) .23% sodium chloride (control), 2) control plus 2.28% calcium chloride, or 3) control plus 1.70% sodium bicarbonate.

A. Escobosa; C. E. Coppock; L. D. Rowe Jr; W. L. Jenkins; C. E. Gates

1984-01-01

46

Effect of Yeast Culture (Saccharomyces cerevisiae) on Adaptation of Cows to Postpartum Diets and on Lactational Performance1  

Microsoft Academic Search

Multiparous (n = 26) and primiparous (n = 18) Holstein cows were fed prepar- tum and postpartum total mixed diets that were, or were not, supplemented with a yeast culture (YC) for approximately 23 d prepartum and 56 d postpartum. Multiparous cows supplemented with YC selected a prepartum diet higher in CP than did unsupplemented cows, although prepartum performance of

P. H. Robinson; J. E. Garrett

47

Genetic and physiological basis of adaptive salt tolerance divergence between coastal and inland Mimulus guttatus.  

PubMed

Local adaptation is a well-established phenomenon whereby habitat-mediated natural selection drives the differentiation of populations. However, little is known about how specific traits and loci combine to cause local adaptation. Here, we conducted a set of experiments to determine which physiological mechanisms contribute to locally adaptive divergence in salt tolerance between coastal perennial and inland annual ecotypes of Mimulus guttatus. Quantitative trait locus (QTL) mapping was used to discover loci involved in salt spray tolerance and leaf sodium (Na(+)) concentration. To determine whether these QTLs confer fitness in the field, we examined their effects in reciprocal transplant experiments using recombinant inbred lines (RILs). Coastal plants had constitutively higher leaf Na(+) concentrations and greater levels of tissue tolerance, but no difference in osmotic stress tolerance. Three QTLs contributed to salt spray tolerance and two QTLs to leaf Na(+) concentration. All three salt-spray tolerance QTLs had a significant fitness effects at the coastal field site but no effects inland. Leaf Na(+) QTLs had no detectable fitness effects in the field. * Physiological results are consistent with adaptation of coastal populations to salt spray and soil salinity. Field results suggest that there may not be trade-offs across habitats for alleles involved in local salt spray adaptations. PMID:19549130

Lowry, David B; Hall, Megan C; Salt, David E; Willis, John H

2009-08-01

48

Dietary instead of pharmacological management to counter the adverse effects of physiological adaptations to space flight  

Microsoft Academic Search

The development of pharmacological counter-measures to the adverse effects of physiological adaptation to microgravity has received relatively more attention than alternatives such as dietary management. The manipulation of dietary cation-anion balance, and its subsequent effects on acid-base metabolism, have been routinely used for some time in managing domestic animal health. More recently, dietary intake by humans of alkalinizing potassium salts

Martin J. Fettman

2000-01-01

49

Predicting organismal vulnerability to climate warming: roles of behaviour, physiology and adaptation  

PubMed Central

A recently developed integrative framework proposes that the vulnerability of a species to environmental change depends on the species' exposure and sensitivity to environmental change, its resilience to perturbations and its potential to adapt to change. These vulnerability criteria require behavioural, physiological and genetic data. With this information in hand, biologists can predict organisms most at risk from environmental change. Biologists and managers can then target organisms and habitats most at risk. Unfortunately, the required data (e.g. optimal physiological temperatures) are rarely available. Here, we evaluate the reliability of potential proxies (e.g. critical temperatures) that are often available for some groups. Several proxies for ectotherms are promising, but analogous ones for endotherms are lacking. We also develop a simple graphical model of how behavioural thermoregulation, acclimation and adaptation may interact to influence vulnerability over time. After considering this model together with the proxies available for physiological sensitivity to climate change, we conclude that ectotherms sharing vulnerability traits seem concentrated in lowland tropical forests. Their vulnerability may be exacerbated by negative biotic interactions. Whether tropical forest (or other) species can adapt to warming environments is unclear, as genetic and selective data are scant. Nevertheless, the prospects for tropical forest ectotherms appear grim.

Huey, Raymond B.; Kearney, Michael R.; Krockenberger, Andrew; Holtum, Joseph A. M.; Jess, Mellissa; Williams, Stephen E.

2012-01-01

50

Physiology  

ERIC Educational Resources Information Center

Underlying recent developments in health care and new treatments for disease are advances in basic medical sciences. This edition of "Webwatch" focuses on sites dealing with basic medical sciences, with particular attention given to physiology. There is a vast amount of information on the web related to physiology. The sites that are included here…

Kay, Ian

2008-01-01

51

Boldness behavior and stress physiology in a novel urban environment suggest rapid correlated evolutionary adaptation  

PubMed Central

Novel or changing environments expose animals to diverse stressors that likely require coordinated hormonal and behavioral adaptations. Predicted adaptations to urban environments include attenuated physiological responses to stressors and bolder exploratory behaviors, but few studies to date have evaluated the impact of urban life on codivergence of these hormonal and behavioral traits in natural systems. Here, we demonstrate rapid adaptive shifts in both stress physiology and correlated boldness behaviors in a songbird, the dark-eyed junco, following its colonization of a novel urban environment. We compared elevation in corticosterone (CORT) in response to handling and flight initiation distances in birds from a recently established urban population in San Diego, California to birds from a nearby wildland population in the species' ancestral montane breeding range. We also measured CORT and exploratory behavior in birds raised from early life in a captive common garden study. We found persistent population differences for both reduced CORT responses and bolder exploratory behavior in birds from the colonist population, as well as significant negative covariation between maximum CORT and exploratory behavior. Although early developmental effects cannot be ruled out, these results suggest contemporary adaptive evolution of correlated hormonal and behavioral traits associated with colonization of an urban habitat.

Cardoso, Goncalo C.; Whittaker, Danielle J.; Campbell-Nelson, Samuel; Robertson, Kyle W.; Ketterson, Ellen D.

2012-01-01

52

Behavioural and physiological adaptations to low-temperature environments in the common frog, Rana temporaria  

PubMed Central

Background Extreme environments can impose strong ecological and evolutionary pressures at a local level. Ectotherms are particularly sensitive to low-temperature environments, which can result in a reduced activity period, slowed physiological processes and increased exposure to sub-zero temperatures. The aim of this study was to assess the behavioural and physiological responses that facilitate survival in low-temperature environments. In particular, we asked: 1) do high-altitude common frog (Rana temporaria) adults extend the time available for larval growth by breeding at lower temperatures than low-altitude individuals?; and 2) do tadpoles sampled from high-altitude sites differ physiologically from those from low-altitude sites, in terms of routine metabolic rate (RMR) and freeze tolerance? Breeding date was assessed as the first day of spawn observation and local temperature recorded for five, paired high- and low-altitude R. temporaria breeding sites in Scotland. Spawn was collected and tadpoles raised in a common laboratory environment, where RMR was measured as oxygen consumed using a closed respiratory tube system. Freeze tolerance was measured as survival following slow cooling to the point when all container water had frozen. Results We found that breeding did not occur below 5°C at any site and there was no significant relationship between breeding temperature and altitude, leading to a delay in spawning of five days for every 100 m increase in altitude. The relationship between altitude and RMR varied by mountain but was lower for individuals sampled from high- than low-altitude sites within the three mountains with the highest high-altitude sites (?900 m). In contrast, individuals sampled from low-altitudes survived freezing significantly better than those from high-altitudes, across all mountains. Conclusions Our results suggest that adults at high-altitude do not show behavioural adaptations in terms of breeding at lower temperatures. However, tadpoles appear to have the potential to adapt physiologically to surviving at high-altitude via reduced RMR but without an increase in freeze tolerance. Therefore, survival at high-altitude may be facilitated by physiological mechanisms that permit faster growth rates, allowing completion of larval development within a shorter time period, alleviating the need for adaptations that extend the time available for larval growth.

2014-01-01

53

Human physiological adaptation to extended Space Flight and its implications for Space Station  

NASA Technical Reports Server (NTRS)

Current work evaluating short-term space flight physiological data on the homeostatic changes due to weightlessness is presented as a means of anticipating Space Station long-term effects. An integrated systems analysis of current data shows a vestibulo-sensory adaptation within days; a loss of body mass, fluids, and electrolytes, stabilizing in a month; and a loss in red cell mass over a month. But bone demineralization which did not level off is seen as the biggest concern. Computer algorithms have been developed to simulate the human adaptation to weightlessness. So far these paradigms have been backed up by flight data and it is hoped that they will provide valuable information for future Space Station design. A series of explanatory schematics is attached.

Kutyna, F. A.; Shumate, W. H.

1985-01-01

54

Local Adaptation to Altitude Underlies Divergent Thermal Physiology in Tropical Killifishes of the Genus Aphyosemion  

PubMed Central

In watersheds of equatorial West Africa, monophyletic groups of killifish species (genus Aphyosemion) occur in discrete altitudinal ranges, low altitude species (LA, sea level to ?350 m) or high altitude species (HA, 350 to 900 m). We investigated the hypothesis that local adaptation to altitude by the LA and HA species would be revealed as divergent effects of temperature on their physiological energetics. Two species from each group (mass ?350 mg) were acclimated to 19, 25 and 28°C, with 19 and 28°C estimated to be outside the thermal envelope for LA or HA, respectively, in the wild. Wild-caught animals (F0 generation) were compared with animals raised in captivity at 25°C (F1 generation) to investigate the contribution of adaptation versus plasticity. Temperature significantly increased routine metabolic rate in all groups and generations. However, LA and HA species differed in the effects of temperature on their ability to process a meal. At 25°C, the specific dynamic action (SDA) response was completed within 8 h in all groups, but acclimation to temperatures beyond the thermal envelope caused profound declines in SDA performance. At 19°C, the LA required ?14 h to complete the SDA, whereas the HA required only ?7 h. The opposite effect was observed at 28°C. This effect was evident in both F0 and F1. Reaction norms for effects of temperature on SDA therefore revealed a trade-off, with superior performance at warmer temperatures by LA being associated with inferior performance at cooler temperatures, and vice-versa in HA. The data indicate that divergent physiological responses to temperature in the LA and HA species reflect local adaptation to the thermal regime in their habitat, and that local adaptation to one thermal environment trades off against performance in another.

McKenzie, David J.; Estivales, Guillan; Svendsen, Jon C.; Steffensen, John F.; Agnese, Jean-Francois

2013-01-01

55

Adaptive divergence in a scleractinian coral: physiological adaptation of Seriatopora hystrix to shallow and deep reef habitats  

PubMed Central

Background Divergent natural selection across environmental gradients has been acknowledged as a major driver of population and species divergence, however its role in the diversification of scleractinian corals remains poorly understood. Recently, it was demonstrated that the brooding coral Seriatopora hystrix and its algal endosymbionts (Symbiodinium) are genetically partitioned across reef environments (0-30 m) on the far northern Great Barrier Reef. Here, we explore the potential mechanisms underlying this differentiation and assess the stability of host-symbiont associations through a reciprocal transplantation experiment across habitats ('Back Reef', 'Upper Slope' and 'Deep Slope'), in combination with molecular (mtDNA and ITS2-DGGE) and photo-physiological analyses (respirometry and HPLC). Results The highest survival rates were observed for native transplants (measured 14 months after transplantation), indicating differential selective pressures between habitats. Host-symbiont assemblages remained stable during the experimental duration, demonstrating that the ability to "shuffle" or "switch" symbionts is restricted in S. hystrix. Photo-physiological differences were observed between transplants originating from the shallow and deep habitats, with indirect evidence of an increased heterotrophic capacity in native deep-water transplants (from the 'Deep Slope' habitat). Similar photo-acclimatisation potential was observed between transplants originating from the two shallow habitats ('Back Reef' and 'Upper Slope'), highlighting that their genetic segregation over depth may be due to other, non-photo-physiological traits under selection. Conclusions This study confirms that the observed habitat partitioning of S. hystrix (and associated Symbiodinium) is reflective of adaptive divergence along a depth gradient. Gene flow appears to be reduced due to divergent selection, highlighting the potential role of ecological mechanisms, in addition to physical dispersal barriers, in the diversification of scleractinian corals and their associated Symbiodinium.

2011-01-01

56

Generation of an index for physiological imbalance and its use as a predictor of primary disease in dairy cows during early lactation.  

PubMed

Physiological imbalance (PI) is a situation in which physiological parameters deviate from the normal and cows consequently have an increased risk of developing production diseases and reduced production or reproduction. The objectives of this work were (1) to generate an index for PI based on several plasma metabolites and (2) to compare the use of this index with calculated energy balance (EBAL) and individual plasma metabolites in relation to risk of disease during early lactation. We used a total of 634 lactations from 317 cows consisting of 3 breeds ranging from a parity of 1 to 4. Weekly blood samples were analyzed for selected metabolites; that is, urea nitrogen, albumin, cholesterol, nonesterified fatty acids (NEFA), glucose, and ?-hydroxybutyrate (BHBA). Energy intake and EBAL were calculated; veterinary treatment records and daily composite milk somatic cell counts were used to determine incidence of disease. Data were adjusted for numerous fixed effects (e.g., parity, breed, and week around calving) before further statistical analysis. The time of disease (TOD) was recorded as the day in which the signs of disease were observed (TOD=0). The week before and after TOD was ± n wk relative to TOD=0. Each week, all plasma metabolites were individually adjusted to an overall mean (=0) and variance (=1). The normalized variables were included in regression analyses by week of lactation to identify metabolites that explain the variation in calculated EBAL, as a reflection of degree of PI. Nonesterified fatty acids, BHBA, and glucose were weighted within each week based on regression coefficients (i.e., x1-x3 below) generated from a model to predict EBAL. Data from wk -1 relative to TOD were analyzed using a mixed linear model to relate degree of PI and metabolites in blood to risk of disease. The weekly PI index was defined as PI=(x1 × [NEFA])+x2 × [BHBA] - x3 × [glucose])/3. For diseases that developed ? 2 wk after calving, no variables were associated with risk of disease. Prepartal PI and plasma NEFA were better predictors of disease (i.e., metritis, retained placenta, and milk fever) at wk 1 than EBAL and plasma BHBA and glucose. Examining the relationship between PI and milk constituents is needed for the development of an automated in-line and real-time surveillance system for early detection of risk animals on-farm. PMID:23403197

Moyes, K M; Larsen, T; Ingvartsen, K L

2013-04-01

57

High sustained +Gz acceleration: physiological adaptation to high-G tolerance  

NASA Technical Reports Server (NTRS)

Since the early 1940s, a significant volume of research has been conducted in an effort to describe the impact of acute exposures to high-G acceleration on cardiovascular mechanisms responsible to maintaining cerebral perfusion and conscious in high performance aircraft pilots during aerial combat maneuvers. The value of understanding hemodynamic characteristics that underlie G-induced loss of consciousness has been instrumental in the evolution of optimal technology development (e.g., G-suits, positive pressure breathing, COMBAT EDGE, etc.) and pilot training (e.g., anti-G straining maneuvers). Although the emphasis of research has been placed on the development of protection against acute high +Gz acceleration effects, recent observations suggest that adaptation of cardiovascular mechanism associated with blood pressure regulation may contribute to a protective 'G-training' effect. Regular training at high G enhances G tolerance in humans, rats, guinea pigs, and dogs while prolonged layoff from exposure in high G profiles (G-layoff) can result in reduced G endurance. It seems probable that adaptations in physiological functions following chronically-repeated high G exposure (G training) or G-layoff could have significant impacts on performance during sustained high-G acceleration since protective technology such as G-suits and anit-G straining maneuvers are applied consistently during these periods of training. The purpose of this paper is to present a review of new data from three experiments that support the notion that repeated exposure on a regular basis to high sustained +Gz acceleration induces significant physiological adaptations which are associated with improved blood pressure regulation and subsequent protection of cerebral perfusion during orthostatic challenges.

Convertino, V. A.

1998-01-01

58

Adaptation to Shift Work: Physiologically Based Modeling of the Effects of Lighting and Shifts' Start Time  

PubMed Central

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers’ sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n?=?8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers’ adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21?00 instead of 00?00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters.

Postnova, Svetlana; Robinson, Peter A.; Postnov, Dmitry D.

2013-01-01

59

Adaptation to shift work: physiologically based modeling of the effects of lighting and shifts' start time.  

PubMed

Shift work has become an integral part of our life with almost 20% of the population being involved in different shift schedules in developed countries. However, the atypical work times, especially the night shifts, are associated with reduced quality and quantity of sleep that leads to increase of sleepiness often culminating in accidents. It has been demonstrated that shift workers' sleepiness can be improved by a proper scheduling of light exposure and optimizing shifts timing. Here, an integrated physiologically-based model of sleep-wake cycles is used to predict adaptation to shift work in different light conditions and for different shift start times for a schedule of four consecutive days of work. The integrated model combines a model of the ascending arousal system in the brain that controls the sleep-wake switch and a human circadian pacemaker model. To validate the application of the integrated model and demonstrate its utility, its dynamics are adjusted to achieve a fit to published experimental results showing adaptation of night shift workers (n?=?8) in conditions of either bright or regular lighting. Further, the model is used to predict the shift workers' adaptation to the same shift schedule, but for conditions not considered in the experiment. The model demonstrates that the intensity of shift light can be reduced fourfold from that used in the experiment and still produce good adaptation to night work. The model predicts that sleepiness of the workers during night shifts on a protocol with either bright or regular lighting can be significantly improved by starting the shift earlier in the night, e.g.; at 21:00 instead of 00:00. Finally, the study predicts that people of the same chronotype, i.e. with identical sleep times in normal conditions, can have drastically different responses to shift work depending on their intrinsic circadian and homeostatic parameters. PMID:23308206

Postnova, Svetlana; Robinson, Peter A; Postnov, Dmitry D

2013-01-01

60

Behavioural and physiological effect of dental environment sensory adaptation on children's dental anxiety.  

PubMed

Dental anxiety is a serious obstacle in conventional oral healthcare delivery. A sensory adapted dental environment (SDE) might be effective in reducing anxiety and inducing relaxation. This study aimed to assess the efficacy of a Snoezelen SDE in reducing anxiety among children undergoing scaling and polishing by a dental hygienist. The Snoezelen environment consists of a partially dimmed room with lighting effects, vibroacoustic stimuli, and deep pressure. Nineteen children, aged 6-11 yr, participated in a cross-over intervention trial. Behavioral parameters included the mean number, duration, and magnitude of anxious behaviors, as monitored by videotaped recordings. Physiological parameters reflecting arousal were monitored by changes in dermal resistance. Results, by all measures, consistently indicated that both behavioral and psychophysiological measures of relaxation improved significantly in the SDE compared with a conventional dental environment. The findings support recommending the SDE as an effective and practical alternative in oral healthcare delivery to anxious children. PMID:18028056

Shapiro, Michele; Melmed, Raphael N; Sgan-Cohen, Harold D; Eli, Ilana; Parush, Shula

2007-12-01

61

Halimione portulacoides (L.) physiological/biochemical characterization for its adaptive responses to environmental mercury exposure.  

PubMed

This study investigates largely unexplored physiological/biochemical strategies adopted by salt marsh macrophyte Halimione portulacoides (L.) Aellen for its adaptation/tolerance to environmental mercury (Hg)-exposure in a coastal lagoon prototype. To this end, a battery of damage (hydrogen peroxide, H2O2; thiobarbituric acid reactive substances, TBARS; electrolyte leakage, EL; reactive carbonyls; osmolyte, proline) and defense [ascorbate peroxidase, APX; catalase, CAT; glutathione peroxidase, GPX; glutathione sulfo-transferase, GST; glutathione reductase, GR; reduced and oxidized glutathione (GSH and GSSG, respectively), and GSH/GSSG ratio] biomarkers, and polypeptide patterns were assessed in H. portulacoides roots and leaves at reference (R) and the sites with highest (L1), moderate (L2) and the lowest (L3) Hg-contamination gradients. Corresponding to the Hg-burdens, roots and leaves exhibited a differential modulation of damage- and defense-endpoints and polypeptide-patterns. Roots exhibiting the highest Hg-burden (at L3) failed to maintain a coordination among enzymatic-defense endpoint responses which resulted into increased oxidation of reduced glutathione (GSH) pool, lowest GSH/GSSG (oxidized) ratio and partial H2O2-metabolism. In contrast, the highest Hg-burden exhibiting leaves (at L1) successfully maintained a coordination among enzymatic-defense endpoints responses which resulted into decreased GSH-oxidation, enhanced reduced GSH pool and GSH/GSSG ratio and lower extent of damage. Additionally, increased leaf-carotenoids content with increasing Hg-burden implies its protective function. H. portulacoides leaf-polypeptides did not respond as per its Hg-burden but the roots did. Overall, the physiological/biochemical characterization of below (roots)- and above (leaves)-ground organs (studied in terms of damage and defense endpoints, and polypeptides modulation) revealed the adaptive responses of H. portulacoides to environmental Hg at whole plant level which cumulatively helped this plant to sustain and execute its Hg-remediation potential. PMID:24641832

Anjum, Naser A; Israr, Mohd; Duarte, Armando C; Pereira, Maria E; Ahmad, Iqbal

2014-05-01

62

Dairy Cow Response to Electrical Environment Final Report Part I. Comparison of Behavioral to Physiological Responses and Part II. Comparison of Treatments Applied during Milking  

Microsoft Academic Search

Part I. A series of experiments were performed to measure behavioral and blood cortisol concentration responses of cows exposed to current applied from front to rear hooves. Increased activity level was not a consistent indicator of response to current, whereas a startle response (flinch) was a consistent and repeatable indicator. Cows responded at lower current levels to the 1-front to

Douglas J. Reinemann; Morten Dam Rasmusssen; Milo C. Wiltbank; Lewis G. Sheffield; Steven D. LeMire

63

Molecular inflammation and adipose tissue matrix remodeling precede physiological adaptations to pregnancy  

PubMed Central

Changes in adipose tissue metabolism are central to adaptation of whole body energy homeostasis to pregnancy. To gain insight into the molecular mechanisms supporting tissue remodeling, we have characterized the longitudinal changes of the adipose transcriptome in human pregnancy. Healthy nonobese women recruited pregravid were followed in early (8–12 wk) and in late (36–38 wk) pregnancy. Adipose tissue biopsies were obtained in the fasting state from the gluteal depot. The adipose transcriptome was examined via whole genome DNA microarray. Expression of immune-related genes and extracellular matrix components was measured using real-time RT-PCR. Adipose mass, adipocyte size, and cell number increased in late pregnancy compared with pregravid measurements (P < 0.001) but remained unchanged in early pregnancy. The adipose transcriptome evolved during pregnancy with 10–15% of genes being differently expressed compared with pregravid. Functional gene cluster analysis revealed that the early molecular changes affected immune responses, angiogenesis, matrix remodeling, and lipid biosynthesis. Increased expression of macrophage markers (CD68, CD14, and the mannose-6 phosphate receptor) emphasized the recruitment of the immune network in both early and late pregnancy. The TLR4/NF-?B signaling pathway was enhanced specifically in relation to inflammatory adipokines and chemokines genes. We conclude that early recruitment of metabolic and immune molecular networks precedes the appearance of pregnancy-related physiological changes in adipose tissue. This biphasic pattern suggests that physiological inflammation is an early step preceding the development of insulin resistance, which peaks in late pregnancy.

Resi, Veronica; Basu, Subhabrata; Haghiac, Maricela; Presley, Larraine; Minium, Judi; Kaufman, Bram; Bernard, Steven; Catalano, Patrick

2012-01-01

64

Free ferulic acid uptake in lactating cows.  

PubMed

Ferulic acid (FRA), a phenolic compound with antioxidant and anticancer activities, naturally occurs in plants as a lignin precursor. Many veins of research have been devoted to releasing FRA from the lignin complex to improve digestibility of ruminant feeds. Thus, the objective of this research was to investigate the transfer of a given dosage of the free form of FRA into the milk of dairy cattle. Six mid- to late-lactation Holstein cows at the Cornell Research Farm (Harford, NY) were given 14-d adaptation to diet and stall position. Ad libitum access to a total mixed ration based on haylage and maize silage (31.1% neutral detergent fiber containing 5.52 mg of FRA/g) was provided during the study. A crossover design was implemented so that each cow alternated weekly between FRA-dosed and control. On d 1, jugular cannulas and urine catheters were placed in all cows. On d 2, FRA-dosed cows received a single dosage of 150 g of pure FRA powder at 0830 h via their fistula (n=4) or a balling gun for nonfistulated cows (n=2). Plasma, urine, feces, feed, orts, milk, and rumen fluid were sampled intensively for the next 36 h and analyzed for FRA concentration. On d 8, the cows crossed over and the experiment was repeated. When compared with the control, FRA administration did not have an effect on dry matter intake, milk yield, milk fat yield, milk protein yield, somatic cell count, or neutral detergent fiber content of orts and feces. The concentration of FRA in the feces did not change as a result of FRA dosage. As expected, FRA concentration increased dramatically upon FRA dosage and decreased over time until returning to basal levels in rumen fluid (4 h after dosage), plasma (5.5 h after dosage), urine (10 h after dosage), and milk (14 h after dosage). Baseline values for FRA in urine and rumen fluid were variable among cows and had an effect on FRA concentration in FRA-dosed cows. From this study, it is observed that orally ingested FRA can be transported into the milk and that the physiological transfer of FRA occurs from rumen to milk within 6.5 h or the first milking after dosage. Ferulic acid may affect the functionality of milk due to its antioxidant, anticancer, and antibacterial activities. Future research will be required to elucidate whether FRA in milk is bioavailable and bioactive, and to evaluate the complete sensory and microbiological effects of increased FRA and FRA degradation products in milk. PMID:22921626

Soberon, M A; Cherney, J H; Liu, R H; Ross, D A; Cherney, D J R

2012-11-01

65

Molecular inflammation and adipose tissue matrix remodeling precede physiological adaptations to pregnancy.  

PubMed

Changes in adipose tissue metabolism are central to adaptation of whole body energy homeostasis to pregnancy. To gain insight into the molecular mechanisms supporting tissue remodeling, we have characterized the longitudinal changes of the adipose transcriptome in human pregnancy. Healthy nonobese women recruited pregravid were followed in early (8-12 wk) and in late (36-38 wk) pregnancy. Adipose tissue biopsies were obtained in the fasting state from the gluteal depot. The adipose transcriptome was examined via whole genome DNA microarray. Expression of immune-related genes and extracellular matrix components was measured using real-time RT-PCR. Adipose mass, adipocyte size, and cell number increased in late pregnancy compared with pregravid measurements (P < 0.001) but remained unchanged in early pregnancy. The adipose transcriptome evolved during pregnancy with 10-15% of genes being differently expressed compared with pregravid. Functional gene cluster analysis revealed that the early molecular changes affected immune responses, angiogenesis, matrix remodeling, and lipid biosynthesis. Increased expression of macrophage markers (CD68, CD14, and the mannose-6 phosphate receptor) emphasized the recruitment of the immune network in both early and late pregnancy. The TLR4/NF-?B signaling pathway was enhanced specifically in relation to inflammatory adipokines and chemokines genes. We conclude that early recruitment of metabolic and immune molecular networks precedes the appearance of pregnancy-related physiological changes in adipose tissue. This biphasic pattern suggests that physiological inflammation is an early step preceding the development of insulin resistance, which peaks in late pregnancy. PMID:22811467

Resi, Veronica; Basu, Subhabrata; Haghiac, Maricela; Presley, Larraine; Minium, Judi; Kaufman, Bram; Bernard, Steven; Catalano, Patrick; Hauguel-de Mouzon, Sylvie

2012-10-01

66

Effects of musical cadence in the acute physiologic adaptations to head-out aquatic exercises.  

PubMed

The purpose of this study was to analyze the relationships between musical cadence and the physiologic adaptations to basic head-out aquatic exercises. Fifteen young and clinically healthy women performed, immersed to the breast, a cardiovascular aquatic exercise called the "rocking horse." The study design included an intermittent and progressive protocol starting at a 90 b.min(-1) rhythm and increasing every 6 minutes, by 15 b.min(-1), up to 195 b.min(-1) or exhaustion. The rating of perceived effort (RPE) at the maximal heart rate achieved during each bout (HRmax), the percentage of the maximal theoretical heart rate estimated (%HRmax), and the blood lactate concentration ([La-]) were evaluated. The musical cadence was also calculated at 4 mmol.L(-1) of blood lactate (R4), the RPE at R4 (RPE@R4), the HR at R4 (HR@R4), and the %HRmax at R4 (%HRmax@R4). Strong relationships were verified between the musical cadence and the RPE (R2 = 0.85; p < 0.01), the HRmax (R2 = 0.66; p < 0.01), the %HRmax (R = 0.61; p < 0.01), and the [La-] (R2 = 0.54; p < 0.01). The R4 was 148.13 +/- 17.53 b.min, the RPE@R4 was 14.53 +/- 2.53, the HR@R4 was 169.33 +/- 12.06 b.min, and the %HRmax@R4 was 85.53 +/- 5.72%. The main conclusion is that increasing musical cadence created an increase in the physiologic response. Therefore, instructors must choose musical cadences according to the goals of the session they are conducting to achieve the desired intensity. PMID:19996781

Barbosa, Tiago M; Sousa, Vítor F; Silva, António J; Reis, Vítor M; Marinho, Daniel A; Bragada, José A

2010-01-01

67

Can supplementation with vitamin C and E alter physiological adaptations to strength training?  

PubMed Central

Background Antioxidant supplementation has recently been demonstrated to be a double-edged sword, because small to moderate doses of exogenous antioxidants are essential or beneficial, while high doses may have adverse effects. The adverse effects can be manifested in attenuated effects of exercise and training, as the antioxidants may shut down some redox-sensitive signaling in the exercised muscle fibers. However, conditions such as age may potentially modulate the need for antioxidant intake. Therefore, this paper describes experiments for testing the hypothesis that high dosages of vitamin C (1000 mg/day) and E (235 mg/day) have negative effects on adaptation to resistance exercise and training in young volunteers, but positive effects in older men. Methods/design We recruited a total of 73 volunteers. The participants were randomly assigned to receiving either vitamin C and E supplementation or a placebo. The study design was double-blinded, and the participants followed an intensive training program for 10–12 weeks. Tests and measurements aimed at assessing changes in physical performance (maximal strength) and physiological characteristics (muscle mass), as well as biochemical and cellular systems and structures (e.g., cell signaling and morphology). Discussion Dietary supplements, such as vitamin C and E, are used by many people, especially athletes. The users often believe that high dosages of supplements improve health (resistance to illness and disease) and physical performance. These assumptions are, however, generally not supported in the scientific literature. On the contrary, some studies have indicated that high dosages of antioxidant supplements have negative effects on exercise-induced adaptation processes. Since this issue concerns many people and few randomized controlled trials have been conducted in humans, further studies are highly warranted. Trial registration ACTRN12614000065695

2014-01-01

68

Key physiological properties contributing to rhizosphere adaptation and plant growth promotion abilities of Azospirillum brasilense.  

PubMed

Azospirillum brasilense is a plant growth promoting rhizobacterium (PGPR) that is being increasingly used in agriculture in a commercial scale. Recent research has elucidated key properties of A. brasilense that contribute to its ability to adapt to the rhizosphere habitat and to promote plant growth. They include synthesis of the auxin indole-3-acetic acid, nitric oxide, carotenoids, and a range of cell surface components as well as the ability to undergo phenotypic variation. Storage and utilization of polybetahydroxyalkanoate polymers are important for the shelf life of the bacteria in production of inoculants, products containing bacterial cells in a suitable carrier for agricultural use. Azospirillum brasilense is able to fix nitrogen, but despite some controversy, as judging from most systems evaluated so far, contribution of fixed nitrogen by this bacterium does not seem to play a major role in plant growth promotion. In this review, we focus on recent advances in the understanding of physiological properties of A. brasilense that are important for rhizosphere performance and successful interactions with plant roots. PMID:22092983

Fibach-Paldi, Sharon; Burdman, Saul; Okon, Yaacov

2012-01-01

69

Susceptibility and Adaptive Response to Bile Salts in Propionibacterium freudenreichii: Physiological and Proteomic Analysis  

PubMed Central

Tolerance to digestive stresses is one of the main factors limiting the use of microorganisms as live probiotic agents. Susceptibility to bile salts and tolerance acquisition in the probiotic strain Propionibacterium freudenreichii SI41 were characterized. We showed that pretreatment with a moderate concentration of bile salts (0.2 g/liter) greatly increased its survival during a subsequent lethal challenge (1.0 g/liter, 60 s). Bile salts challenge led to drastic morphological changes, consistent with intracellular material leakage, for nonadapted cells but not for preexposed ones. Moreover, the physiological state of the cells during lethal treatment played an important role in the response to bile salts, as stationary-phase bacteria appeared much less sensitive than exponentially growing cells. Either thermal or detergent pretreatment conferred significantly increased protection toward bile salts challenge. In contrast, some other heterologous pretreatments (hypothermic and hyperosmotic) had no effect on tolerance to bile salts, while acid pretreatment even might have sensitized the cells. Two-dimensional electrophoresis experiments revealed that at least 24 proteins were induced during bile salts adaptation. Identification of these polypeptides suggested that the bile salts stress response involves signal sensing and transduction, a general stress response (also triggered by thermal denaturation, oxidative toxicity, and DNA damage), and an alternative sigma factor. Taken together, our results provide new insights into the tolerance of P. freudenreichii to bile salts, which must be taken into consideration for the use of probiotic strains and the improvement of technological processes.

Leverrier, Pauline; Dimova, Diliana; Pichereau, Vianney; Auffray, Yanick; Boyaval, Patrick; Jan, Gwenael

2003-01-01

70

Compensation of the metabolic costs of antibiotic resistance by physiological adaptation in Escherichia coli.  

PubMed

Antibiotic resistance is often associated with metabolic costs. To investigate the metabolic consequences of antibiotic resistance, the genomic and transcriptomic profiles of an amoxicillin-resistant Escherichia coli strain and the wild type it was derived from were compared. A total of 125 amino acid substitutions and 7 mutations that were located <1,000 bp upstream of differentially expressed genes were found in resistant cells. However, broad induction and suppression of genes were observed when comparing the expression profiles of resistant and wild-type cells. Expression of genes involved in cell wall maintenance, DNA metabolic processes, cellular stress response, and respiration was most affected in resistant cells regardless of the absence or presence of amoxicillin. The SOS response was downregulated in resistant cells. The physiological effect of the acquisition of amoxicillin resistance in cells grown in chemostat cultures consisted of an initial increase in glucose consumption that was followed by an adaptation process. Furthermore, no difference in maintenance energy was observed between resistant and sensitive cells. In accordance with the transcriptomic profile, exposure of resistant cells to amoxicillin resulted in reduced salt and pH tolerance. Taken together, the results demonstrate that the acquisition of antibiotic resistance in E. coli is accompanied by specifically reorganized metabolic networks in order to circumvent metabolic costs. The overall effect of the acquisition of resistance consists not so much of an extra energy requirement, but more a reduced ecological range. PMID:23716056

Händel, Nadine; Schuurmans, J Merijn; Brul, Stanley; ter Kuile, Benno H

2013-08-01

71

Genetic and Physiological Adaptation of the Copepod EURYTEMORA AFFINIS to Seasonal Temperatures  

PubMed Central

Evidence of significant additive genetic (genic) variance in temperature tolerance of the copepod Eurytemora affinis was derived from several sources. Differences were observed between average tolerances of progeny of animals exposed and not exposed to heat shock in a power plant. Genic variance was estimated using offspring-parent regressions, full-sib, and half-sib covariances, with quite consistent results. Expressed genic variance between male progeny was always higher than that among female progeny.—The pairs of estimates obtained were as follows: female heritabilities first, 0.40 ± 0.09 and 0.84 ± 0.35 (half-sibs); 0.20 ± 0.09 and 0.79 ± 0.24 (full-sibs); 0.11 ± 0.10 and 0.89 ± 0.45 (full-sibs); 0.28 ± 0.18 and 0.78 ± 0.29 (full-sibs); 0.11 ± 0.44 and 0.72 ± 0.26 (offspring-parent regression). There was no evidence of either nonadditive genetic variance or common environmental (maternal and brood) effects, implying that the genetic variance was mostly additive and was not maintained because of heterozygous advantage.—The presence of so much genetic variance is surprising in view of the high physiological adaptation found earlier, especially in females.

Bradley, Brian P.

1978-01-01

72

Compensation of the Metabolic Costs of Antibiotic Resistance by Physiological Adaptation in Escherichia coli  

PubMed Central

Antibiotic resistance is often associated with metabolic costs. To investigate the metabolic consequences of antibiotic resistance, the genomic and transcriptomic profiles of an amoxicillin-resistant Escherichia coli strain and the wild type it was derived from were compared. A total of 125 amino acid substitutions and 7 mutations that were located <1,000 bp upstream of differentially expressed genes were found in resistant cells. However, broad induction and suppression of genes were observed when comparing the expression profiles of resistant and wild-type cells. Expression of genes involved in cell wall maintenance, DNA metabolic processes, cellular stress response, and respiration was most affected in resistant cells regardless of the absence or presence of amoxicillin. The SOS response was downregulated in resistant cells. The physiological effect of the acquisition of amoxicillin resistance in cells grown in chemostat cultures consisted of an initial increase in glucose consumption that was followed by an adaptation process. Furthermore, no difference in maintenance energy was observed between resistant and sensitive cells. In accordance with the transcriptomic profile, exposure of resistant cells to amoxicillin resulted in reduced salt and pH tolerance. Taken together, the results demonstrate that the acquisition of antibiotic resistance in E. coli is accompanied by specifically reorganized metabolic networks in order to circumvent metabolic costs. The overall effect of the acquisition of resistance consists not so much of an extra energy requirement, but more a reduced ecological range.

Handel, Nadine; Schuurmans, J. Merijn; Brul, Stanley

2013-01-01

73

Physiological Adaptation of Desulfitobacterium hafniense Strain TCE1 to Tetrachloroethene Respiration?†  

PubMed Central

Desulfitobacterium spp. are ubiquitous organisms with a broad metabolic versatility, and some isolates have the ability to use tetrachloroethene (PCE) as terminal electron acceptor. In order to identify proteins involved in this organohalide respiration process, a comparative proteomic analysis was performed. Soluble and membrane-associated proteins obtained from cells of Desulfitobacterium hafniense strain TCE1 that were growing on different combinations of the electron donors lactate and hydrogen and the electron acceptors PCE and fumarate were analyzed. Among proteins increasingly expressed in the presence of PCE compared to fumarate as electron acceptor, a total of 57 proteins were identified by mass spectrometry analysis, revealing proteins involved in stress response and associated regulation pathways, such as PspA, GroEL, and CodY, and also proteins potentially participating in carbon and energy metabolism, such as proteins of the Wood-Ljungdahl pathway and electron transfer flavoproteins. These proteomic results suggest that D. hafniense strain TCE1 adapts its physiology to face the relative unfavorable growth conditions during an apparent opportunistic organohalide respiration.

Prat, Laure; Maillard, Julien; Grimaud, Regis; Holliger, Christof

2011-01-01

74

Cool Cow Quiz.  

ERIC Educational Resources Information Center

Provides a game to help develop the skill of estimating and making educated guesses. Uses facts about cows to explain some problems associated with the dairy industry. Includes cards and rules for playing, class adaptation procedures, follow-up activities, and availability of background information on humane concerns. (RT)

DeRosa, Bill

1988-01-01

75

Comparison of hepatic adaptation in extreme metabolic phenotypes observed in early lactation dairy cows on-farm.  

PubMed

The aim was to study the variation in metabolic responses in early-lactating dairy cows (n = 232) on-farm that were pre-selected for a high milk fat content (>45 g/l) and a high fat/protein ratio in milk (>1.5) in their previous lactation. Blood was assayed for concentrations of metabolites and hormones. Liver was measured for mRNA abundance of 25 candidate genes encoding enzymes and receptors involved in gluconeogenesis (6), fatty acid ?-oxidation (6), fatty acid and triglyceride synthesis (5), cholesterol synthesis (4), ketogenesis (2) and the urea cycle (2). Two groups of cows were formed based on the plasma concentrations of glucose, non-esterified fatty acids (NEFA) and ?-hydroxybutyric acid (BHBA) (GRP+, high metabolic load; glucose <3.0 mm, NEFA >300 ?m and BHBA >1.0 mm, n = 30; GRP-, low metabolic load; glucose >3.0 mm, NEFA <300 ?m and BHBA <1.0 mm, n = 30). No differences were found between GRP+ and GRP- for the milk yield at 3 weeks post-partum, but milk fat content was higher (p < 0.01) for GRP+ than for GRP-. In week 8 post-partum, milk yield was higher in GRP+ in relation to GRP- (37.5 vs. 32.5 kg/d; p < 0.01). GRP+ in relation to GRP- had higher (p < 0.001) NEFA and BHBA and lower glucose, insulin, IGF-I, T3 , T4 concentrations (p < 0.01). The mRNA abundance of genes related to gluconeogenesis, fatty acid ?-oxidation, fatty acid and triglyceride synthesis, cholesterol synthesis and the urea cycle was different in GRP+ compared to GRP- (p < 0.05), although gene transcripts related to ketogenesis were similar between GRP+ and GRP-. In conclusion, high metabolic load post-partum in dairy cows on-farm corresponds to differences in the liver in relation to dairy cows with low metabolic load, even though all cows were pre-selected for a high milk fat content and fat/protein ratio in milk in their previous lactation. PMID:24033645

van Dorland, H A; Graber, M; Kohler, S; Steiner, A; Bruckmaier, R M

2014-08-01

76

Hematological and physiological adaptations following 46 weeks of moderate altitude residence.  

PubMed

Although acclimatization to moderate altitude (MA) is thought to be unnecessary or to require minimal adaptation, retrospective data from the U.S. Air Force Academy (USAFA), a military college located at 2210 m, suggested otherwise. To further examine the utility of USAFA as a model for MA acclimatization, a longitudinal experimental design was prospectively utilized to determine the magnitude and time course of selected hematological and performance parameters following 46 weeks at this unique MA setting. Incoming USAFA male freshmen (n=55) were divided into experimental groups based on prior residence at sea level (SL) or MA. Hematological and performance parameters were repeatedly assessed during their entire first year at MA. Hematological data consisted of a complete blood count (CBC) with reticulocyte parameters, as well as determination of serum levels of ferritin, erythropoietin, and soluble transferrin receptor (sTfR). Performance testing included aerobic (1.5-mile run) and physical (push-ups, sit-ups, pull-ups, and standing long jump) fitness tests, maximal aerobic capacity, and running economy. Significant (p<0.05; main effect) hematological differences between SL and MA subjects were observed for the majority of the study. MA subjects had a significantly higher hemoglobin concentration ([Hb], +5.5%), hematocrit (+2.8%), and serum ferritin (+59.0%) and significantly lower sTfR (-11.4%) values than their SL peers. Although both serum ferritin and sTfR demonstrated a significant altitude group x time interaction, [Hb] and hematocrit did not. A significant main effect of altitude without interaction was also observed for performance parameters, with SL subjects having a significantly lower Vo2peak (-5.9%), slower 1.5- mile run time (+5.4%), poorer running economy (+6.6%), and lower composite physical fitness test score (-13.9%) than MA subjects. These results suggest that complete acclimatization to 2210 m by former SL residents may require lengthy physiological adaptations, as both hematological and physical performance differences persisted between groups. Further research at this uniquely well controlled MA setting is warranted. PMID:20919886

Brothers, Michael D; Doan, Brandon K; Zupan, Michael F; Wile, Al L; Wilber, Randall L; Byrnes, William C

2010-01-01

77

Oxidative stress indicators and metabolic adaptations in response to the omission of the dry period in dairy cows.  

PubMed

The effects of dry period omission on oxidative stress and metabolic indicators around calving were studied. Seventeen Italian Friesian cows were randomly assigned to two groups, homogeneous for milk yield and parity, and managed either with a traditional 55-d dry off period (n=8) or continuously milked till parturition (n=9). Between 60 d before expected calving and 90 d after calving, body condition (BCS) was recorded and blood samples were collected to measure cortisol, urea, cholesterol, glucose, NEFA, triglycerides, insulin, malondialdehyde (MDA), total glutathione (GSH) and glutathione peroxidase (GPx) activity. BCS changes after calving were not different between the two groups. The normally dried group showed lower (P<0.05) glucose concentrations on day 7 before calving, greater (P<0.01) non-esterified fatty acid concentrations at 7 d and 15 d after calving, and greater (P<0.01) triglyceride concentrations for all the period before calving. On the other hand, plasma MDA was not different between groups. On average, plasma GSH concentrations were greater in continuously milked cows after calving (P<0.05), while plasma GPx was greater with continuous milking up to parturition (P<0.01). The results confirmed that omitting the dry period leads to an improved energy balance. The degree of oxidative stress was not detrimental for animal health, and the slight modifications of GPx observed prepartum were possibly related to continuous milk secretion. The differences in plasma GSH observed after calving may depend upon sulphur amino acid sparing in continuously milked cows. PMID:20334713

Mantovani, Roberto; Sgorlon, Sandy; Marinelli, Lieta; Bailoni, Lucia; Bittante, Giovanni; Gabai, Gianfranco

2010-08-01

78

Synthetic physiology strategies for adapting tools from nature for genetically targeted control of fast biological processes.  

PubMed

The life and operation of cells involve many physiological processes that take place over fast timescales of milliseconds to minutes. Genetically encoded technologies for driving or suppressing specific fast physiological processes in intact cells, perhaps embedded within intact tissues in living organisms, are critical for the ability to understand how these physiological processes contribute to emergent cellular and organismal functions and behaviors. Such "synthetic physiology" tools are often incredibly complex molecular machines, in part because they must operate at high speeds, without causing side effects. We here explore how synthetic physiology molecules can be identified and deployed in cells, and how the physiology of these molecules in cellular contexts can be assessed and optimized. For concreteness, we discuss these methods in the context of the "optogenetic" light-gated ion channels and pumps that we have developed over the past few years as synthetic physiology tools and widely disseminated for use in neuroscience for probing the role of specific brain cell types in neural computations, behaviors, and pathologies. We anticipate that some of the insights revealed here may be of general value for the field of synthetic physiology, as they raise issues that will be of importance for the development and use of high-performance, high-speed, side-effect free physiological control tools in heterologous expression systems. PMID:21601097

Chow, Brian Y; Chuong, Amy S; Klapoetke, Nathan C; Boyden, Edward S

2011-01-01

79

Annual Research Review: The Neurobiology and Physiology of Resilience and Adaptation across the Life Course  

ERIC Educational Resources Information Center

Background: Adaptation is key to survival. An organism must adapt to environmental challenges in order to be able to thrive in the environment in which they find themselves. Resilience can be thought of as a measure of the ability of an organism to adapt, and to withstand challenges to its stability. In higher animals, the brain is a key player in…

Karatoreos, Ilia N.; McEwen, Bruce S.

2013-01-01

80

Matched adaptations of electrophysiological, physiological, and histological properties of skeletal muscles in response to chronic hypoxia  

Microsoft Academic Search

This study tried to differentiate the consequences of chronic hypoxia on the electrophysiological and physiological properties and the histological characteristics of slow and fast muscles in rats. Animals inhaled a 10% O2 concentration for a 1-month period. Then, slow [soleus (SOL)] and fast [extensor digitorum longus (EDL)] muscles were analyzed in vitro by physiological and electrophysiological measurements and histological analyses.

Marion Faucher; Chantal Guillot; Tanguy Marqueste; Nathalie Kipson; Marie-Hélène Mayet-Sornay; Dominique Desplanches; Yves Jammes; Monique Badier

2005-01-01

81

Physiological Adaptations of Salmonid Fishes (Salmo clarki henshawi, Salmo gairdneri, and Oncorhynchus kisutch) to Alkaline Saline Water and Its Toxic Effects.  

National Technical Information Service (NTIS)

Two studies were conducted to determine the physiological adaptations of 3 salmonid fishes to the alkaline, slightly saline waters of Pyramid Lake, NV, and their toxic effects. In the acclimation study, growth rates and blood parameters of fingerling Laho...

D. L. Koch J. Knoll J. Sommer L. Hoffman R. Knoll

1979-01-01

82

Estimating the capability of microalgae to physiological acclimatization and genetic adaptation to petroleum and diesel oil contamination.  

PubMed

There is increasing scientific interest in how phytoplankton reacts to petroleum contamination, since crude oil and its derivatives are generating extensive contamination of aquatic environments. However, toxic effects of short-term petroleum exposure are more widely known than the adaptation of phytoplankton to long-term petroleum exposure. An analysis of short-term and long-term effects of petroleum exposure was done using experimental populations of freshwater (Scenedesmus intermedius and Microcystis aeruginosa) and marine (Dunaliella tertiolecta) microalgae isolated from pristine sites without crude oil product contamination. These strains were exposed to increased levels of petroleum and diesel oil. Short-term exposure to petroleum or diesel oil revealed a rapid inhibition of photosynthetic performance and cell proliferation in freshwater and marine phytoplankton species. A broad degree of inter-specific variation in lethal contamination level was observed. When different strains were exposed to petroleum or diesel oil over the long-term, the cultures showed massive destruction of the sensitive cells. Nonetheless, after further incubation, some cultures were able to grow again due to cells that were resistant to the toxins. By means of a fluctuation analysis, discrimination between cells that had become resistant due to physiological acclimatization and resistant cells arising from rare spontaneous mutations was accomplished. In addition, an analysis was done as to the maximum capacity of adaptation to a gradual contamination process. An experimental ratchet protocol was used, which maintains a strong selection pressure in a temporal scale up to several months over very large experimental populations of microalgae. Microalgae are able to survive to petroleum contamination as a result of physiological acclimatization without genetic changes. However, when petroleum concentration exceeds the physiological limits, survival depends exclusively on the occurrence on mutations that confer resistance and subsequent selection of these mutants. Finally, it is certain that further mutations and selection will ultimately determine adaptation of microalgae to the environmental forcing. PMID:22982500

Romero-Lopez, Julia; Lopez-Rodas, Victoria; Costas, Eduardo

2012-11-15

83

An Approximation to the Adaptive Exponential Integrate-and-Fire Neuron Model Allows Fast and Predictive Fitting to Physiological Data  

PubMed Central

For large-scale network simulations, it is often desirable to have computationally tractable, yet in a defined sense still physiologically valid neuron models. In particular, these models should be able to reproduce physiological measurements, ideally in a predictive sense, and under different input regimes in which neurons may operate in vivo. Here we present an approach to parameter estimation for a simple spiking neuron model mainly based on standard f–I curves obtained from in vitro recordings. Such recordings are routinely obtained in standard protocols and assess a neuron’s response under a wide range of mean-input currents. Our fitting procedure makes use of closed-form expressions for the firing rate derived from an approximation to the adaptive exponential integrate-and-fire (AdEx) model. The resulting fitting process is simple and about two orders of magnitude faster compared to methods based on numerical integration of the differential equations. We probe this method on different cell types recorded from rodent prefrontal cortex. After fitting to the f–I current-clamp data, the model cells are tested on completely different sets of recordings obtained by fluctuating (“in vivo-like”) input currents. For a wide range of different input regimes, cell types, and cortical layers, the model could predict spike times on these test traces quite accurately within the bounds of physiological reliability, although no information from these distinct test sets was used for model fitting. Further analyses delineated some of the empirical factors constraining model fitting and the model’s generalization performance. An even simpler adaptive LIF neuron was also examined in this context. Hence, we have developed a “high-throughput” model fitting procedure which is simple and fast, with good prediction performance, and which relies only on firing rate information and standard physiological data widely and easily available.

Hertag, Loreen; Hass, Joachim; Golovko, Tatiana; Durstewitz, Daniel

2012-01-01

84

COGNITIVE BEHAVIORAL STRESS MANAGEMENT EFFECTS ON PSYCHOSOCIAL AND PHYSIOLOGICAL ADAPTATION IN WOMEN UNDERGOING TREATMENT FOR BREAST CANCER  

PubMed Central

BACKGROUND A diagnosis of breast cancer and treatment are psychologically stressful events, particularly over the first year after diagnosis. Women undergo many demanding and anxiety-arousing treatments such as surgery, radiation and chemotherapy. Psychosocial interventions that promote psychosocial adaptation to these challenges may modulate physiological processes (neuroendocrine and immune) that are relevant for health outcomes in breast cancer patients. METHODS Women with Stage 1 – 3 breast cancer recruited 4 – 8 weeks after surgery were randomized to either a 10-week group-based cognitive behavioral stress management (CBSM) intervention or a 1-day psychoeducational control group and completed questionnaires and late afternoon blood samples at study entry and 6 and 12 months after assignment to experimental condition. RESULTS Of 128 women initially providing psychosocial questionnaire and blood samples at study entry, 97 provided complete data for anxiety measures and cortisol analysis at all time points, and immune assays were run on a subset of 85 of these women. Those assigned to a 10-week group-based CBSM intervention evidenced better psychosocial adaptation (lower reported cancer-specific anxiety and interviewer-rated general anxiety symptoms) and physiological adaptation (lower cortisol, greater Th1 cytokine [interleukin-2 and interferon-? production and IL-2:IL-4 ratio) after their adjuvant treatment compared to those in the control group. Effects on psychosocial adaptation indicators and cortisol appeared to hold across the entire 12-month observation period. Th1 cytokine regulation changes held only over the initial 6-month period. CONCLUSIONS This intervention may have facilitated a “recovery or maintenance” of Th1 cytokine regulation during or after the adjuvant therapy period. Behavioral interventions that address dysregulated neuroendocrine function could play a clinically significant role in optimizing host immunologic resistance during a vulnerable period.

Antoni, Michael H.; Lechner, Suzanne; Diaz, Alain; Vargas, Sara; Holley, Heather; Phillips, Kristin; McGregor, Bonnie; Carver, Charles S.; Blomberg, Bonnie

2009-01-01

85

Functional validation of hydrophobic adaptation to physiological temperature in the small heat shock protein ?A-crystallin.  

PubMed

Small heat shock proteins (sHsps) maintain cellular homeostasis by preventing stress and disease-induced protein aggregation. While it is known that hydrophobicity impacts the ability of sHsps to bind aggregation-prone denaturing proteins, the complex quaternary structure of globular sHsps has made understanding the significance of specific changes in hydrophobicity difficult. Here we used recombinant protein of the lenticular sHsp ? A-crystallin from six teleost fishes environmentally adapted to temperatures ranging from -2°C to 40°C to identify correlations between physiological temperature, protein stability and chaperone-like activity. Using sequence and structural modeling analysis we identified specific amino acid differences between the warm adapted zebrafish and cold adapted Antarctic toothfish that could contribute to these correlations and validated the functional consequences of three specific hydrophobicity-altering amino acid substitutions in ?A-crystallin. Site directed mutagenesis of three residues in the zebrafish (V62T, C143S, T147V) confirmed that each impacts either protein stability or chaperone-like activity or both, with the V62T substitution having the greatest impact. Our results indicate a role for changing hydrophobicity in the thermal adaptation of ? A-crystallin and suggest ways to produce sHsp variants with altered chaperone-like activity. These data also demonstrate that a comparative approach can provide new information about sHsp function and evolution. PMID:22479631

Posner, Mason; Kiss, Andor J; Skiba, Jackie; Drossman, Amy; Dolinska, Monika B; Hejtmancik, J Fielding; Sergeev, Yuri V

2012-01-01

86

Modern Human Physiology with Respect to Evolutionary Adaptations that Relate to Diet in the Past  

Microsoft Academic Search

This paper reviews evidence from human physiology as to which foods may have been typically consumed by the hominin ancestral\\u000a lineage up to the advent of anatomically modern humans. Considerable evidence suggests that many common diseases can be prevented\\u000a by hunter-gatherer diets. Apparently, human nutritional metabolism is not perfectly fine-tuned for recently introduced staple\\u000a foods, such as cereals, dairy products,

87

Behavioural and physiological effect of dental environment sensory adaptation on childrens dental anxiety  

Microsoft Academic Search

Dental anxiety is a serious obstacle in conventional oral healthcare delivery. A sensory adapted dental environment (SDE) might be effective in reducing anxiety and inducing relaxation. This study aimed to assess the efficacy of a Snoezelen SDE in reducing anxiety among children undergoing scaling and polishing by a dental hygienist. The Snoezelen environment consists of a partially dimmed room with

Michele Shapiro; Raphael N. Melmed; Harold D. Sgan-Cohen; Ilana Eli; Shula Parush; Beit Issie Shapiro

2007-01-01

88

Cow Madness  

NSDL National Science Digital Library

Mad Cows: The Why Files, provided by the University of Wisconsin, provides brief information on Mad Cow disease in layperson's language with hypertext links. Although prion research has been going on for over 25 years, the scientific and medical communities have only recently acknowledged the existence of prions and there remains serious debate over their role in a variety of neurological diseases. The name "prion" is derived from "proteinaceous infectious particles," and was coined by Dr. Stanley Prusiner, who discovered the agents and who recently received the Nobel Prize for Medicine for his work. Prions are thought to be the first transmissible and heritable disease-causing agents that lack DNA and RNA. They are composed solely of protein and appear to be the cause of such diseases as kuru and Creutzfeldt-Jakob disease in humans, and bovine spongiform encephalopathies, mad cow disease, and scrapie in sheep and goats.

1997-01-01

89

Distinct roles of HIF1A in endothelial adaptations to physiological and ambient oxygen.  

PubMed

Fetoplacental endothelial cells reside under physiological normoxic conditions (?2-8% O2) in vivo. Under such conditions, cells are believed to sense O2 changes primarily via hypoxia inducible factor 1 ? (HIF1A). However, little is known regarding the role of HIF1A in fetoplacental endothelial function under physiological normoxia. We recently reported that physiological chronic normoxia (PCN; 20-25 day, 3% O2) enhanced FGF2- and VEGFA-stimulated proliferation and migration of human umbilical vein endothelial cells (HUVECs) via the MEK/ERK1/2 and PI3K/AKT1 pathways compared to standard cell culture normoxia (SCN; ambient O2: ?21% O2). Here, we investigated the action of HIF1A in regulating these cellular responses in HUVECs. HIF1A adenovirus infection in SCN-cells increased HIF1A protein expression, enhanced FGF2- and VEGFA-stimulated cell proliferation by 2.4 and 2.0-fold respectively, and promoted VEGFA-stimulated cell migration by 1.4-fold. HIF1A adenovirus infection in SCN-cells did not affect either basal or FGF2- and VEGFA-induced ERK1/2 activation, but it decreased basal AKT1 phosphorylation. Interestingly, HIF1A knockdown in PCN-cells via specific HIF1A siRNA transfection did not alter FGF2- and VEGFA-stimulated cell proliferation and migration, or ERK1/2 activation; however, it inhibited FGF2-induced AKT1 activation by ?50%. These data indicate that HIF1A differentially regulates cell proliferation and migration, and ERK1/2 and AKT1 activation in PCN- and SCN-HUVECs. These data also suggest that HIF1A critically regulates cell proliferation and migration in SCN-, but not in PCN-HUVECs. PMID:24796659

Jiang, Yi-Zhou; Li, Yan; Wang, Kai; Dai, Cai-Feng; Huang, Shi-An; Chen, Dong-Bao; Zheng, Jing

2014-06-25

90

Transcriptional and Functional Adaptations of Human Endothelial Cells to Physiological Chronic Low Oxygen1  

PubMed Central

ABSTRACT Endothelial cells chronically reside in low-O2 environments in vivo (2%–13% O2), which are believed to be critical for cell homeostasis. To elucidate the roles of this physiological chronic normoxia in human endothelial cells, we examined transcriptomes of human umbilical vein endothelial cells (HUVECs), proliferation and migration of HUVECs in response to fibroblast growth factor 2 (FGF2) and vascular endothelial growth factor A (VEGFA), and underlying signaling mechanisms under physiological chronic normoxia. Immediately after isolation, HUVECs were cultured steadily under standard cell culture normoxia (SCN; 21% O2) or physiological chronic normoxia (PCN; 3% O2) up to 25 days. We found that PCN up-regulated 41 genes and down-regulated 21 genes, 90% of which differed from those previously reported from HUVECs cultured under SCN and exposed to acute low O2. Gene ontology analysis indicated that PCN-regulated genes were highly related to cell proliferation and migration, consistent with the results from benchtop assays that showed that PCN significantly enhanced FGF2- and VEGFA-stimulated cell proliferation and migration. Interestingly, preexposing the PCN cells to 21% O2 up to 5 days did not completely diminish PCN-enhanced cell proliferation and migration. These PCN-enhanced cell proliferations and migrations were mediated via augmented activation of MEK1/MEK2/ERK1/ERK2 and/or PI3K/AKT1. Importantly, these PCN-enhanced cellular responses were associated with an increase in activation of VEGFR2 but not FGFR1, without altering their expression. Thus, PCN programs endothelial cells to undergo dramatic changes in transcriptomes and sensitizes cellular proliferative and migratory responses to FGF2 and VEGFA. These PCN cells may offer a unique endothelial model, more closely mimicking the in vivo states.

Jiang, Yi-Zhou; Wang, Kai; Li, Yan; Dai, Cai-Feng; Wang, Ping; Kendziorski, Christina; Chen, Dong-Bao; Zheng, Jing

2013-01-01

91

Effect of fetal adrenalectomy on catecholamine release and physiologic adaptation at birth in sheep.  

PubMed Central

Plasma catecholamine levels increase dramatically at birth. To determine the contribution of adrenal catecholamine secretion to the surge in catecholamines at birth and the role in newborn adaptation, we performed surgical adrenalectomy or sham operation on near-term ovine fetuses. After recovery in utero, the animals were delivered and supported by mechanical ventilation. Plasma catecholamine levels, heart rate, blood pressure, cardiac output, pulmonary function, surfactant secretion, and release of free fatty acids (FFA) and glucose were compared in control and adrenalectomized animals. Plasma epinephrine increased rapidly at birth in controls but was undetectable in adrenalectomized animals. Norepinephrine levels were not statistically different. Heart rate, blood pressure, cardiac output and contractility increased abruptly after cord cutting in controls but did not increase in adrenalectomized animals. Lung compliance, pulmonary function, surfactant pool size, glucose and FFA levels were significantly decreased in adrenalectomized animals. These results suggest that adrenal epinephrine secretion is vital to many of the adaptive events at birth.

Padbury, J; Agata, Y; Ludlow, J; Ikegami, M; Baylen, B; Humme, J

1987-01-01

92

Physiological Mechanisms of Onset Adaptation and Contralateral Suppression of DPOAEs in the Rat  

Microsoft Academic Search

An investigation was undertaken to measure medial olivocochlear (MOC) reflexes in anesthetized rats before and after sectioning of the middle-ear muscles. Distortion product otoacoustic emission (DPOAE) magnitude and phase temporal responses were measured ipsilaterally to study MOC-mediated “DPOAE onset adaptation” and in the presence of a contralateral noise to study MOC-mediated contralateral “suppression” (terms as used by previous researchers). Distortion

E. M. Relkin; A. Sterns; W. Azeredo; B. A. Prieve; C. I. Woods

2005-01-01

93

Physiological framework for adaptation of stomata to CO2 from glacial to future concentrations  

PubMed Central

In response to short-term fluctuations in atmospheric CO2 concentration, ca, plants adjust leaf diffusive conductance to CO2, gc, via feedback regulation of stomatal aperture as part of a mechanism for optimizing CO2 uptake with respect to water loss. The operational range of this elaborate control mechanism is determined by the maximum diffusive conductance to CO2, gc(max), which is set by the size (S) and density (number per unit area, D) of stomata on the leaf surface. Here, we show that, in response to long-term exposure to elevated or subambient ca, plants alter gc(max) in the direction of the short-term feedback response of gc to ca via adjustment of S and D. This adaptive feedback response to ca, consistent with long-term optimization of leaf gas exchange, was observed in four species spanning a diverse taxonomic range (the lycophyte Selaginella uncinata, the fern Osmunda regalis and the angiosperms Commelina communis and Vicia faba). Furthermore, using direct observation as well as flow cytometry, we observed correlated increases in S, guard cell nucleus size and average apparent 1C DNA amount in epidermal cell nuclei with increasing ca, suggesting that stomatal and leaf adaptation to ca is linked to genome scaling.

Franks, Peter J.; Leitch, Ilia J.; Ruszala, Elizabeth M.; Hetherington, Alistair M.; Beerling, David J.

2012-01-01

94

Physiological framework for adaptation of stomata to CO2 from glacial to future concentrations.  

PubMed

In response to short-term fluctuations in atmospheric CO(2) concentration, c(a), plants adjust leaf diffusive conductance to CO(2), g(c), via feedback regulation of stomatal aperture as part of a mechanism for optimizing CO(2) uptake with respect to water loss. The operational range of this elaborate control mechanism is determined by the maximum diffusive conductance to CO(2), g(c(max)), which is set by the size (S) and density (number per unit area, D) of stomata on the leaf surface. Here, we show that, in response to long-term exposure to elevated or subambient c(a), plants alter g(c(max)) in the direction of the short-term feedback response of g(c) to c(a) via adjustment of S and D. This adaptive feedback response to c(a), consistent with long-term optimization of leaf gas exchange, was observed in four species spanning a diverse taxonomic range (the lycophyte Selaginella uncinata, the fern Osmunda regalis and the angiosperms Commelina communis and Vicia faba). Furthermore, using direct observation as well as flow cytometry, we observed correlated increases in S, guard cell nucleus size and average apparent 1C DNA amount in epidermal cell nuclei with increasing c(a), suggesting that stomatal and leaf adaptation to c(a) is linked to genome scaling. PMID:22232765

Franks, Peter J; Leitch, Ilia J; Ruszala, Elizabeth M; Hetherington, Alistair M; Beerling, David J

2012-02-19

95

The c-ring stoichiometry of ATP synthase is adapted to cell physiological requirements of alkaliphilic Bacillus pseudofirmus OF4  

PubMed Central

The c-rings of ATP synthases consist of individual c-subunits, all of which harbor a conserved motif of repetitive glycine residues (GxGxGxG) important for tight transmembrane ?-helix packing. The c-ring stoichiometry determines the number of ions transferred during enzyme operation and has a direct impact on the ion-to-ATP ratio, a cornerstone parameter of cell bioenergetics. In the extreme alkaliphile Bacillus pseudofirmus OF4, the glycine motif is replaced by AxAxAxA. We performed a structural study on two mutants with alanine-to-glycine changes using atomic force microscopy and X-ray crystallography, and found that mutants form smaller c12 rings compared with the WT c13. The molar growth yields of B. pseudofirmus OF4 cells on malate further revealed that the c12 mutants have a considerably reduced capacity to grow on limiting malate at high pH. Our results demonstrate that the mutant ATP synthases with either c12 or c13 can support ATP synthesis, and also underscore the critical importance of an alanine motif with c13 ring stoichiometry for optimal growth at pH >10. The data indicate a direct connection between the precisely adapted ATP synthase c-ring stoichiometry and its ion-to-ATP ratio on cell physiology, and also demonstrate the bioenergetic challenges and evolutionary adaptation strategies of extremophiles.

Preiss, Laura; Klyszejko, Adriana L.; Hicks, David B.; Liu, Jun; Fackelmayer, Oliver J.; Yildiz, Ozkan; Krulwich, Terry A.; Meier, Thomas

2013-01-01

96

Regulation of T-lymphocyte physiology by the Chat-H/CasL adapter complex.  

PubMed

The Cas family of proteins consists of at least four members implicated in the regulation of diverse cellular processes such as cell proliferation, adhesion, motility, and cancer cell metastasis. Cas family members have conserved C-termini that mediate constitutive heterotypic interactions with members of a different group of proteins, the NSP family. Both the Cas and NSP proteins have conserved domains that mediate protein-protein interactions with other cytoplasmic intermediates. Signaling modules assembled by these proteins in turn regulate signal transduction downstream of a variety of receptors including integrin, chemokine, and antigen receptors. T lymphocytes express the NSP protein NSP3/Chat-H and the Cas protein Hef1/CasL, which are found in a constitutive complex in naive T cells. We recently showed that Chat-H and Hef1/CasL regulate integrin-mediated adhesion and promote T-cell migration and trafficking downstream of activated chemokine receptors. It is currently unclear if the Chat-H/CasL module also plays a role in antigen receptor signaling. Here we review our current knowledge of how Chat-H and Hef1/CasL regulate T-cell physiology and whether this protein complex plays a functional role downstream of T-cell receptor activation. PMID:19909363

Alexandropoulos, Konstantina; Regelmann, Adam G

2009-11-01

97

Cell adaptation to a physiologically relevant ECM mimic with different viscoelastic properties  

PubMed Central

To successfully induce tissue repair or regeneration in vivo, bioengineered constructs must possess both optimal bioactivity and mechanical strength. This is because cell interaction with the extracellular matrix (ECM) produces two different but concurrent signaling mechanisms: ligation-induced signaling, which depends on ECM biological stimuli, and traction-induced signaling, which depends on ECM mechanical stimuli. In this report, we provide a fundamental understanding of how alterations in mechanical stimuli alone, produced by varying the viscoelastic properties of our bioengineered construct, modulate phenotypic behavior at the whole-cell level. Using a physiologically-relevant ECM mimic composed of hyaluronan and fibronectin, we found that adult human dermal fibroblasts modify their mechanical response in order to match substrate stiffness. More specifically, the cells on stiffer substrates had higher modulus and a more stretched and organized actin cytoskeleton (and vice versa), which translated into larger traction forces exerted on the substrate. This modulation of cellular mechanics had contrasting effects on migration and proliferation, where cells migrated faster on softer substrates while proliferating preferentially on the stiffer ones. These findings implicate substrate rigidity as a critical design parameter in the development of bioengineered constructs aimed at eliciting maximal cell and tissue function.

Ghosh, Kaustabh; Pan, Zhi; Guan, E; Ge, Shouren; Liu, Yajie; Nakamura, Toshio; Ren, Xiang-Dong; Rafailovich, Miriam; Clark, Richard A.F.

2009-01-01

98

Physiological and morphological adaptations in relation to water use efficiency in Mediterranean accessions of Solanum lycopersicum.  

PubMed

The physiological traits underlying the apparent drought resistance of 'Tomàtiga de Ramellet' (TR) cultivars, a population of Mediterranean tomato cultivars with delayed fruit deterioration (DFD) phenotype and typically grown under non-irrigation conditions, are evaluated. Eight different tomato accessions were selected and included six TR accessions, one Mediterranean non-TR accession (NTR(M)) and a processing cultivar (NTR(O)). Among the TR accessions two leaf morphology types, normal divided leaves and potato-leaf, were selected. Plants were field grown under well-watered (WW) and water-stressed (WS) treatments, with 30 and 10% of soil water capacity, respectively. Accessions were clustered according to the leaf type and TR phenotype under WW and WS, respectively. Correlation among parameters under the different water treatments suggested that potential improvements in the intrinsic water-use efficiency (A(N)/g(s)) are possible without negative impacts on yield. Under WS TR accessions displayed higher A(N)/g(s), which was not due to differences in Rubisco-related parameters, but correlated with the ratio between the leaf mesophyll and stomatal conductances (g(m)/g(s)). The results confirm the existence of differential traits in the response to drought stress in Mediterranean accessions of tomato, and demonstrate that increases in the g(m)/g(s) ratio would allow improvements in A(N)/g(s) in horticultural crops. PMID:20955222

Galmés, Jeroni; Conesa, Miquel Àngel; Ochogavía, Joan Manuel; Perdomo, Juan Alejandro; Francis, David M; Ribas-Carbó, Miquel; Savé, Robert; Flexas, Jaume; Medrano, Hipólito; Cifre, Josep

2011-02-01

99

Cellular, physiological, and molecular adaptive responses of Erwinia amylovora to starvation.  

PubMed

Erwinia amylovora causes fire blight, a destructive disease of rosaceous plants distributed worldwide. This bacterium is a nonobligate pathogen able to survive outside the host under starvation conditions, allowing its spread by various means such as rainwater. We studied E. amylovora responses to starvation using water microcosms to mimic natural oligotrophy. Initially, survivability under optimal (28 °C) and suboptimal (20 °C) growth temperatures was compared. Starvation induced a loss of culturability much more pronounced at 28 °C than at 20 °C. Natural water microcosms at 20 °C were then used to characterize cellular, physiological, and molecular starvation responses of E. amylovora. Challenged cells developed starvation-survival and viable but nonculturable responses, reduced their size, acquired rounded shapes and developed surface vesicles. Starved cells lost motility in a few days, but a fraction retained flagella. The expression of genes related to starvation, oxidative stress, motility, pathogenicity, and virulence was detected during the entire experimental period with different regulation patterns observed during the first 24 h. Further, starved cells remained as virulent as nonstressed cells. Overall, these results provide new knowledge on the biology of E. amylovora under conditions prevailing in nature, which could contribute to a better understanding of the life cycle of this pathogen. PMID:24476337

Santander, Ricardo D; Oliver, James D; Biosca, Elena G

2014-05-01

100

Physiological Adaptations and Countermeasures Associated with Long-Duration Space Flights  

NASA Technical Reports Server (NTRS)

On earth, the presence of gravity imposes weight-bearing gradients on tissues which influence the functions of multiple integrative systems. On the other hand, conditions of actual or simulated microgravity can modify and/or nullify these gradients and subsequently alter structure and function. The purpose of this symposium is to discuss the results from short-term Shuttle flights, long term Skylab or Mir missions, or long-term ground based experiments which indicate or suggest that performance has been or could be compromised in space missions of long durations (>one year) or with space tasks (e.g. building space stations) with the goal of identifying countermeasures that could minimize or eliminate the expected anatomical and physiological consequences. After an overview by C. Tipton from the U. Arizona, the countermeasures necessary for the fluid shifts and select functions of the cardiovascular system will be discussed by A. Hargens from NASA Ames Research Center. He will be followed by K. Baldwin of the U. California at Irvine who will discuss the countermeasures needed to prevent the changes that alter the structure, function and control of skeletal muscles. Since changes in bone mass with microgravity are a major concern of NASA, V. Schneider from NASA Headquarters will present data and the countermeasures for bone. Although the results are limited, the changes in the endocrine and immune system deserve mentioning and C. Tipton will assume this responsibility. V. Convertino from the Air Force School of Aerospace Medicine has the challenge of discussing the role, importance, and the specificity of exercise as an effective countermeasure while I. Kozlovskaya from Moscow will elaborate on the Russian experiences with past countermeasures and provide a viewpoint on future ones. After the brief (25 min.) presentations, the speakers will assemble as a panel to discuss the issues raised and the concerns of the audience.

Tipton, C. M.; Hargens, A. R.; Baldwin, K. M.; Schneider, V.; Convertino, V. A.; Kozlovskaya, I.; Wade, Charles E. (Technical Monitor)

1994-01-01

101

Reproductive impacts and physiological adaptations of zebrafish to elevated dietary nickel.  

PubMed

Nickel (Ni) concentrations in the environment can rise due to human industrial activities. The toxicity of waterborne Ni to aquatic animals has been examined in a number of previous studies; however, little is known about the impacts of elevated dietary Ni. In the present study, zebrafish were chronically fed diets containing two concentrations of Ni [3.7 (control) and 116?g Ni/g diet]. Ni-exposed males, but not females, were significantly smaller (26%) compared to controls at 80days. In addition, total egg production was decreased by 65% in the Ni treatment at 75-78days of the experiment. Ni was ubiquitously distributed in control animals (similar to previous studies), and concentrations varied between tissues by 15-fold. Ni exposure resulted in modest but significant Ni accumulation in some tissues (increases were highest in brain, vertebrae and gut; 44%, 34% and 25%, respectively), an effect observed only at 80days. The limited Ni accumulation may be due to (1) the lack of an acidified stomach in zebrafish and/or (2) the efficient upregulation of Ni transport and excretion mechanisms, as indicated by the 4.5-fold increase in waterborne (63)Ni uptake by Ni-exposed fish. Eggs from Ni-exposed adults had Ni concentrations that were 5.2-fold higher than controls. However, by 4days post fertilization, larvae had similar Ni concentrations as controls, demonstrating a capacity for rapid Ni depuration. Larvae from Ni-exposed adults were also more resistant to waterborne Ni (35% increase in the 96-h LC50 over controls). In conclusion, elevated dietary Ni significantly affected zebrafish reproduction despite only modest tissue Ni accumulation. There were also indications of adaptation, including increased Ni uptake rates and increased Ni tolerance of offspring from Ni-exposed adults. Ni concentrations were particularly elevated in the brain with exposure; possible relations to growth and reproductive impacts require further study. PMID:24858402

Alsop, Derek; Lall, Santosh P; Wood, Chris M

2014-09-01

102

Explaining bathymetric diversity patterns in marine benthic invertebrates and demersal fishes: physiological contributions to adaptation of life at depth.  

PubMed

Bathymetric biodiversity patterns of marine benthic invertebrates and demersal fishes have been identified in the extant fauna of the deep continental margins. Depth zonation is widespread and evident through a transition between shelf and slope fauna from the shelf break to 1000 m, and a transition between slope and abyssal fauna from 2000 to 3000 m; these transitions are characterised by high species turnover. A unimodal pattern of diversity with depth peaks between 1000 and 3000 m, despite the relatively low area represented by these depths. Zonation is thought to result from the colonisation of the deep sea by shallow-water organisms following multiple mass extinction events throughout the Phanerozoic. The effects of low temperature and high pressure act across hierarchical levels of biological organisation and appear sufficient to limit the distributions of such shallow-water species. Hydrostatic pressures of bathyal depths have consistently been identified experimentally as the maximum tolerated by shallow-water and upper bathyal benthic invertebrates at in situ temperatures, and adaptation appears required for passage to deeper water in both benthic invertebrates and demersal fishes. Together, this suggests that a hyperbaric and thermal physiological bottleneck at bathyal depths contributes to bathymetric zonation. The peak of the unimodal diversity-depth pattern typically occurs at these depths even though the area represented by these depths is relatively low. Although it is recognised that, over long evolutionary time scales, shallow-water diversity patterns are driven by speciation, little consideration has been given to the potential implications for species distribution patterns with depth. Molecular and morphological evidence indicates that cool bathyal waters are the primary site of adaptive radiation in the deep sea, and we hypothesise that bathymetric variation in speciation rates could drive the unimodal diversity-depth pattern over time. Thermal effects on metabolic-rate-dependent mutation and on generation times have been proposed to drive differences in speciation rates, which result in modern latitudinal biodiversity patterns over time. Clearly, this thermal mechanism alone cannot explain bathymetric patterns since temperature generally decreases with depth. We hypothesise that demonstrated physiological effects of high hydrostatic pressure and low temperature at bathyal depths, acting on shallow-water taxa invading the deep sea, may invoke a stress-evolution mechanism by increasing mutagenic activity in germ cells, by inactivating canalisation during embryonic or larval development, by releasing hidden variation or mutagenic activity, or by activating or releasing transposable elements in larvae or adults. In this scenario, increased variation at a physiological bottleneck at bathyal depths results in elevated speciation rate. Adaptation that increases tolerance to high hydrostatic pressure and low temperature allows colonisation of abyssal depths and reduces the stress-evolution response, consequently returning speciation of deeper taxa to the background rate. Over time this mechanism could contribute to the unimodal diversity-depth pattern. PMID:24118851

Brown, Alastair; Thatje, Sven

2014-05-01

103

Novel roles of ohrR-ohr in Xanthomonas sensing, metabolism, and physiological adaptive response to lipid hydroperoxide.  

PubMed

Lipid hydroperoxides are highly toxic to biological systems. Here, the Xanthomonas campestris pv. phaseoli sensing and protective systems against linoleic hydroperoxide (LOOH) were investigated by examining the phenotypes, biochemical and regulatory characteristics of various Xanthomonas mutants in known peroxide resistance pathways. Analysis of LOOH resistance levels indicates that both alkyl hydroperoxide reductase (AhpC) and organic hydroperoxide resistance enzyme (Ohr) have important and nonredundant roles in the process. Nonetheless, inactivation of ohr leads to a marked reduction in LOOH resistance levels. The regulatory characteristics of an ohr mutant add further support to its primary role in LOOH protection. Northern analysis shows that LOOH had differential effects on induction of ahpC and ohr expression with the latter being more sensitive to the inducer. Analysis of the ahpC and ohr promoters confirmed that the LOOH-dependent induction of these promoters is mediated by the transcription regulators OxyR and OhrR, respectively. Using the in vivo promoter assays and the in vitro gel mobility shift assay, we show that LOOH directly oxidized OhrR at the sensing residue Cys-22 leading to its inactivation. In addition, physiological analysis shows that pretreatment of X. campestris pv. phaseoli with a sublethal dose of LOOH induced high levels of resistance to subsequent exposure to lethal concentrations of LOOH. This novel LOOH-induced adaptive response requires a functional ohrR-ohr operon. These data illustrate an important novel physiological role for the ohrR-ohr system in sensing and inactivating lipid hydroperoxides. PMID:15838057

Klomsiri, Chananat; Panmanee, Warunya; Dharmsthiti, Saovanee; Vattanaviboon, Paiboon; Mongkolsuk, Skorn

2005-05-01

104

The interruption of thyroid and interrenal and the inter-hormonal interference in fish: does it promote physiologic adaptation or maladaptation?  

PubMed

Endocrines, the chief components of chemical centers which produce hormones in tune with intrinsic and extrinsic clues, create a chemical bridge between the organism and the environment. In fishes also hormones integrate and modulate many physiologic functions and its synthesis, release, biological actions and metabolic clearance are well regulated. Consequently, thyroid hormones (THs) and cortisol, the products of thyroid and interrenal axes, have been identified for their common integrative actions on metabolic and osmotic functions in fish. On the other hand, many anthropogenic chemical substances, popularly known as endocrine disrupting chemicals, have been shown to disrupt the hormone-receptor signaling pathways in a number fish species. These chemicals which are known for their ability to induce endocrine disruption particularly on thyroid and interrenals can cause malfunction or maladaptation of many vital processes which are involved in the development, growth and reproduction in fish. On the contrary, evidence is presented that the endocrine interrupting agents (EIAs) can cause interruption of thyroid and interrenals, resulting in physiologic compensatory mechanisms which can be adaptive, though such hormonal interactions are less recognized in fishes. The EIAs of physical, chemical and biological origins can specifically interrupt and modify the hormonal interactions between THs and cortisol, resulting in specific patterns of inter-hormonal interference. The physiologic analysis of these inter-hormonal interruptions during acclimation and post-acclimation to intrinsic or extrinsic EIAs reveals that combinations of anti-hormonal, pro-hormonal or stati-hormonal interference may help the fish to fine-tune their metabolic and osmotic performances as part of physiologic adaptation. This novel hypothesis on the phenomenon of inter-hormonal interference and its consequent physiologic interference during thyroid and interrenal interruption thus forms the basis of physiologic acclimation. This interfering action of TH and cortisol during hormonal interruption may subsequently promote ecological adaptation in fish as these physiologic processes ultimately favor them to survive in their hostile environment. PMID:22001502

Peter, Valsa S; Peter, M C Subhash

2011-12-01

105

Leap of faith: voluntary emersion behaviour and physiological adaptations to aerial exposure in a non-aestivating freshwater fish in response to aquatic hypoxia.  

PubMed

Lowland stream fauna in areas of intensive agriculture are increasingly under threat from anthropogenic activities leading to eutrophication and subsequent hypoxia. Survival of hypoxic episodes depends upon a combination of behavioural and physiological adaptations. Responses of inanga (Galaxias maculatus: Galaxiidae) to aquatic hypoxia were investigated in the laboratory. Contrary to expectation inanga did not display behaviour that might reduce energy expenditure during oxygen limitation, with swimming activity slightly, but significantly elevated relative to normoxia. Instead, as dissolved oxygen concentrations decreased, the fish moved higher in the water column, increased their swimming speed and exhibited aquatic surface respiration. Physiological changes such as enhanced opercular frequency were also noted. As hypoxia deepened inanga started to leap out of the water, emersing themselves on a floating platform. Once emersed, fish exhibited an enhanced oxygen consumption rate compared to hypoxic fish. Thus inanga appear better adapted to escape hypoxia (a behavioural adaptation) rather than tolerate it (physiological adaptation). The emersion strategy used for inanga in response to severe hypoxia is in agreement with their ability to take up more oxygen from the air than from hypoxic water and therefore may justify the potentially increased risks of desiccation and predation associated with leaving the water. PMID:21316378

Urbina, Mauricio A; Forster, Malcolm E; Glover, Chris N

2011-05-01

106

Modulation of the Somatotropic Axis in Periparturient Dairy Cows  

PubMed Central

This review focuses on modulation of growth hormone (GH) and its downstream actions on periparturient dairy cows undergoing physiological and metabolic adaptations. During the periparturient period, cows experience a negative energy balance implicating that the feed intake does not meet the total energy demand for the onset of lactation. To regulate this metabolic condition, key hormones of somatotropic axis such as GH, IGF-I and insulin must coordinate adaptations required for the preservation of metabolic homeostasis. The hepatic GHR1A transcript and GHR protein are reduced at parturition, but recovers on postpartum. However, plasma IGF-I concentration remains low even though hepatic abundance of the GHR and IGF-I mRNA return to pre-calving value. This might be caused by alternation in IGFBPs and ALS genes, which consequently affect the plasma IGF-I stability. Plasma insulin level declines in a parallel manner with the decrease in plasma IGF-I after parturition. Increased GH stimulates the lipolytic effects and hepatic glucose synthesis to meet the energy requirement for mammary lactose synthesis, suggesting that GH antagonizes insulin-dependent glucose uptake and attenuates insulin action to decrease gluconeogenesis.

Kim, Jin Wook

2014-01-01

107

Adaptation of the hydrocarbonoclastic bacterium Alcanivorax borkumensis SK2 to alkanes and toxic organic compounds: a physiological and transcriptomic approach.  

PubMed

The marine hydrocarbonoclastic bacterium Alcanivorax borkumensis is able to degrade mixtures of n-alkanes as they occur in marine oil spills. However, investigations of growth behavior and physiology of these bacteria when cultivated with n-alkanes of different chain lengths (C6 to C30) as the substrates are still lacking. Growth rates increased with increasing alkane chain length up to a maximum between C12 and C19, with no evident difference between even- and odd-numbered chain lengths, before decreasing with chain lengths greater than C19. Surface hydrophobicity of alkane-grown cells, assessed by determination of the water contact angles, showed a similar pattern, with maximum values associated with growth rates on alkanes with chain lengths between C11 and C19 and significantly lower values for cells grown on pyruvate. A. borkumensis was found to incorporate and modify the fatty acid intermediates generated by the corresponding n-alkane degradation pathway. Cells grown on distinct n-alkanes proved that A. borkumensis is able to not only incorporate but also modify fatty acid intermediates derived from the alkane degradation pathway. Comparing cells grown on pyruvate with those cultivated on hexadecane in terms of their tolerance toward two groups of toxic organic compounds, chlorophenols and alkanols, representing intensely studied organic compounds, revealed similar tolerances toward chlorophenols, whereas the toxicities of different n-alkanols were significantly reduced when hexadecane was used as a carbon source. As one adaptive mechanism of A. borkumensis to these toxic organic solvents, the activity of cis-trans isomerization of unsaturated fatty acids was proven. These findings could be verified by a detailed transcriptomic comparison between cultures grown on hexadecane and pyruvate and including solvent stress caused by the addition of 1-octanol as the most toxic intermediate of n-alkane degradation. PMID:23645199

Naether, Daniela J; Slawtschew, Slavtscho; Stasik, Sebastian; Engel, Maria; Olzog, Martin; Wick, Lukas Y; Timmis, Kenneth N; Heipieper, Hermann J

2013-07-01

108

Adaptation of the Hydrocarbonoclastic Bacterium Alcanivorax borkumensis SK2 to Alkanes and Toxic Organic Compounds: a Physiological and Transcriptomic Approach  

PubMed Central

The marine hydrocarbonoclastic bacterium Alcanivorax borkumensis is able to degrade mixtures of n-alkanes as they occur in marine oil spills. However, investigations of growth behavior and physiology of these bacteria when cultivated with n-alkanes of different chain lengths (C6 to C30) as the substrates are still lacking. Growth rates increased with increasing alkane chain length up to a maximum between C12 and C19, with no evident difference between even- and odd-numbered chain lengths, before decreasing with chain lengths greater than C19. Surface hydrophobicity of alkane-grown cells, assessed by determination of the water contact angles, showed a similar pattern, with maximum values associated with growth rates on alkanes with chain lengths between C11 and C19 and significantly lower values for cells grown on pyruvate. A. borkumensis was found to incorporate and modify the fatty acid intermediates generated by the corresponding n-alkane degradation pathway. Cells grown on distinct n-alkanes proved that A. borkumensis is able to not only incorporate but also modify fatty acid intermediates derived from the alkane degradation pathway. Comparing cells grown on pyruvate with those cultivated on hexadecane in terms of their tolerance toward two groups of toxic organic compounds, chlorophenols and alkanols, representing intensely studied organic compounds, revealed similar tolerances toward chlorophenols, whereas the toxicities of different n-alkanols were significantly reduced when hexadecane was used as a carbon source. As one adaptive mechanism of A. borkumensis to these toxic organic solvents, the activity of cis-trans isomerization of unsaturated fatty acids was proven. These findings could be verified by a detailed transcriptomic comparison between cultures grown on hexadecane and pyruvate and including solvent stress caused by the addition of 1-octanol as the most toxic intermediate of n-alkane degradation.

Naether, Daniela J.; Slawtschew, Slavtscho; Stasik, Sebastian; Engel, Maria; Olzog, Martin; Wick, Lukas Y.; Timmis, Kenneth N.

2013-01-01

109

Teaching the physiology of adaptation to hypoxic stress with the aid of a classic paper on high altitude by Houston and Riley  

NSDL National Science Digital Library

Many pathological conditions exist where tissues exhibit hypoxia or low oxygen tension. Hypoxic hypoxia arises when there is a reduction in the amount of oxygen entering the blood and occurs in healthy people at high altitude. In 1946, research sponsored by the United States Navy led to the collection and subsequent publication of masses of data demonstrating the physiological consequences and adaptations of ascent to high altitude. This article describes how a figure from a 1947 paper from the American Physiological Society Legacy collection (Houston CS, Riley RL. Respiratory and circulatory changes during acclimatization to high altitude. Am J Physiol 149: 565ÃÂ588) may be used to allow students to review their understanding of some of the generalized effects of hypoxia on the body. In particular, this figure summarizes some of the adaptive responses that take place in the oxygen transport system as a consequence of prolonged hypoxia.

E M Tansey (Wellcome Institute for the History of Medicine)

2007-12-19

110

Physiologic adaptation of man in space; Proceedings of the Seventh International Man in Space Symposium, Houston, TX, Feb. 10-13, 1986  

NASA Technical Reports Server (NTRS)

Topics discussed in this volume include space motion sickness, cardiovascular adaptation, fluid shifts, extravehicular activity, general physiology, perception, vestibular response modifications, vestibular physiology, and pharmacology. Papers are presented on the clinical characterization and etiology of space motion sickness, ultrasound techniques in space medicine, fluid shifts in weightlessness, Space Shuttle inflight and postflight fluid shifts measured by leg volume changes, and the probability of oxygen toxicity in an 8-psi space suit. Consideration is also given to the metabolic and hormonal status of crewmembers in short-term space flights, adaptive changes in perception of body orientation and mental image rotation in microgravity, the effects of a visual-vestibular stimulus on the vestibulo-ocular reflex, rotation tests in the weightless phase of parabolic flight, and the mechanisms of antimotion sickness drugs.

Holland, Albert W. (editor)

1987-01-01

111

Synthetic Physiology: Strategies for Adapting Tools from Nature for Genetically-Targeted Control of Fast Biological Processes  

PubMed Central

The life and operation of cells involve many physiological processes that take place over fast timescales of milliseconds to minutes. Genetically-encoded technologies for driving or suppressing specific fast physiological processes in intact cells, perhaps embedded within intact tissues in living organisms, are critical for the ability to understand how these physiological processes contribute to emergent cellular and organismal functions and behaviors. Such “synthetic physiology” tools are often incredibly complex molecular machines, in part because they must operate at high speeds, without causing side effects. We here explore how synthetic physiology molecules can be identified and deployed in cells, and how the physiology of these molecules in cellular contexts can be assessed and optimized. For concreteness, we discuss these methods in the context of the “optogenetic” light-gated ion channels and pumps that we have developed over the past few years as synthetic physiology tools, and widely disseminated for use in neuroscience for probing the role of specific brain cell types in neural computations, behaviors, and pathologies. We anticipate that some of the insights revealed here may be of general value for the field of synthetic physiology, as they raise issues that will be of importance for the development and use of high-performance, high-speed, side-effect free physiological control tools, in heterologous expression systems.

Chow, Brian Y.; Chuong, Amy S.; Klapoetke, Nathan C.; Boyden, Edward S.

2013-01-01

112

Prepartum dietary energy source fed to beef cows: I. Effects on pre- and postpartum cow performance.  

PubMed

Mature Angus-cross beef cows (n = 144) were used to determine effects of late gestation dietary energy source on pre- and postpartum cow performance in a complete randomized block design experiment. Cows were adapted to diets starting at 167 +/- 9 d of gestation and fed until 1 wk before expected calving date. Cows were fed 1 of 3 dietary energy sources: grass hay (HY), corn (CN), or dried distillers grains (DDGS). Cows allotted to HY were allowed ad libitum access to round-bale grass hay, and average hay disappearance was 12.4 kg/d. Limit-fed corn and DDGS diets contained 5.3 kg of whole-shelled corn or 4.1 kg of DDGS, respectively, plus 2.1 kg of hay, and 1.0 kg of supplement to meet cow nutritional needs during late gestation and to allow for an energy intake similar to HY. Every 21 d, BW, BCS, and ultrasound measurement of backfat between the 12th and 13th ribs were collected. At 210 d in gestation, jugular blood samples were collected from cows at 0, 3, 6, and 9 h postfeeding and were analyzed for glucose, insulin, NEFA, and blood urea N (BUN) concentrations. After parturition, cows were fed a common diet and managed similarly. Milk production was determined by weigh-suckle-weigh procedure on d 31, 100, and 176 postpartum. Cows fed DDGS during late gestation gained more (P = 0.04) BW than cows fed HY or CN; however, no difference in BCS change was detected (P = 0.28) among treatments. Plasma glucose concentrations were similar among treatments (P = 0.64), whereas insulin concentrations at 3 h postfeeding were greater (P = 0.002) for cows fed DDGS than those fed HY or CN. Plasma BUN concentrations were greater (P < or = 0.02) for cows fed DDGS vs. CN or HY up to 6 h postfeeding. Birth weight was greater (P < 0.001) for calves from cows fed CN and DDGS than for those fed HY, but this did not result in any differences in frequency of dystocia (P = 0.21). Prepartum energy source did not affect conception rates (P = 0.79), milk production (P > or = 0.51), or milk composition (P > or = 0.39). Maternal dietary energy source in late gestation did not affect pre- or postpartum cow performance, but did change plasma hormones and metabolites during gestation. Heavier birth weights in calves from cows fed CN or DDGS indicate the changes in maternal metabolism affected energy partitioning of nutrients to the fetus and subsequent fetal growth. PMID:20453084

Radunz, A E; Fluharty, F L; Day, M L; Zerby, H N; Loerch, S C

2010-08-01

113

Mad Cow Disease  

MedlinePLUS

... disease (vCJD). Researchers believe that people who eat beef from cows that have BSE are at risk ... believe that the people got vCJD after eating beef products from cows that had BSE. Because vCJD ...

114

Regulation of lipid droplet-associated proteins following growth hormone administration and feed restriction in lactating Holstein cows.  

PubMed

Lipid metabolism plays a crucial role in the adaptation of dairy cows to periods of energy insufficiency. The objective of the current study was to determine if lipolytic proteins are consistently regulated when energy mobilization is stimulated by different factors. We evaluated 2 models of altered energy balance in mid-lactation Holstein cows, including feed restriction (FR) and administration of bovine growth hormone (GH), by quantifying the abundance and (or) phosphorylation of hormone-sensitive lipase (HSL), perilipin (PLIN), and adipose triglyceride lipase (ATGL). For GH administration, adipose tissue and blood samples were collected 4d before and 3 and 7d after administration of GH (n=20 cows). Similarly, adipose and blood samples were obtained 6d before and 1 and 4d after initiation of FR (n=18 cows). Estimated net energy balance decreased and nonesterified fatty acid concentration increased in both experimental models. Decreased ATGL and PLIN protein abundance was observed with GH administration and FR. Additionally, the abundance of phosphorylated HSLSer565 decreased in both models. Decreased abundance of phosphorylated PLIN was observed with GH administration, but not FR. Decreased ATGL protein abundance appears to be a consistent response to energy insufficiency in lactating cows, as this response was also described with negative energy balance at the onset of lactation. In contrast, the abundance of PLIN protein and phosphorylation of HSL using antibodies targeting serine residue 565 of HSL (HSLSer565) were altered in the current research, but not at the onset of lactation. Our findings demonstrate that lipolysis is altered through the regulation of multiple proteins, and that this regulation differs according to physiological state in lactating cows. PMID:24630665

Faylon, M P; Koltes, D E; Spurlock, D M

2014-05-01

115

Teaching Skeletal Muscle Adaptations to Aerobic Exercise Using an American Physiological Society Classic Paper by Dr. Philip Gollnick and Colleagues  

NSDL National Science Digital Library

Discussion of a strategy for using a classic paper to enhance the studentsÃÂ ability to understand research, increase their knowledge of the adaptations to exercise, and learn computer skills in data analysis and presentation

PhD Gregory A. Brown (University of Nebraska, Kearney Department of Health, Physical Education, Recreation, and Leisure Studies)

2006-09-01

116

Application of Physiological Self-Regulation and Adaptive Task Allocation Techniques for Controlling Operator Hazardous States of Awareness  

NASA Technical Reports Server (NTRS)

Prinzel, Hadley, Freeman, and Mikulka found that adaptive task allocation significantly enhanced performance only when used at the endpoints of the task workload continuum (i.e., very low or high workload), but that the technique degraded performance if invoked during other levels of task demand. These researchers suggested that other techniques should be used in conjunction with adaptive automation to help minimize the onset of hazardous states of awareness (HSA) and keep the operator 'in-the-loop.' The paper reports on such a technique that uses psychophysiological self-regulation to modulate the level of task engagement. Eighteen participants were assigned to three groups (self-regulation, false feedback, and control) and performed a compensatory tracking task that was cycled between three levels of task difficulty on the basis of the electroencephalogram (EEG) record. Those participants who had received self-regulation training performed significantly better and reported lower NASA-TLX scores than participants in the false feedback and control groups. Furthermore, the false feedback and control groups had significantly more task allocations resulting in return-to-manual performance decrements and higher EEG difference scores. Theoretical and practical implications of these results for adaptive automation are discussed.

Prinzel, Lawrence J., III; Pope, Alan T.; Freeman, Frederick G.

2001-01-01

117

The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage  

PubMed Central

Background We describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing. Results Our phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented. Conclusions Our comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders.

2013-01-01

118

The western painted turtle genome, a model for the evolution of extreme physiological adaptations in a slowly evolving lineage.  

PubMed

BACKGROUND: We describe the genome of the western painted turtle, Chrysemys picta bellii, one of the most widespread, abundant, and well-studied turtles. We place the genome into a comparative evolutionary context, and focus on genomic features associated with tooth loss, immune function, longevity, sex differentiation and determination, and the species' physiological capacities to withstand extreme anoxia and tissue freezing. RESULTS: Our phylogenetic analyses confirm that turtles are the sister group to living archosaurs, and demonstrate an extraordinarily slow rate of sequence evolution in the painted turtle. The ability of the painted turtle to withstand complete anoxia and partial freezing appears to be associated with common vertebrate gene networks, and we identify candidate genes for future functional analyses. Tooth loss shares a common pattern of pseudogenization and degradation of tooth-specific genes with birds, although the rate of accumulation of mutations is much slower in the painted turtle. Genes associated with sex differentiation generally reflect phylogeny rather than convergence in sex determination functionality. Among gene families that demonstrate exceptional expansions or show signatures of strong natural selection, immune function and musculoskeletal patterning genes are consistently over-represented. CONCLUSIONS: Our comparative genomic analyses indicate that common vertebrate regulatory networks, some of which have analogs in human diseases, are often involved in the western painted turtle's extraordinary physiological capacities. As these regulatory pathways are analyzed at the functional level, the painted turtle may offer important insights into the management of a number of human health disorders. PMID:23537068

Shaffer, H Bradley; Minx, Patrick; Warren, Daniel E; Shedlock, Andrew M; Thomson, Robert C; Valenzuela, Nicole; Abramyan, John; Amemiya, Chris T; Badenhorst, Daleen; Biggar, Kyle K; Borchert, Glen M; Botka, Christopher W; Bowden, Rachel M; Braun, Edward L; Bronikowski, Anne M; Bruneau, Benoit G; Buck, Leslie T; Capel, Blanche; Castoe, Todd A; Czerwinski, Mike; Delehaunty, Kim D; Edwards, Scott V; Fronick, Catrina C; Fujita, Matthew K; Fulton, Lucinda; Graves, Tina A; Green, Richard E; Haerty, Wilfried; Hariharan, Ramkumar; Hernandez, Omar; Hillier, Ladeana W; Holloway, Alisha K; Janes, Daniel; Janzen, Fredric J; Kandoth, Cyriac; Kong, Lesheng; de Koning, Ap Jason; Li, Yang; Literman, Robert; McGaugh, Suzanne E; Mork, Lindsey; O'Laughlin, Michelle; Paitz, Ryan T; Pollock, David D; Ponting, Chris P; Radhakrishnan, Srihari; Raney, Brian J; Richman, Joy M; St John, John; Schwartz, Tonia; Sethuraman, Arun; Spinks, Phillip Q; Storey, Kenneth B; Thane, Nay; Vinar, Tomas; Zimmerman, Laura M; Warren, Wesley C; Mardis, Elaine R; Wilson, Richard K

2013-03-28

119

Feeding patterns and performance of cows in controlled cow traffic in automatic milking systems.  

PubMed

Two groups of dairy cows monitored from 3 to 19 wk postpartum were subjected to 2 different cow traffic routines in an automatic milking system with control gates and an open waiting area. Using different time settings in the control gates, the groups of cows were separated by average milking frequency; cows in the high milking frequency routine had a minimum of 4 h between milkings (MF(4)) and were milked 3.2 +/- 0.1 times daily, whereas cows in the low milking frequency routine had at least 8 h between milkings (MF8) and were milked 2.1 +/- 0.1 times daily. Cows in the 2 groups were switched to the opposite milking frequency control for wk 18 and 19. The increased milking frequency resulted in a higher milk yield of about 9% through 16 wk of early lactation Although the higher milk yield was not significant when measured as energy-corrected milk, significant interactions of milking frequency and study period for milk yield and energy-corrected milk yield were consistent with a yield response when cows were milked more frequently. Meal criteria estimated for each individual cow were used to group feeding visits into meals. During MF4, cows fed in fewer meals per day and had longer meals than during MF8. The control gates were used efficiently, with only a few passages not resulting in actual meals. Although the voluntary meal intervals seemed to be short, the average milking frequency was far below that theoretically possible. This was explained by individual differences in milking frequency and long intervals from when a cow was redirected in a control gate until it arrived in the milking unit. A wide individual range in the voluntary interval between the first and the second meal in the milking cycle suggests that fixed time limits for control gates set on group level have no justifiable biological basis. It was also concluded that primiparous cows were well adapted to the automatic milking system after 2 wk in the barn. PMID:16230697

Melin, M; Svennersten-Sjaunja, K; Wiktorsson, H

2005-11-01

120

Functional evidence for physiological mechanisms to circumvent neurotoxicity of cardenolides in an adapted and a non-adapted hawk-moth species  

PubMed Central

Because cardenolides specifically inhibit the Na+K+-ATPase, insects feeding on cardenolide-containing plants need to circumvent this toxic effect. Some insects such as the monarch butterfly rely on target site insensitivity, yet other cardenolide-adapted lepidopterans such as the oleander hawk-moth, Daphnis nerii, possess highly sensitive Na+K+-ATPases. Nevertheless, larvae of this species and the related Manduca sexta are insensitive to injected cardenolides. By radioactive-binding assays with nerve cords of both species, we demonstrate that the perineurium surrounding the nervous tissue functions as a diffusion barrier for a polar cardenolide (ouabain). By contrast, for non-polar cardenolides such as digoxin an active efflux carrier limits the access to the nerve cord. This barrier can be abolished by metabolic inhibitors and by verapamil, a specific inhibitor of P-glycoproteins (PGPs). This supports that a PGP-like transporter is involved in the active cardenolide-barrier of the perineurium. Tissue specific RT-PCR demonstrated expression of three PGP-like genes in hornworm nerve cords, and immunohistochemistry further corroborated PGP expression in the perineurium. Our results thus suggest that the lepidopteran perineurium serves as a diffusion barrier for polar cardenolides and provides an active barrier for non-polar cardenolides. This may explain the high in vivo resistance to cardenolides observed in some lepidopteran larvae, despite their highly sensitive Na+K+-ATPases.

Petschenka, Georg; Pick, Christian; Wagschal, Vera; Dobler, Susanne

2013-01-01

121

Do telomeres adapt to physiological stress? Exploring the effect of exercise on telomere length and telomere-related proteins.  

PubMed

Aging is associated with a tissue degeneration phenotype marked by a loss of tissue regenerative capacity. Regenerative capacity is dictated by environmental and genetic factors that govern the balance between damage and repair. The age-associated changes in the ability of tissues to replace lost or damaged cells is partly the cause of many age-related diseases such as Alzheimer's disease, cardiovascular disease, type II diabetes, and sarcopenia. A well-established marker of the aging process is the length of the protective cap at the ends of chromosomes, called telomeres. Telomeres shorten with each cell division and with increasing chronological age and short telomeres have been associated with a range of age-related diseases. Several studies have shown that chronic exposure to exercise (i.e., exercise training) is associated with telomere length maintenance; however, recent evidence points out several controversial issues concerning tissue-specific telomere length responses. The goals of the review are to familiarize the reader with the current telomere dogma, review the literature exploring the interactions of exercise with telomere phenotypes, discuss the mechanistic research relating telomere dynamics to exercise stimuli, and finally propose future directions for work related to telomeres and physiological stress. PMID:24455708

Ludlow, Andrew T; Ludlow, Lindsay W; Roth, Stephen M

2013-01-01

122

Physiological Effects of Training.  

National Technical Information Service (NTIS)

With the evolution of exercise science a vast amount of information concerning the physiological effects of training has been generated. Understanding the basic training responses and adaptations of various modes of conditioning can give the clinician ins...

W. J. Kraemer W. L. Daniels

1985-01-01

123

Effect of walking stress on growth, physiological adaptability and endocrine responses in Malpura ewes in a semi-arid tropical environment  

NASA Astrophysics Data System (ADS)

Sheep in hot semi-arid environments are mostly reared using extensive systems. In addition to thermal stress and feed scarcity, the animals need to walk long distances for grazing in this ecological zone. A study was conducted to assess the effect of long-distance walking on adaptive capability in terms of physiological, biochemical and endocrine responses in Malpura ewes. Fourteen adult Malpura non-pregnant ewes weighing between 33 and 35 kg were used in the study. The ewes were randomly allocated into two groups of seven animals each: GI ( n = 7; Control), and GII ( n = 7; walking stress). The animals were stall-fed with a diet consisting of 70% roughage and 30% concentrate. Both GI and GII ewes had uniform access to feed and water. The walking stress group (GII) ewes were made to walk 14 km in two spans between 0900 and 1500 hours with 1 h 30 min for each span (7 km) of walking. The ewes subjected to walking stress (GII) were prevented from grazing by applying a face mask made of cotton thread. The study was conducted for a period of two estrous cycles (35 days) during the autumn season (October-November). Physiological responses were recorded twice daily at 0800 and 1400 hours at weekly intervals. Blood samples were collected from the jugular vein at weekly intervals to study the effects of walking stress on blood biochemical and endocrine parameters. The results indicate that walking stress had significant ( P < 0.05) influence on body weight, average daily gain, respiration rate (RR), rectal temperature (RT), haemoglobin (Hb), packed cell volume (PCV), plasma glucose, calcium, phosphorus, aspartate amino transferase (AST), alanine amino transferase (ALT), tri-iodo-thyronine (T3), thyroxin (T4), and cortisol. However, walking stress did not influence the reproductive hormone levels. The significant changes in RR, RT, plasma cortisol, T3 and T4 show that Malpura ewes have the capability to adapt to long-distance walking, and that adrenal and thyroid gland hormones play a significant role in such adaptation.

Sejian, Veerasamy; Maurya, Vijai P.; Naqvi, Syed M. K.

2012-03-01

124

Effect of walking stress on growth, physiological adaptability and endocrine responses in Malpura ewes in a semi-arid tropical environment.  

PubMed

Sheep in hot semi-arid environments are mostly reared using extensive systems. In addition to thermal stress and feed scarcity, the animals need to walk long distances for grazing in this ecological zone. A study was conducted to assess the effect of long-distance walking on adaptive capability in terms of physiological, biochemical and endocrine responses in Malpura ewes. Fourteen adult Malpura non-pregnant ewes weighing between 33 and 35 kg were used in the study. The ewes were randomly allocated into two groups of seven animals each: GI (n?=?7; Control), and GII (n?=?7; walking stress). The animals were stall-fed with a diet consisting of 70% roughage and 30% concentrate. Both GI and GII ewes had uniform access to feed and water. The walking stress group (GII) ewes were made to walk 14 km in two spans between 0900 and 1500 hours with 1 h 30 min for each span (7 km) of walking. The ewes subjected to walking stress (GII) were prevented from grazing by applying a face mask made of cotton thread. The study was conducted for a period of two estrous cycles (35 days) during the autumn season (October-November). Physiological responses were recorded twice daily at 0800 and 1400 hours at weekly intervals. Blood samples were collected from the jugular vein at weekly intervals to study the effects of walking stress on blood biochemical and endocrine parameters. The results indicate that walking stress had significant (P?adapt to long-distance walking, and that adrenal and thyroid gland hormones play a significant role in such adaptation. PMID:21455731

Sejian, Veerasamy; Maurya, Vijai P; Naqvi, Syed M K

2012-03-01

125

A model system for studying the transcriptomic and physiological changes associated with mammalian host-adaptation by Leptospira interrogans serovar Copenhageni.  

PubMed

Leptospirosis, an emerging zoonotic disease with worldwide distribution, is caused by spirochetes belonging to the genus Leptospira. More than 500,000 cases of severe leptospirosis are reported annually, with >10% of these being fatal. Leptospires can survive for weeks in suitably moist conditions before encountering a new host. Reservoir hosts, typically rodents, exhibit little to no signs of disease but shed large numbers of organisms in their urine. Transmission occurs when mucosal surfaces or abraded skin come into contact with infected urine or urine-contaminated water or soil. In humans, leptospires can cause a variety of clinical manifestations, ranging from asymptomatic or mild fever to severe icteric (Weil's) disease and pulmonary haemorrhage. Currently, little is known about how Leptospira persist within a reservoir host. Prior in vitro studies have suggested that leptospires alter their transcriptomic and proteomic profiles in response to environmental signals encountered during mammalian infection. However, no study has examined gene expression by leptospires within a mammalian host-adapted state. To obtain a more faithful representation of how leptospires respond to host-derived signals, we used RNA-Seq to compare the transcriptome of L. interrogans cultivated within dialysis membrane chambers (DMCs) implanted into the peritoneal cavities of rats with that of organisms grown in vitro. In addition to determining the relative expression levels of "core" housekeeping genes under both growth conditions, we identified 166 genes that are differentially-expressed by L. interrogans in vivo. Our analyses highlight physiological aspects of host adaptation by leptospires relating to heme uptake and utilization. We also identified 11 novel non-coding transcripts that are candidate small regulatory RNAs. The DMC model provides a facile system for studying the transcriptional and antigenic changes associated with mammalian host-adaptation, selection of targets for mutagenesis, and the identification of previously unrecognized virulence determinants. PMID:24626166

Caimano, Melissa J; Sivasankaran, Sathesh K; Allard, Anna; Hurley, Daniel; Hokamp, Karsten; Grassmann, André A; Hinton, Jay C D; Nally, Jarlath E

2014-03-01

126

Larval exposure to 4-nonylphenol and 17??-estradiol affects physiological and behavioral development of seawater adaptation in Atlantic salmon smolts  

USGS Publications Warehouse

Population declines of anadromous salmonids are attributed to anthropogenic disturbances including dams, commercial and recreational fisheries, and pollutants, such as estrogenic compounds. Nonylphenol (NP), a xenoestrogen, is widespread in the aquatic environment due to its use in agricultural, industrial, and household products. We exposed Atlantic salmon yolk-sac larvae to waterborne 10 or 100 ??g L-1 NP (NP-L or NP-H, respectively), 2 ??g L-1 17??-estradiol (E2), or vehicle, for 21 days to investigate their effects on smolt physiology and behavior 1 year later. NP-H caused approximately 50% mortality during exposure, 30 days after exposure, and 60 days after exposure. Mortality rates of NP-L and E2 fish were not affected until 60 days after treatment, when they were 4-fold greater than those of controls. Treatment with NP-L or E2 as yolk-sac larvae decreased gill sodium-potassium-activated adenosine triphosphatase (Na+,K +-ATPase) activity and seawater (SW) tolerance during smolt development, 1 year after exposure. Exposure to NP-L and E2 resulted in a latency to enter SW and reduced preference for SW approximately 2- and 5-fold, respectively. NP-L-exposed fish had 20% lower plasma insulin-like growth factor I (IGF-I) levels and 35% lower plasma triiodothyronine (T3). Plasma growth hormone and thyroxine (T4) were unaffected. Exposure to E2 did not affect plasma levels of IGF-I, GH, T3, or T4. Both treatment groups exhibited increased plasma Cortisol and decreased osmoregulatory capacity in response to a handling stressor. These results suggest that early exposure to environmentally relevant concentrations of NP, and other estrogenic compounds, can cause direct and delayed mortalities and that this exposure can have long term, "organizational" effects on life-history events in salmonids. ?? 2007 American Chemical Society.

Lerner, D. T.; Bjornsson, B. T.; Mccormick, S. D.

2007-01-01

127

Physiological adaptation of Escherichia coli after transfer onto refrigerated ground meat and other solid matrices: a molecular approach.  

PubMed

Bacteria on meat are subjected to specific living conditions that differ drastically from typical laboratory procedures in synthetic media. This study was undertaken to determine the behavior of bacteria when transferred from a rich-liquid medium to solid matrices, as is the case during microbial process validation. Escherichia coli cultured in Brain-Heart Infusion (BHI) broth to different growth phases were inoculated in ground beef (GB) and stored at 5°C for 12 days or spread onto BHI agar and cooked meat medium (CMM), and incubated at 37°C for several hours. We monitored cell densities and the expression of ? factors and genes under their control over time. The initial growth phase of the inoculum influenced growth resumption after transfer onto BHI agar and CMM. Whatever the solid matrix, bacteria adapted to their new environment and did not perceive stress immediately after inoculation. During this period, the ?(E) and ?(H) regulons were not activated and rpoD mRNA levels adjusted quickly. The rpoS and gadA mRNA levels did not increase after inoculation on solid surfaces and displayed normal growth-dependent modifications. After transfer onto GB, dnaK and groEL gene expression was affected more by the low temperature than by the composition of a meat environment. PMID:22850375

Guernec, Anthony; Robichaud-Rincon, Philippe; Saucier, Linda

2012-10-01

128

Transverse diameter of the chest and of the heart of infants in the course of physiological cardiorespiratory adaptation.  

PubMed

The morphology of the lungs and heart was analysed in 824 newborn infants with normal cardiorespiratory adaptation. Under normal conditions, the air content of the lungs became satisfactory in the first 6--12 hours and normal in all cases after 24 hours. The values for the transverse diameter of the chest and heart were brought into correlation with birth weight, body length and gestational age. The transverse diameter of the chest and heart did not change during the early postnatal period (between 6--12 hours and 5 days). Both diameters were correlated with birth weight. The closest correlation was found in newborns under 1500 g, a varying one in those between 1500 and 2000 g and a close correlation in the category over 2000 g. The correlation of the two diameters with both length was linear and close, without any difference between the values obtained at different times of examination. A rather loose correlation was found between the transverse diameter of the chest and heart, and gestational age. PMID:613734

Weisenbach, J; Hajpál, A; Várady, S; Jászai, V; Schmelzer, M; Schultz, K; Pap, L; Rippl, I

1977-01-01

129

Grazing Soybean to Increase Voluntary Cow Traffic in a Pasture-based Automatic Milking System  

PubMed Central

Pasture-based automatic milking systems (AMS) require cow traffic to enable cows to be milked. The interval between milkings can be manipulated by strategically allocating pasture. The current experiment investigated the effect of replacing an allocation of grazed pasture with grazed soybean (Glycine max) with the hypothesis that incorporating soybean would increase voluntary cow traffic and milk production. One hundred and eighty mixed age, primiparous and multiparous Holstein-Friesian/Illawarra cows were randomly assigned to two treatment groups (n = 90/group) with a 2×2 Latin square design. Each group was either offered treatments of kikuyu grass (Pennisetum clandestinum Hoach ex Chiov.) pasture (pasture) or soybean from 0900 h to 1500 h during the experimental period which consisted of 2 periods of 3 days following 5 days of training and adaptation in each period with groups crossing over treatments after the first period. The number of cows trafficking to each treatment was similar together with milk yield (mean ?18 L/cow/d) in this experiment. For the cows that arrived at soybean or pasture there were significant differences in their behaviour and consequently the number of cows exiting each treatment paddock. There was greater cow traffic (more cows and sooner) exiting pasture allocations. Cows that arrived at soybean stayed on the allocation for 25% more time and ate more forage (8.5 kg/cow/d/allocation) relative to pasture (4.7 kg/cow/d/allocation). Pasture cows predominantly replaced eating time with rumination. These findings suggest that replacing pasture with alternative grazeable forages provides no additional incentive to increase voluntary cow traffic to an allocation of feed in AMS. This work highlights the opportunity to increase forage intakes in AMS through the incorporation of alternative forages.

Clark, C. E. F.; Horadagoda, A.; Kerrisk, K. L.; Scott, V.; Islam, M. R.; Kaur, R.; Garcia, S. C.

2014-01-01

130

Space physiology and medicine  

SciTech Connect

The state of knowledge in space physiology and medicine are reviewed. Overviews of manned space flight, the space environment, spaceflight systems and procedures, physiological adaptation to space flight, health maintenance of space crew members, and medical problems of space flight are presented.

Nicogossian, A.E.; Parker J.F. Jr.

1982-01-01

131

Ruminant metabolic systems biology: reconstruction and integration of transcriptome dynamics underlying functional responses of tissues to nutrition and physiological state.  

PubMed

High-throughput 'omics' data analysis via bioinformatics is one key component of the systems biology approach. The systems approach is particularly well-suited for the study of the interactions between nutrition and physiological state with tissue metabolism and functions during key life stages of organisms such as the transition from pregnancy to lactation in mammals, ie, the peripartal period. In modern dairy cows with an unprecedented genetic potential for milk synthesis, the nature of the physiologic and metabolic adaptations during the peripartal period is multifaceted and involves key tissues such as liver, adipose, and mammary. In order to understand such adaptation, we have reviewed several works performed in our and other labs. In addition, we have used a novel bioinformatics approach, Dynamic Impact Approach (DIA), in combination with partly previously published data to help interpret longitudinal biological adaptations of bovine liver, adipose, and mammary tissue to lactation using transcriptomics datasets. Use of DIA with transcriptomic data from those tissues during normal physiological adaptations and in animals fed different levels of energy prepartum allowed visualization and integration of most-impacted metabolic pathways around the time of parturition. The DIA is a suitable tool for applying the integrative systems biology approach. The ultimate goal is to visualize the complexity of the systems at study and uncover key molecular players involved in the tissue's adaptations to physiological state or nutrition. PMID:22807626

Bionaz, Massimo; Loor, Juan J

2012-01-01

132

Addition of Sodium Bicarbonate to Rations of Pre and Postpartum Dairy Cows1  

Microsoft Academic Search

Sodium bicarbonate was added to complete mixed rations to evaluate the effect of buffer addition on adaptation to high-energy rations by dairy cows in early lactation. Forty-five Holstein cows were assigned to one of three treatment groups: control pre- and postpartum; control prepartum, buffer postpartum; and buffer pre- and postpartum. Rations consisted of 85% chopped grass hay: 15% concentrate prepartum

L. H. Kilmer; L. D. Muller; P. J. Wangsness

1980-01-01

133

GnRH-Induced Ca2+ Signaling Patterns and Gonadotropin Secretion in Pituitary Gonadotrophs. Functional Adaptations to Both Ordinary and Extraordinary Physiological Demands  

PubMed Central

Pituitary gonadotrophs are a small fraction of the anterior pituitary population, yet they synthesize gonadotropins: luteinizing (LH) and follicle-stimulating (FSH), essential for gametogenesis and steroidogenesis. LH is secreted via a regulated pathway while FSH release is mostly constitutive and controlled by synthesis. Although gonadotrophs fire action potentials spontaneously, the intracellular Ca2+ rises produced do not influence secretion, which is mainly driven by Gonadotropin-Releasing Hormone (GnRH), a decapeptide synthesized in the hypothalamus and released in a pulsatile manner into the hypophyseal portal circulation. GnRH binding to G-protein-coupled receptors triggers Ca2+ mobilization from InsP3-sensitive intracellular pools, generating the global Ca2+ elevations necessary for secretion. Ca2+ signaling responses to increasing (GnRH) vary in stereotyped fashion from subthreshold to baseline spiking (oscillatory), to biphasic (spike-oscillatory or spike-plateau). This progression varies somewhat in gonadotrophs from different species and biological preparations. Both baseline spiking and biphasic GnRH-induced Ca2+ signals control LH/FSH synthesis and exocytosis. Estradiol and testosterone regulate gonadotropin secretion through feedback mechanisms, while FSH synthesis and release are influenced by activin, inhibin, and follistatin. Adaptation to physiological events like the estrous cycle, involves changes in GnRH sensitivity and LH/FSH synthesis: in proestrus, estradiol feedback regulation abruptly changes from negative to positive, causing the pre-ovulatory LH surge. Similarly, when testosterone levels drop after orquiectomy the lack of negative feedback on pituitary and hypothalamus boosts both GnRH and LH secretion, gonadotrophs GnRH sensitivity increases, and Ca2+ signaling patterns change. In addition, gonadotrophs proliferate and grow. These plastic changes denote a more vigorous functional adaptation in response to an extraordinary functional demand.

Duran-Pasten, Maria Luisa; Fiordelisio, Tatiana

2013-01-01

134

Associations between locomotion score and kinematic measures in dairy cows with varying hoof lesion types.  

PubMed

During this study we explored the gait attributes commonly used in subjective locomotion scoring systems and use new technology to evaluate these gait attributes objectively on 60 Holstein lactating dairy cattle. Kinematic gait analysis more commonly used in sports and equine science was adapted for use on dairy cattle to assess stride characteristics, joint flexion, and spine posture in dairy cows with different lameness status. Cows that were lame had shorter stride length and had negative tracking distance compared with nonlame cattle. Lame cattle did not show any difference in spine posture when walking. Gait alterations were more evident in cows with sole ulcers, which showed considerable shortening of stride and had more negative tracking compared with cows with no hoof lesions. Cows with sole ulcers also showed significant shortening of the spine when walking than cows with no hoof lesions. PMID:23548277

Blackie, N; Bleach, E C L; Amory, J R; Scaife, J R

2013-06-01

135

Physiology Online  

NSDL National Science Digital Library

Physiology Online, the electronic information service of the Physiological Society, provides information about its three journals: Journal of Physiology, Proceedings of the Physiological Society, and Experimental Physiology. Also included are selected abstracts, as well as information about recent monographs, job listings (mostly in the U.K.), information about Society grants, a physiology file and software archive for both PC and Mac platforms, pointers to other physiology resources on the Internet, and a listing of upcoming meetings and conferences within the field.

1994-01-01

136

Cow-milk allergy.  

PubMed

Hereditary predisposition is the major denominator of allergy, and hypersensitivity reactions contribute to the expression of the genetic predisposition. The route of sensitization varies with age so that dietary antigens predominate in infancy. The immaturity of the immune system and the gastrointestinal barrier may explain the peak prevalence of food allergies at an early age. The treatment of choice for cow-milk allergy is complete avoidance of cow-milk antigens. The approach to control allergic inflammation by antigen elimination, however, has not been satisfactory. New approaches are urgently needed for the management of patients with cow-milk allergy. These may include: (i) immunotherapy to counteract the immunological dysfunction, and (ii) stabilisation of the gut mucosal barrier to strengthen endogenous defence mechanisms. PMID:21781812

Isolauri, E

1997-11-01

137

Cow's milk allergenicity.  

PubMed

In this review, clinical and epidemiological aspects of milk allergy along with current data on the structure and function of the main cow's milk allergens, are presented. Milk allergy is the most frequent food allergy in childhood. One of the reasons why allergy to cow's milk shows its highest prevalence in children is its early introduction into the diets of infants when breast feeding is not possible. The major allergens are caseins, a-lactalbumin and ?-lactoglobulin, but allergies to other minor proteins (immunoglobulins, bovine serum albumin) have also been reported. Milk allergenicity can be reduced by various processing methods (mainly hydrolysis), and processed formulas based on cow's milk can often be safely introduced to children allergic to milk proteins. Cross reactivity has been described between different mammalian milks and between milk and meat or animal dander. PMID:24450454

Tsabouri, Sophia; Douros, Kostas; Priftis, Kostas N

2014-03-01

138

Physiological Adaptations of Arctic Mammals.  

National Technical Information Service (NTIS)

Contents: Cold Acclimation in Arctic Lemmings; Tolerance of Arctic Lemmings to Hypothermia and Dehydration; Renal Function in Hypothermic Arctic Lemmings; Cold Acclimation in the Tundra Vole (Microtus oeconomus); Induction of Summer Hibernation in the 13-...

G. E. Folk M. A. Folk J. J. Berberich J. J. Minor K. Magoon

1975-01-01

139

Ovariectomy by colpotomy in cows.  

PubMed

For the purpose of collecting active ovarian structures for cell culture, unilateral ovariectomy (n = 34 ovaries) was performed per vagina on 17 dairy cows having normal estrous cycles, bilateral ovariectomy was performed on 9 (n = 18 ovaries) dairy cows, and corpora lutea (n = 13) were removed from 11 beef cows having normal estrous cycles. None of the cows was clinically ill after the operation. Nine of 37 cows developed adhesions of both uterine horns and the body of the uterus. Three instruments were used to perform colpotomy. The described surgical technique for removal of the ovaries or corpora lutea is practical and inexpensive, and has low morbidity associated with it. PMID:1548167

Drost, M; Savio, J D; Barros, C M; Badinga, L; Thatcher, W W

1992-02-01

140

Kinematics - Roller-Skating Cow  

NSDL National Science Digital Library

The representation depicts the position and velocity of a roller-skating cow as it travels in a horizontal direction. The student can select the initial position, velocity, and acceleration of the cow. As the cow moves forward according to the parameters set by the student, a position-time graph is created. A velocity-time graph positioned next to the position-time graph is simultaneously created.

141

Assessing Cows’ Welfare: weighing the Cow in a Milking Robot  

Microsoft Academic Search

Four strain gauge balances were installed into a milking robot after careful inspection of the positions of the legs of all 40 cows from a herd. It was found that 90% of the cows would have all the legs on the balances at least during every second milking. The balances were connected to a four channel amplifier and the data

M. Pastell; H. Takko; H. Gröhn; M. Hautala; V. Poikalainen; J. Praks; I. Veermäe; M. Kujala; J. Ahokas

2006-01-01

142

Procedures of Exercise Physiology Laboratories  

NASA Technical Reports Server (NTRS)

This manual describes the laboratory methods used to collect flight crew physiological performance data at the Johnson Space Center. The Exercise Countermeasures Project Laboratory is a standard physiology laboratory; only the application to the study of human physiological adaptations to spaceflight is unique. In the absence of any other recently published laboratory manual, this manual should be a useful document staffs and students of other laboratories.

Bishop, Phillip A.; Fortney, Suzanne; Greenisen, Michael; Siconolfi, Steven F.; Bamman, Marcas M.; Moore, Alan D., Jr.; Squires, William

1998-01-01

143

How the COW happened  

NASA Astrophysics Data System (ADS)

In the course of a casual conversation during a social gathering, in the spring of 1974, we were discussing some recent developments in the area of diffraction from perfect crystals, namely, interferometry in the Angstrom region. I (R.C.) was asked by Al Overhauser whether or not I knew anything about the subject. “Not much” was my answer, “but I can read some papers”. Al then proceeded to describe a possible experiment, namely, the effect of gravity on the quantum mechanical phase of the neutron, in essence, what later was called the COW experiment (Colella, Overhauser, Werner).

Colella, R.; Overhauser, A. W.

2006-11-01

144

The Development of Real-Time Physiological Monitoring and Training Software for Remote Applications  

NASA Technical Reports Server (NTRS)

Autogenic Feedback Training Exercise (AFTE) is an protocol and technology developed by Dr. Patricia Cowings and her associates at NASA Ames Research Center as a means to facilitate astronaut adaptation to space and exposure to the microgravity. AFTE is a training method which involves teaching subjects to voluntarily control several of their own physiological responses to environmental stressors. As the procedures matured, the training program was expanded to determine if technology developed to facilitate astronaut adaptation to space would be valuable in treating patients suffering from autonomic and vestibular pathologies and symptomatic relief from nausea and/or blood pressure control anomalies such as hypo- or hypertension. The present study, performed in conjunction with Morehouse School of Medicine, Biomedical Engineering at The University of Akron and NASA Ames Research Center has demonstrated that this technology can be successfully applied over vast distances. The specific purpose of this research was to develop a PC based system which could handle processing of twenty channels of acquired physiological data in addition to the necessary duplex communication protocols that would, for example, permit a patient in Atlanta, GA to be trained by a clinician stationed in San Jose, CA. Sixteen channels of physiological data and 20 channels of processed data are included.

2005-01-01

145

The interruption of thyroid and interrenal and the inter-hormonal interference in fish: Does it promote physiologic adaptation or maladaptation?  

Microsoft Academic Search

Endocrines, the chief components of chemical centers which produce hormones in tune with intrinsic and extrinsic clues, create a chemical bridge between the organism and the environment. In fishes also hormones integrate and modulate many physiologic functions and its synthesis, release, biological actions and metabolic clearance are well regulated. Consequently, thyroid hormones (THs) and cortisol, the products of thyroid and

Valsa S. Peter; M. C. Subhash Peter

146

Cow's milk and goat's milk.  

PubMed

Cow's milk is increasingly suggested to play a role in the development of chronic degenerative, non-communicable disorders whereas goat's milk is advocated as having several health benefits. Cow's milk is a rich and cheap source of protein and calcium, and a valuable food for bone health. Despite their high content in saturated fats, consumption of full-fat dairy products does not seem to cause significant changes in cardiovascular disease risk variables. Early introduction of cow's milk is a strong negative determinant of iron status. Unmodified cow's milk does not meet nutritional requirements of infants although it is acceptable to add small volumes of cow's milk to complementary foods. Cow's milk protein allergy has a prevalence ranging from 2 to 7%, and the age of recovery is usually around 2-3 years. The evidence linking cow's milk intake to a later risk of type 1 diabetes or chronic degenerative, non-communicable disorders (obesity, metabolic syndrome, type 2 diabetes, hypertension) is not convincing. Milk probably protects against colorectal cancer, diets high in calcium are a probable cause of prostate cancer, and there is limited evidence suggesting that high consumption of milk and dairy products increases the risk for prostate cancer. There is no evidence to support the use of a cow's milk-free diet as a primary treatment for individuals with autistic spectrum disorders. Unmodified goat's milk is not suitable for infants because of the high protein and minerals content and of a low folate content. Goat's milk has no clear nutritional advantage over cow's milk and is not less allergenic. The European Food Safety Authority recently stated that proteins from goat's milk can be suitable as a protein source for infant and follow-on formula, provided the final product complies with the compositional criteria laid down in Directive 2006/141/EC. PMID:24029787

Turck, Dominique

2013-01-01

147

Physiological Waterfalls  

ERIC Educational Resources Information Center

Provides background information, defining areas within organ systems where physiological waterfalls exist. Describes pressure-flow relationships of elastic tubes (blood vessels, airways, renal tubules, various ducts). (CS)

Leith, David E.

1976-01-01

148

Effect of ambient temperature and sodium bicarbonate supplementation on water and electrolyte balances in dry and lactating Holstein cows.  

PubMed

The aim of this study was to quantify the effect of the interaction between 2 constant ambient temperatures [thermoneutrality (TN; 15°C) and high temperature (HT; 28°C)] and 2 levels of Na bicarbonate supplementation [calculated to provide diet Na contents of 0.20%DM (Na-) and 0.50%DM (Na+)] on water partitioning in dairy cows. Treatments were compared on 4 dry and 4mid-lactation Holstein cows according to 2 Latin squares (1 for each physiological stage) over the course of 4 periods of 15d. Diets consisted of a total mixed ration based on maize silage. Dry cows were restricted to their protein and energy requirements, whereas lactating cows were fed ad libitum. The daily average temperature-humidity index was 59.4 for TN and 73.2 for HT. Lactating and dry cows had higher vaginal temperatures at HT than at TN, but the increase was more pronounced in lactating cows (+1.05 vs. +0.12°C for vaginal temperature, respectively). Dry matter intake (DMI) of lactating cows decreased by 2.3kg/d at HT. Free water intake (FWI) and estimated volume of water lost to evaporation increased at HT in both lactating and dry cows; no interactions were observed between temperature and physiological stage. When expressed as a proportion of DMI, the increase in evaporation that occurred with increasing temperature was completely compensated for by an increase in FWI for both physiological stages. The urinary water excretion increased slightly at HT in lactating cows but not in dry cows, which may be related to the low chloride content of the offered diet. High Na supplementation increased DMI slightly in lactating cows, but milk yield was not affected. Sodium supplementation did not limit the decrease in DMI observed in lactating cows at HT; this observation is likely due to the high diet electrolyte balance of the offered diets. Sodium supplementation increased FWI in lactating cows and urinary flow in both physiological states. The interaction between ambient temperature and Na supplementation did not affect either water intake or water evaporation. This study demonstrates that the development of predictive models for water intake that include environmental variables could be based on mechanistic models of evaporation. PMID:24485695

Khelil-Arfa, H; Faverdin, P; Boudon, A

2014-04-01

149

Conservation physiology  

Microsoft Academic Search

Conservation biologists increasingly face the need to provide legislators, courts and conservation managers with data on causal mechanisms underlying conservation problems such as species decline. To develop and monitor solutions, conservation biologists are progressively using more techniques that are physiological. Here, we review the emerging discipline of conservation physiology and suggest that, for conservation strategies to be successful, it is

Martin Wikelski; Steven J. Cooke

2006-01-01

150

Rowing Physiology.  

ERIC Educational Resources Information Center

This review of the literature discusses and examines the methods used in physiological assessment of rowers, results of such assessments, and future directions emanating from research in the physiology of rowing. The first section discusses the energy demands of rowing, including the contribution of the energy system, anaerobic metabolism, and the…

Spinks, W. L.

151

Health and Physiological Effects of an Emotional Disclosure Intervention Adapted for Application at Home: A Randomized Clinical Trial in Rheumatoid Arthritis  

Microsoft Academic Search

Background: The efficacy of emotional disclosure in alleviating psychological and physical stress has been well documented in controlled laboratory studies. A next step is to evaluate its clinical utility in ‘real world’ settings. We adapted the emotional disclosure intervention for use in home-based settings by stimulating the suggested effective ingredients of cognitive-emotional processing, and evaluated its psychological and clinical effectiveness.

Henriët van Middendorp; Rinie Geenen; Marjolijn J. Sorbi; Lorenz J. P. van Doornen; Johannes W. J. Bijlsma

2009-01-01

152

Mad Cow Disease (For Parents)  

MedlinePLUS

... there is a system in which samples of animals are tested. This is one way to help prevent contaminated meat from reaching the shelves. The testing system helped officials identify a contaminated cow in ...

153

Effects of feeding various dosages of Saccharomyces cerevisiae fermentation product in transition dairy cows.  

PubMed

Feeding 56 versus 0g/d of Saccharomyces cerevisiae fermentation product (SCFP; Diamond V Original XP; Diamond V, Cedar Rapids, IA) can increase feed intake and milk production in transition dairy cows. To evaluate the effects of various dosages of SCFP, Holstein cows were given individually a supplement containing 0 (n=14), 56 (n=15), or 112g (n=13) of SCFP daily during morning lockup as a topdressing to their total mixed ration. The supplement consisted of 0, 56, or 112g of SCFP mixed with 84g of molasses and 168, 112, or 56g of corn meal, respectively. Supplement feeding began 28d before predicted calving date (no less than 14d) and ended 28d postpartum, and supplement intake was evaluated daily. Blood samples were collected at d -21, -14, -7, -3, -1, 0, 1, 3, 7, 14, 21, and 28 to measure serum concentrations of macrominerals, metabolites, acute-phase proteins, immunoglobulin, and hormones. Milk weights were measured and milk samples were collected 2 times/wk on nonconsecutive days and analyzed for milk fat, protein, lactose, and somatic cell count (SCC). During the first day after calving, feeding SCFP versus no SCFP decreased serum cortisol concentrations and at least tended to increase supplement intake and serum concentrations of calcium, glucose, urea N, and serum amyloid A. During the first 4wk postpartum, feeding SCFP versus no SCFP decreased milk SCC and increased milk production and serum phosphorus concentrations. Feeding 112 versus 56g of SCFP/d did not show additional effects. Feeding SCFP may have a dosage-independent beneficial effect in supporting the physiologic adaptations after parturition, resulting in higher milk production and lower milk SCC. PMID:24612807

Zaworski, E M; Shriver-Munsch, C M; Fadden, N A; Sanchez, W K; Yoon, I; Bobe, G

2014-05-01

154

Anti-inflammatory salicylate treatment alters the metabolic adaptations to lactation in dairy cattle.  

PubMed

Adapting to the lactating state requires metabolic adjustments in multiple tissues, especially in the dairy cow, which must meet glucose demands that can exceed 5 kg/day in the face of negligible gastrointestinal glucose absorption. These challenges are met through the process of homeorhesis, the alteration of metabolic setpoints to adapt to a shift in physiological state. To investigate the role of inflammation-associated pathways in these homeorhetic adaptations, we treated cows with the nonsteroidal anti-inflammatory drug sodium salicylate (SS) for the first 7 days of lactation. Administration of SS decreased liver TNF-? mRNA and marginally decreased plasma TNF-? concentration, but plasma eicosanoids and liver NF-?B activity were unaltered during treatment. Despite the mild impact on these inflammatory markers, SS clearly altered metabolic function. Plasma glucose concentration was decreased by SS, but this was not explained by a shift in hepatic gluconeogenic gene expression or by altered milk lactose secretion. Insulin concentrations decreased in SS-treated cows on day 7 compared with controls, which was consistent with the decline in plasma glucose concentration. The revised quantitative insulin sensitivity check index (RQUICKI) was then used to assess whether altered insulin sensitivity may have influenced glucose utilization rate with SS. The RQUICKI estimate of insulin sensitivity was significantly elevated by SS on day 7, coincident with the decline in plasma glucose concentration. Salicylate prevented postpartum insulin resistance, likely causing excessive glucose utilization in peripheral tissues and hypoglycemia. These results represent the first evidence that inflammation-associated pathways are involved in homeorhetic adaptations to lactation. PMID:23678026

Farney, Jaymelynn K; Mamedova, Laman K; Coetzee, Johann F; KuKanich, Butch; Sordillo, Lorraine M; Stoakes, Sara K; Minton, J Ernest; Hollis, Larry C; Bradford, Barry J

2013-07-15

155

Anti-inflammatory salicylate treatment alters the metabolic adaptations to lactation in dairy cattle  

PubMed Central

Adapting to the lactating state requires metabolic adjustments in multiple tissues, especially in the dairy cow, which must meet glucose demands that can exceed 5 kg/day in the face of negligible gastrointestinal glucose absorption. These challenges are met through the process of homeorhesis, the alteration of metabolic setpoints to adapt to a shift in physiological state. To investigate the role of inflammation-associated pathways in these homeorhetic adaptations, we treated cows with the nonsteroidal anti-inflammatory drug sodium salicylate (SS) for the first 7 days of lactation. Administration of SS decreased liver TNF-? mRNA and marginally decreased plasma TNF-? concentration, but plasma eicosanoids and liver NF-?B activity were unaltered during treatment. Despite the mild impact on these inflammatory markers, SS clearly altered metabolic function. Plasma glucose concentration was decreased by SS, but this was not explained by a shift in hepatic gluconeogenic gene expression or by altered milk lactose secretion. Insulin concentrations decreased in SS-treated cows on day 7 compared with controls, which was consistent with the decline in plasma glucose concentration. The revised quantitative insulin sensitivity check index (RQUICKI) was then used to assess whether altered insulin sensitivity may have influenced glucose utilization rate with SS. The RQUICKI estimate of insulin sensitivity was significantly elevated by SS on day 7, coincident with the decline in plasma glucose concentration. Salicylate prevented postpartum insulin resistance, likely causing excessive glucose utilization in peripheral tissues and hypoglycemia. These results represent the first evidence that inflammation-associated pathways are involved in homeorhetic adaptations to lactation.

Farney, Jaymelynn K.; Mamedova, Laman K.; Coetzee, Johann F.; KuKanich, Butch; Sordillo, Lorraine M.; Stoakes, Sara K.; Minton, J. Ernest; Hollis, Larry C.

2013-01-01

156

Expression and detection of estrus in dairy cows: the role of new technologies.  

PubMed

Despite the widespread adoption of hormonal synchronization protocols that allow for timed artificial insemination (AI), detection of estrus plays an important role in the reproductive management program on most dairies in the United States. Increased physical activity is a secondary sign of estrus in dairy cattle, and a new generation of electronic systems that continuously monitor physical activity to predict timing of AI have been developed and marketed to the dairy industry. A variety of management and physiologic challenges inhibit detection of behavioral estrus on farms, but the prevalence of anouvular cows near the end of the voluntary waiting period is particularly problematic. Only 70% of lactating Holstein cows were detected in estrus when using an activity monitoring system, with the remaining 20% of cows classified as anovular and 10% ovulating without showing signs of activity. Mean time of AI in relation to ovulation based on the activity monitoring system was acceptable for most of the cows with increased activity, however, variability in the duration of estrus and timing of AI in relation to ovulation could result in poor pregnancy outcomes in some cows. Use of a Presynch-Ovsynch protocol for submission of cows for first AI has been widely adopted by dairies in the United States, and a combined approach in which AI based on activity is followed by submission of cows not detected with activity to timed AI after synchronization of ovulation may be an effective strategy for submission of cows to first AI. Based on a field trial on a large commercial dairy in the United States, the activity monitoring system detected 70% of cows with increased activity after the second PGF2? injection of a Presynch-Ovsynch protocol, however, cows inseminated to increased activity had fewer pregnancies per AI (P/AI) compared with cows with increased activity after the second PGF2? injection that received timed AI after completing the Presynch-Ovsynch protocol. Based on an economic model comparing reproductive management programs with varying levels of AI to estrus v. timed AI, the rate of estrus detection and the P/AI to inseminations based on AI to detected estrus v. timed AI affected the decision to inseminate based on activity v. timed AI. In conclusion, an activity monitoring system detected increased activity in about 70% of lactating Holstein cows on a large commercial dairy in the United States, however, synchronization of ovulation and timed AI was beneficial to inseminate cows not detected with increased activity by the activity monitoring system. PMID:24680286

Fricke, P M; Carvalho, P D; Giordano, J O; Valenza, A; Lopes, G; Amundson, M C

2014-05-01

157

Out of the deep sea into a land-based aquarium environment: investigating physiological adaptations in the hydrothermal vent mussel Bathymodiolus azoricus  

Microsoft Academic Search

Deep-sea hydrothermal vents are considered to be some of the most\\u000a extreme environments in the world, yet the animals dwelling around the\\u000a vent sites exhibit high productivity and must therefore deal with\\u000a unusual levels of heavy metals, pH, temperature, CO2, and sulphides, in\\u000a addition to environmental microbes. In an attempt to understand the\\u000a physiological reactions of animals able to endure

Raul Bettencourt; Valentina Costa; Mario Laranjo; Domitilia Rosa; Luis Pires; Ana Colaco; Humberto Lopes; Ricardo Serrao Santos

2011-01-01

158

Role of Cellular Immunity in Cow's Milk Allergy: Pathogenesis, Tolerance Induction, and Beyond  

PubMed Central

Food allergy is an aberrant immune-mediated reaction against harmless food substances, such as cow's milk proteins. Due to its very early introduction, cow's milk allergy is one of the earliest and most common food allergies. For this reason cow's milk allergy can be recognized as one of the first indications of an aberrant inflammatory response in early life. Classically, cow's milk allergy, as is true for most other allergies as well, is primarily associated with abnormal humoral immune responses, that is, elevation of specific immunoglobulin E levels. There is growing evidence indicating that cellular components of both innate and adaptive immunity play significant roles during the pathogenesis of cow's milk allergy. This is true for the initiation of the allergic phenotype (stimulation and skewing towards sensitization), development and outgrowth of the allergic disease. This review discusses findings pertaining to roles of cellular immunity in allergic inflammation, and tolerance induction against cow's milk proteins. In addition, a possible interaction between immune mechanisms underlying cow's milk allergy and other types of inflammation (infections and noncommunicable diseases) is discussed.

Garssen, Johan

2014-01-01

159

Low cortisol levels in blood from dairy cows with ketosis: a field study  

PubMed Central

Background An elevated plasma glucose concentration has been considered to be a potential risk factor in the pathogenesis of left-displaced abomasums (DA). Therefore the present study was performed to investigate if spontaneous disease (parturient paresis, metritis, ketosis etc) in dairy cows results in elevated concentrations of glucose and cortisol in blood as cortisol is the major regulator of glucose in ruminants. Methods Cortisol, insulin, ?-hydroxybutyric acid (BHBA), non esterified fatty acids (NEFA), and serum calcium were analyzed in blood serum and glucose, in whole blood, from 57 spontaneously diseased cows collected at different farms. The cows were grouped according to the disease; parturient paresis, recumbent for other reasons, mastitis, metritis, ketosis, inappetance and others. Results No elevated concentrations of cortisol or glucose were found in cows with metritis and mastitis but both cortisol and glucose were elevated in cows stressed by recumbency. Cows with ketonemia (BHBA > 1.5 mmol/l) did not have low concentration of glucose in blood but significantly low levels of cortisol. Some of these cows even had cortisol concentrations below the detection limit of the analysing method (< 14 nmol/l). Conclusions The study gives patho-physiological support to the treatment strategies of ketosis, recommending glucocorticoids, insulin etc. However further studies of this problem are needed to understand why cows with ketosis have low levels of cortisol and normal levels of glucose. To what extent elevated cortisol and glucose levels in hypocalcemic and recumbent cows are involved in the ethiology and /or the pathogenesis of DA also will need further research.

2010-01-01

160

Salinity adaptation of the invasive New Zealand mud snail (Potamopyrgus antipodarum) in the Columbia River estuary (Pacific Northwest, USA): physiological and molecular studies  

USGS Publications Warehouse

In this study, we examine salinity stress tolerances of two populations of the invasive species New Zealand mud snail Potamopyrgus antipodarum, one population from a high salinity environment in the Columbia River estuary and the other from a fresh water lake. In 1996, New Zealand mud snails were discovered in the tidal reaches of the Columbia River estuary that is routinely exposed to salinity at near full seawater concentrations. In contrast, in their native habitat and throughout its spread in the western US, New Zealand mud snails are found only in fresh water ecosystems. Our aim was to determine whether the Columbia River snails have become salt water adapted. Using a modification of the standard amphipod sediment toxicity test, salinity tolerance was tested using a range of concentrations up to undiluted seawater, and the snails were sampled for mortality at daily time points. Our results show that the Columbia River snails were more tolerant of acute salinity stress with the LC50 values averaging 38 and 22 Practical Salinity Units for the Columbia River and freshwater snails, respectively. DNA sequence analysis and morphological comparisons of individuals representing each population indicate that they were all P. antipodarum. These results suggest that this species is salt water adaptable and in addition, this investigation helps elucidate the potential of this aquatic invasive organism to adapt to adverse environmental conditions.

Hoy, Marshal; Boese, Bruce L.; Taylor, Louise; Reusser, Deborah; Rodriguez, Rusty

2012-01-01

161

Predicting nutritional requirements and lactation performance of dual-purpose cows using a dynamic model  

Microsoft Academic Search

A dynamic application of the Cornell Net Carbohydrate and Protein System (CNCPS) model was developed to predict annual cycles in animal nutrient requirements and performance of dual-purpose (milk and beef) cows. Interactions from mobilisation and repletion of body tissue reserves and feed biological values are accounted with a time step of one day, which considers physiological status of the animal,

O. Reynoso-Campos; D. G. Fox; R. W. Blake; M. C. Barry; L. O. Tedeschi; C. F. Nicholson; H. M. Kaiser; P. A. Oltenacu

2004-01-01

162

Early mammary gland metabolic and immune responses during natural-like and forceful drying-off in high-yielding dairy cows.  

PubMed

The present work compared metabolic and immune responses in genetically high-producing cows that produced a low amount of milk before expected involution and in cows with the same genetic potential that produced copious amounts of milk before their scheduled drying-off. Ten multiparous lactating Israeli Holstein cows producing approximately 10,500 L in the current lactation, without bacterial infection and scheduled for drying-off approximately 60 d before their expected parturition, were studied. Five of the cows that exhibited a sharp, spontaneous reduction in milk yield at the end of their lactation and produced less than ~14L/d were defined as cows approaching natural involution (ANI), and 5 cows that produced between 25 and 35 L/d were defined as cows approaching forced involution (AFI). Three days before scheduled drying-off, milking was stopped and milk samples were collected from each quarter. After milking cessation, only modest swelling was observed in the udders of the ANI cows. In the ANI cows, lactose and fat concentrations decreased and the fat:lactose concentration ratio indicated that on d 1 and 2 fat concentrations decreased faster than lactose concentration, whereas on d 3, the rate of reduction was about the same for lactose and fat. In contrast, in AFI cows, fat concentrations increased on d 1 and the fat:lactose ratio indicated that changes in fat secretion were minor compared with those of lactose secretion. Rennet clotting time of milk after drying-off in the ANI cows increased, whereas curd firmness decreased rapidly, such that mammary secretions did not coagulate on d 3. In the AFI cows, such significant changes were observed only on d 3. The inflammatory response increased in both groups, but at each stage the increase was greater in ANI cows than in AFI cows. On d 1, the increase in leukocyte numbers in the ANI cows was made up of mononuclear cells (i.e., T lymphocytes and macrophages). In contrast, in the AFI cows, we observed a marked increase in leukocyte numbers, mainly in the form of polymorphonuclear cells. Our data indicate that the abrupt mammary involution induced in AFI cows provoked signs of distress, which were associated with neutrophilia in milk. In contrast, in the ANI cows, cessation of milking occurred without evidence of engorgement of the udder. Physiological differences in ANI and AFI cows are distinct and are reflected in the differences in the leukocyte populations in milk. PMID:23932133

Silanikove, Nissim; Merin, Uzi; Shapiro, Fira; Leitner, Gabriel

2013-10-01

163

Immune response of postpartum dairy cows fed flaxseed.  

PubMed

Thirty Holstein cows were allotted at calving to 10 groups of three cows blocked for similar calving dates to determine the effects of dietary fatty acids on functional properties of immunocompetent cells in early lactation and at breeding. Cows were assigned at calving to one of three isonitrogenous, isoenergetic, and isolipidic supplements based on either calcium salts of palm oil, Megalac, micronized soybeans, or whole flaxseed. On the day of AI and 20 d later, cows were injected with ovalbumin to measure the antibody response. Blood samples were taken at different times after calving (d 5, 21, 42, and 105) and after AI (d 0, 10, 20, and 40) for quantification of serum progesterone, fatty acids, and prostaglandin E2 concentrations. Isolated peripheral blood mononuclear cells were cultured to evaluate the proliferative response to concanavalin A and in vitro productions of interferon-gamma and prostaglandin E2. In general, feeding flaxseed increased serum omega-3 fatty acids concentration compared with feeding Megalac or soybeans, which decreased the omega-6 to omega-3 fatty acids ratio. There was a significant diet x day interaction for the proliferative response of mononuclear cells after calving and AI, indicating that cell responses from cows fed flaxseed were transiently reduced compared with those fed Megalac and soybeans. Moreover, during the breeding period, serum progesterone concentration was significantly greater in cows fed flaxseed compared with those fed Megalac, whereas serum concentration of prostaglandin E2 was significantly lower in cows fed flaxseed than in those fed Megalac or soybeans. Dietary treatments had no effect on the antibody response to ovalbumin and on in vitro productions of interferon-gamma and prostaglandin E2. However, interferon-gamma and prostaglandin E2 were impaired in the first 3 wk after parturition regardless of dietary treatment. These results suggest that changes in fatty acids, progesterone, and prostaglandins E2 concentrations in serum due to dietary treatment and physiological status influenced systemic immunity as shown by reduced proliferative response. However, other mechanisms must be considered and are discussed to explain dietary effect on lymphocyte proliferative response to mitogenic stimulation and other immune functions. PMID:12939089

Lessard, M; Gagnon, N; Petit, H V

2003-08-01

164

Genome-wide expression patterns in physiological cardiac hypertrophy  

Microsoft Academic Search

BACKGROUND: Physiological left ventricular hypertrophy (LVH) involves complex cardiac remodeling that occurs as an adaptive response to chronic exercise. A stark clinical contrast exists between physiological LVH and pathological cardiac remodeling in response to diseases such as hypertension, but little is known about the precise molecular mechanisms driving physiological adaptation. RESULTS: In this study, the first large-scale analysis of publicly

Ignat Drozdov; Sophia Tsoka; Christos A Ouzounis; Ajay M Shah

2010-01-01

165

New Approaches to Feeding Dry Cows  

Microsoft Academic Search

Interest has surged recently in use of high- straw low-energy diets for dry cows. When implemented correctly, these diets have been successful in decreasing incidences of peripartal health disorders. These diets may work by controlling overall energy intake by cows and thereby prevent metabolic changes similar to those that develop in fat cows. By formulating high-bulk TMR that will limit

James K. Drackley; Nicole A. Janovick-Guretzky; Heather M. Dann

2007-01-01

166

Cow's Milk Protein Allergy Mimicking Acrodermatitis Enteropathica  

PubMed Central

Cow’s milk protein allergy is an adverse immune reaction to one or more of the constituent proteins of milk obtained from any animal, most commonly alpha s 1-casein cow’s milk. In many cases, the allergy is genetic in origin. The infants may experience symptoms within minutes after feeding (rapid onset) or commonly after 7-10 days of consuming the cow’s milk (slower onset). Many children with cow’s milk protein allergy develop symptoms in at least two of the following organ systems: gastrointestinal, skin and respiratory tract. Acrodermatitis Enteropathica (primary or secondary zinc deficiency) can also produce lesions in the skin and also gastro intestinal symptoms which can mimic milk protein allergy and differentiating between these two may be difficult. We are reporting a case of cow’s milk protein allergy in an infant, which was initially diagnosed as Acrodermatitis Enteropathica and treated with zinc. The lesions did not subside completely even after achieving adequate zinc levels, but on stopping the cow’s milk all the symptoms and signs disappeared completely and there was no recurrence on long term follow up.

Solomon, John; Kamalammal, Rugmini; Sait, Mohammed Yaseen; Lohith, Harita

2014-01-01

167

Marine worms (genus Osedax ) colonize cow bones  

Microsoft Academic Search

Bone-eating worms of the genus Osedax colonized and grew on cow bones deployed at depths ranging from 385 to 2893 m in Monterey Bay, California. Colonization occurred as rapidly as two months following deployment of the cow bones, similar to the time it takes to colonize exposed whalebones. Some Osedax females found on the cow bones were producing eggs and

William J. Jones; Shannon B. Johnson; Greg W. Rouse; Robert C. Vrijenhoek

2008-01-01

168

Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes  

PubMed Central

Background Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg). High product titers and the retention of the protein in the endoplasmic reticulum (ER) are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. Results The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20). Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI) and the ER associated degradation (ERAD) pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily) indicating that potential degradation of HBsAg could proceed via the ERAD pathway and through the proteasome. However, the amount of HBsAg did not show any significant decline during the cultivation revealing its general protection from proteolytic degradation. During the methanol fed-batch phase, induction of vacuolar proteases (e.g. strong increase of APR1) and constitutive autophagic processes were observed. Vacuolar enclosures were mainly found around peroxisomes and not close to HBsAg deposits and, thus, were most likely provoked by peroxisomal components damaged by reactive oxygen species generated by methanol oxidation. Conclusions In the methanol fed-batch phase P. pastoris is exposed to dual stress; stress resulting from methanol degradation and stress resulting from the production of the recombinant protein leading to the induction of oxidative stress and unfolded protein response pathways, respectively. Finally, the modest increase of methanol assimilatory enzymes compared to the strong increase of methanol dissimilatory enzymes suggests here a potential to increase methanol incorporation into biomass/product through metabolic enhancement of the methanol assimilatory pathway.

2012-01-01

169

Differences in the Fecal Concentrations and Genetic Diversities of Campylobacter jejuni Populations among Individual Cows in Two Dairy Herds  

PubMed Central

Dairy cows have been identified as common carriers of Campylobacter jejuni, which causes many of the human gastroenteritis cases reported worldwide. To design on-farm management practices that control the human infection sourced from dairy cows, the first step is to acquire an understanding of the excretion patterns of the cow reservoir. We monitored the same 35 cows from two dairy farms for C. jejuni excretion fortnightly for up to 12 months. The objective was to examine the concentration of C. jejuni and assess the genetic relationship of the C. jejuni populations excreted by individual cows. Significant differences (P < 0.01) in C. jejuni fecal concentration were observed among the 35 cows, with median concentrations that varied by up to 3.6 log10 · g?1 feces. A total of 36 different genotypes were identified from the 514 positive samples by using enterobacterial repetitive intergenic consensus (ERIC)-PCR. Although 22 of these genotypes were excreted by more than one cow, the analysis of frequencies and distribution of the genotypes by model-based statistics revealed a high degree of individuality in the C. jejuni population in each cow. The observed variation in the frequency of excretion of a genotype among cows and the analysis by multilocus sequence typing (MLST) of these genotypes suggest that excretion of C. jejuni in high numbers is due to a successful adaptation of a particular genotype to a particular cow's gut environment, but that animal-related factors render some individual cows resistant to colonization by particular genotypes. The reasons for differences in C. jejuni colonization of animals warrant further investigation.

Ross, Colleen M.; Pleydell, Eve J.; Muirhead, Richard W.

2012-01-01

170

Regulatory Physiology  

NASA Technical Reports Server (NTRS)

As noted elsewhere in this report, a central goal of the Extended Duration Orbiter Medical Project (EDOMP) was to ensure that cardiovascular and muscle function were adequate to perform an emergency egress after 16 days of spaceflight. The goals of the Regulatory Physiology component of the EDOMP were to identify and subsequently ameliorate those biochemical and nutritional factors that deplete physiological reserves or increase risk for disease, and to facilitate the development of effective muscle, exercise, and cardiovascular countermeasures. The component investigations designed to meet these goals focused on biochemical and physiological aspects of nutrition and metabolism, the risk of renal (kidney) stone formation, gastrointestinal function, and sleep in space. Investigations involved both ground-based protocols to validate proposed methods and flight studies to test those methods. Two hardware tests were also completed.

Lane, Helen W.; Whitson, Peggy A.; Putcha, Lakshmi; Baker, Ellen; Smith, Scott M.; Stewart, Karen; Gretebeck, Randall; Nimmagudda, R. R.; Schoeller, Dale A.; Davis-Street, Janis

1999-01-01

171

Physiological and Proteomic Adaptation of "Aromatoleum aromaticum" EbN1 to Low Growth Rates in Benzoate-Limited, Anoxic Chemostats  

PubMed Central

“Aromatoleum aromaticum” EbN1 was cultivated at different growth rates in benzoate-limited chemostats under nitrate-reducing conditions. Physiological characteristics, proteome dynamics, phospholipid-linked fatty acid (PLFA) composition, and poly(3-hydroxybutyrate) (PHB) content were analyzed in steady-state cells at low (?low) (0.036 h?1), medium (?med) (0.108 h?1), and high (?high) (0.180 h?1) growth rates. A positive correlation to growth rate was observed for cellular parameters (cell size, and DNA and protein contents). The free energy consumed for biomass formation steadily increased with growth rate. In contrast, the energy demand for maintenance increased only from ?low to ?med and then remained constant until ?high. The most comprehensive proteomic changes were observed at ?low compared to ?high. Uniformly decreased abundances of protein components of the anaerobic benzoyl coenzyme A (benzoyl-CoA) pathway, central carbon metabolism, and information processing agree with a general deceleration of benzoate metabolism and cellular processes in response to slow growth. In contrast, increased abundances were observed at ?low for diverse catabolic proteins and components of uptake systems in the absence of the respective substrate (aromatic or aliphatic compounds) and for proteins involved in stress responses. This potential catabolic versatility and stress defense during slow growth may be interpreted as preparation for future needs.

Trautwein, Kathleen; Lahme, Sven; Wohlbrand, Lars; Feenders, Christoph; Mangelsdorf, Kai; Harder, Jens; Steinbuchel, Alexander; Blasius, Bernd; Reinhardt, Richard

2012-01-01

172

The cow as an induced ovulator: timed AI after synchronization of ovulation.  

PubMed

Timed-AI after synchronization of ovulation has become one of the most used reproductive technologies developed during the past 40 years. Various adaptations of this technology are now extensively used worldwide, in the beef and dairy cattle industry. Our well-cited report, published in Theriogenology in 1995, presented a method termed Ovsynch, that used GnRH and PGF2? to perform synchronization of ovulation and timed AI in lactating dairy cows. This report introduced Ovsynch, more as a concept of induced ovulation, and demonstrated the ovarian dynamics during the protocol. Validation and improvements on this method were subsequently performed in numerous university studies and on commercial dairies, worldwide. This review will provide a brief historical background, some personal recollections, and certain modifications that have been made in synchronization of ovulation protocols. Each section emphasizes the physiology that underlies the most widely-used synchronization of ovulation protocols and key modifications and some practical application of these protocols on commercial operations. Finally, the effect of timed AI in the US dairy industry and in the Brazilian beef cattle industry are compared. Although numerous studies have been done using these protocols, there is still substantial need for research to improve the synchronization, efficacy, simplicity, and practical application of these protocols. PMID:24274420

Wiltbank, Milo C; Pursley, J Richard

2014-01-01

173

Milk yield and composition from Angus and Angus-cross beef cows raised in southern Brazil.  

PubMed

This study assessed milk yield and composition of Angus and Angus-cross beef cows raised in southern Brazil. A total of 128 records were collected in 2 consecutive calving seasons from cows between 3 and 5 yr of age of 4 breed compositions: Angus (ANAN), Caracu × Angus (CRAN), Hereford × Angus (HHAN), and Nelore × Angus (NEAN). These cows were mated to Brangus (BN) or Braford (BO) bulls and managed under extensive grazing conditions in southern Brazil. Milk production of these cows was assessed by 2 procedures: indirectly by the calf weigh-suckle-weigh procedure (WD) and directly by machine milking (MM). Lactation curves were estimated using nonlinear regression and the following related traits were derived: peak yield (PY), peak week (PW), total yield at 210 d (TY210), and lactation persistence (PERS). Milk composition and calf weaning weight adjusted to 210 d (WW210) were also determined. The MM technique was considered more accurate because of lower standard errors of estimated means, greater statistical power, and greater correlation between TY210 and WW210 (0.50) compared to WD (0.36). Considering the more precise evaluation by MM, the CRAN and NEAN cows had greater TY210 (1070 and 1116 kg, respectively) and PY (8.1 and 7.8 kg, respectively) compared to ANAN and HHAN cows, which had 858 and 842 kg for TY210 and 6.6 and 6.3 kg for PY, respectively. The NEAN cows had the latest PW at 10.8 wk. Late-calving cows had 21% lower TY210 compared to cows that calved earlier. Milk composition was influenced by cow genotype, with CRAN and NEAN cows producing milk with greater fat (3.8 and 3.9%, respectively) and protein (3.2 and 3.1%, respectively) content compared to ANAN and HHAN cows. Regardless of the genotype, fat, protein, and total solids increased in concentration from beginning to end of lactation, while lactose content decreased. Crossbreeding of Angus with adapted breeds of taurine or indicine origin can be effective in increasing milk yield and nutrient content and, consequently, producing heavier calves at weaning under extensive grazing in southern Brazil and other similar subtropical climate regions. PMID:24753378

Rodrigues, P F; Menezes, L M; Azambuja, R C C; Suñé, R W; Barbosa Silveira, I D; Cardoso, F F

2014-06-01

174

Body temperature in early postpartum dairy cows.  

PubMed

A strategy widely adopted in the modern dairy industry is the introduction of postpartum health monitoring programs by trained farm personnel. Within these fresh cow protocols, various parameters (e.g., rectal temperature, attitude, milk production, uterine discharge, ketones) are evaluated during the first 5 to 14 days in milk (DIMs) to diagnose relevant diseases. It is well documented that 14% to 66% of healthy cows exhibit at least one temperature of 39.5 °C or greater within the first 10 DIM. Although widely adopted, data on diagnostic performance of body temperature (BT) measurement to diagnose infectious diseases (e.g., metritis, mastitis) are lacking. Therefore, the objective of this study was to identify possible factors associated with BT in postpartum dairy cows. A study was conducted on a commercial dairy farm including 251 cows. In a total of 217 cows, a vaginal temperature logger was inserted from DIM 2 to 10, whereas 34 cows did not receive a temperature logger as control. Temperature loggers measured vaginal temperature every 10 minutes. Rectal temperature was measured twice daily in all cows. On DIM 2, 5, and 10, cows underwent a clinical examination. Body temperature was influenced by various parameters. Primiparous cows had 0.2 °C higher BT than multiparous cows. Multiparous cows that calved during June and July had higher BT than those that calved in May. In primiparous cows, this effect was only evident from DIM 7 to 10. Furthermore, abnormal calving conditions (i.e., assisted calving, dead calf, retained placenta, twins) affected BT in cows. This effect was more pronounced in multiparous cows. Abnormal vaginal discharge did increase BT in primiparous and multiparous cows. Primiparous cows suffering from hyperketonemia (beta-hydroxybutyrat ? 1.4 mmol/L) had higher BT than those not affected. In multiparous cows, there was no association between hyperketonemia and BT. The results of this study clearly demonstrate that BT is influenced by various parameters in dairy cows. Therefore, these parameters have to be considered when interpreting measurements of BT in dairy cows. This information helps to explain the high incidence of type I and II errors when measuring BT and clearly illustrates that measures of BT should not be used as a single criterion to decide whether or not to provide antibiotic treatment to dairy cows. However, research-based test characteristics of other parameters (e.g., vaginal discharge) alone or in combination with BT are still lacking. PMID:24742963

Burfeind, O; Suthar, V S; Voigtsberger, R; Bonk, S; Heuwieser, W

2014-07-01

175

Reproductive physiology  

USGS Publications Warehouse

Conclusions: Although the general pattern of avian physiology applies to cranes, we have identified many physiological mechanisms (e.g., effects of disturbance) that need further study. Studies with cranes are expensive compared to those done with domestic fowl because of the crane's larger size, low reproductive rate, and delayed sexual maturity. To summarize, the crane reproductive system is composed of physiological and anatomical elements whose function is controlled by an integrated neural-endocrine system. Males generally produce semen at a younger age than when females lay eggs. Eggs are laid in clutches of two (1 to 3), and females will lay additional clutches if the preceding clutches are removed. Both sexes build nests and incubate the eggs. Molt begins during incubation and body molt may be completed annually in breeding pairs. However, remiges are replaced sequentially over 2 to 3 years, or abruptly every 2 to 3 years in other species. Most immature birds replace their juvenal remiges over a 2 to 3 year period. Stress interferes with reproduction in cranes by reducing egg production or terminating the reproductive effort. In other birds, stress elevates corticosterone levels and decreases LHRH release. We know little about the physiological response of cranes to stress.

Gee, G.F.; Russman, S.E.

1996-01-01

176

Fractal physiology  

Microsoft Academic Search

The nature of fractals and the use of fractals instead of classical scaling concepts to describe the irregular surfaces, structures, and processes exhibited by physiological systems are described. The mathematical development of fractals is reviewed, and examples of natural fractals are cited. Relationships among power laws, noise, and fractal time signals are examined

William Deering; Bruce J. West

1992-01-01

177

Intracranial Schwannoma in a Cow  

PubMed Central

A nine year old Hereford crossbred cow with a history of progressive neurological signs was referred to the Western College of Veterinary Medicine, Saskatoon. A large intracranial mass, histologically identified as a schwannoma, was found to be compressing the left brain stem and appeared to have arisen from the left fifth cranial nerve. ImagesFigure 1.Figure 2.Figure 3.

Mitcham, S. A.; Kasari, T. R.; Parent, J. M.; Naylor, J. M.

1984-01-01

178

Physiological and performance adaptations to an in-season soccer camp in the heat: associations with heart rate and heart rate variability.  

PubMed

The aim of the present study was to examine the associations between adaptive responses to an in-season soccer training camp in the heat and changes in submaximal exercising heart rate (HRex, 5-min run at 9 ?km/h), postexercise HR recovery (HRR) and HR variability (HRV). Fifteen well-trained but non-heat-acclimatized male adult players performed a training week in Qatar (34.6?±?1.9°C wet bulb globe temperature). HRex, HRR, HRV (i.e. the standard deviation of instantaneous beat-to-beat R-R interval variability measured from Poincaré plots SD1, a vagal-related index), creatine kinase (CK) activity, plasma volume (PV) changes, and post-5-min run rate of perceived exertion (RPE) were collected at six occasions in temperate environmental conditions (22°C). Players also performed the yo-yo intermittent recovery test level 1 (Yo-Yo IR1) in the same environmental conditions (22°C), both at the beginning and at the end of the training week. Throughout the intervention, HRex and HRV showed decreasing (P?

Buchheit, M; Voss, S C; Nybo, L; Mohr, M; Racinais, S

2011-12-01

179

Physiological Interactions  

Microsoft Academic Search

\\u000a Improvement in both temporal and spatial resolution of MDCT has brought the ability to explore both the heart and lung within\\u000a a single examination and opened the field of functional evaluation. However, interactions between heart and lung have long\\u000a been identified as important physiological phenomena in pathology (Pinsky 2005). For the radiologist, they are involved in difficulties of interpretation in

Francois Laurent; Michel Montaudon

180

Neonatal renal physiology.  

PubMed

The renal system plays a tremendous role in growth and development of infants and children. The kidney itself also undergoes a maturation process as it transitions from the fetal to the extrauterine environment. Renal function continues to undergo further adaptive changes in the neonatal period. It is important for the clinician caring for neonates to be aware of the expected fluid shifts, electrolyte handling, and renal functional capacity as these "normal" changes will become quite relevant when medical or surgical pathology is present. The preterm neonates are especially vulnerable due to their functionally immature kidneys. Renal function in the preterm neonate is not only immature at birth but there is a significant delay in the renal function to achieve its full capacity. This review highlights the physiologic adaptations of the kidney and its effects on the body during the neonatal period. PMID:24331094

Sulemanji, Mustafa; Vakili, Khashayar

2013-11-01

181

[Evolutionary-physiological aspects of adaptation of the Pacific salmon fry of the Oncorhynchus genus to migration to the sea water].  

PubMed

A complex of adaptive changes occurring in the Pacific salmon fry in the process of migration to the sea is described, including behavior, ion content in carcasses, and morphological changes in Stannius bodies, gill epithelium, and nephron tubular epithelium. Participating in experiments with transfer from fresh water into a two-layer aquarium (the lower layer - sea water, the upper layer - fresh water) were smolts of chum salmon and underyearlings of masu salmon as well as the trachurus and leiurus forms of the three-spined stickleback Casterosteus aculeatus. All fish, regardless of their salt preference, at once after placement into the two-layer aquarium, occupied the sea water zone, at the very bottom of the aquarium. After 1 h, there started brief excursions of masu salmon and chum salmon to the upper, fresh water layer; however, both forms of the three-spined stickleback did not participate in these excursions. After 12 h, the chum salmon settled down in the lower, sea water layer, while the masu salmon - in the upper, fresh water layer. Both forms of the three-spined stickleback never left the sea water layer and felt quite comfortably on the aquarium bottom. It seems that the high tolerance of the both stickleback forms to wide salinity limits allows them to choose the convenient position regardless of the water salt composition. By analyzing the material obtained for three years (2001-2003) on structure and functions of the gill epithelium chloride cells (CC), we have come to the conclusion that the fresh water fry of two salmon species, chum and masu salmons, caught at the same time and practically in the same water reservoirs can be divided into three groups. The underyearlings of the masu salmon as a rule are characterized by the thickened epithelium of secondary gill lamellae, but by a very small number of CC. In smolts of chum salmon, on the contrary, the epithelium is sufficiently thin, but enriched in the CC that demonstrate an active structure in the very beginning of migration to sea. However, with approaching the sea (and with an increase of terms of migration) the CC activity drops, but their amount does not change. And only after migration to the sea the CC activity rises again, although their amount seems to remain unchanged. The described peculiarities of behavior and of the ion composition regulation in the migrating salmon fry confirm the hypothesis that the salmons evolutionized in fresh water, that the Oncorhynchus genus appeared in large spaces of saltish waters, such as the Japan Sea at the period of the early Pleistocene, and that learning of fry of the Oncorhynchus genus (for instance, of O. gorbuscha and O. keta) is the most specialized in the salmons migrating to the sea, whereas the fresh water species of chars (Salvelinus) and of trouts (Salmo) are more primitive. PMID:18411513

Maksimovich, A A

2008-01-01

182

Acute effects of cow-calf separation on heart rate, plasma cortisol and behaviour in multiparous dairy cows  

Microsoft Academic Search

Removing the calf after bonding may induce acute stress in the dairy cow. We examined the responses of dairy cows immediately after the removal of their calves. Eight dairy cows were successively separated from their calves on the third day post-partum and heart rate and behaviour of the cows were recorded. In addition, the cows were blood sampled before and

Hans Hopster; Janet M. O'Connell; Harry J. Blokhuis

1995-01-01

183

Physiology of man and animals in the Tenth Five-Year Plan: Proceedings of the Thirteenth Congress of the I. P. Pavlov All-Union Physiological Society  

NASA Technical Reports Server (NTRS)

Research in the field of animal and human physiology is reviewed. The following topics on problems of physiological science and related fields of knowledge are discussed: neurophysiology and higher nervous activity, physiology of sensory systems, physiology of visceral systems, evolutionary and ecological physiology, physiological cybernetics, computer application in physiology, information support of physiological research, history and theory of development of physiology. Also discussed were: artificial intelligence, physiological problems of reflex therapy, correlation of structure and function of the brain, adaptation and activity, microcirculation, and physiological studies in nerve and mental diseases.

Lange, K. A.

1980-01-01

184

BSE (Bovine Spongiform Encephalopathy, or Mad Cow Disease)  

MedlinePLUS

... Agriculture (USDA) confirmed a BSE case in a dairy cow in California. For more information, see the ... positive cow. (see Bovine Spongiform Encephalopathy in a Dairy Cow - Washington State, 2003 .) On June 24, 2005, ...

185

Allergenicity of goat’s milk in children with cow’s milk allergy  

Microsoft Academic Search

Background: Cow’s milk allergy (CMA) is a common disease of infancy and childhood. An appropriate cow’s milk (CM) substitute is necessary for feeding babies with CMA. CM substitutes are soy formulas and casein- or whey-based extensively hydrolyzed formulas. In several countries, including Italy, goat’s milk (GM) formulas are available, and some physicians recommend them for feeding babies with CMA. Objective:

Barbara Bellioni-Businco; Roberto Paganelli; Patrizia Lucenti; Paolo G. Giampietro; Hans Perborn; Luisa Businco

1999-01-01

186

Physiological Coping: A Model for Teaching Pathophysiology  

ERIC Educational Resources Information Center

The author discusses the use of a teaching model she developed for use in a pathophysiology. The model is based on the physiological component of C. Roy's adaptation model, which encourages students to look for physiological cues and apply relevant knowledge in patient care through a problem-solving approach. (TA)

Porth, Carol M.

1977-01-01

187

Effect of a short dry period on milk yield and content, colostrum quality, fertility, and metabolic status of Holstein cows.  

PubMed

We evaluated the effect of shortening the dry period (DP) on milk and energy-corrected milk (ECM) yields, milk components, colostrum quality, metabolic status, and reproductive parameters. Primiparous (n=372) and multiparous (n=400) Israeli Holstein cows from 5 commercial dairy herds were subjected to a 60-d or 40-d DP. Cows within each herd were paired according to milk production, age, days in milk, and expected calving. Analysis of the data from all cows, irrespective of age, revealed significant differences in milk and ECM yields that favored the 60-d DP, with a prominent effect in 2 of 5 examined herds. In primiparous cows, milk and ECM yields were similar between groups in 4 of 5 farms. In multiparous cows undergoing a 60-d (vs. 40-d) DP, milk and ECM yields were higher in 3 herds. These differences could not be explained by milk and ECM yields in cows diagnosed with metritis, ketosis, and mastitis (defined by a somatic cell count threshold of 250,000 cell/mL), distribution of infected and noninfected cows, or new infections during DP and after calving. Including the milk and ECM yields from an average of 19.55d from the previous lactation revealed higher milk and ECM yields for 40-d (vs. 60-d) DP cows in all herds. Analyzing 2 consecutive lactations revealed similar milk and ECM yields between groups in 4 out of 5 herds. In 1 herd, yields were higher in the 40-d compared with the 60-d DP group. One week after calving, the nonesterified fatty acid concentrations of 40-d DP cows were significantly lower than those of 60-d DP cows, indicating better postpartum energy balance. Colostrum quality, measured as IgG concentration, did not differ between the 2 DP groups. Cows assigned to 40-d DP had better reproductive performance, as reflected by fewer days to first insemination, a lower proportion with >90d to first insemination, and fewer days to pregnancy. With respect to primiparous cows, a short DP increased conception rate after first artificial insemination and decreased the proportion of nonpregnant cows after 150d in milk. In light of these findings, we suggest that a short DP be applied for its economic and physiological benefits. This is highly relevant to dairy herds located in regions such as Israel, Spain, and Florida that suffer from reduced milk production during the hot season. PMID:24630671

Shoshani, E; Rozen, S; Doekes, J J

2014-05-01

188

Respiratory Physiology on a Chip  

PubMed Central

Our current understanding of respiratory physiology and pathophysiological mechanisms of lung diseases is often limited by challenges in developing in vitro models faithful to the respiratory environment, both in cellular structure and physiological function. The recent establishment and adaptation of microfluidic-based in vitro devices (?FIVDs) of lung airways have enabled a wide range of developments in modern respiratory physiology. In this paper, we address recent efforts over the past decade aimed at advancing in vitro models of lung structure and airways using microfluidic technology and discuss their applications. We specifically focus on ?FIVDs covering four major areas of respiratory physiology, namely, artificial lungs (AL), the air-liquid interface (ALI), liquid plugs and cellular injury, and the alveolar-capillary barrier (ACB).

Kumar Mahto, Sanjeev; Tenenbaum-Katan, Janna; Sznitman, Josue

2012-01-01

189

Gastrointestinal parasites presence during the peripartum decreases total milk production in grazing dairy Holstein cows.  

PubMed

Parasitism in cattle is known to impair growth and development. Recent findings suggest that productivity of adult animals is also affected, but little is known about the physiological mechanisms involved. Furthermore, development of nematode resistance to drugs makes imperative the search of management practices that avoid whole herd treatment. We undertook an epidemiological and endocrine study in a grass based dairy farm in Argentina to study the effect of parasites on milk production and the underlying mechanisms involved, and identify individual animals that would benefit from antiparasitic treatment. All the cows in the dairy were followed monthly for egg parasite output in feces. Samples were cultured for genera determination. Milk production and reproductive results were recorded and periodical bleedings for hormone determination were performed. Nematode egg output (EPG) was maximal in late Summer and Autumn and minimal in Spring in coincidence with the Ostertagia inhibition-disinhibition cycle as this genus had the highest prevalence in all the study. The highest proportion of positive samples was found in the high producing herd and maximal counts were found in the peripartal period. Milk production did not correlate with EPG mean values but, when cows were grouped by EPG positivity around parturition, a significant difference in total milk production between EPG null and positive cows was observed. Positive cows produced 7%, 12% or 15% less milk than null EPG cows, depending on the sampling month/s chosen for classification. The highest difference was seen when both prepartum and postpartum samples were taken into account. No difference in lactation length and a marginal effect on partum to first service interval were encountered. Endocrine studies revealed a decrease in serum growth hormone (GH), type I insulin-like growth factor (IGF-I) and prolactin during lactation in cows with positive EPG in the first postpartum sample with respect to null EPG cows at that time. GH levels decreased and prolactin and IGF-I levels increased in both groups of cows from month 0 to 6 in milk. Serum insulin levels remained stable throughout lactation and were similar in both groups of cows. In conclusion, EPG around parturition may be a useful tool for identifying cows that will have a decrease in productivity due to parasite effects and would possibly benefit from an antiparasitic treatment. Besides, our results suggest that detrimental effect of parasites on milk production may be mediated by GH, IGF-I and prolactin serum levels. PMID:21269774

Perri, A F; Mejía, M E; Licoff, N; Lazaro, L; Miglierina, M; Ornstein, A; Becu-Villalobos, D; Lacau-Mengido, I M

2011-06-10

190

Effects of Physically Effective Fiber on Digestive Processes and Milk Fat Content in Early Lactating Dairy Cows Fed Total Mixed Rations  

Microsoft Academic Search

Data from recent research studies were analyzed quantitatively, and the random effect of experiment was assessed to define the physiological responses of dairy cows in early lactation to intake of physically effective neutral detergent fiber (peNDF). All studies were conducted with lactating Holstein cows (84.8 ± 3.54 days in milk) in Latin square designs, and feeds were offered ad libitum

Q. Zebeli; M. Tafaj; H. Steingass; B. Metzler; W. Drochner

2006-01-01

191

Short communication: Changes in heart rate variability of dairy cows during conventional milking with nonvoluntary exit.  

PubMed

Heart rate variability (HRV), as a physiological measure of animal welfare, was investigated in 36 cows milked in a parallel milking parlor with nonvoluntary exit. Heart rate variability parameters measured during the morning resting (baseline period) were compared with those measured during different stages of the entire milking process. No differences were found in HRV parameters between the baseline period, preparation, and main milking. A considerable reduction in vagal activity was detected during the movement of the cows to the milking parlor (driving) and while cows were in the holding area. The parasympathetic measures of HRV decreased whereas the sympatho-vagal balance increased compared with baseline. The same pattern was observed regarding the stage between removing the teat cups and leaving the milking parlor (waiting). No differences in any sympathetic measures were observed between the baseline period and any of the milking stages. These findings indicate that the milking process itself (preparation and main milking) is not stressful for cows. Decreased parasympathetic activity during driving might be the result of the physical activity of the cows, whereas waiting in the holding area and in the milking stall after milking caused stress for animals. PMID:24140325

Kovács, L; T?zsér, J; Bakony, M; Jurkovich, V

2013-12-01

192

Changes in mammary secretory tissue during lactation in ovariectomized dairy cows.  

PubMed

In dairy animals, the milk yield (MY) changes during a lactation and is influenced by several physiological, livestock management and environmental factors. The MY produced by a mammary gland depends on synthetic activity of mammary epithelial cells (MECs) as well as MEC number and mammary secretory tissue organization. It has been suggested that ovarian steroids (estradiol and progesterone) have a negative effect on MY in lactating cows. In a previous study, we showed that the suppression of ovarian secretions by an ovariectomy improved lactation persistency in dairy cows. Here we were interested in the effects of ovariectomy on plasma estradiol and progesterone concentrations and on changes that occur in mammary secretory tissue during lactation. We demonstrated that the ovariectomy of lactating cows at the time of the lactation peak induced a rapid and dramatic drop in plasma progesterone and a smaller reduction in plasma estradiol. Interestingly, the study of the changes in mammary secretory tissue over time revealed that the improvement of MY measured in the ovariectomized cows was associated with a limited increase in estradiol receptivity in MECs, a reduced mammary tissue remodeling and reduced blood protein concentration in milk, in late lactation. These results suggest that ovarian secretions, particularly estradiol and progesterone, act to enhance processes for mammary gland involution in late-lactating dairy cows. PMID:23811017

Yart, L; Lollivier, V; Finot, L; Dupont, J; Wiart, S; Boutinaud, M; Marnet, P G; Dessauge, F

2013-10-01

193

Proteomic analysis of cow, yak, buffalo, goat and camel milk whey proteins: quantitative differential expression patterns.  

PubMed

To aid in unraveling diverse genetic and biological unknowns, a proteomic approach was used to analyze the whey proteome in cow, yak, buffalo, goat, and camel milk based on the isobaric tag for relative and absolute quantification (iTRAQ) techniques. This analysis is the first to produce proteomic data for the milk from the above-mentioned animal species: 211 proteins have been identified and 113 proteins have been categorized according to molecular function, cellular components, and biological processes based on gene ontology annotation. The results of principal component analysis showed significant differences in proteomic patterns among goat, camel, cow, buffalo, and yak milk. Furthermore, 177 differentially expressed proteins were submitted to advanced hierarchical clustering. The resulting clustering pattern included three major sample clusters: (1) cow, buffalo, and yak milk; (2) goat, cow, buffalo, and yak milk; and (3) camel milk. Certain proteins were chosen as characterization traits for a given species: whey acidic protein and quinone oxidoreductase for camel milk, biglycan for goat milk, uncharacterized protein (Accession Number: F1MK50 ) for yak milk, clusterin for buffalo milk, and primary amine oxidase for cow milk. These results help reveal the quantitative milk whey proteome pattern for analyzed species. This provides information for evaluating adulteration of specific specie milk and may provide potential directions for application of specific milk protein production based on physiological differences among animal species. PMID:23464874

Yang, Yongxin; Bu, Dengpan; Zhao, Xiaowei; Sun, Peng; Wang, Jiaqi; Zhou, Lingyun

2013-04-01

194

Genome-Wide Scans for Candidate Genes Involved in the Aquatic Adaptation of Dolphins  

PubMed Central

Since their divergence from the terrestrial artiodactyls, cetaceans have fully adapted to an aquatic lifestyle, which represents one of the most dramatic transformations in mammalian evolutionary history. Numerous morphological and physiological characters of cetaceans have been acquired in response to this drastic habitat transition, such as thickened blubber, echolocation, and ability to hold their breath for a long period of time. However, knowledge about the molecular basis underlying these adaptations is still limited. The sequence of the genome of Tursiops truncates provides an opportunity for a comparative genomic analyses to examine the molecular adaptation of this species. Here, we constructed 11,838 high-quality orthologous gene alignments culled from the dolphin and four other terrestrial mammalian genomes and screened for positive selection occurring in the dolphin lineage. In total, 368 (3.1%) of the genes were identified as having undergone positive selection by the branch-site model. Functional characterization of these genes showed that they are significantly enriched in the categories of lipid transport and localization, ATPase activity, sense perception of sound, and muscle contraction, areas that are potentially related to cetacean adaptations. In contrast, we did not find a similar pattern in the cow, a closely related species. We resequenced some of the positively selected sites (PSSs), within the positively selected genes, and showed that most of our identified PSSs (50/52) could be replicated. The results from this study should have important implications for our understanding of cetacean evolution and their adaptations to the aquatic environment.

Liu, He-Qun; Irwin, David M.; Shen, Yong-Yi; Zhang, Ya-Ping

2013-01-01

195

Time-dependent mRNA expression of selected pro-inflammatory factors in the endometrium of primiparous cows postpartum  

Microsoft Academic Search

BACKGROUND: Inflammatory processes and infections of the uterine wall must be accepted as a physiological event in dairy cows after calving. This might result in clinical or subclinical endometritis which is assumed to impair reproductive performance in the current lactation. Several cytokines and acute phase proteins have been discussed as local and systemic mediators of these inflammatory processes. The aim

Christoph Gabler; Claudia Fischer; Marc Drillich; Ralf Einspanier; Wolfgang Heuwieser

2010-01-01

196

Prepartum and postpartum nutritional management to optimize fertility in high-yielding dairy cows in confined TMR systems.  

PubMed

The 6 to 8-week period centered on parturition, known as the transition or periparturient period, is critical to welfare and profitability of individual cows. Fertility of high-producing cows is compromised by difficult transitions. Deficiencies in either nutritional or non-nutritional management increase risk for periparturient metabolic disorders and infectious diseases, which decrease subsequent fertility. A primary factor impeding fertility is the extent of negative energy balance (NEB) early postpartum, which may inhibit timing of first ovulation, return to cyclicity, and oocyte quality. In particular, pronounced NEB during the first 10 days to 2 weeks (the time of greatest occurrence of health problems) is critical for later reproductive efficiency. Avoiding over-conditioning and preventing cows from over-consuming energy relative to their requirements in late gestation result in higher dry matter intake (DMI) and less NEB after calving. A pooled statistical analysis of previous studies in our group showed that days to pregnancy are decreased (by 10 days) by controlling energy intake to near requirements of cows before calving compared with allowing cows to over-consume energy. To control energy intake, total mixed rations (TMR) must be well balanced for metabolizable protein, minerals and vitamins yet limit total DM consumed, and cows must uniformly consume the TMR without sorting. Dietary management to maintain blood calcium and rumen health around and after calving also are important. Opportunities may exist to further improve energy status in fresh cows. Recent research to manipulate the glucogenic to lipogenic balance and the essential fatty acid content of tissues are intriguing. High-producing cows that adapt successfully to lactation can have high reproductive efficiency, and nutritional management of the transition period both pre- and post-calving must facilitate that adaptation. PMID:24844126

Drackley, J K; Cardoso, F C

2014-05-01

197

Physiological Adaptation of Women to Heat Stress.  

National Technical Information Service (NTIS)

Three studies were conducted to investigate age related changes in thermoregulation observed in previous heat stress studies. Sweating threshold and capacity under thermal stress were studied in ten postmenopausal women and ten younger women. Age effects ...

B. L. Drinkwater S. M. Horvath

1982-01-01

198

[Physiologic adaptation of the thermal manikin].  

PubMed

At present time thermal manikins (TM) are used as standard method to determine the thermal quality of clothing. Besides, in the last time TM's apply to estimate indoor climate. Now used types of TM enable quantitative assertions on human convective and conductive heat exchange, as for the whole body as for different parts. The limited factor for this heat flow is the topical value of TM's skin temperature which is regulated by software. As a rule, this temperature is the same like human's skin temperature at thermal comfort conditions. Distal change of skin temperature takes a leading part to determine thermal conditions which are still tolerable regarding human thermoregulation. The influence of this kind of thermal regulation on topical convection and conductive heat exchange was examined by variation of TM's skin temperature on a concrete indoor situation and defined clothing and metabolic conditions. PMID:2631467

Bischof, W; Bánhidi, L

1989-12-01

199

Loser cows in Danish dairy herds: definition, prevalence and consequences.  

PubMed

During the last few years, many Danish dairy farmers have expressed increasing concerns regarding a group of cows, which we have chosen to term 'loser cows'. Until now, a loser cow has not been described scientifically. We defined a loser cow on the basis of a clinical examination of the cow. A total of 15,151 clinical examinations were made on 6,451 individual cows from 39 randomly selected, large Danish dairy herds with loose-housing systems using a clinical protocol. Scores for the clinical signs lameness, body condition, hock lesions, other cutaneous lesions, vaginal discharge, condition of hair coat and general condition were converted into a loser cow score. Cows with a loser cow score of 8 or more were classified as loser cows. The overall prevalence of loser cows was 2.15%, 4.50% and 2.98% during the first, second and third round of herd visits, respectively. The associations between the loser cow state and milk production, mortality, morbidity, culling and workload for the farmer were evaluated using data from herd visits and from the Danish Cattle Database and a number of different statistical techniques. It was concluded that the loser cow state has significant negative consequences for both the farmer and the cow. On average, loser cows yielded 0.61 to 2.24 kg energy corrected milk less per day than non-loser cows depending on parity. Hazard ratio for death or euthanasia was 5.69 for loser cows compared to non-loser cows. Incidence rate ratio for disease treatments was 0.69 for non-loser cows compared to loser cows. Loser cows were often culled in an 'unfavourable' way and generally caused extra workload for the farmer. A simplified version of the loser cow score was evaluated and is recommended for future research and use in practice. PMID:17210193

Thomsen, Peter T; Østergaard, Søren; Sørensen, Jan Tind; Houe, Hans

2007-05-16

200

Bone metabolism in cow milk allergic children.  

PubMed

Children with cow milk allergy are suspected to develop calcium metabolism disturbances. We observed increased markers of bone turnover in these children. Children with cow milk allergy are more prone to develop the disturbances of the bone mineralization even in the first year of life. PMID:23942440

Jakusova, Lubica; Jesenak, Milos; Schudichova, Jela; Banovcin, Peter

2013-07-01

201

Measuring Milk Flow of Dairy Cows  

Microsoft Academic Search

Milk flow measurements on 124 cows were analyzed to deternfine how they are affected by vacuum level, pulsation rate, pulsation ratio of the milking maehine, and the breed, age, stage of laetation, and milk yield of the cow. Average rate of flow prior to machine stripping, yield during the first minute, and yield during the first 2 rain of milking

G. H. Schmidt; L. D. Van Vleck

1969-01-01

202

Cow's Milk Allergy in Thai Children  

Microsoft Academic Search

SUMMARY Cow's milk allergy (CMA) is nowadays a common problem in Thai children. We reviewed medical records of patients with CMA from the Department of Pediatrics at King Chulalongkorn Memorial Hospital of the past 10 years, from 1998 to 2007. The criteria for the diagnosis of CMA included: elimination of cow's milk formula resulting in improvement of symptoms, and: recurrence

Jarungchit Ngamphaiboon; Pantipa Chatchatee; Thaneya Thongkaew

2008-01-01

203

MRSA transmission between cows and humans  

Microsoft Academic Search

We isolated methicillin-resistant Staphylococcus aureus (MRSA) from cows with subclinical mastitis and from a person who worked with these animals. The bovine and human strains were indistinguishable by phenotyping and genotyping methods and were of a low frequency spa type. To our knowledge, this finding indicates the first documented case of direct transmission of MRSA between cows and humans.

Eva Juhasz-Kaszanyitzky; S. Janosi; P. Somogyi; A. Dan; Graaf-van Bloois van der L; Dulijkeren van E; J. A. Wagenaar

2007-01-01

204

Regulatory physiology discipline science plan  

NASA Technical Reports Server (NTRS)

The focus of the Regulatory Physiology discipline of the Space Physiology and Countermeasures Program is twofold. First, to determine and study how microgravity and associated factors of space flight affect the regulatory mechanisms by which humans adapt and achieve homeostasis and thereby regulate their ability to respond to internal and external signals; and, second, to study selected physiological systems that have been demonstrated to be influenced by gravity. The Regulatory Physiology discipline, as defined here, is composed of seven subdisciplines: (1) Circadian Rhythms, (2) Endocrinology, (3) Fluid and Electrolyte Regulation, (4) Hematology, (5) Immunology, (6) Metabolism and Nutrition, and (7) Temperature Regulation. The purpose of this Discipline Science Plan is to provide a conceptual strategy for NASA's Life Sciences Division research and development activities in the area of regulatory physiology. It covers the research areas critical to NASA's programmatic requirements for the Extended-Duration Orbiter, Space Station Freedom, and exploration mission science activities. These science activities include ground-based and flight; basic, applied, and operational; and animal and human research and development. This document summarizes the current status of the program, outlines available knowledge, establishes goals and objectives, identifies science priorities, and defines critical questions in regulatory physiology. It contains a general plan that will be used by both NASA Headquarters Program Offices and the field centers to review and plan basic, applied, and operational intramural and extramural research and development activities in this area.

1991-01-01

205

Massive vulvar edema in 2 prepartum dairy cows.  

PubMed

Two late gestation Holstein cows about to begin the third lactation developed massive vulvar edema. These were the only affected animals in the herd of 500 milking cows. The vulvar edema spontaneously regressed postpartum for both cows. Massive vulvar swelling is seldom observed in dairy cows in advanced pregnancy and is not described in the literature. PMID:24790232

Cheong, Soon Hon; Gilbert, Robert O

2014-05-01

206

Rumen-Protected Methionine and Lysine: Effects on Animal Performance, Milk Protein Yield, and Physiological Measures1  

Microsoft Academic Search

Eight midlactation Holstein cows were used in a three-period (28 d) switchback design to evaluate addition of a combina- tion of ruminally protected methionine (15 g\\/d) and lysine (40 g\\/d) on animal performance, milk protein yield, and physiological measures. Cows were fed for ad libitum intake a total mixed diet consisting of 50% corn silage and 50% concentrate (DM basis)

S. S. Donkin; G. A. Varga; T. F. Sweeney; L. D. Muller

1989-01-01

207

Effects of heat stress on energetic metabolism in lactating Holstein cows.  

PubMed

Heat stress has an enormous economic impact on the global dairy industry, but the mechanisms by which hyperthermia negatively affect systemic physiology and milk synthesis are not clear. Study objectives were to evaluate production parameters and metabolic variables in lactating dairy cows during short-term heat stress or pair-fed conditions coupled with bST administration. Twenty-two multiparous Holstein cows were subjected to 3 experimental periods: 1) thermoneutral conditions with ad libitum intake for 7 d (P1); 2) heat stress (HS) with ad libitum intake (n=10) or pair-fed (PF) in thermoneutral conditions (n=12) for 7 d (P2), and 3) 7 d of HS or PF in conditions as described in P2 with recombinant bovine somatotropin administered on d 1 (P3). All cows received an intravenous glucose tolerance test (GTT) on d 5 of each period. Heat stress conditions were cyclical and temperatures ranged from 29.4 to 38.9 degrees C. Rectal temperatures and respiration rates increased during heat stress (38.6-40.4 degrees C and 44-89 breaths/min, respectively). Heat stress reduced dry matter intake by 30% and by design PF cows had similar intake reductions (28%). During heat stress and pair-feeding, milk yield decreased by 27.6% (9.6kg) and 13.9% (4.8kg), respectively, indicating that reduced feed intake accounted for only 50% of the decreased milk production. Milk yield increased with recombinant bovine somatotropin in both HS (9.7%) and PF (16.1%) cows. Cows in both groups were in positive energy balance (3.95 Mcal/d) during P1 but entered negative energy balance during P2 and P3 (-5.65 Mcal/d). Heat stress and pair-feeding treatments decreased (9.3%) basal glucose concentrations. Heat stress conditions had no effect on basal NEFA levels during P2; however, PF cows (despite a similar calculated energy balance) had a 2-fold increase in basal NEFA concentrations. Both groups had increased plasma urea nitrogen levels during P2 and P3 compared with P1. Basal insulin levels increased (37%) during P2 and P3 in HS cows but did not differ between periods in PF cows. During P2 and compared with P1, PF cows had a decreased rate of glucose disposal, whereas HS cows had a similar disposal rate following the GTT. During P2 and compared with P1, PF cows had a reduced insulin response whereas HS cows had a similar insulin response to the GTT. In summary, reduced nutrient intake accounted for only 50% of heat stress-induced decreases in milk yield, and feed intake-independent shifts in postabsorptive glucose and lipid homeostasis may contribute to the additional reduction in milk yield. PMID:20105536

Wheelock, J B; Rhoads, R P; Vanbaale, M J; Sanders, S R; Baumgard, L H

2010-02-01

208

Comparison of long-term controlled internal drug release-based protocols to synchronize estrus and ovulation in postpartum beef cows.  

PubMed

Two experiments were conducted to examine the necessity of adding a GnRH injection to a 14-d controlled internal drug release (CIDR)-based protocol for synchronization of estrus and ovulation in postpartum beef cows. The experiments were designed to characterize long-term CIDR-based protocols in cyclic and noncyclic postpartum beef cows on the basis of estrous response, follicular dynamics, and serum steroid hormone concentrations. In Exp. 1 and 2, crossbred lactating beef cows (n = 40 and 38, respectively) were randomly assigned to 1 of 2 treatments by age, days postpartum (DPP), BCS, and estrous cyclicity status: 1) cows received a CIDR from d 0 to 14 followed by GnRH 9 d after CIDR removal (d 23) and PGF2? on d 30 (CIDR Select) or 2) CIDR administration from d 0 to 14 followed by PGF2? 16 d later (d 30; Show-Me-Synch). Estrus detection was performed using HeatWatch transmitters applied from CIDR removal to AI. Cows in Exp. 1 were artificially inseminated based on detected estrus whereas cows in Exp. 2 were inseminated at a fixed time. In both experiments, follicle turnover on d 25 of treatment was greater among CIDR Select-treated cows (P < 0.001) compared with Show-Me-Synch-treated cows. In Exp. 1, CIDR Select-treated cows tended to have a reduced (P = 0.06) variance for the interval to estrus after PGF2? than Show-Me-Synch-treated cows. Also, cows assigned to the CIDR Select protocol had greater concentrations of progesterone (P < 0.05) on the day before PGF2? administration as well as greater concentrations of estradiol-17? (P < 0.01) 48 h after PGF2? administration. In Exp. 2, mean dominant follicle diameter on d 23 and at fixed-time AI (FTAI) did not differ between treatments (P > 0.10), but Show-Me-Synch-treated cows had larger follicles at d 28 (P < 0.001) and tended to have larger follicles at PGF2? (d 30; P = 0.06) compared with cows assigned to CIDR Select. In summary, the administration of GnRH on d 23 of a long-term CIDR-based estrus synchronization protocol increased follicle turnover; however, both long-term CIDR-based protocols yielded similar physiological outcomes among estrous-cycling and anestrous postpartum beef cows. PMID:23572255

Nash, J M; Mallory, D A; Ellersieck, M R; Poock, S E; Smith, M F; Patterson, D J

2013-07-01

209

Effect of Diet Quality on Adenosine5?-triphosphate Concentration and Adenylate Energy Charge of Rumen Microbes from Fistulated Cows1  

Microsoft Academic Search

Two fistulated, nonlactating Holstein cows were fed a high quality diet of dairy concentrate mixed with corn silage or a low quality diet of weathered hay. Both animals were adapted in turn for 6 wk to the high quality and then to the low quality diet prior to sampling of rumen contents. The high quality diet was fed daily as

J. D. Erfle; S. Mahadevan; F. D. Sauer

1979-01-01

210

Respiratory heat loss of Holstein cows in a tropical environment  

NASA Astrophysics Data System (ADS)

In order to develop statistical models to predict respiratory heat loss in dairy cattle using simple physiological and environmental measurements, 15 Holstein cows were observed under field conditions in a tropical environment, in which the air temperature reached up to 40°C. The measurements of latent and sensible heat loss from the respiratory tract of the animals were made by using a respiratory mask. The results showed that under air temperatures between 10 and 35°C sensible heat loss by convection decreased from 8.24 to 1.09 W m-2, while the latent heat loss by evaporation increased from 1.03 to 56.51 W m-2. The evaporation increased together with the air temperature in almost a linear fashion until 20°C, but it became increasingly high as the air temperature rose above 25°C. Convection was a mechanism of minor importance for respiratory heat transfer. In contrast, respiratory evaporation was an effective means of thermoregulation for Holsteins in a hot environment. Mathematical models were developed to predict both the sensible and latent heat loss from the respiratory tract in Holstein cows under field conditions, based on measurements of the ambient temperature, and other models were developed to predict respiration rate, tidal volume, mass flow rate and expired air temperature as functions of the ambient temperature and other variables.

Campos Maia, Alex Sandro; Gomes Dasilva, Roberto; Battiston Loureiro, Cintia Maria

2005-05-01

211

Nutritional evaluation of transgenic cottonseed in the ration of lactating dairy cows.  

PubMed

The effects of feeding transgenic (Bt) whole cottonseed (WCS) were studied in lactating cows. Twenty multiparous crossbred cows (Karan Swiss x Karan Fries) in early lactation were given a concentrate mixture containing 40% crushed delinted non-transgenic (non-Bt) WCS, 2 kg wheat straw and green fodder ad lib for a 15-day adaptation period. Thereafter, the cows were divided in two similar groups of 10 each on the basis of milk yield, body weight (BW) and date of calving. The non-Bt control group continued on same ration, while for the Bt group the non-Bt WCS was replaced by transgenic WCS, in a feeding trial of four weeks. The diets provided a minimum of 2 kg cottonseed/cow/d. Mean DMI/100 kg BW and milk yield of non-Bt and Bt groups was 3.48 and 3.45 kg and 11.4 and 12.0 kg/d, respectively. Intake of nutrients, digestibility, milk production and body condition score (BCS) did not differ between the groups (P > 0.05), but BW gain was higher (P < 0.05) in the Bt group than the non-Bt group, probably as a result of hoof problem in two cows of non-Bt group, which when compared excluding two animals from each group did not differ significantly (P > 0.05). Transgenic protein (Cry1C) was not detected in the weekly milk samples or in blood plasma at the end of the experiment, showing that delinted WCS containing Cry1C protein can safely be fed to lactating cows. PMID:19701795

Mohanta, Ranjan K; Singhal, Kamal K; Tyagi, Amrish K; Rajput, Y S; Prasad, Shiv

2010-03-01

212

Potassium Depletion in Lactating Dairy Cows1  

Microsoft Academic Search

A change-over feeding experiment involv- ing eight individually fed lactating dairy cows was conducted to study potassium deficiency symptoms in lactating cows. Potassium deficient (0.06% and 0.15%K) and potassium adequate (0.80% K) rations were tested and responses to both compared. The deficient animals showed a marked de- crease in feed intake, symptoms of pica, loss of hair glossiness, decreased pliability

K. Pradhan; R. W. Hemken

1968-01-01

213

Eliminative behaviour of dairy cows at pasture  

Microsoft Academic Search

Despite a strong avoidance of grazing near dung patches, cattle have traditionally been considered not to avoid bodily contact with faeces, regardless of any risk of disease. Little is understood of the behaviour of pasture-kept dairy cows at the time of defaecation and therefore, the eliminative behaviour of 40 Holstein-Friesian cows was observed at pasture for 6h each day between

Lindsay Kay Whistance; Liam A. Sinclair; David Richard Arney; Clive Julian Christie Phillips

2011-01-01

214

[Four milk cows dead by electrocution].  

PubMed

Two dairy cows were found dead in their cubicles and a third was found lying dazed in a stall but the animal stood up 5 minutes later. Two days later; two other cows were found dead in the same row of cubicles. Death was due to electrocution caused by an electric wire in a steel pipe connected to front of the cubicles. Post-mortem findings supported this diagnosis. PMID:18225715

Verhoeff, J; Hogendoorn, M P; Wouda, W

2007-12-15

215

Cow's Milk Protein Allergy Mimicking Acrodermatitis Enteropathica.  

PubMed

Cow's milk protein allergy is an adverse immune reaction to one or more of the constituent proteins of milk obtained from any animal, most commonly alpha s 1-casein cow's milk. In many cases, the allergy is genetic in origin. The infants may experience symptoms within minutes after feeding (rapid onset) or commonly after 7-10 days of consuming the cow's milk (slower onset). Many children with cow's milk protein allergy develop symptoms in at least two of the following organ systems: gastrointestinal, skin and respiratory tract. Acrodermatitis Enteropathica (primary or secondary zinc deficiency) can also produce lesions in the skin and also gastro intestinal symptoms which can mimic milk protein allergy and differentiating between these two may be difficult. We are reporting a case of cow's milk protein allergy in an infant, which was initially diagnosed as Acrodermatitis Enteropathica and treated with zinc. The lesions did not subside completely even after achieving adequate zinc levels, but on stopping the cow's milk all the symptoms and signs disappeared completely and there was no recurrence on long term follow up. PMID:24783119

Solomon, John; Kamalammal, Rugmini; Sait, Mohammed Yaseen; Lohith, Harita

2014-03-01

216

Effects of Monensin on the Reproduction, Health, and Milk Production of Dairy Cows  

Microsoft Academic Search

A randomized clinical trial including 1109 cows from 12 Australian dairy herds was used to evaluate the effects of monensin on the health (n = >686 cows), production (n = 915 cows), and reproduction (n = >908 cows) of dairy cows. Cows were allocated to a treatment group receiving a slow-release intrarumi- nal bolus containing 32 g of sodium monensin

S. Beckett; I. Lean; R. Dyson; W. Tranter; L. Wade

1998-01-01

217

Scaling physiological pharmacokinetic models by physiological time  

SciTech Connect

This paper shows that a multicompartment physiological pharmacokinetic model, used to account for inhalation exposure to volatile chlorohydrocarbons in mammalian species, can be made species-independent if chronological time is re-expressed in terms of physiological time. Physiological time is defined as chronological time divided by species body weight to the 1/4 power. We demonstrate the usefulness of this time scaling of the multicompartment physiological pharmacokinetic model by using it to model the inhalation of the volatile chlorinated hydrocarbon tetrachloroethylene in mice, rats, and humans. 8 refs., 2 figs.

Ward, R.C.; Travis, C.C.

1987-01-01

218

Risk factors relating to helminth infections in cows during the peripartum.  

PubMed

The aim of this study was to investigate whether season, lactation number, breed standard and milk production were risk factors relating to occurrences of gastrointestinal nematodes in dairy cows during the peripartum period. Eighty-four cows were randomly selected through proportional stratified sampling. In order to analyze the fecal egg per gram (EPG) count, the data were subjected to the Spearman test, Kruskal-Wallis test at 5% significance and linear regression. At the time of calving, the cows showed high EPG counts in relation to all variables analyzed. Among the animals studied, we observed that purebred Holstein cows at their first lactation and with high milk production showed high EPG counts (600) and comprised the group most at risk within the herd studied. In this group, the animals showed moderate EPG during the prepartum period (300) and a significant increase (p < 0.01) in EPG count from the time of calving (900), i.e. an increase of the order of 300%. Selection of animals for milk production in tropical countries should be based not only on productive potential, but also on adaptive features. PMID:22832746

Silva, Jenevaldo Barbosa da; Rangel, Charles Passos; Baêta, Bruna de Azevedo; Fonseca, Adivaldo Henrique da

2012-01-01

219

The Roy Adaptation Model. Testing the Adaptation Model in Practice  

ERIC Educational Resources Information Center

The Roy Adaptation Model sees man as having four modes of adaptation--basic physiological needs, self-concept, role function, and interdependence. The study described tests the feasibility of the Model for nursing practice in both episodic and distributive settings. (TA)

Wagner, Patricia

1976-01-01

220

Cardiovascular physiology - Effects of microgravity  

NASA Technical Reports Server (NTRS)

Experiments during spaceflight and its groundbase analog, bedrest, provide consistent data which demonstrate that numerous changes in cardiovascular function occur as part of the physiological adaptation process to the microgravity environment. These include elevated heart rate and venous compliance, lowered blood volume, central venous pressure and stroke volume, and attenuated autonomic reflex functions. Although most of these adaptations are not functionally apparent during microgravity exposure, they manifest themselves during the return to the gravitational challenge of earth's terrestrial environment as orthostatic hypotension and instability, a condition which could compromise safety, health and productivity. Development and application of effective and efficient countermeasures such as saline "loading," intermittent venous pooling, pharmacological treatments, and exercise have become primary emphases of the space life sciences research effort with only limited success. Successful development of countermeasures will require knowledge of the physiological mechanisms underlying cardiovascular adaptation to microgravity which can be obtained only through controlled, parallel groundbased research to complement carefully designed flight experiments. Continued research will provide benefits for both space and clinical applications as well as enhance the basic understanding of cardiovascular homeostasis in humans.

Convertino, V.; Hoffler, G. W.

1992-01-01

221

Alteration of the endometrial EGF profile as a potential mechanism connecting the alterations in the ovarian steroid hormone profile to embryonic loss in repeat breeders and high-producing cows.  

PubMed

Poor reproductive efficiency is a worldwide problem that has affected the dairy industry during the last several decades. In an attempt to explain the changes in reproductive physiology caused by high milk production, a model of elevated steroid metabolism in lactating dairy cows has been proposed. A slow increase in levels and low peak levels of estradiol (E?) and progesterone (P?) characterize endocrine changes in high producing cows. Similar changes have been reported in the repeat breeder cows. The abnormal changes in E? and P? concentrations of these cows may cause an improper uterine environment due to disturbed expression of growth factors and cytokines in the endometrium. This review focuses on the alteration in epidermal growth factor (EGF) profile in the endometrium during the estrous cycle. The normal cow has two peaks of EGF concentrations on days 2-4 and 13-14. Low concentrations of EGF on these days distinguished both high-producing and repeat breeder cows from normal cows. Alteration of the EGF profile could be found in 70 and 40% of the repeat breeder and high-producing cows, respectively. Treatment with a high dose of estradiol benzoate and an intravaginal progesterone-releasing device restored the normal EGF profile in about 70% of the affected cows. The cows having a normal EGF profile after treatment showed a higher pregnancy rate than the cows with the altered profile. Further studies to understand the etiology of the alteration in the EGF profile are needed to develop another treatment option and preventive management for this problem. PMID:24162805

Katagiri, Seiji; Moriyoshi, Masaharu

2013-10-01

222

Short communication: validation of a point-of-care glucometer for use in dairy cows.  

PubMed

The purpose of this study was to evaluate the diagnostic performance of a hand-held electronic glucometer (Precision Xtra; Abbott Diabetes Care Inc., Mississauga, ON, Canada) for cow-side use in dairy cattle. This device has been validated for measuring blood concentrations of ?-hydroxybutyrate in dairy cows. This study was designed to assess the accuracy of whole-blood glucose measurements from the glucose meter relative to a reference chemical analyzer in a diagnostic laboratory. Duplicate samples were taken from the same cows at the same time, into blood tubes with either the glycolysis-inhibiting preservative sodium fluoride (NaF) or without preservative. Glucometer readings were taken on whole blood with no preservative, and laboratory measurements were conducted on serum preserved with NaF. Blood samples were collected from cows between 3 wk before and 5 wk after calving, including during a glucose tolerance test conducted 1 wk before expected calving. Passing-Bablok and Bland-Altman data analyses were used to evaluate the performance of the glucometer relative to the laboratory results. A strong correlation was observed in 709 samples from 81 cows between the hand-held meter and serum from samples preserved with NaF (R(2)=0.95). Overall, 96% of measurements with the glucometer fell within the 95% confidence limits of analysis in the laboratory, although at higher-than-physiologic glucose concentrations (>5.2mmol/L) the glucometer tended to overestimate. The hand-held glucometer appears suitable for rapid measurement of glucose under field conditions in dairy cattle. PMID:23684029

Wittrock, J A M; Duffield, T F; LeBlanc, S J

2013-07-01

223

physiologyINFO.org  

NSDL National Science Digital Library

What is physiology exactly? It's a good question, and one that is answered quite thoroughly on this website provided by The American Physiology Society (APS). The homepage starts things off with a basic introduction to physiology, complete with a pronunciation guide for the actual word. Moving on, the site contains four primary sections: "What is Physiology?", "Current Research", "Milestones in Physiology" and "Research Issues". The first section expands on the site's introduction by offering information on the questions physiologist ask, along with links to some online experiments culled from physiologists around the world. The "Current Research" section offers white papers from the APS, links to relevant journals, and abstracts from recently published physiology papers. Visitors will also want to look over the "Milestones in Physiology" area, as they can browse the timeline of physiology and also read 46 classic research articles taken from the American Journal of Physiology archives.

224

Cow Dung Ingestion and Inhalation Dependence: A Case Report  

ERIC Educational Resources Information Center

Although abuse of several unusual inhalants had been documented, addiction to cow dung fumes or their ashes has not been reported in medical literature as yet. We are reporting a case of cow dung dependence in ingestion and inhalational form.

Khairkar, Praveen; Tiple, Prashant; Bang, Govind

2009-01-01

225

Variation in hepatic regulation of metabolism during the dry period and in early lactation in dairy cows.  

PubMed

The purpose of this study was to investigate variations in hepatic regulation of metabolism during the dry period, after parturition, and in early lactation in dairy cows. For this evaluation, cows were divided into 2 groups based on the plasma concentration of beta-hydroxybutyric acid (BHBA) in wk 4 postpartum (PP; group HB, BHBA >0.75 mmol/L; group LB, BHBA <0.75 mmol/L, respectively). Liver biopsies were obtained from 28 cows at drying off (mean 59 +/- 8 d antepartum), on d 1, and in wk 4 and 14 PP. Blood samples were collected every 2 wk during this entire period. Liver samples were analyzed for mRNA abundance of genes related to carbohydrate metabolism (pyruvate carboxylase, PC; phosphoenolpyruvate carboxykinase, PEPCK; citrate synthase, CS), fatty acid biosynthesis (ATP citrate lyase, ACLY) and oxidation (acyl-CoA synthetase long-chain, ACSL; carnitine palmitoyltransferase 1A, CPT 1A; carnitine palmitoyltransferase 2, CPT 2; acyl-coenzyme A dehydrogenase very long chain, ACADVL), cholesterol biosynthesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 1, HMGCS1), ketogenesis (3-hydroxy-3-methylglutaryl-coenzyme A synthase 2, HMGCS2), and of genes encoding the transcription factors peroxisome proliferator-activated receptor alpha (PPARalpha), peroxisome proliferator-activated receptor gamma (PPARgamma), and sterol regulatory element binding factor 1 (SREBF1). Blood plasma was assayed for concentrations of glucose, BHBA, nonesterified fatty acids, cholesterol, triglycerides, insulin, insulin-like growth factor-I, and thyroid hormones. In both groups, plasma parameters followed a pattern usually observed in dairy cows. However, changes were moderate and the energy balance in cows turned positive in wk 7 PP for both groups. Additionally, the energy balance and milk yield were similar for both groups after parturition onwards. Significant group effects were found at drying off, when plasma concentrations of triglycerides were higher in LB than in HB, and in wk 4 PP, when plasma concentrations of glucose and IGF-I were lower in HB than in LB. Similarly, moderate changes in mRNA expression of hepatic genes between the different time points were observed, although HB cows showed more adaptive performance than LB cows based on changes in mRNA expression of PEPCKc, PEPCKm, CS, CPT 1A, CPT 2, and PPARalpha. Part of the variation measured in this study was explained by parity. Significant Spearman rank correlation coefficients between the variables were not similar at each time point and were not similar between the groups at each time point, suggesting that metabolic regulation differs between cows. In conclusion, metabolic regulation in dairy cows is a dynamic system, and differs obviously between cows at different metabolic stages related to parturition. PMID:19389950

van Dorland, H A; Richter, S; Morel, I; Doherr, M G; Castro, N; Bruckmaier, R M

2009-05-01

226

Intestinal mucosal atrophy and adaptation  

PubMed Central

Mucosal adaptation is an essential process in gut homeostasis. The intestinal mucosa adapts to a range of pathological conditions including starvation, short-gut syndrome, obesity, and bariatric surgery. Broadly, these adaptive functions can be grouped into proliferation and differentiation. These are influenced by diverse interactions with hormonal, immune, dietary, nervous, and mechanical stimuli. It seems likely that clinical outcomes can be improved by manipulating the physiology of adaptation. This review will summarize current understanding of the basic science surrounding adaptation, delineate the wide range of potential targets for therapeutic intervention, and discuss how these might be incorporated into an overall treatment plan. Deeper insight into the physiologic basis of adaptation will identify further targets for intervention to improve clinical outcomes.

Shaw, Darcy; Gohil, Kartik; Basson, Marc D

2012-01-01

227

Effects of methionine hydroxy copper supplementation on lactation performance, nutrient digestibility, and blood biochemical parameters in lactating cows.  

PubMed

The objective of this study was to investigate the effects of methionine hydroxy Cu [(HMTBA)(2)-Cu] supplementation on lactation performance, nutrient digestibility, and blood biochemical parameters in lactating cows. Thirty lactating Holstein cows were assigned to 1 of 3 treatments in a randomized block design: (1) Cu sulfate only (S): 12 mg of Cu provided by CuSO(4) per kilogram of concentrate; (2) Cu sulfate and (HMTBA)(2)-Cu (SM): 6 mg of Cu provided by CuSO(4) and 6 mg of Cu provided by (HMTBA)(2)-Cu per kilogram of concentrate; or (3) (HMTBA)(2)-Cu only (M): 12 mg of Cu provided by (HMTBA)(2)-Cu per kilogram of concentrate. The level of dietary Cu was determined according to the NRC (2001) requirement. This experiment lasted for 120 d, with the first 20 d for adaptation and with sample and data collection beginning on d 21. The milk yield and 4% fat-corrected milk yield of cows in the SM treatment tended to increase compared with those in the S and M treatments. Cows fed SM also tended to have higher NDF and ADF apparent digestibility values than did cows fed S or M. Plasma Cu concentration significantly increased for the SM treatment compared with the S and M treatments. Cows fed S had higher plasma K concentration than did cows in the other 2 treatments. In conclusion, replacing one-half of the dietary Cu sulfate with (HMTBA)(2)-Cu increased plasma Cu concentration and tended to improve the neutral and acid detergent fiber apparent digestibility values and the lactation performance of lactating dairy cattle. PMID:22921627

Wang, F; Li, S L; Xin, J; Wang, Y J; Cao, Z J; Guo, F C; Wang, Y M

2012-10-01

228

Polyamines in plant physiology.  

PubMed Central

The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their chemistry and pathways of biosynthesis and metabolism are well characterized. They occur in the free form as cations, but are often conjugated to small molecules like phenolic acids and also to various macromolecules. Their titer varies from approximately micromolar to more than millimolar, and depends greatly on environmental conditions, especially stress. In cereals, the activity of one of the major polyamine biosynthetic enzymes, arginine decarboxylase, is rapidly and dramatically increased by almost every studied external stress, leading to 50-fold or greater increases in putrescine titer within a few hours. The physiological significance of this increase is not yet clear, although most recent work suggests an adaptive, protective role. Polyamines produced through the action of ornithine decarboxylase, by contrast, seem essential for DNA replication and cell division. The application of exogenous polyamines produces effects on patterns of senescence and morphogenesis, suggesting but not proving a regulatory role for polyamines in these processes. The evidence for such a regulatory role is growing.

Galston, A W; Sawhney, R K

1990-01-01

229

Polyamines in plant physiology  

NASA Technical Reports Server (NTRS)

The diamine putrescine, the triamine spermidine, and the tetramine spermine are ubiquitous in plant cells, while other polyamines are of more limited occurrence. Their chemistry and pathways of biosynthesis and metabolism are well characterized. They occur in the free form as cations, but are often conjugated to small molecules like phenolic acids and also to various macromolecules. Their titer varies from approximately micromolar to more than millimolar, and depends greatly on environmental conditions, especially stress. In cereals, the activity of one of the major polyamine biosynthetic enzymes, arginine decarboxylase, is rapidly and dramatically increased by almost every studied external stress, leading to 50-fold or greater increases in putrescine titer within a few hours. The physiological significance of this increase is not yet clear, although most recent work suggests an adaptive, protective role. Polyamines produced through the action of ornithine decarboxylase, by contrast, seem essential for DNA replication and cell division. The application of exogenous polyamines produces effects on patterns of senescence and morphogenesis, suggesting but not proving a regulatory role for polyamines in these processes. The evidence for such a regulatory role is growing.

Galston, A. W.; Sawhney, R. K.

1990-01-01

230

Treatment of Cow's Milk Protein Allergy  

PubMed Central

The diagnosis and treatment of cow's milk protein allergy (CMPA) is still a challenge. A systematic literature search was performed using Embase, Medline, The Cochrane Database of Systematic Reviews and Cochrane Central Register of Controlled Clinical Trials for the diagnosis and treatment of cow's milk allergy (CMA). Since none of the symptoms of CMPA is specific and since there is no sensitive diagnostic test (except a challenge test), the diagnosis of CMPA remains difficult. A "symptom-based score" is useful in children with symptoms involving different organ systems. The recommended dietary treatment is an extensive cow milk based hydrolysate. Amino acid based formula is recommended in the most severe cases. However, soy infant formula and hydrolysates from other protein sources (rice) are gaining popularity, as they taste better and are cheaper than the extensive cow's milk based hydrolysates. Recent meta-analyses confirmed the safety of soy and estimate that not more than 10-15% of CMPA-infants become allergic to soy. An accurate diagnosis of CMA is still difficult. The revival of soy and the development of rice hydrolysates challenge the extensive cow's milk based extensive hydrolysates as first option and amino acid formula.

De Greef, Elisabeth; Devreker, Thierry

2014-01-01

231

A prospective study of humoral immune responses to cow milk antigens in the first year of life.  

PubMed

Previous studies have shown that in cow milk allergy the specific immune response to dietary cow milk antigens is deficient. This study aimed at delineating the development of humoral immune response to cow milk antigens in healthy infants. Twenty-five healthy newborns were enrolled, and seen at scheduled visits at the ages of three, six and eleven months, and they formed two groups: those breastfed and those fed adapted cow milk formulae. The local immune response in the gut was approximated using the ELISPOT assay of circulating antibody secreting cells. At the age of three months, in the formula fed group, cells secreting specific IgA to cow milk antigens were detected despite low levels of IgA serum antibodies. The total number of IgA secreting cells increased with age (p = 0.001). The milk in the infant diet directly influenced this development so that the age related increase was significantly greater in the formula fed group (p = 0.04). The results indicate that diet has a significant effect on the developing immune system, and that healthy infants are able to respond in an antigen specific fashion to dietary antigens, which may be central in attaining clinical tolerance of such antigens. PMID:7951758

Kaila, M; Arvilommi, H; Soppi, E; Laine, S; Isolauri, E

1994-08-01

232

Milk Ejection in Cows Mechanically Stimulated During Late Lactation  

Microsoft Academic Search

Twelve Holstein cows in late lactation were divided into three groups by previous milk production. The average time in lactation for all cows was 223 days. Cows were subjected to four treatments of teat stimulation: 1) no stimulation, 2) manual stimulation for 60 s, 3) positive pressure pulsation (during first 60 s after teat cup application), and 4) fast pulsation

R. Sagi; R. C. Gorewit; S. A. Zinn

1980-01-01

233

Effects of supplementation of Tinospora cordifolia to crossbred cows peripartum  

Microsoft Academic Search

Guduchi (Tinospora cordifolia), a medicinal plant used in ayurveda is well documented for its immunomodulatory properties. Since the crossbred periparturient cow is highly susceptible to various diseases that effectively reduces its reproductive performance postpartum we explored the possibility of enhancing the reproductive performance of crossbred cows by guduchi supplementation peripartum. A total of 15 pregnant Karan Fries cows were selected

Smrutirekha Mallick; B. S. Prakash

2011-01-01

234

Cow effects and estimation of success of first and following inseminations in Dutch dairy cows.  

PubMed

The objective of this research was to determine the contribution of cow factors to the probability of successful insemination accounting for the serial number of inseminations in analysis. The investigation was performed with 101,297 insemination records in 51,525 lactations of different cows from 1368 herds obtained from the Dutch milk production recording database. Cows that had a first insemination (AI) between 40 and 150 days post-partum with one or more inseminations (?6 inseminations) were selected. An insemination was defined successful when not followed by another insemination and when the cow calved between 267 and 295 days after insemination, or when the cow was culled between 135 and 295 days after the last insemination. Breed, parity, days in milk, lactation curve characteristics, milk production traits, moment of AI related to peak milk yield time (before or after peak milk yield), the last calf (female, male, twin or stillbirth) and season of insemination were selected as independent parameters for a model with successful rate of insemination as dependent parameter. A multivariable logistic regression model was used within cow and farm as a random effect. The probability of successful insemination was the highest in the first insemination and decreased in the following inseminations. However, the success rate of all inseminations increased in a later stage of lactation. The improvement in the successful inseminations in a later stage of lactation was better in multiparous cows than in first parity cows. Insemination in summer and before peak milk yield time reduced the success of insemination. The success rate was the lowest in 100% Holstein Friesian cows compared with other breeds and was the highest when the last calf was a female calf compared to a male calf, twin or stillbirth. In conclusion, the success of first and following inseminations depended on parity, breed, season of insemination, last calf status, daily milk yield at insemination date, serial insemination number and days in milk at insemination date. PMID:21470315

Inchaisri, C; Jorritsma, R; Vernooij, J C M; Vos, P L A M; van der Weijden, G C; Hogeveen, H

2011-12-01

235

Physiological and Environmental Influences on the Metabolism of Thyroid Hormones.  

National Technical Information Service (NTIS)

The nature of adaptations in thyroid function and in particular the peripheral metabolism of thyroid hormones which participate in physiological and environmental alterations in bodily economy (heat and cold exposure, exercise, prolonged emotional stress,...

J. T. Dowling R. E. Cutler C. J. Goodner

1964-01-01

236

Identification of Sequential IgE-Binding Epitopes on Bovine ?s2Casein in Cow’s Milk Allergic Patients  

Microsoft Academic Search

Background: Caseins are the major allergens responsible for cow’s milk allergy (CMA). We have previously identified the IgE-binding epitopes of the major cow’s milk (CM) proteins except for ?s2-casein. Methods: Overlapping decapeptides representing the entire length of ?s2-casein were synthesized on a cellulose-derivatized membrane. Sera from 13 CM-allergic children, 4–15 years of age, with a median level of CM-specific IgE

Paula J. Busse; Kirsi-Marjut Järvinen; Leticia Vila; Kirsten Beyer; Hugh A. Sampson

2002-01-01

237

Supplementary feeding in maternity hospitals and the risk of cow’s milk allergy: A prospective study of 6209 infants  

Microsoft Academic Search

Background: Early feeding with cow’s milk (CM) may increase the risk of cow’s milk allergy (CMA). Objective: We sought to examine prospectively whether supplementary feeding of CM at the maternity hospital would increase the risk when compared with feeding with pasteurized human milk or hydrolyzed formula. Methods: We studied 6209 unselected healthy, full-term infants, of whom 5385 (87%) required supplementary

Kristiina Mertta Saarinen; Kaisu Juntunen-Backman; Anna-Liisa Järvenpää; Pekka Kuitunen; Leena Lope; Martin Renlund; Matti Siivola; Erkki Savilahti

1999-01-01

238

Influence of Dietary Sodium and Potassium Bicarbonate and Total Potassium on Heat-Stressed Lactating Dairy Cows1  

Microsoft Academic Search

Objectives were to study effects of heat stress, 0 or .85% sodium bicarbonate, 0 or 1.0% potassium bicarbonate, and 1.0 or 1.5% total dietary potassium on production and physiological responses of dairy cows. Eighteen lactating Holsteins were assigned to shade (control) or no shade (heat stress) lots continuously for three consecutive 35-day periods and to different dietary treatments each period.

P. L. Schneider; D. K. Beede; C. J. Wilcox; R. J. Collier

1984-01-01

239

Characterization of epidemic diarrhea outbreaks associated with bovine torovirus in adult cows.  

PubMed

Bovine torovirus (BToV) is recognized as an enteric pathogen of calves, but its etiological role in diarrhea and epidemiological characterization in adult cows remain unclear. In 2007-2008, three outbreaks of epidemic diarrhea occurred in adult cows at three dairy farms in Niigata Prefecture, Japan. BToV was the only enteric pathogen detected in these outbreaks, as determined by electron microscopy, reverse transcription-PCR, bacteria and parasite tests of fecal samples, and antibody tests with paired sera. The epidemiological features of the three outbreaks were similar to those of bovine coronavirus infection, except for the absence of bloody diarrhea, with diarrhea spreading among most adult cows, but not in calves, within several days and diarrhea lasting for 3-5 days with anorexia. Decreased milk production and mild respiratory symptoms were also observed in two of the outbreaks. Nucleotide sequence analysis of the BToV nucleocapsid, spike, and hemagglutinin-esterase (HE) genes revealed a close relatedness among the detected BToV strains from each outbreak and those of Japanese BToV strain Aichi/2004. Furthermore, we isolated a BToV strain, designated Niigata (TC), from a fecal sample using a human rectal tumor cell line. Sequence analysis of this isolate and Aichi/2004 indicated that both strains have truncated HE genes with deletions in the 3' region that occurred through cell culture-adaptation. The short projections that are believed to be formed by the HE protein on virus particles were not observed in these cultured strains by electron microscopy. Taken together, these results suggest that BToV causes epidemic diarrhea in adult cows and should be included in the differential diagnosis of diarrhea in adult cows. In addition, our findings indicate that the HE protein of BToV may not be necessary for viral replication. PMID:22167249

Aita, Tsunehiko; Kuwabara, Masaki; Murayama, Kazunori; Sasagawa, Yuri; Yabe, Shizuka; Higuchi, Ryohei; Tamura, Tsutomu; Miyazaki, Ayako; Tsunemitsu, Hiroshi

2012-03-01

240

The Botanical Garden - A Tool to Teach Systematics, Physiology and a Lot More  

NSDL National Science Digital Library

As the UBC botanical gardens are arranged, there exists multiple teaching opportunities in areas such as: systematics, domesticated plants, environmental and physiological adaptations, micropropagation, biotechnology and others.

Iain E.P. Taylor (University of British Columbia;); Gerald B. Straley (University of British Columbia;)

1988-06-06

241

Chewing Over Physiology Integration  

ERIC Educational Resources Information Center

An important challenge for both students and teachers of physiology is to integrate the differentareas in which physiological knowledge is didactically divided. In developing countries, such an issue is even more demanding, because budget restrictions often affect the physiology program with laboratory classes being the first on the list when it…

Abdulkader, Fernando; Azevedo-Martins, Anna Karenina; de Arcisio Miranda, Manoel; Brunaldi, Kellen

2005-01-01

242

Scaling Physiological Pharmacokinetic Models by Physiological Time.  

National Technical Information Service (NTIS)

This paper shows that a multicompartment physiological pharmacokinetic model, used to account for inhalation exposure to volatile chlorohydrocarbons in mammalian species, can be made species-independent if chronological time is re-expressed in terms of ph...

R. C. Ward C. C. Travis

1987-01-01

243

Intestinal malrotation with suspected cow's milk allergy: a case report  

PubMed Central

Background Intestinal malrotation is an incomplete rotation of the intestine. Failure to rotate leads to abnormalities in intestinal positioning and attachment that leave obstructing bands across the duodenum and a narrow pedicle for the midgut loop, thus making it susceptible to volvulus. One of the important differential diagnoses for malrotation is an allergy to cow’s milk. Several studies have described infants with surgical gastrointestinal diseases and cow’s milk allergy. However, to our knowledge, no study has reported infants with intestinal malrotation who have been symptomatic before surgery was performed and have been examined by allergen-specific lymphocyte stimulation test and food challenge tests with long-term follow-up. Case presentation The patient was a Japanese male born at 39 weeks of gestation. He was breast-fed and received commercial cow’s milk supplementation starting the day of birth and was admitted to our hospital at 6 days of age due to bilious vomiting. Plain abdominal radiography showed a paucity of gas in the distal bowel. Because we demonstrated malpositioning of the intestine by barium enema, we repositioned the bowel in a normal position by laparotomy. The patient was re-started on only breast milk 2 days post surgery because we suspected the presence of a cow’s milk allergy, and the results of an allergen-specific lymphocyte stimulation test showed a marked increase in lymphocyte response to kappa-casein. At 5 months of age, the patient was subjected to a cow’s milk challenge test. After the patient began feeding on cow’s milk, he had no symptoms and his laboratory investigations showed no abnormality. In addition, because the patient showed good weight gain and no symptoms with increased cow’s milk intake after discharge, we concluded that the present case was not the result of a cow’s milk allergy. At 1 year, the patient showed favorable growth and development, and serum allergy investigations revealed no reaction to cow’s milk. Conclusion When physicians encounter infants with surgical gastrointestinal disease, including intestinal malrotation, they should consider cow’s milk allergy as a differential diagnosis or complication and should utilize food challenge tests for a definitive diagnosis.

2012-01-01

244

A metabolomics approach to uncover the effects of grain diets on rumen health in dairy cows.  

PubMed

Dairy cows fed high-grain diets during early lactation have a high incidence of metabolic disorders. However, the precise mechanism(s) of how grain feeding causes disease is not clear. In an effort to understand how this diet transition alters the rumen environment and potentially leads to certain metabolic disorders in dairy cattle, we undertook a comprehensive, quantitative metabolomic analysis of rumen fluid samples from dairy cows fed 4 different diets. Using a combination of proton nuclear magnetic resonance spectroscopy, gas chromatography-mass spectrometry, and direct flow injection tandem mass spectroscopy, we identified and quantified 93 metabolites in rumen samples taken from 8 dairy cows fed graded amounts of barley grain (i.e., 0, 15, 30, and 45% of diet dry matter). We also studied temporal changes in the rumen by studying metabolite concentration differences between the first day and the last day of each diet phase following the diet adaptation period. Multivariate analysis showed that rumen metabolites arising from the diet containing 45% barley grain were clearly different from those containing 0, 15, and 30% barley grain. Likewise, a clear separation of the metabolic composition of the ruminal fluid was evident at the beginning and at the end of each diet phase-contrary to the belief that 11 d are suitable for the adaptation of cows to high-grain diets. High-grain diets (>30%) resulted in increased rumen fluid concentrations of several toxic, inflammatory, and unnatural compounds including putrescine, methylamines, ethanolamine, and short-chain fatty acids. Perturbations in several amino acids (phenylalanine, ornithine, lysine, leucine, arginine, valine, and phenylacetylglycine) were also evident. The present study confirms and greatly extends earlier observations on dietary effects on rumen fluid composition and shows that the use of multiple metabolomic platforms permits a far more detailed understanding of metabolic causes and effects. These results may improve our understanding of diet-related rumen metabolism and the influence of grain on the overall health of dairy cattle. PMID:22959937

Saleem, F; Ametaj, B N; Bouatra, S; Mandal, R; Zebeli, Q; Dunn, S M; Wishart, D S

2012-11-01

245

Cow's milk protein-sensitive enteropathy. Clinical and histological results of the cow's milk provocation test.  

PubMed

Nineteen infants suspected of having cow's milk protein-sensitive enteropathy were studied. They all showed failure to thrive, diarrhoea and/or vomiting when fed a diet of cow's milk, and improved when their diet was changed to casein hydrolysate. Jejunal biopsy was done before and 18--23 hours after a milk challenge. Of the 19 infants, 12 presented histological evidence of cow's milk protein intolerance. Eight suffered from vomiting and diarrhoea within 9 days of the milk challenge, but in 4 cases the histological abnormalities were not accompanied by clinical symptoms. In one case a chicken meat intolerance was documented. The histological appearance of the intestinal mucosa after chicken challenge was identical to that observed after milk challenge. In our opinion, repeated intestinal biopsies before and after an acute challenge is the best method to establish the diagnosis not only of cow's milk protein intolerance but also of intolerance to other alimentary proteins. PMID:521297

Vitoria, J C; Camarero, C; Solaguren, R; Aranjuelo, M; Oliveros, R; Navajas, A; Rodríguez-Soriano, J

1979-09-01

246

Reintroduction of Cow’s Milk in Milk-Allergic Children: Safety and Risk Factors  

Microsoft Academic Search

Background: Although development of clinical tolerance is the rule in allergy to cow’s milk (CM), food challenges are required in order to reintroduce CM into the patient’s diet. Less ‘invasive’ procedures able to predict tolerance would be useful as clinical tools. The purpose of this study was to identify potential risk factors for clinical reactivity in CM-allergic children assessed for

Emilia Vassilopoulou; George Konstantinou; Dimitrios Kassimos; Nikolaos Douladiris; Paraskevi Xepapadaki; Emmanuel Manoussakis; Photini Saxoni-Papageorgiou; Nikolaos G. Papadopoulos

2008-01-01

247

Effect of pre-grazing herbage mass on dairy cow performance, grass dry matter production and output from perennial ryegrass (Lolium perenne L.) pastures.  

PubMed

A grazing study was undertaken to examine the effect of maintaining three levels of pre-grazing herbage mass (HM) on dairy cow performance, grass dry matter (DM) production and output from perennial ryegrass (Lolium perenne L.) pastures. Cows were randomly assigned to one of three pre-grazing HM treatments: 1150 - Low HM (L), 1400 - Medium HM (M) or 2000 kg DM/ha - High HM (H). Herbage accumulation under grazing was lowest (P<0.01) on the L treatment and cows grazing the L pastures required more grass silage supplementation during the grazing season (+73 kg DM/cow) to overcome pasture deficits due to lower pasture growth rates (P<0.05). Treatment did not affect daily milk production or pasture intake, although cows grazing the L pastures had to graze a greater daily area (P<0.01) and increase grazing time (P<0.05) to compensate for a lower pre-grazing HM (P<0.01). The results indicate that, while pre-grazing HM did not influence daily milk yield per cow, adapting the practise of grazing low HM (1150 kg DM/ha) pasture reduces pasture DM production and at a system level may increase the requirement for imported feed. PMID:24229787

Wims, C M; Delaby, L; Boland, T M; O'Donovan, M

2014-01-01

248

Dairy cows seek isolation at calving and when ill.  

PubMed

Dairy cows are typically gregarious, but isolate themselves in the hours before calving when kept on pasture. Self-isolation is also a common behavior of ill animals. The objectives of this study were to determine if dairy cows would (1) isolate to calve when housed indoors in an individual maternity pen and (2) continue to isolate when ill after calving. We selected individuals from a pool of 79 multiparous Holstein dairy cows based on inclusion criteria created to address each objective. Cows were moved from a group pen to 1 of 10 adjacent maternity pens. Half of these individual pens were partially covered with plywood, creating a secluded corner as well as a window that provided visual access to the group pen. The other individual pens were uncovered on all sides. For our first objective, we selected 39 cows that were moved into the maternity pens >8h before calving (partially covered: n=19; uncovered: n=20). For our second objective, we selected 18 cows housed in the partially covered pens: 9 cows with high rectal temperature after calving and signs of an infectious disease (mastitis, metritis, pneumonia, or some combination), and 9 healthy cows paired with ill cows based on the amount of time they spent in the maternity pen before calving. Ten-minute scan sampling was used to record the location and lying time from 6h before to 72h after calving. Individual feed intake was measured after calving. Binomial tests were used to determine if cows in both pen types were more likely to calve in the corner or window side of the pen. Repeated-measures ANOVA were used to determine if cows used the corner more as calving approached and if ill cows spent more time lying or more time in the corner compared with healthy cows in the 72h after calving. Cows in the uncovered pens were equally likely to calve on both sides of the pen (10 vs. 10), but 79% of cows in the partially covered pens calved on the corner side of the pen (15 vs. 4). Cows in the partially covered pens used the corner side of the pen more in the 1h before and after calving compared with those housed in the uncovered pens. Ill cows housed in the partially covered pens ate less, tended to spend more time lying down, and spent more time in the corner of the pen compared with healthy cows. These results indicate that periparturient dairy cows seek seclusion to calve and when ill, which suggests that adding a secluded area to maternity and hospital pens may be beneficial. PMID:24630650

Proudfoot, K L; Jensen, M B; Weary, D M; von Keyserlingk, M A G

2014-05-01

249

The challenge of cow milk protein allergy  

Microsoft Academic Search

Hypersensitivity to cow milk proteins is one of the main food allergies and affects mostly but not exclusively infants, while it may also persist through adulthood and can be very severe. Different clinical symptoms of milk allergy have been established. The diagnosis of milk allergy differs widely due to the multiplicity and degrees of symptoms, and can be achieved by

E. I. El-Agamy

2007-01-01

250

Cerebellar Disease in an Adult Cow  

PubMed Central

This is the report of clinical signs and lesions of a cerebellar disorder in an adult four year old Limousin cow grazing perennial ryegrass (Lolium perenne). The most striking histopathological lesion was a marked paucity of Purkinje cells throughout the cerebellum. ImagesFigure 1.Figure 2.

Oz, H. H.; Nicholson, S. S.; Al-Bagdadi, F. K.; Zeman, D. H.

1986-01-01

251

Production diseases of the transition cow  

Microsoft Academic Search

Production diseases of the dairy cow are caused by a level of production inconsistent with nutrient intake, provision of an inadequate diet, an unsuitable environment, an inappropriate breeding policy or various combinations of these factors. Although the transition period of 3 weeks pre-calving until 3 weeks post-calving is associated with a peak incidence of production disease, the effects of these

F. J. Mulligan; M. L. Doherty

2008-01-01

252

Cow's Eye Dissection in the Physics Lab.  

ERIC Educational Resources Information Center

Proposes the science demonstration of dissecting a cow's eye to integrate biology and physics in the study of optics and lenses. Reviews the anatomy of the eye, describes the visual process and covers topics as index of refraction of the cornea, microscopic receptors, the lens, and the retina. (MDH)

Lapp, David R.; Keenan, James E.

1991-01-01

253

Epigenetics: a possible role in acute and transgenerational regulation of dairy cow milk production.  

PubMed

A potential role for epigenetic mechanisms in the regulation of mammary function in the dairy cow is emerging. Epigenetics is the study of heritable changes in genome function that occur because of chemical changes rather than DNA sequence changes. DNA methylation is an epigenetic event that results in the silencing of gene expression and may be passed on to the next generation. However, recent studies investigating different physiological states and changes in milk protein gene expression suggest that DNA methylation may also play an acute, regulatory, role in gene transcription. This overview will highlight the role of DNA methylation in the silencing of milk protein gene expression during mastitis and mammary involution. Moreover, environmental factors such as nutrition may induce epigenetic modifications of gene expression. The current research investigating the possibility of in utero, hence cross-generational, epigenetic modifications in dairy cows will also be discussed. Understanding how the mammary gland responds to environmental cues provides a potential to enhance milk production not only of the dairy cow but also of her daughter. PMID:22436216

Singh, K; Molenaar, A J; Swanson, K M; Gudex, B; Arias, J A; Erdman, R A; Stelwagen, K

2012-03-01

254

Determination of presence of Tritrichomonas foetus in uterine lavages from cows with reproductive problems.  

PubMed

The aim of this study was to determine the presence of Tritrichomonas foetus in two dairy herds on the Altiplano Cundiboyacense. Twenty-one low-volume uterine lavages from cows with a history of reproductive problems in two dairy herds located in the municipality of Sibaté (Cundinamarca) and Ventaquemada (Boyacá) were evaluated. In the first herd, 10 cows were sampled and in the second, 11 cows, based on three inclusion criteria. The uterine lavages were obtained through infusion of physiological saline solution into the uterine body. The samples were centrifuged and seeded in Tritrichomonas basal medium for 10-15 days at 37 ºC. The protozoa were evaluated on the day of sampling and 10 and 15 days after incubation by means of direct viewing under a dark-field microscope. Positive samples were stained with Wright and Lugol to identify the morphological characteristics. This study showed that T. foetus was present in 61.8% of the animals sampled. The determination that T. foetus was present in 61.8% of the samples analyzed is a significant finding given that in the herds evaluated, this agent had not previously been diagnosed. PMID:23070427

González-Carmona, Lady Carolina; Sánchez-Ladino, Milena Jineth; Castañeda-Salazar, Rubiela; Pulido-Villamarín, Adriana Del Pilar; Guáqueta-Munar, Humberto; Aranda-Silva, Moisés; Rueda-Varón, Milton Januario

2012-01-01

255

Plasma progesterone, metabolic hormones and beta-hydroxybutyrate in Holstein-Friesian cows after superovulation.  

PubMed

Metabolic hormones [insulin, leptin, insulin-like growth factor-I (IGF-I), thyroxine (T4) and triiodothyronine (T3)], progesterone (P4) and beta-hydroxybutyrate (BHB) serum concentrations were evaluated and their effect on the superovulation results of donor cows was investigated in a semi-arid environment. Body weight, body condition score (BCS) and lactation stage were also included in the analysis. Twenty-three Holstein-Friesian cows were superovulated with 600 IU FSHp following the routine procedure and flushed on day 7 in a Multiple Ovulation and Embryo Transfer Centre in the semi-arid area of Brazil. The corpora lutea (CL) were counted and blood samples were collected for assays. All of the hormones investigated and BHB serum concentrations were within the physiological ranges. There was a positive correlation between hormones, except between BHB and all the others. The leptin level was influenced by feeding status, as indicated by the BCS. Insulin, T4, T3 and BHB levels were affected by milking status. Dry cows had higher levels of all hormones except BHB. An optimum level of leptin resulted in the highest number of CL, while the linear increase of P4, T4 and IGF significantly increased the number of CL. PMID:22079709

Bényei, Balázs; Komlósi, István; Pécsi, Anna; Kulcsár, Margit; Huzsvai, László; Barros, C W C; Huszenicza, Gyula

2011-12-01

256

Phenotyping of leukocytes and granulocyte and monocyte phagocytic activity in the peripheral blood and uterus of cows with endometritis.  

PubMed

This study was a comparative evaluation of selected immunological parameters in peripheral blood and uterine wash samples from cows with a normal postpartum period compared with cows with endometritis. We aimed to determine the usefulness of these parameters in monitoring the puerperium. In total, 40 cows were included in the study: 20 had endometritis (experimental group), and 20 did not have uterine inflammation (control group). Animals were chosen on the basis of cytological and bacteriological test results. The tests were conducted 5, 22, and 40 days postpartum. In both groups, flow cytometric analysis of the surface molecules CD4, CD8, CD21, CD25, and CD14 in the peripheral blood and uterine washings was performed. Granulocyte and monocyte phagocytic activity was determined using a commercial Phagotest kit that was adapted for flow cytometry. The percentage of phagocytic granulocytes and monocytes in both the peripheral blood and the uterine washings was significantly lower for cows in the experimental group compared with the control group (P < 0.01). A significant decrease (P < 0.01) in the percentage of CD4+, CD25+, CD14+, and CD4 + CD25(high) leukocyte subpopulations was also observed in the peripheral blood of cows with endometritis. A significant decrease (P < 0.01) in CD21+ lymphocytes and an increase in CD8+ lymphocytes was detected in uterine washings. The results of this work indicate that cell immunity dysfunction may be the main factor causing advanced inflammation of the uterus in endometritis. Knowledge of the immunological mechanisms observed in cows with endometritis might aid in choosing the correct immunomodulating agent-based adjuvant therapy. PMID:24857644

Brodzki, P; Kostro, K; Brodzki, A; Lisiecka, U; Kurek, L; Marczuk, J

2014-08-01

257

Physiology Educational Research Consortium  

NSDL National Science Digital Library

The Physiology Educational Research Consortium (PERC) is a collaborative research and development effort among 13 physiologists and physiology educators representing 12 post-secondary institutions, ranging from community colleges to medical schools. PERC develops materials and techniques that can help students build "better mental models of physiological systems" and, in order to create more productive learning environments, educates teachers on how to incorporate these techniques into a classroom setting. The site offers research papers, abstracts, workshop and course information, and network support for those needing ideas on how to approach a topic or set of topics in physiology.

1998-01-01

258

Effect of heat stress on milk production, rectal temperature, respiratory rate and blood chemistry in Holstein, Jersey and Australian Milking Zebu cows.  

PubMed

The effect of heat stress on changes in milk production, rectal temperature, respiratory rate and blood chemistry was evaluated in three groups of six mature Holstein, Jersey and Australian Milking Zebu (AMZ) dairy cows. These animals were subjected to a cool environment when the mean temperature-humidity index (THI) was 72+/-1.4 (dry bulb temperature of 22.2-24.4 degrees C and relative humidity of 100-60%) during the month of December. This experiment was repeated during the hotter month of July of the following year, when the mean THI was 93+/-3.1 (dry bulb temperature of 35.6-43.9 degrees C and relative humidity 95-35%). Holstein cows produced more (p <0.01) milk than AMZ and Jersey cows during the cooler months of the year and all the cows were dry during the hotter months from June until September. Heat stress increased (p<0.01) rectal temperature and respiratory rate in all three breeds. Heat stress had no effect on blood pH in Holstein and AMZ cows but lowered (p <0.01) blood pH from 7.42 to 7.34 in Jersey cows. In addition, heat stress lowered (p <0.01) blood pCO2 (kPa), bicarbonate (HCO3, mmol/L), base excess (BE, mmol/L) and plasma chloride (Cl-, mmol/L) in all three breeds. The total haemoglobin (THb, g/dl) was elevated (p <0.01) in all three breeds when they were subjected to heat stress. Heat stress increased (p<0.01) oxygen saturation (O2SAT, %) in Jersey and AMZ cows but lowered it (p <0.01) in Holstein cows. On the other hand, heat stress increased (p <0.01)pO2 (kPa) in Holstein and Jersey cows but lowered it (p <0.01) in AMZ cows. Heat stress increased (p <0.01) plasma potassium (K, mmol/L) and calcium (Ca, mmol/L) only in Holstein and Jersey cows but lowered them (p<0.01) in AMZ cows. The plasma glucose (GLU, mmol/L) increased (p<0.01) with heat stress in Holstein and AMZ cows but decreased (p <0.01) in Jersey cows. Heat stress increased (p<0.01) plasma creatinine (CR, (mol/L) but lowered (p<0.01) plasma creatinine phosphokinase (CPK, IU/L), aspartate aminotransferase (AST, IU/L) and blood urea nitrogen (BUN, mmol/L) in all three breeds. These results indicate that heat-stressed Holstein and AMZ cows were able to maintain their acid-base balance with a marginal change in their pH of 0.02 when their rectal temperatures increased by 0.47 and 0.38 degrees C, respectively. When heat stress increased the rectal temperature in Jersey cows by 0.70 degrees C, the pH decreased (p<0.01) from 7.42 to 7.34. However, even with this decrease 0.08 the pH is still within the lower physiological limit of 7.31. PMID:15563029

Srikandakumar, A; Johnson, E H

2004-10-01

259

Evaluation of Coarsely Ground Wheat as a Replacement for Ground Corn in the Diets of Lactating Dairy Cows  

PubMed Central

Eight multiparous Holstein cows (569±47 kg of BW; 84±17 DIM) were used to evaluate the effects of different levels of coarsely ground wheat (CGW) as replacements for ground corn (GC) in diets on feed intake and digestion, ruminal fermentation, lactation performance, and plasma metabolites profiles in dairy cows. The cows were settled in a replicated 4×4 Latin square design with 3-wk treatment periods; four cows in one of the replicates were fitted with rumen cannulas. The four diets contained 0, 9.6, 19.2, and 28.8% CGW and 27.9, 19.2, 9.6, and 0% GC on dry matter (DM) basis, respectively. Increasing dietary levels of CGW, daily DM intake tended to increase quadratically (p = 0.07); however, apparent digestibility of neutral detergent fiber (NDF) and acid detergent fiber (ADF) were significantly decreased (p<0.01) in cows fed the 28.8% CGW diets. Ruminal pH remained in the normal physiological range for all dietary treatments at all times, except for the 28.8% CGW diets at 6 h after feeding; moreover, increasing dietary levels of CGW, the daily mean ruminal pH decreased linearly (p = 0.01). Increasing the dietary levels of CGW resulted in a linear increase in ruminal propionate (p<0.01) and ammonia nitrogen (NH3-N) (p = 0.06) concentration, while ruminal acetate: propionate decreased linearly (p = 0.03) in cows fed the 28.8% CGW diets. Milk production was not affected by diets; however, percentage and yield of milk fat decreased linearly (p = 0.02) when the level of CGW was increased. With increasing levels of dietary CGW, concentrations of plasma beta-hydroxybutyric acid (BHBA) (p = 0.07) and cholesterol (p<0.01) decreased linearly, whereas plasma glucose (p = 0.08), insulin (p = 0.02) and urea nitrogen (p = 0.02) increased linearly at 6 h after the morning feeding. Our results indicate that CGW is a suitable substitute for GC in the diets of dairy cows and that it may be included up to a level of 19.2% of DM without adverse effects on feed intake and digestion, ruminal fermentation, lactation performance, and plasma metabolites if the cows are fed fiber-sufficient diets.

Guo, Y. Q.; Zou, Y.; Cao, Z. J.; Xu, X. F.; Yang, Z. S.; Li, S. L.

2013-01-01

260

Milk composition, milk fatty acid profile, digestion, and ruminal fermentation in dairy cows fed whole flaxseed and calcium salts of flaxseed oil.  

PubMed

Four ruminally lactating Holstein cows averaging 602+/-25 kg of body weight and 64+/-6 d in milk at the beginning of the experiment were randomly assigned to a 4 x 4 Latin square design to determine the effects of feeding whole flaxseed and calcium salts of flaxseed oil on dry matter intake, digestibility, ruminal fermentation, milk production and composition, and milk fatty acid profile. The treatments were a control with no flaxseed products (CON) or a diet (on a dry matter basis) of 4.2% whole flaxseed (FLA), 1.9% calcium salts of flaxseed oil (SAL), or 2.3% whole flaxseed and 0.8% calcium salts of flaxseed oil (MIX). The 4 isonitrogenous and isoenergetic diets were fed for ad libitum intake. Experimental periods consisted of 21 d of diet adaptation and 7 d of data collection and sampling. Dry matter intake, digestibility, milk production, and milk concentrations of protein, lactose, urea N, and total solids did not differ among treatments. Ruminal pH was reduced for cows fed the CON diet compared with those fed the SAL diet. Propionate proportion was higher in ruminal fluid of cows fed CON than in that of those fed SAL, and cows fed the SAL and CON diets had ruminal propionate concentrations similar to those of cows fed the FLA and MIX diets. Butyrate concentration was numerically higher for cows fed the SAL diet compared with those fed the FLA diet. Milk fat concentration was lower for cows fed SAL than for those fed CON, and there was no difference between cows fed CON and those fed FLA and MIX. Milk yields of protein, fat, lactose, and total solids were similar among treatments. Concentrations of cis-9 18:1 and of intermediates of ruminal biohydrogenation of fatty acids such as trans-9 18:1 were higher in milk fat of cows fed SAL and MIX than for those fed the CON diet. Concentration of rumenic acid (cis-9, trans-11 18:2) in milk fat was increased by 63% when feeding SAL compared with FLA. Concentration of alpha-linolenic acid was higher in milk fat of cows fed SAL and MIX than in milk of cows fed CON (75 and 61%, respectively), whereas there was no difference between FLA and CON. Flaxseed products (FLA, SAL, and MIX diets) decreased the n-6 to n-3 fatty acid ratio in milk fat. Results confirm that flax products supplying 0.7 to 1.4% supplemental fat in the diet can slightly improve the nutritive value of milk fat for better human health. PMID:20630232

Côrtes, C; da Silva-Kazama, D C; Kazama, R; Gagnon, N; Benchaar, C; Santos, G T D; Zeoula, L M; Petit, H V

2010-07-01

261

Variation in fat mobilization during early lactation differently affects feed intake, body condition, and lipid and glucose metabolism in high-yielding dairy cows.  

PubMed

Fat mobilization to meet energy requirements during early lactation is inevitable because of insufficient feed intake, but differs greatly among high-yielding dairy cows. Therefore, we studied milk production, feed intake, and body condition as well as metabolic and endocrine changes in high-yielding dairy cows to identify variable strategies in metabolic and endocrine adaptation to overcome postpartum metabolic load attributable to milk production. Cows used in this study varied in fat mobilization around calving, as classified by mean total liver fat concentrations (LFC) postpartum. German Holstein cows (n=27) were studied from dry off until d 63 postpartum in their third lactation. All cows were fed the same total mixed rations ad libitum during the dry period and lactation. Plasma concentrations of metabolites and hormones were measured in blood samples taken at d 56, 28, 15, and 5 before expected calving and at d 1 and once weekly up to d 63 postpartum. Liver biopsies were taken on d 56 and 15 before calving, and on d 1, 14, 28, and 49 postpartum to measure LFC and glycogen concentrations. Cows were grouped accordingly to mean total LFC on d 1, 14, and 28 in high, medium, and low fat-mobilizing cows. Mean LFC (±SEM) differed among groups and were 351±14, 250±10, and 159±9 mg/g of dry matter for high, medium, and low fat-mobilizing cows, respectively, whereas hepatic glycogen concentrations postpartum were the highest in low fat-mobilizing cows. Cows in the low group showed the highest dry matter intake and the least negative energy balance postpartum, but energy-corrected milk yield was similar among groups. The decrease in body weight postpartum was greatest in high fat-mobilizing cows, but the decrease in backfat thickness was greatest in medium fat-mobilizing cows. Plasma concentrations of nonesterified fatty acids and ?-hydroxybutyrate were highest around calving in high fat-mobilizing cows. Plasma triglycerides were highest in the medium group and plasma cholesterol concentrations were lowest in the high group at calving. During early lactation, the decrease in plasma glucose concentrations was greatest in the high group, and plasma insulin concentrations postpartum were highest in the low group. The revised quantitative insulin sensitivity check index values decreased during the transition period and postpartum, and were highest in the medium group. Plasma cortisol concentrations during the transition period and postpartum period and plasma leptin concentrations were highest in the medium group. In conclusion, cows adapted differently to the metabolic load and used variable strategies for homeorhetic regulation of milk production. Differences in fat mobilization were part of these strategies and contributed to the individual adaptation of energy metabolism to milk production. PMID:23127904

Weber, C; Hametner, C; Tuchscherer, A; Losand, B; Kanitz, E; Otten, W; Singh, S P; Bruckmaier, R M; Becker, F; Kanitz, W; Hammon, H M

2013-01-01

262

The energy expenditure of 2 Holstein cow strains in an organic grazing system.  

PubMed

Until recently, measurements of energy expenditure (EE; herein defined as heat production) in respiration chambers did not account for the extra energy requirements of grazing dairy cows on pasture. As energy is first limiting in most pasture-based milk production systems, its efficient use is important. Therefore, the aim of the present study was to compare EE, which can be affected by differences in body weight (BW), body composition, grazing behavior, physical activity, and milk production level, in 2 Holstein cow strains. Twelve Swiss Holstein-Friesian (HCH; 616kg of BW) and 12 New Zealand Holstein-Friesian (HNZ; 570kg of BW) cows in the third stage of lactation were paired according to their stage of lactation and kept in a rotational, full-time grazing system without concentrate supplementation. After adaption, the daily milk yield, grass intake using the alkane double-indicator technique, nutrient digestibility, physical activity, and grazing behavior recorded by an automatic jaw movement recorder were investigated over 7d. Using the (13)C bicarbonate dilution technique in combination with an automatic blood sampling system, EE based on measured carbon dioxide production was determined in 1 cow pair per day between 0800 to 1400h. The HCH were heavier and had a lower body condition score compared with HNZ, but the difference in BW was smaller compared with former studies. Milk production, grass intake, and nutrient digestibility did not differ between the 2 cow strains, but HCH grazed for a longer time during the 6-h measurement period and performed more grazing mastication compared with the HNZ. No difference was found between the 2 cow strains with regard to EE (291±15.6kJ) per kilogram of metabolic BW, mainly due to a high between-animal variation in EE. As efficiency and energy use are important in sustainable, pasture-based, organic milk production systems, the determining factors for EE, such as methodology, genetics, physical activity, grazing behavior, and pasture quality, should be investigated and quantified in more detail in future studies. PMID:24630659

Thanner, S; Dohme-Meier, F; Görs, S; Metges, C C; Bruckmaier, R M; Schori, F

2014-05-01

263

Cow's milk allergy: From allergens to new forms of diagnosis, therapy and prevention?  

PubMed Central

The first adverse reactions to cow’s milk were already described 2000 years ago. However, it was only 50 years ago that several groups started with the analysis of cow’s milk allergens. Meanwhile the spectrum of allergy eliciting proteins within cow’s milk is identified and several cow’s milk allergens have been characterized regarding their biochemical properties, fold and IgE binding epitopes. The diagnosis of cow’s milk allergy is diverse ranging from fast and cheap in vitro assays to elaborate in vivo assays. Considerable effort was spent to improve the diagnosis from an extract-based into a component resolved concept. There is still no suitable therapy available against cow’s milk allergy except avoidance. Therefore research needs to focus on the development of suitable and safe immunotherapies that do not elicit severe side effect.

Hochwallner, Heidrun; Schulmeister, Ulrike; Swoboda, Ines; Spitzauer, Susanne; Valenta, Rudolf

2014-01-01

264

Microbial physiology vol. 29  

SciTech Connect

This book contains the following chapters: Hydrogen metabolism in Rhizobium: energetics, regulation, enzymology and genetics; The physiology and biochemistry of pili; Carboxysomes and ribulose bisphosphate carboxylase/oxygenase; Archaebacteria: the comparative enzymology of their central metabolic pathways; and Physiology of lipoteichoic acids in bacteria.

Rose, A.H. (School of Biological Sciences, Bath Univ. (GB)); Tempest, D.W. (Dept. of Microbiology Univ. of Sheffield (GB))

1988-01-01

265

The aging gut: physiology.  

PubMed

Changes in the physiology of the gastrointestinal tract with aging are less obvious than are seen in other organs, such as the brain. Nevertheless, physiologic changes play a role in the anorexia of aging, postprandial hypotension, aspiration pneumonia, increased Clostridium difficile infections, fecal incontinence, gallstones, and altered drug metabolism. PMID:17923336

Morley, John E

2007-11-01

266

Insect Physiology Online  

NSDL National Science Digital Library

A large database dedicated to research articles about various topics of insect physiology. Topics range from excretion to diapause to temperature and water regulation. There are also extensive listings of resources (academic units, funding, journals) and course data on insect physiology.

0002-11-30

267

Crop Physiology and Nutrition  

Microsoft Academic Search

In the context of physiology and nutrition, many of the treatments which affect crop yields do so by influencing either the total photosynthesis per unit area of land or the partition of assimilates within the plant or both. Examples are given to illustrate the inter-relationships of nutrition, crop physiology, leaf growth and yields in cereals, grasses, potatoes and sugar beet

J. D. Ivins

1973-01-01

268

Naturally occurring, physiologically normal, primate chimeras  

PubMed Central

Callitrichids, South American primates including marmosets and tamarins, have evolved a unique physiology. Twins share a placenta during gestation and exchange stem cells, resulting in naturally occurring chimeric adults. Our study used a quantitative PCR-based assay to address whether this chimerism was restricted to blood and other cells of the hematopoietic lineage or whether it extended to other somatic tissues. These studies help to characterize species that have adapted evolutionarily to pervasive chimerism, with every individual healthy and unperturbed. This experiment of evolution offers insight into transplantation and histocompatibility, reproductive biology and behavior, and innate and adaptive immunity.

Sweeney, Carolyn; Ward, Joshua; Vallender, Eric J.

2012-01-01

269

Human Adaptation and Readaptation for MARS Mission.  

National Technical Information Service (NTIS)

Human adaptation and readaptation in space appears to involve complex physiological and psychological interactions and adjustments. There is no comprehensive clinical characterization of the symptoms of these interactions, much less a comprehensive examin...

H. H. Schmitt

1986-01-01

270

Physiology of Alpine skiing.  

PubMed

Physiological profiles of elite Alpine skiers reveal the importance of muscular strength, anaerobic power, anaerobic endurance, aerobic endurance, coordination, agility, balance, and flexibility. On-hill snow training and dryland training programmes should focus on the elevation of these fitness components. Physical characteristics of elite skiers reveal an average height and body mass. Today, successful skiers are taller and heavier than their predecessors. Slalom skiers tend to be leaner than skiers in other events while the downhill racers are the heaviest. Elite skiers have strong legs when peak torque is measured during isometric and isokinetic conditions involving knee extension, which may be a specific adaptation since the skier is in a crouched position for a prolonged period when racing. Leg strength correlates significantly with performance in the downhill and giant slalom events. The glycolytic contribution in the slalom and giant slalom events is about 40% of the total energy cost. Following a race, blood lactate concentration averages 9 to 13 mmol/L. A muscle lactate concentration of 24 mmol/kg wet muscle tissue has been reported. Elite skiers have higher lactate values than advanced or novice skiers. The aerobic demands of competitive Alpine skiing may approach (90 to 95%) of the athlete's maximal aerobic power. Maximal heart rate is achieved during the latter part of the race. Elite skiers have a high VO2max. This may reflect their training programme and not the actual demands of the sport. When turning, muscular activity acts to impede blood flow and oxygen delivery. As a consequence, anaerobic metabolism is increased. Glycogen studies show significant utilisation from both slow and fast twitch muscle fibres. Skilled and unskilled skiers differ with respect to glycogen utilisation. Skilled skiers have greater glycogen depletion in the slow twitch fibres compared to unskilled skiers. Muscle glycogen decreases by about 32 mmol/kg wet muscle tissue following a day of ski training. Glycogen depletion may contribute to the injury pattern which peaks toward the end of the ski day. The risk of injury has been estimated at 17 injuries per 1000 skier days. When the severity criterion was an injury causing the skier to miss 3 days of skiing or visit a physician, the risk was 2 injuries per 1000 skier-days.(ABSTRACT TRUNCATED AT 400 WORDS) PMID:3067309

Andersen, R E; Montgomery, D L

1988-10-01

271

Increased muscle fatty acid oxidation in dairy cows with intensive body fat mobilization during early lactation.  

PubMed

The beginning of lactation requires huge metabolic adaptations to meet increased energy demands for milk production of dairy cows. One of the adaptations is the mobilization of body reserves mainly from adipose tissue as reflected by increased plasma nonesterified fatty acid (NEFA) concentrations. The capacity of the liver for complete oxidation of NEFA is limited, leading to an increased formation of ketone bodies, reesterification, and accumulation of triglycerides in the liver. As the skeletal muscle also may oxidize fatty acids, it may help to decrease the fatty acid load on the liver. To test this hypothesis, 19 German Holstein cows were weekly blood sampled from 7 wk before until 5 wk after parturition to analyze plasma NEFA concentrations. Liver biopsies were obtained at d 3, 18, and 30 after parturition and, based on the mean liver fat content, cows were grouped to the 10 highest (HI) and 9 lowest (LO). In addition, muscle biopsies were obtained at d -17, 3, and 30 relative to parturition and used to quantify mRNA abundance of genes involved in fatty acid degradation. Plasma NEFA concentrations peaked after parturition and were 1.5-fold higher in HI than LO cows. Muscle carnitine palmitoyltransferase 1? and ? mRNA was upregulated in early lactation. The mRNA abundance of muscle peroxisome proliferator-activated receptor ? (PPARG) increased in early lactation and was higher in HI than in LO cows, whereas the abundance of PPARA continuously decreased after parturition. The mRNA abundance of muscle PPARD, uncoupling protein 3, and the ?-oxidative enzymes 3-hydroxyacyl-coenzyme A (CoA) dehydrogenase, very long-chain acyl-CoA dehydrogenase, and 3-ketoacyl-CoA was greatest at d 3 after parturition, whereas the abundance of PPAR? coactivator 1? decreased after parturition. Our results indicate that around parturition, oxidation of fatty acids in skeletal muscle is highly activated, which may contribute to diminish the fatty acid load on the liver. The decline in muscle fatty acid oxidation within the first 4 wk of lactation accompanied with increased feed intake refer to greater supply of ruminally derived acetate, which as the preferred fuel of the muscle, saves long-chain fatty acids for milk fat production. PMID:23910553

Schäff, C; Börner, S; Hacke, S; Kautzsch, U; Sauerwein, H; Spachmann, S K; Schweigel-Röntgen, M; Hammon, H M; Kuhla, B

2013-10-01

272

Cesarean delivery and cow milk allergy/intolerance.  

PubMed

The present study provides support for a positive association between cesarean delivery and persistent cow milk allergy/cow's milk intolerance. Correspondingly, a negative association was seen between cesarean delivery and early outgrown cow milk allergy/intolerance. A possible explanation is that cesarean delivery, rather than increasing the overall risk of food allergy, increases the risk of persistency of disease among food allergic children. PMID:16076303

Eggesbø, M; Botten, G; Stigum, H; Samuelsen, S O; Brunekreef, B; Magnus, P

2005-09-01

273

Effects of supplementation of Tinospora cordifolia to crossbred cows peripartum.  

PubMed

Guduchi (Tinospora cordifolia), a medicinal plant used in ayurveda, is well documented for its immunomodulatory properties. Since the crossbred periparturient cow is highly susceptible to various diseases that effectively reduces its reproductive performance postpartum we explored the possibility of enhancing the reproductive performance of crossbred cows by guduchi supplementation peripartum. A total of 15 pregnant Karan Fries cows were selected and divided into two groups: treatment group of 8 cows which were supplemented with guduchi at 60 g/day for 45 days prepartum and 120 g/day for 45 days postpartum and unsupplemented control group of 7 cows. Jugular blood samples were collected from all cows during the periparturient period for analysis of endocrine (progesterone, total estrogens and PGFM), immunological and hematological parameters. Incidence of retention of fetal membranes, endometritis, pyometra and calf mortality were higher in control group of cows in comparison to those recorded in treated group. The guduchi supplemented cows exhibited faster uterine involution (28 days vs. 42 days) and early commencement of cyclicity (37 days vs. 58 days; based on plasma progesterone profiles) in comparison to untreated control group of cows. Mean birth weight of calves from treatment group of cows was significantly higher than those from control group however no significant difference was observed in average daily body weight gain of calves in both the groups. A higher total leukocyte, lymphocyte, neutrophil count along with increased neutrophil lymphocyte ratio was recorded in guduchi supplemented cows in comparison to untreated cows although plasma total antioxidant activity was similar between the two groups. Prepartum plasma progesterone concentration was significantly lowered in the treated group however there was no significant change in peripartum plasma total estrogens and PGFM levels due to guduchi supplementation. PMID:21163594

Mallick, Smrutirekha; Prakash, B S

2011-01-01

274

Implantation and placental development in somatic cell clone recipient cows.  

PubMed

Successful somatic cloned animal production has been reported in various domesticated species, including cattle; however, it is associated with a high rate of pregnancy failure. The low cloning yield could possibly arise from either an abnormal and/or poorly developed placenta. In comparison to control cows, fewer placentomes were found in somatic cell nuclear recipient (NT) cows at day 60 of gestation, suggesting a retardation of fetal/placental growth in these animals. NT cows not only had fewer numbers of chorionic villi but also had poorly developed caruncles. Macroscopic examination revealed atypical development of the placentome in terms of shape and size. Histological disruption of chorionic villi and caruncular septum was found in NT cows. Of particular interest was that the expression of genes, as well as proteins in the placentome, was disparate between NT and artificially inseminated cows, especially placental lactogen (PL) and pregnancy-associated glycoprotein (PAG). In contrast, prolactin-related protein-1 (PRP-1) signals were comparable across cows, including NT cows carrying immotile fetuses. The expression of extracellular matrix degrading molecule, heparanase (HPA), in NT cows was divergent from that of control cows. Microarray data suggest that gene expression was disorientated in early stages of implantation in NT cows, but this was eliminated with progression of gestation. These findings strongly support a delay in trophoblast development during early stages of placentation in NT cows, and suggest that placental specific proteins, including PLs, PAGs, and HPA, are key indicators for the aberration of gestation and placental function in cows. PMID:12398801

Hashizume, Kazuyoshi; Ishiwata, Hiroko; Kizaki, Keiichiro; Yamada, Osamu; Takahashi, Toru; Imai, Kei; Patel, Osman V; Akagi, Satoshi; Shimizu, Manabu; Takahashi, Seiya; Katsuma, Susumu; Shiojima, Satoshi; Hirasawa, Akira; Tsujimoto, Gozo; Todoroki, Junichi; Izaike, Yoshiaki

2002-01-01

275

Diet-induced alterations in total and metabolically active microbes within the rumen of dairy cows.  

PubMed

DNA-based techniques are widely used to study microbial populations; however, this approach is not specific to active microbes, because DNA may originate from inactive and/or dead cells. Using cDNA and DNA, respectively, we aimed to discriminate the active microbes from the total microbial community within the rumen of dairy cows fed diets with increasing proportions of corn silage (CS). Nine multiparous lactating Holstein cows fitted with ruminal cannulas were used in a replicated 3×3 Latin square (32-d period; 21-d adaptation) design to investigate diet-induced shifts in microbial populations by targeting the rDNA gene. Cows were fed a total mixed ration with the forage portion being either barley silage (0% CS), a 50?50 mixture of barley silage and corn silage (50% CS), or corn silage (100% CS). No differences were found for total microbes analyzed by quantitative PCR, but changes were observed within the active ones. Feeding more CS to dairy cows was accompanied by an increase in Prevotella rRNA transcripts (P?=?0.10) and a decrease in the protozoal rRNA transcripts (P<0.05). Although they were distributed differently among diets, 78% of the amplicons detected in DNA- and cDNA-based fingerprints were common to total and active bacterial communities. These may represent a bacterial core of abundant and active cells that drive the fermentation processes. In contrast, 10% of amplicons were specific to total bacteria and may represent inactive or dead cells, whereas 12% were only found within the active bacterial community and may constitute slow-growing bacteria with high metabolic activity. It appears that cDNA-based analysis is more discriminative to identify diet-induced shifts within the microbial community. This approach allows the detection of diet-induced changes in the microbial populations as well as particular bacterial amplicons that remained undetected using DNA-based methods. PMID:23593365

Lettat, Abderzak; Benchaar, Chaouki

2013-01-01

276

Diet-Induced Alterations in Total and Metabolically Active Microbes within the Rumen of Dairy Cows  

PubMed Central

DNA-based techniques are widely used to study microbial populations; however, this approach is not specific to active microbes, because DNA may originate from inactive and/or dead cells. Using cDNA and DNA, respectively, we aimed to discriminate the active microbes from the total microbial community within the rumen of dairy cows fed diets with increasing proportions of corn silage (CS). Nine multiparous lactating Holstein cows fitted with ruminal cannulas were used in a replicated 3×3 Latin square (32-d period; 21-d adaptation) design to investigate diet-induced shifts in microbial populations by targeting the rDNA gene. Cows were fed a total mixed ration with the forage portion being either barley silage (0% CS), a 50?50 mixture of barley silage and corn silage (50% CS), or corn silage (100% CS). No differences were found for total microbes analyzed by quantitative PCR, but changes were observed within the active ones. Feeding more CS to dairy cows was accompanied by an increase in Prevotella rRNA transcripts (P?=?0.10) and a decrease in the protozoal rRNA transcripts (P<0.05). Although they were distributed differently among diets, 78% of the amplicons detected in DNA- and cDNA-based fingerprints were common to total and active bacterial communities. These may represent a bacterial core of abundant and active cells that drive the fermentation processes. In contrast, 10% of amplicons were specific to total bacteria and may represent inactive or dead cells, whereas 12% were only found within the active bacterial community and may constitute slow-growing bacteria with high metabolic activity. It appears that cDNA-based analysis is more discriminative to identify diet-induced shifts within the microbial community. This approach allows the detection of diet-induced changes in the microbial populations as well as particular bacterial amplicons that remained undetected using DNA-based methods.

Lettat, Abderzak; Benchaar, Chaouki

2013-01-01

277

Intrathoracic Ectopic Liver in a Cow  

PubMed Central

ABSTRACT A solitary spherical mass was found in the caudal part of the cranial lobe of the left lung of a 28-month-old Japanese Black cow. The mass was circumscribed, embedded in the lung parenchyma and not connected to the liver or diaphragm. Histologically, the mass comprised hepatocytes, portal structures consisting of interlobular bile ducts, interlobular arteries and interlobular veins, and central veins. Based on the histological findings, a diagnosis of intrathoracic ectopic liver was made. Considering the absence of any previous history of traumatic diaphragmatic hernia or surgery, the mass might have resulted from a congenital abnormality. To our knowledge, this is the first report of intrathoracic ectopic liver in a cow that might have resulted from a congenital abnormality.

HIFUMI, Tatsuro; KAWAGUCHI, Hiroaki; YAMADA, Manabu; MIYOSHI, Noriaki

2014-01-01

278

Intrathoracic ectopic liver in a cow.  

PubMed

A solitary spherical mass was found in the caudal part of the cranial lobe of the left lung of a 28-month-old Japanese Black cow. The mass was circumscribed, embedded in the lung parenchyma and not connected to the liver or diaphragm. Histologically, the mass comprised hepatocytes, portal structures consisting of interlobular bile ducts, interlobular arteries and interlobular veins, and central veins. Based on the histological findings, a diagnosis of intrathoracic ectopic liver was made. Considering the absence of any previous history of traumatic diaphragmatic hernia or surgery, the mass might have resulted from a congenital abnormality. To our knowledge, this is the first report of intrathoracic ectopic liver in a cow that might have resulted from a congenital abnormality. PMID:24419875

Hifumi, Tatsuro; Kawaguchi, Hiroaki; Yamada, Manabu; Miyoshi, Noriaki

2014-05-01

279

Ventral laparoscopic abomasopexy on adult cows  

PubMed Central

Abstract Displacement of the abomasum is frequently diagnosed by veterinarians in bovine practice and numerous surgical techniques have been developed to treat and prevent this condition. Complications secondary to those techniques are related to their degree of invasiveness and the development of postoperative wound infections. The objectives of this study were to describe a safe and reliable abomasopexy technique by laparoscopy and to assess postoperative adhesion formation. A ventral laparoscopic abomasopexy was performed on 10 adult dry cows. The abomasum was fixed with 4 simple interrupted sutures using USP 2 polydioxanone suture material. No major complications were encountered during the surgery. Abomasal adhesions were visually evaluated by laparoscopy 3 mo postoperatively. This technique proved to be simple and safe, and it provided adequate abomasum fixation in healthy dry cows. It could be used to surgically correct left displaced abomasum.

Desrochers, Andre; Boure, Ludovic; Helie, Pierre

2006-01-01

280

Electrostatic Radionuclide Separation: A New Version of Rutherford's "Thorium Cow".  

ERIC Educational Resources Information Center

Describes three experiments (also useful as demonstrations) using a "thorium cow," a device which concentrates the daughter products from thorium compounds by precipitation on a charged electrode. (JN)

Eiswirth, Marcus; And Others

1982-01-01

281

Nasal chondrosarcoma in a Simmental cow  

PubMed Central

Abstract The pathologic features of a nasal chondrosarcoma, a rare tumor of bovines, in a Simmental cow are described. Upon clinical examination, stertor, difficulty in breathing, poor body condition, and a nasal mass were found. Histopathologic examination revealed that the mass was composed mostly of numerous cartilaginous lobules surrounded by spindle-shaped cells, often showing mitotic figures, atypical chondrocytes, and lacunae containing 2 or more cells. On the basis of the histological features, the mass was diagnosed as a nasal chondrosarcoma.

Kilic, E.; Ozturk, S.; Ozba, B.

2006-01-01

282

Effects of Recombinant Bovine Somatotropin on Milk Production, Body Composition, and Physiological Parameters1  

Microsoft Academic Search

Twenty-eight multiparous Holstein cows were utilized to determine effects of long-term administration of recombi- nant bovine somatotropin on lactational performance, body condition, body com- position, hormones, blood constituents, and physiological parameters. Treatments were 0 (control), 10.3, 20.6, and 41.2 mg recombinant bovine somatotropin admin- istered daily as subcutaneous injections beginning 4 to 5 wk postpartum and continuing for 38 wk.

C. G. Soderholm; D. E. Otterby; J. G. Linn; F. R. Ehle; J. E. Wheaton; W. P. Hansen; R. J. Annexstad

1988-01-01

283

Environmental stressors influencing hormones and systems physiology in cattle.  

PubMed

Environmental stressors undoubtedly influence organismal biology, specifically the endocrine system that, in turn, impact cattle at the systems physiology level. Despite the significant advances in understanding the genetic determinants of the ideal dairy or beef cow, there is a grave lack of understanding of the systems physiology and effects of the environmental stressors that interfere with the endocrine system. This is a major problem because the lack of such knowledge is preventing advances in understanding gene-environment interactions and developing science-based solutions to these challenges. In this review, we synthesize the current knowledge on the nature of the major environmental stressors, such as climate (heat, cold, wind, and humidity), nutrition (feeds, feeding systems, and endocrine disruptors) and management (housing density and conditions, transportation, weaning practices). We summarize the impact of each one of these factors on cattle at the systems level, and provide solutions for the challenges. PMID:24996419

Bova, Toree L; Chiavaccini, Ludovica; Cline, Garrett F; Hart, Caitlin G; Matheny, Kelli; Muth, Ashleigh M; Voelz, Benjamin E; Kesler, Darrel; Memili, Erdo?an

2014-01-01

284

Environmental stressors influencing hormones and systems physiology in cattle  

PubMed Central

Environmental stressors undoubtedly influence organismal biology, specifically the endocrine system that, in turn, impact cattle at the systems physiology level. Despite the significant advances in understanding the genetic determinants of the ideal dairy or beef cow, there is a grave lack of understanding of the systems physiology and effects of the environmental stressors that interfere with the endocrine system. This is a major problem because the lack of such knowledge is preventing advances in understanding gene-environment interactions and developing science-based solutions to these challenges. In this review, we synthesize the current knowledge on the nature of the major environmental stressors, such as climate (heat, cold, wind, and humidity), nutrition (feeds, feeding systems, and endocrine disruptors) and management (housing density and conditions, transportation, weaning practices). We summarize the impact of each one of these factors on cattle at the systems level, and provide solutions for the challenges.

2014-01-01

285

Space physiology and medicine (2nd edition)  

NASA Technical Reports Server (NTRS)

The fundamental biomedical issues involved in manned space flight are examined in review chapters contributed by leading U.S. experts. Sections are devoted to the history of manned space flight, the space environment, space-flight systems and procedures, physiological adaptation to space flight, health maintenance of space crewmembers, and medical problems of space flight. Extensive diagrams, drawings, graphs, photographs, and tables of numerical data are provided.

Nicogossian, Arnauld E. (editor); Huntoon, Carolyn Leach (editor); Pool, Sam L. (editor)

1989-01-01

286

Cow's milk allergy in multiple sclerosis patients  

PubMed Central

Background: Exposure to some environmental agent such as different nutrition and contact with allergens may have a role in developing multiple sclerosis (MS). The present study was aimed to evaluate the cow's milk allergy (CMA) in MS patients compared to healthy controls. Materials and Methods: Between March 2012 and July 2012, 48 MS patients were selected and compared with 48 healthy subjectsto assess the frequency of CMA in MS patients compared to healthy control. Cow's milk specific immunoglobin E (IgE) was determined by Immuno CAP. Sex and the frequency of CMA were compared between study groups by Chi-square test. Results: Total of 96 subjects were assessed (22% male and 78% female). The mean age of the study subjects was 30.8 ± 6.6 years. Mean age of case and control groups was 30.7 (±6.9) versus 30.9 ± 6.3, respectively (P value = 0.83). There were no detection of cow's milk specific IgE in serum of MS patients and healthy subjects. Conclusion: There was no difference between MS and healthy subjects regarding CMA.

Ashtari, Fereshteh; Jamshidi, Fatemeh; Shoormasti, Raheleh Shokouhi; Pourpak, Zahra; Akbari, Mojtaba

2013-01-01

287

Current Topics for Teaching Skeletal Muscle Physiology  

NSDL National Science Digital Library

Contractions of skeletal muscles provide the stability and power for all body movements. Consequently, any impairment in skeletal muscle function results in some degree of instability or immobility. Factors that influence skeletal muscle structure and function are therefore of great interest both scientifically and clinically. Injury, disease, and old age are among the factors that commonly contribute to impairment in skeletal muscle function. The goal of this article is to update current concepts of skeletal muscle physiology. Particular emphasis is placed on mechanisms of injury, repair, and adaptation in skeletal muscle as well as mechanisms underlying the declining skeletal muscle structure and function associated with aging. For additional materials please refer to the "Skeletal Muscle Physiology" presentation located on the American Physiological Society Archive of Teaching Resources Web site (http://www.apsarchive.org).

Susan V. Brooks (University of Michigan)

2003-12-01

288

[From quantum to integrative physiology].  

PubMed

Physiology studies the functions of different organs, systems and how they maintain the integrity of organisms. Nervous and endocrine systems react to stimulus, causality plays a key role in their activities. Physical and chemical conditions of fluids in the internal environment serve as a background and an active modulator for regulatory influences. Autacoid formation is in many respects based on probable events. It has been proved, that during the formation of regulatory systems in cell evolution the appearance of regulatory molecules was based on statistical probability of quantum events: sporadical appearance in cells during metabolism of peptides, lipids, hydrolysis of larger molecules on fragments, quanta, which received physiological activity in the form of function regulators. These processes in their adapted, according to Darwin's mechanism of natural selection, value were recorded into the genome since synthesis readings of the polypeptides were fixed. The formation of multicellular organisms was promoted by the arise of regulatory systems and their integration under the supervision of the nervous system. PMID:21427965

Natochin, Iu V

2010-11-01

289

Physiologic and pharmacokinetic changes in pregnancy  

PubMed Central

Physiologic changes in pregnancy induce profound alterations to the pharmacokinetic properties of many medications. These changes affect distribution, absorption, metabolism, and excretion of drugs, and thus may impact their pharmacodynamic properties during pregnancy. Pregnant women undergo several adaptations in many organ systems. Some adaptations are secondary to hormonal changes in pregnancy, while others occur to support the gravid woman and her developing fetus. Some of the changes in maternal physiology during pregnancy include, for example, increased maternal fat and total body water, decreased plasma protein concentrations, especially albumin, increased maternal blood volume, cardiac output, and blood flow to the kidneys and uteroplacental unit, and decreased blood pressure. The maternal blood volume expansion occurs at a larger proportion than the increase in red blood cell mass, which results in physiologic anemia and hemodilution. Other physiologic changes include increased tidal volume, partially compensated respiratory alkalosis, delayed gastric emptying and gastrointestinal motility, and altered activity of hepatic drug metabolizing enzymes. Understating these changes and their profound impact on the pharmacokinetic properties of drugs in pregnancy is essential to optimize maternal and fetal health.

Costantine, Maged M.

2014-01-01

290

Anorectal physiology and testing.  

PubMed

A good understanding of anorectal physiology is essential for the diagnosis and appropriate treatment of various anorectal disorders, such as fecal incontinence, constipation, and pain. This article reviews the physiology of the anorectum and details the various investigations used to diagnose anorectal physiology disorders. These anatomic and functional tests include anal manometry, endoanal ultrasound, defecography, balloon expulsion test, magnetic resonance imaging, pudendal nerve terminal motor latency, electromyography, and colonic transit studies. Indications for investigations, steps in performing the tests, and interpretation of results are discussed. PMID:24280396

Van Koughnett, Julie Ann M; da Silva, Giovanna

2013-12-01

291

Liquid supplement and forage intake by range beef cows.  

PubMed

One hundred eighty crossbred cows were assigned to one of six native range pastures during two winters to evaluate forage and supplement intake as affected by liquid supplement (yr 1: 50% crude protein, 84% from urea; yr 2: 57% crude protein, 91% from urea) delivery method and cow age (2, 3, 4, 5, or 6 yr). Treatments were: 1) no supplement (Control); 2) a lick-wheel feeder containing liquid supplement (ADLIB); and 3) a computer-controlled lick-wheel feeder that dispensed 0.9 kg x cow(-1) x d(-1) of liquid supplement (average 0.5 kg of dry matter x cow(-1) x d(-1); Restricted). Each treatment was applied to two pastures. Forage digestibility was increased (P = 0.03) by supplementation. Supplemented cows lost less (P = 0.05) body condition than unsupplemented cows (average -0.3 vs -0.6). Blood urea nitrogen (BUN) was highest (P = 0.001) for ADLIB (8.7 mg/dL), intermediate for Restricted (6.2 mg/dL), and lowest for Control (2.3 mg/dL). Forage DMI was 31% higher (P = 0.01) in 1995 than in 1996, and was increased (P = 0.02) by supplementation both years. Cows supplemented with ADLIB consumed 23% more forage dry matter than Control cows, whereas Restricted cows consumed 21% more dry matter than ADLIB cows. Supplement intake by cows on ADLIB was greater (P = 0.001) than by cows on Restricted in both years. Supplement intake was lowest (P = 0.002) by 2-yr-old cows, intermediate by 3-yr-olds, and greatest by 4-, 5-, and 6-yr-old cows. Variation in supplement intake by individual cows was higher (P = 0.09) for cows in the Restricted treatment (coefficient of variation [CV] = 117%) than those on ADLIB (CV = 68%) during the first year, but did not differ between supplement treatments (average CV = 62%) in the second year. The proportions of cows consuming less than 0.3 kg/d of supplement dry matter intake (DMI) and consuming less than the target amount of supplement (0.5 kg DMI) were less (P = 0.001) for ADLIB than for Restricted during both years. ADLIB cows spent more (P = 0.001) time at the supplement feeder and had more (P < 0.002) supplement feeding bouts than Restricted cows during both years. During the first year, 2- and 3-yr-old cows spent less (P < 0.01) time at the feeder and had fewer feeding bouts per day than 6-yr-old cows. Age had no effect (P > 0.24) on feeding behavior during the second year. Supplementation of beef cows grazing winter range with 50 to 57% crude protein liquid supplement increased forage digestibility and intake. Restricting supplement access increased forage consumption and variability of supplement intake. PMID:12597401

Sowell, B F; Bowman, J G P; Grings, E E; MacNeil, M D

2003-01-01

292

Characteristics of patients suffering from cow milk allergy.  

PubMed

The most frequent symptoms among the manifestations of cow milk allergy (CMA) are gastrointestinal. CMA pathogenesis involves immunological mechanisms with participation of immunocompetent cells, production of immunoglobulin E (IgE) and immunoglobulin G (IgG). We aim to determine whether cow milk-specific IgE antibodies coexist with cow milk-specific IgG antibodies in CMA patients with diarrhea symptom, and if there is any relationship between both antibody types. 65 CMA patients (average age of 17 years, ranging from 2 to 74 years), all of who had diarrhea symptom of CMA, were enrolled in this study. The total cow IgE and IgG subclass in serum were measured by electrochemiluminescence immunoassay and rate immune scatter turbidimetry, respectively. And also the cow milk-specific IgE was determined by enzyme-linked immunosorbent assay. The number of eosinophils in serum was calculated by Sysmex XE-2100 Hematology Analyzer. Our data showed that both cow milk-specific IgG and IgE levels were significantly elevated in CMA patients compared to those of age-matched control subjects. Out of the 65 CMA patients, 40 showed elevated cow milk-specific IgE antibody level, among which, 28 cases presented highly sensitive reaction to cow milk-specific IgG, along with each six of moderate and mild sensitive reaction to cow milk-specific IgG; while 20 showed elevated total IgG levels. The IgG3 positive rate was 16.9%, which was the highest. A moderate correlation between cow milk-specific IgE and cow milk-specific IgG was found in the CMA patients (r=0.415, P=0.001). The results indicated that cow milk-specific IgE antibodies could coexist with cow milk-specific IgG antibodies in patients suffering from CMA. The aberrant changes in the concentration of cow milk-specific IgE antibodies were associated with cow milk-specific IgG antibodies. PMID:22722049

Liu, Li-Li; Yao, Hong; Zhang, Xiao-Ling; Zhang, Hui-Lin; Chao, Peng-Li; Tong, Man-Li; Liu, Gui-Li; Lin, Li-Rong; Fan-Liu; Zhang, Zhong-Ying; Yang, Tian-Ci

2012-09-01

293

Effects of maternal nutrient restriction followed by realimentation during early and midgestation on beef cows. I. Maternal performance and organ weights at different stages of gestation.  

PubMed

The objectives were to evaluate the effects of nutrient restriction during early to midgestation followed by realimentation on maternal performance and organ mass in pregnant beef cows. On d 30 of pregnancy, multiparous, nonlactating cows (initial BW = 620.5 ± 11.3 kg and BCS = 5.1 ± 0.1) were assigned to 1 of 3 dietary treatments: control (CON; 100% NRC; n = 18) and restricted (RES; 60% NRC; n = 30). On d 85, cows were slaughtered (CON, n = 6; R, n = 6), remained on control (CC; n = 12) and restricted (RR; n = 12), or were realimented to control (RC; n = 11). On d 140, cows were slaughtered (CC, n = 6; RR, n = 6; RC, n = 5), remained on control (CCC, n = 6; RCC, n = 5), or were realimented to control (RRC, n = 6). On d 254, all remaining cows were slaughtered. Cows were weighed before slaughter and all maternal organs were dissected and weighed. The diet consisted of grass hay to meet 100 or 60% NEm recommendations for fetal growth and to meet or exceed recommendations for other nutrients. At d 85 slaughters, BW and empty BW (EBW) were not affected (P ? 0.84) by maternal nutrition. However back fat was decreased (P = 0.05) in RES vs. CON cows. Large intestine and abomasum mass were increased (P ? 0.05) in RES cows vs. CON. At d 140, BW was decreased (P = 0.05) and EBW tended to be decreased (P = 0.10) in RRC cows vs. CCC and RCC being intermediate. Liver mass was decreased (P = 0.02) in RR vs. CC with RC being intermediate. Ruminal mass was decreased (P = 0.003) in RR vs. CC and RC cows. At d 254, BW and EBW were similar (P ? 0.78) across treatments. We observed partial changes in maternal weight and organ masses due to different lengths of maternal nutrient restriction followed by realimentation. It appears that the dam undergoes some adaptations during an early to midgestation nutrient restriction and becomes more efficient in the utilization of nutrients after being realimented and as gestation advances. PMID:24664560

Camacho, L E; Lemley, C O; Van Emon, M L; Caton, J S; Swanson, K C; Vonnahme, K A

2014-02-01

294

Chromosome fragility in river buffalo cows exposed to dioxins.  

PubMed

Fifty river buffalo (Bubalus bubalis, 2n?=?50) cows reared in two different provinces of Campania (southern Italy) underwent cytogenetic investigations to ascertain possible differences in their chromosome stability. One group (Caserta province) was under legal sequestration due to the presence in the milk mass of higher mean values of dioxins [21.79 pg/g of fat as sum of polychloro-dibenzo-dioxins (PCDDs), polychloro-dibenzo-furans (PCDFs) and dioxin-like polychlorobiphenyls (DL-PCBs)] than both those permitted (6.0 pg/g of fat as WHO-TEQ) and those (1.3 pg/g of fat as WHO-TEQ) observed in the control group raised in Salerno province. Two types of peripheral blood cell cultures were performed: without (normal cultures for the chromosome abnormality (CA) test: chromatid breaks, chromosome breaks, fragments) and with the addition of BrdU for the sister chromatid exchange (SCE) test). The CA test revealed a significantly (P?cows compared to the control. Indeed, mean values of CA/cell were 1.26?±?1.15 in exposed cows and 0.37?±?0.71 in the control. Mean SCE was higher in exposed cows (8.50?±?3.35) than that (8.29?±?3.51) found in the control but the difference was not significant. Comparison within the same group of cows at first (FL) and multiple (ML) lactations revealed significantly (P?cows vs FL-cows while no statistical differences were found between ML-cows and FL-cows in the control farm. By contrast, significantly (P?cows versus ML-cows. Comparisons with other previous studied species (sheep and cattle) were also performed. PMID:22415351

Genualdo, V; Perucatti, A; Iannuzzi, A; Di Meo, G P; Spagnuolo, S M; Caputi-Jambrenghi, A; Coletta, A; Vonghia, G; Iannuzzi, L

2012-05-01

295

Adventures in Exercise Physiology  

NSDL National Science Digital Library

The author altered the format of an exercise physiology course from traditional lecture to emphasizing daily reading quizzes and group problem-solving activities. The SALGains evaluation was used to compare the two approaches and significant improvements

Fitzpatrick, Kathleen A.

2004-09-01

296

Anatomy and Physiology Everyday  

NSDL National Science Digital Library

Students use information from newspaper articles to write a paper or presentation on the correlation of information from the article and their understanding of it using knowledge gained in anatomy and physiology class.

Teresa Alvarez (St. Louis Community College Forest Park AHNS)

2008-08-22

297

Endogenous Pyrogen Physiology.  

ERIC Educational Resources Information Center

Discusses the physiology of endogenous pyrogen (EP), the fever-producing factor of cellular origin. Included are: its hormone-like role, its molecular nature, bioassay procedures, cellular production and mechanisms of EP action. (SA)

Beisel, William R.

1980-01-01

298

Physiology Without Borders  

NSDL National Science Digital Library

This article is a discussion about the limits of the field of Physiology saying that the wide range of affiliations and topics reflects the enormously broad range of interests that are covered by physiologists.

MD/PhD Ulrich Pohl (University Munich Physiology Inst)

2005-06-01

299

Bridging innate and adaptive immunity.  

PubMed

The Nobel Prize in Physiology or Medicine for 2011 to Jules Hoffmann, Bruce Beutler, and the late Ralph Steinman recognizes accomplishments in understanding and unifying the two strands of immunology, the evolutionarily ancient innate immune response and modern adaptive immunity. PMID:22153065

Paul, William E

2011-12-01

300

Ecological Restoration and Physiology: An Overdue Integration  

NSDL National Science Digital Library

There is growing recognition that opportunities exist to use physiology as part of the conservation and management of populations and ecosystems. However, this idea has rarely been extended to the field of restoration ecology. Physiological metrics (e.g., gas exchange, energy transfer and metabolism, stress response, nutritional condition, gene expression) from a range of taxa can be used to understand the function of ecosystems as well as the factors that influence their structure. Such knowledge can assist the development and implementation of effective restoration strategies that recognize the role of habitat quality on organismal performance. Furthermore, physiological tools can be used to monitor the success of restoration projects during their implementation and as part of postproject monitoring. The often rapid response of physiological metrics provides more immediate information, enabling an adaptive approach to restoration, than can usually be obtained if the focus is solely on population- or ecosystem-level metrics. Greater integration of physiological responses into ecological restoration will provide practitioners with fundamental scientific information needed to design, implement, and monitor restoration activities to aid in repairing ecosystems around the globe.

Steven J. Cooke (Carleton University;)

2008-11-03

301

Liquid supplement and forage intake by range beef cows1  

Microsoft Academic Search

One hundred eighty crossbred cows were assigned to one of six native range pastures during two winters to evaluate forage and supplement intake as affected by liquid supplement (yr 1: 50% crude pro- tein, 84% from urea; yr 2: 57% crude protein, 91% from urea) delivery method and cow age (2, 3, 4, 5, or 6 yr). Treatments were: 1)

B. F. Sowell; J. G. P. Bowman; E. E. Grings; M. D. MacNeil

2010-01-01

302

Plasma Fibrinogen Levels in Normal and Sick Cows  

PubMed Central

Mean plasma fibrinogen levels were determined in 133 normal calves, bulls, non-pregnant and pregnant cows. These were 508, 505, 660, and 581 mg per 100 ml of plasma respectively. The levels in 233 sick cows were often greatly increased. This appeared to be related to inflammation and tissue destruction. Lower than normal levels were sometimes seen in liver disease and terminal states.

McSherry, B. J.; Horney, F. D.; deGroot, J. J.

1970-01-01

303

Metabolism of Silage Alcohols in Lactating Dairy Cows  

Microsoft Academic Search

Dairycowsfedsilagearesubjectedtovariousalcohols and low molecular weight esters. Four lactating Hol- stein cows fitted with ruminal cannulas and permanent indwelling catheters in the hepatic portal vein, hepatic vein, mesenteric vein, and mesenteric artery were used to study the absorption of alcohols into portal blood and the metabolism of feed alcohols in the rumen and splanchnic tissues. The cows were allocated to 4

N. B. Kristensen; A. Storm; B. M. L. Raun; B. A. Røjen; D. L. Harmon

2007-01-01

304

Mad Cow Disease and U.S. Beef Trade.  

National Technical Information Service (NTIS)

The 110th Congress is expected to monitor closely U.S. efforts to regain foreign markets that banned U.S. beef when a cow in Washington state tested positive for bovine spongiform encephalopathy (BSE, or mad cow disease) in December 2003. Rebuilding forei...

C. E. Hanrahan G. S. Becker

2006-01-01

305

Pollen analysis of Iron Age cow dung in southern Africa  

Microsoft Academic Search

Thick accumulations of consolidated cow dung occur in ancientkraals (byres or corrals) in the bushveld and highveld areas of Zimbabwe, Botswana, and South Africa dating from the last 2000 years. They originated from long-term cattle herding by Iron Age people. The “vitrified” or baked dung deposits are thought to be a product of the burning of cow dung as fuel,

José S. Carrión; Louis Scott; Tom Huffman; Cobus Dreyer

2000-01-01

306

Cow-Related Risk Factors for Milk Leakage  

Microsoft Academic Search

Milk leakage in dairy cows is a symptom of impaired teat sphincter function. Milk leakage is related to an increased risk of mastitis in heifers and cows, and causes hygiene problems. The aim of our study was to assess whether teat shape, condition of teat orifice, and peak milk flow rate are risk factors for milk leakage. We conducted a

I. C. Klaas; C. Enevoldsen; A. K. Ersbøll; U. Tölle

2005-01-01

307

Factors Associated with Colostral Specific Gravity in Dairy Cows  

Microsoft Academic Search

The objectives of this study were to identify factors associated with colostral specific gravity in dairy cows, as measured by a commercially available hydrometer (Colostrometer). Colostral specific gravity was mea- sured in 1085 first-milking colostrum samples from 608 dairy cows of four breeds on a single farm during a 5- yr period. Effects of breed, lactation number, and month and

D. E. Morin; P. D. Constable; F. P. Maunsell; G. C. McCoy

2001-01-01

308

Cow Body Shape and Automation of Condition Scoring  

Microsoft Academic Search

The feasibility of including a body shape measure in methods for automatic monitoring of body reserves of cattle was evaluated. The hypothesis tested was that the body shape of a fatter cow is rounder than that of a thin cow and, therefore, may better fit a parabolic shape. An image-processing model was designed that calculates a parameter to assess body

I. Halachmi; P. Polak; D. J. Roberts; M. Klopcic

2008-01-01

309

A La Carts: You Want Wireless Mobility? Have a COW  

ERIC Educational Resources Information Center

Computers on wheels, or COWs, combine the wireless technology of today with the audio/visual carts of yesteryear for an entirely new spin on mobility. Increasingly used by districts with laptop computing initiatives, COWs are among the hottest high-tech sellers in schools today, according to market research firm Quality Education Data. In this…

Villano, Matt

2006-01-01

310

Induction of ovulation in postpartum suckled beef cows: A review  

Microsoft Academic Search

Prolonged postpartum acyclicity in suckled beef cows reduces the calf crop, and causes economic loss to beef cattle producers. Once anterior pituitary LH stores have been replenished between Days 15 and 30 post partum in suckled beef cows, methods to initiate cyclicity include non-hormonal methods such as weaning of calves (either complete, temporary or partial), or exposure to bulls, and

Y. Yavas; J. S. Wallon

2000-01-01

311

Short communication: Flooring preferences of dairy cows at calving.  

PubMed

The present study investigated the flooring preference during the 30h before parturition in Holstein dairy cows housed individually in a maternity pen. Seventeen multiparous cows were moved, on average, 2 d before expected calving date into an individual maternity pen with 3 different flooring surfaces: 10cm of sand, pebble-top rubber mats, or concrete flooring, each covered with 15cm of straw. Calving location, lying time, and total time and number of lying bouts on each of the floor types were recorded during 2 periods: precalving (24 to 29h before calving) and at calving (0 to 5h before calving). Ten cows calved on sand, 6 on concrete, and 1 on the rubber mat. Lying bouts increased during the hours closest to calving, regardless of flooring. The number of lying bouts did not differ between flooring types precalving but cows had more lying bouts on sand and concrete compared with rubber at calving. Cows spent more time lying down on sand and concrete compared with rubber precalving, but lying times did not differ between treatments at calving. Cows that calved on sand spent more time lying on sand at calving compared with the other 2 flooring types. Cows that calved on concrete did not show a flooring preference at calving. These results indicate that rubber mats are the least preferred by dairy cows in the maternity pens, even when covered with a deep layer of straw. PMID:24359828

Campler, M; Munksgaard, L; Jensen, M B; Weary, D M; von Keyserlingk, M A G

2014-02-01

312

Diagnosis of cow's milk allergy in children: determining the gold standard?  

PubMed

Cow's milk protein allergy (CMPA) affect many organs, from mouth to gut, with, immediate and delayed reactions, including infantile colic, food protein induced enterocolitis syndrome, enteropathy, eosinophilic disorders, among which infantile proctocolitis, and "dysmotility" disturbances, gastro-esophageal reflux and constipation. Diagnosis follows usual steps, careful history taking and medical examination, before starting an elimination diet, for diagnosis and treatment. Beyond, laboratory tests may help, but definitive conclusion will arise from the oral food challenge. The double-blind-placebo-controlled-food challenge, the "gold standard", is needed in clinical research. The food challenge includes the progressive at-home reintroduction of milk, all the more needed since most cases of CMPA in infants are delayed: in clinical practice, diagnosing CMPA is more than saying if the child reacts to cow's milk. One has to define the syndrome the child is suffering from, the risk implied, the best replacement formula. When tolerance develops, a second diagnostic procedure allows seeing if the child has outgrown his disease and, if not, what is the expected outcome and which type of food is best adapted: small amounts of milk, or transformed forms, such as baked milk. Primary care practice is adapted to non-IgE mediated CMPA. When CMPA is part of multiple food allergies or of an eosinophilic disorder, referral centers will perform multiple allergy testing, endoscopic procedures and complex dietary guidance. PMID:24410539

Dupont, Christophe

2014-02-01

313

Effects on Nutrient and Hormonal Profile of Long-Term Infusions of Glucose or Insulin Plus Glucose in Cows Treated with Recombinant Bovine Somatotropin Before Peak Milk Yield  

Microsoft Academic Search

Ten Holstein cows were treated with 30.9 mg·d-1 of recombinant bST from 15 to 41 d of lactation. The Latin square design included three infusion periods of 6 d each with 3 d of rest between infusion periods. Infusions were physiological saline, glucose (50 g·h-1) , and insulin plus glucose (12.5 IU·h-1 +5 0 g·h-1) . Blood was collected continuously

Martin Léonard; Elliot Block

1997-01-01

314

Lead absorption in cows: biological indicators of ambient lead exposure  

SciTech Connect

In order to determine actual lead exposure from residual amounts of lead in the environmental soil following the introduction of effective engineering emission controls in a lead smeltery, the absorption of lead in cows grazing in the vicinity was investigated. Four groups of cows were examined: two groups of cows exposed to different ambient lead concentration, compared with two normal groups of cows. In each cow aminolevulinic acid dehydratase (ALAD), erythrocyte protoporphyrin (EP) and blood lead (Pb-B) were determined, two years prior to and four years after the technical sanitation of the lead emission source. The results demonstrated normalization of ALAD, EP and Pb-B after the technical sanitation. In spite of normalization, biological indicators ALAD and Pb-B determined four years after the technical sanitation showed increased lead absorption in comparison with the results of the control group. This indirectly indicates lead contamination of the environment from residual amounts of lead in the soil.

Karacic, V.; Prpic-Majic, D.; Skender, L.

1984-03-01

315

Intrauterine ozone treatment of retained fetal membrane in Simmental cows.  

PubMed

The aim of research was to determine influence of intrauterine application of two different ozone preparations on reproductive performance in Simmental cows with retained fetal membranes (RFM). The study was performed on 143 Simmental cows aged 2-8 years and divided in three groups. Group A (n=46) consisted of cows treated with foam spray ozone applied into the body of the uterus for 5s using a sterile catheter. Group B (n=50) consisted of cows treated using six ozone pearls intrauterinely at once, as deeply and hygienically possible. Cows were observed and treated during early puerperium, 24-36h after parturition. The third group (n=47) consisted of cows without RFM (control group). To assess the reproductive performance of cows, the interval from calving to first insemination (days not pregnant to first service, DOFS), interval from calving to pregnancy (days not pregnant to pregnancy, DOP), relative pregnancy rate (%), first service conception rate (FSCR, %) and all service conception rate (ASCR, %) were measured. The estimate of hazard ratio for the Groups A and B relative to control group with DOFS were 0.423 (P=0.0006) and 0.434 (P=0.0005), and with DOP were 0.701 (P=0.003) and 0.411 (P=0.0003), respectively, implying that cows in the control group were not pregnant longer until first insemination and pregnancy. Variables that had an influence on DOFS were postpartum fever (PPF) (HR=0.458; P=0.003) and milk yield (HR=0.999; P<0.0001) and an influence on DOP were PPF (HR=0.314; P=0.001) and milk yield (HR=0.999; P<0.0001). Cows with RFM treated with intrauterine Riger spray or Ripromed ovuli O(3) have similar or enhanced reproductive performance results compared to the control group of cows demonstrating the effectiveness of therapy with intrauterine ozone products. PMID:22959513

Djuricic, D; Vince, S; Ablondi, M; Dobranic, T; Samardzija, M

2012-10-01

316

Faecal Microbiota and Short-Chain Fatty Acid Levels in Faeces from Infants with Cow‘s Milk Protein Allergy  

Microsoft Academic Search

Background: The present study was designed to compare the faecal microbiota and concentrations of faecal short-chain fatty acid and ammonia between healthy and cow’s milk protein allergic (CMPA) infants. Methods: The population comprised 92 infants aged 2–12 months who were nonallergic (n = 46) or diagnosed as having CMPA (n = 46). Faecal samples were analyzed by fluorescent in situ

Oscar C. Thompson-Chagoyan; Matteo Fallani; José Maldonado; José M. Vieites; Sheila Khanna; Christine Edwards; Joël Doré; Angel Gil

2011-01-01

317

Production diseases of the transition cow.  

PubMed

Production diseases of the dairy cow are caused by a level of production inconsistent with nutrient intake, provision of an inadequate diet, an unsuitable environment, an inappropriate breeding policy or various combinations of these factors. Although the transition period of 3 weeks pre-calving until 3 weeks post-calving is associated with a peak incidence of production disease, the effects of these diseases on dairy cow health and productivity extend far into the following lactation. Recent advances in understanding of production diseases include the emergence of propylene glycol and rumen protected choline as the supplements of choice for preventing fatty liver and the absence of any preventative effect of increased energy density in the close-up dry period diet on this condition; the linear negative influence of dietary cation anion difference (DCAD) on the incidence of milk fever regardless of urinary pH or the target level of dietary DCAD achieved; the inflammatory response associated with subacute rumen acidosis and its effect on feed intake; an increased awareness of the potential for antioxidant status to improve immunity and health in the transition period; the development of more standardised diagnostic criteria and treatment protocols for uterine infection. A significant body of knowledge already exists which should allow for the optimal management and prevention of bovine production diseases. One of the important challenges facing the dairy industry is the development, implementation and economic assessment of practical, integrated, blueprints of best practice for prevention of the production diseases and other diseases of the dairy cow. PMID:18342556

Mulligan, F J; Doherty, M L

2008-04-01

318

Performance of dairy cows fed high levels of acetic acid or ethanol.  

PubMed

Ethanol and acetic acid are common end products from silages. The main objective of this study was to determine whether high concentrations of ethanol or acetic acid in total mixed ration would affect performance in dairy cows. Thirty mid-lactation Holstein cows were grouped in 10 blocks and fed one of the following diets for 7 wk: (1) control (33% Bermuda hay + 67% concentrates), (2) ethanol [control diet + 5% ethanol, dry matter (DM) basis], or (3) acetic acid (control diet + 5% acetic acid, DM basis). Ethanol and acetic acid were diluted in water (1:2) and sprayed onto total mixed rations twice daily before feeding. An equal amount of water was mixed with the control ration. To adapt animals to these treatments, cows were fed only half of the treatment dose during the first week of study. Cows fed ethanol yielded more milk (37.9 kg/d) than those fed the control (35.8 kg/d) or acetic acid (35.3 kg/d) diets, mainly due to the higher DM intake (DMI; 23.7, 22.2, and 21.6 kg/d, respectively). The significant diet × week interaction for DMI, mainly during wk 2 and 3 (when acetic acid reached the full dose), was related to the decrease in DMI observed for the acetic acid treatment. There was a diet × week interaction in excretion of milk energy per DMI during wk 2 and 3, due to cows fed acetic acid sustained milk yield despite lower DMI. Energy efficiency was similar across diets. Blood metabolites (glucose, insulin, nonesterified fatty acids, ethanol, and ?-glutamyl transferase activity) and sensory characteristics of milk were not affected by these treatments. Animal performance suggested similar energy value for the diet containing ethanol compared with other diets. Rumen conversion of ethanol to acetate and a concomitant increase in methane production might be a plausible explanation for the deviation of the predicted energy value based on the heat of combustion. Therefore, the loss of volatile compounds during the drying process in the laboratory should be considered when calculating energy content of fermented feedstuffs. PMID:23141834

Daniel, J L P; Amaral, R C; Sá Neto, A; Cabezas-Garcia, E H; Bispo, A W; Zopollatto, M; Cardoso, T L; Spoto, M H F; Santos, F A P; Nussio, L G

2013-01-01

319

Does diverse grazing behavior of suckler cows have an impact on predicted methane emissions?  

PubMed

A modeling study based on a dataset from a large-scale grazing study was used to identify the potential impact of grazing behavior and performance of diverse cow genotypes on predicted methane (CH4) emissions. Lactating cows grazing extensive seminatural grassland and heath vegetation were monitored with Global Positioning System collars and activity sensors. The diet selected by cows of 3 different genotypes, Aberdeen Angus cross Limousin (AxL), Charolais (CHA), and Luing (LUI), was simulated by matching their locations during active periods with hill vegetation maps. Measured performance and activity were used to predict energy requirements, DMI, and CH4 output. The cumulative effect of actual performance, diet selection, and actual physical activity on potential CH4 output and yield was estimated. Sensitivity analyses were performed for the digestibility of intake, energy cost of activity, proportion of milk consumed by calves, and reproductive efficiency. Although with a better performance (P < 0.05), LUI required less total energy than the other genotypes (P < 0.001) as the other 2 spent more energy for maintenance (P < 0.001) and activity (P < 0.001). By selecting a better quality diet (P < 0.03), estimated CH4 of CHA cow-calf pairs was lower than AxL (P = 0.001) and slightly lower than LUI (P = 0.08). Energy lost as CH4 was 0.17 and 0.58% lower for LUI than AxL and CHA (P < 0.002). This study suggests for the first time that measured activity has a major impact on estimated CH4 outputs. A 15% difference of the cow-calf pair CH4 was estimated when using different coefficients to convert actual activity into energy. Predicted CH4 was highly sensitive to small changes in diet quality, suggesting the relative importance of diet selection on heterogeneous rangelands. Extending these results to a farm systems scale, CH4 outputs were also highly sensitive to reductions in weaning rates, illustrating the impact on CH4 at the farm-system level of using poorly adapted genotypes on habitats where their performances may be compromised. This paper demonstrates that variations in grazing behavior and grazing choice have a potentially large impact on CH4 emissions, illustrating the importance of including these factors in calculating realistic national and global estimates. PMID:24665106

Ricci, P; Umstätter, C; Holland, J P; Waterhouse, A

2014-03-01

320

Pathologic and physiologic phimosis  

PubMed Central

OBJECTIVE To review the differences between physiologic and pathologic phimosis, review proper foreskin care, and discuss when it is appropriate to seek consultation regarding a phimotic foreskin. SOURCES OF INFORMATION This paper is based on selected findings from a MEDLINE search for literature on phimosis and circumcision referrals and on our experience at the Children’s Hospital of Eastern Ontario Urology Clinic. MeSH headings used in our MEDLINE search included “phimosis,” “referral and consultation,” and “circumcision.” Most of the available articles about phimosis and foreskin referrals were retrospective reviews and cohort studies (levels II and III evidence). MAIN MESSAGE Phimosis is defined as the inability to retract the foreskin. Differentiating between physiologic and pathologic phimosis is important, as the former is managed conservatively and the latter requires surgical intervention. Great anxiety exists among patients and parentsregarding non-retractile foreskins. Most phimosis referrals seen in pediatric urology clinics are normal physiologically phimotic foreskins. Referrals of patients with physiologic phimosis to urology clinics can create anxiety about the need for surgery among patients and parents, while unnecessarily expanding the waiting list for specialty assessment. Uncircumcised penises require no special care. With normal washing, using soap and water, and gentle retraction during urination and bathing, most foreskins will become retractile over time. CONCLUSION Physiologic phimosis is often seen by family physicians. These patients and their parents require reassurance of normalcy and reinforcement of proper preputial hygiene. Consultation should be sought when evidence of pathologic phimosis is present, as this requires surgical management.

McGregor, Thomas B.; Pike, John G.; Leonard, Michael P.

2007-01-01

321

Alopecia Areata (Pelade) in a Cow  

PubMed Central

A case of alopecia areata (pelade) is described in a cow. Alopecia areata is a rare idiopathic dermatosis of cattle. It is characterized by asymptomatic, solitary or multiple, annular areas of noninflammatory alopecia. Scrapings and cultures are negative, and the diagnosis is confirmed by skin biopsies taken from early lesions, which reveal accumulations of lymphocytes around the bulbs of anagen hair follicles. There is no known effective and practical treatment for affected cattle. The dermatitis is a cosmetic problem, but does not seem to affect general health and production, and spontaneous remission may occur. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.

Paradis, Manon; Fecteau, Gilles; Scott, Danny W.

1988-01-01

322

Orbital (retrobulbar) meningioma in a Simmental cow.  

PubMed

A 12-year-old Simmental cow was presented with a moderately firm irregular whitish mass of approximately 5 cm in diameter, occupying the right orbit. Microscopically, a poorly differentiated neoplasm was observed. The immunohistochemical panel included cytokeratins, vimentin, epithelial membrane antigen, Factor VIII, CD34, Mart-1, Melan A, smooth muscle actin, desmin, chromogranin, neuron-specific enolase, S-100 protein, and MIB-1. The neoplasm was negative for all of them, with the exception of vimentin and S-100 protein. Transmission electron microscopy revealed abundant desmosomes. These findings support the diagnosis of orbital (retrobulbar) meningioma. PMID:17606511

Reis, J L; Kanamura, C T; Machado, G M; França, R O; Borges, J R J; Santos, R L

2007-07-01

323

Effects of metabolizable protein supply and amino acid supplementation on nitrogen utilization, milk production, and ammonia emissions from manure in dairy cows.  

PubMed

Two experiments were conducted with the objective of investigating the effects of rumen-protected methionine (RPMet) supplementation of metabolizable protein (MP)-deficient or MP-adequate but Met-deficient diets on dairy cow performance. Experiment (Exp.) 1 utilized 36 Holstein dairy cows blocked in 12 blocks of 3 cows each. Cows within block were assigned to one of the following dietary treatments: (1) MP-adequate diet [AMP; positive MP balance according to the National Research Council (2001) dairy model]; (2) an MP-deficient diet supplemented with 100g of rumen-protected Lys (RPLys)/cow per day (DMPL); and (3) DMPL supplemented with 24 g of RPMet/cow per day (DMPLM). Experiment 2 utilized 120 Holstein cows assigned to 6 pens of 20 cows each. Pens (3 per treatment) were assigned to one of the following dietary treatments: (1) AMP diet supplemented with 76 g of RPLys/cow per day (AMPL); and (2) AMPL (74 g of RPLys/cow per day) supplemented with 24 g of RPMet/cow per day (AMPLM). Each experiment lasted for 10 wk (2-wk adaptation and 8-wk experimental periods) following a 2-wk covariate period (i.e., a total of 12 wk). In Exp. 1, the MP-deficient diets decreased apparent total-tract nutrient digestibility but had no statistical effect on dry matter intake (DMI), milk yield, or milk fat percentage and yield. Compared with AMP, DMPL decreased milk protein content; both DMPL and DMPLM diets decreased milk protein yield. Urinary N losses and milk urea-N concentration were decreased by the MP-deficient diets compared with AMP. The ammonia emitting potential of manure from the MP-deficient diets was decreased by about 37% compared with that of AMP manure. Plasma Lys and Met concentrations were not affected by treatment, but concentrations of His, Thr, and Val were lower for the MP-deficient diets compared with AMP. In Exp. 2, the AMPLM diet had lower milk yield than AMPL due to numerically lower DMI; no other effects were observed in Exp. 2. In conclusion, feeding MP-deficient diets supplemented with RPLys and RPMet did not statistically decrease milk yield in dairy cows in Exp. 1. However, without RPMet supplementation, milk protein content was decreased compared with the MP-adequate diet. Other amino acids, possibly His, may limit milk production in MP-deficient, corn or corn silage-based diets. A summary of 97 individual cow data from trials in which MP-deficient diets were fed suggested the National Research Council (2001) model under-predicts milk yield in cows fed MP-deficient diets (MP balance of -20 to -666 g/d) in a linear manner: milk yield under-prediction [National Research Council (2001) MP-allowable milk yield, kg/d - actual milk yield, kg/d] = 0.0991 (±0.0905) + 0.0230 (±0.0003) × MP balance, g/d (R(2)=0.99). PMID:22916930

Lee, C; Hristov, A N; Heyler, K S; Cassidy, T W; Lapierre, H; Varga, G A; Parys, C

2012-09-01

324

Human physiology in space  

NASA Technical Reports Server (NTRS)

The universality of gravity (1 g) in our daily lives makes it difficult to appreciate its importance in morphology and physiology. Bone and muscle support systems were created, cellular pumps developed, neurons organised and receptors and transducers of gravitational force to biologically relevant signals evolved under 1g gravity. Spaceflight provides the only microgravity environment where systematic experimentation can expand our basic understanding of gravitational physiology and perhaps provide new insights into normal physiology and disease processes. These include the surprising extent of our body's dependence on perceptual information, and understanding the effect and importance of forces generated within the body's weightbearing structures such as muscle and bones. Beyond this exciting prospect is the importance of this work towards opening the solar system for human exploration. Although both appear promising, we are only just beginning to taste what lies ahead.

Vernikos, J.

1996-01-01

325

Plant and Cell Physiology  

NSDL National Science Digital Library

This journal has recently been made available online. The Japanese Society of Plant Physiologists, in combination with Oxford Journals Online, has posted recent issues of the journal Plant and Cell Physiology, an international journal covering original research in the fields of "physiology, biochemistry, biophysics, chemistry, molecular biology, cell biology and gene engineering of plants and micro-organisms." Online coverage includes full-text and abstracts from July 2000 to the present. Note that the electronic version of this journal is free through the end of 2000.

326

Evaluation of the use of dry cow antibiotics in low somatic cell count cows.  

PubMed

The goal of dry cow therapy (DCT) is to reduce the prevalence of intramammary infections (IMI) by eliminating existing IMI at drying off and preventing new IMI from occurring during the dry period. Due to public health concerns, however, preventive use of antibiotics has become questionable. This study evaluated selective DCT in 1,657 cows with low somatic cell count (SCC) at the last milk recording before drying off in 97 Dutch dairy herds. Low SCC was defined as <150,000 cells/mL for primiparous and <250,000 cells/mL for multiparous cows. A split-udder design was used in which 2 quarters of each cow were treated with dry cow antibiotics and the other 2 quarters remained as untreated controls. The effect of DCT on clinical mastitis (CM), bacteriological status, SCC, and antibiotic use were determined at the quarter level using logistic regression and chi-squared tests. The incidence rate of CM was found to be 1.7 times (95% confidence interval=1.4-2.1) higher in quarters dried off without antibiotics as compared with quarters dried off with antibiotics. Streptococcus uberis was the predominant organism causing CM in both groups. Somatic cell count at calving and 14 d in milk was significantly higher in quarters dried off without antibiotics (772,000 and 46,000 cells/mL, respectively) as compared with the quarters dried off with antibiotics (578,000 and 30,000 cells/mL, respectively). Quarters with an elevated SCC at drying off and quarters with a positive culture for major pathogens at drying off had a higher risk for an SCC above 200,000 cells/mL at 14 d in milk as compared with quarters with a low SCC at drying off and quarters with a negative culture for major pathogens at drying off. For quarters that were culture-positive for major pathogens at drying off, a trend for a higher risk on CM was also found. Selective DCT, not using DCT in cows that had a low SCC at the last milk recording before drying off, significantly increased the incidence rate of CM and SCC. The decrease in antibiotic use by drying off quarters without DCT was not compensated by an increase in antibiotic use for treating CM. Total antibiotic use related to mastitis was reduced by 85% in these quarters. PMID:24746132

Scherpenzeel, C G M; den Uijl, I E M; van Schaik, G; Olde Riekerink, R G M; Keurentjes, J M; Lam, T J G M

2014-06-01

327

Genome-wide expression patterns in physiological cardiac hypertrophy  

PubMed Central

Background Genome-wide expression patterns in physiological cardiac hypertrophy. Co-expression patterns in physiological cardiac hypertrophy Results In this study, the first large-scale analysis of publicly available genome-wide expression data of several in vivo murine models of physiological LVH was carried out using network analysis. On evaluating 3 million gene co-expression patterns across 141 relevant microarray experiments, it was found that physiological adaptation is an evolutionarily conserved processes involving preservation of the function of cytochrome c oxidase, induction of autophagy compatible with cell survival, and coordinated regulation of angiogenesis. Conclusion This analysis not only identifies known biological pathways involved in physiological LVH, but also offers novel insights into the molecular basis of this phenotype by identifying key networks of co-expressed genes, as well as their topological and functional properties, using relevant high-quality microarray experiments and network inference.

2010-01-01

328

Factors associated with colostral specific gravity in dairy cows.  

PubMed

The objectives of this study were to identify factors associated with colostral specific gravity in dairy cows, as measured by a commercially available hydrometer (Colostrometer). Colostral specific gravity was measured in 1085 first-milking colostrum samples from 608 dairy cows of four breeds on a single farm during a 5-yr period. Effects of breed, lactation number, and month and year of calving on colostral specific gravity were determined, as were correlations between colostral specific gravity, nonlactating period length, and 305-d yields of milk, protein, and fat. For 75 multiparous Holstein cows, relationships between colostral specific gravity, colostral IgG1, protein, and fat concentrations, and season of calving were determined. Colostral specific gravity values were lower for Brown Swiss and Ayrshire cows than for Jersey and Holstein cows, and lower for cows entering first or second lactation than third or later lactations. Month of calving markedly affected colostral specific gravity values, with highest values occurring in autumn and lowest values in summer. In multiparous Holstein cows, colostral specific gravity was more strongly correlated with colostral protein concentration (r = 0.76) than IgG1 concentration (r = 0.53), and colostral protein concentration varied seasonally (higher in autumn than summer). Our results demonstrate that colostral specific gravity more closely reflects colostral protein concentration than IgG1 concentration and is markedly influenced by month of calving. These results highlight potential limitations of using colostral specific gravity as an indicator of IgG1 concentration. PMID:11352170

Morin, D E; Constable, P D; Maunsell, F P; McCoy, G C

2001-04-01

329

Effects of weightlessness on human fluid and electrolyte physiology  

NASA Technical Reports Server (NTRS)

Skylab and Spacelab data on changes occurring in human fluid and electrolyte physiology during the acute and adaptive phases of adaptation to spaceflight are summarized. The combined results for all three Spacelab studies show that hyponatremia developed within 20 h after the onset of weightlessness and continued throughout the flights, and hypokalemia developed by 40 h. Antidiuretic hormone was increased in plasma throughout the flights. Aldosterone decreased by 40 h, but after 7 days it had reached preflight levels.

Leach, Carolyn S.; Johnson, Philip C., Jr.

1991-01-01

330

Simulated Exercise Physiology Laboratories.  

ERIC Educational Resources Information Center

This book consists of a lab manual and computer disks for either Apple or IBM hardware. The lab manual serves as "tour guide" for the learner going through the various lab experiences. The manual contains definitions, proper terminology, and other basic information about physiological principles. It is organized so a step-by-step procedure may be…

Morrow, James R., Jr.; Pivarnik, James M.

331

Renal Physiology of Pregnancy  

PubMed Central

Pregnancy involves remarkable orchestration of physiologic changes. The kidneys are central players in the evolving hormonal milieu of pregnancy, responding and contributing to the changes in the environment for the pregnant woman and fetus. The functional impact of pregnancy on kidney physiology is widespread, involving practically all aspects of kidney function. The glomerular filtration rate increases 50% with subsequent decrease in serum creatinine, urea, and uric acid values. The threshold for thirst and antidiuretic hormone secretion are depressed, resulting in lower osmolality and serum sodium levels. Blood pressure drops approximately 10 mmHg by the second trimester despite a gain in intravascular volume of 30% to 50%. The drop in systemic vascular resistance is multifactorial, attributed in part to insensitivity to vasoactive hormones, and leads to activation of the renin-aldosterone-angiostensin system. A rise in serum aldosterone results in a net gain of approximately 1000 mg of sodium. A parallel rise in progesterone protects the pregnant woman from hypokalemia. The kidneys increase in length and volume, and physiologic hydronephrosis occurs in up to 80% of women. This review will provide an understanding of these important changes in kidney physiology during pregnancy, which is fundamental in caring for the pregnant patient.

Cheung, Katharine L.; Lafayette, Richard A.

2014-01-01

332

Physiology of alpine skiing.  

PubMed

The extreme environment of cold, altitude and movement complexity makes alpine ski racing a difficult sport to study. This review comprises >30 years of research and includes 29 on-snow investigations of specific physiology relating to the various ski racing disciplines, nine off-snow investigations of the physiological capacities of ski racers of varying ability and four review articles. Alpine ski racing appears to involve a complex integration of many different physiological systems, none of which may be more important than the other to overall performance. While technical ability appears to be the greatest influencing factor on performance, the ability to continually exhibit technical competence through a long competitive season requires high capabilities within all physiological systems. Identifying the optimal approach and time to concurrently develop these systems is a challenge for sport scientists. Further research is required using modern portable investigative tools for determining aerobic and anaerobic demands and abilities, especially in the areas of muscle function and relative energy system contribution during both single and multiple runs on varying terrain. PMID:19335589

Turnbull, J R; Kilding, A E; Keogh, J W L

2009-04-01

333

Physiological effects of hypnosis  

Microsoft Academic Search

There are many studies indicating that sensory, circulatory, gastrointestinal, and cutaneous functions can be altered by means of hypnosis. There also are many studies indicating that similar physiological effects can be produced by symbolic stimulation without hypnosis. The assumption that hypnotic behavior is a function of the trance state is open to question. From Psyc Abstracts 36:01:3II90B.

Theodore Xenophon Barber

1961-01-01

334

Physiology of Cholangiocytes  

PubMed Central

Cholangiocytes are epithelial cells that line the intra- and extrahepatic ducts of the biliary tree. The main physiologic function of cholangiocytes is modification of hepatocyte-derived bile, an intricate process regulated by hormones, peptides, nucleotides, neurotransmitters, and other molecules through intracellular signaling pathways and cascades. The mechanisms and regulation of bile modification are reviewed herein.

Tabibian, James H.; Masyuk, Anatoliy I.; Masyuk, Tetyana V.; O'Hara, Steven P.; LaRusso, Nicholas F.

2013-01-01

335

Physiological studies on Rhizobium  

Microsoft Academic Search

In recent years a number of investigations have been conducted to study the influence of u wide variety of materials upon the oxygen utilization of Rhizobium. The results secured, while giving indications of growth effects, furnish only a very incomplete picture of the physiological changes brought about by the organisms. In order to follow more closely the oxidative and reductive

D. W. Thorne; O. R. Neal; R. H. Walker

1936-01-01

336

Research on gravitational physiology  

NASA Technical Reports Server (NTRS)

The topic of gravitational plant physiology was studied through aspects of plant development (in ARABIDOPSIS) and of behavior (in HELIANTHUS) as these were affected by altered g experience. The effect of increased g levels on stem polarity (in COLEUS) was also examined.

Brown, A. H.; Dahl, A. O.

1974-01-01

337

Physiology in microgravity.  

PubMed

Studies of physiology in microgravity are remarkably recent, with almost all the data being obtained in the past 40 years. The first human spaceflight did not take place until 1961. Physiological measurements in connection with the early flights were crude, but, in the past 10 years, an enormous amount of new information has been obtained from experiments on Spacelab. The United States and Soviet/Russian programs have pursued different routes. The US has mainly concentrated on relatively short flights but with highly sophisticated equipment such as is available in Spacelab. In contrast, the Soviet/Russian program concentrated on first the Salyut and then the Mir space stations. These had the advantage of providing information about long-term exposure to microgravity, but the degree of sophistication of the measurements in space was less. It is hoped that the International Space Station will combine the best of both approaches. The most important physiological changes caused by microgravity include bone demineralization, skeletal muscle atrophy, vestibular problems causing space motion sickness, cardiovascular problems resulting in postflight orthostatic intolerance, and reductions in plasma volume and red cell mass. Pulmonary function is greatly altered but apparently not seriously impaired. Space exploration is a new frontier with long-term missions to the moon and Mars not far away. Understanding the physiological changes caused by long-duration microgravity remains a daunting challenge. PMID:10904075

West, J B

2000-07-01

338

Programmable physiological infusion  

NASA Technical Reports Server (NTRS)

A programmable physiological infusion device and method are provided wherein a program source, such as a paper tape, is used to actuate an infusion pump in accordance with a desired program. The system is particularly applicable for dispensing calcium in a variety of waveforms.

Howard, W. H.; Young, D. R.; Adachi, R. R. (inventors)

1974-01-01

339

Hyperbaric Physiology Research Support.  

National Technical Information Service (NTIS)

This report describes advances made in the development of physiological monitoring and analysis systems for use in hyperbaric research. The systems, designed around a mini-computer configuration, are able to monitor up to 16 channels of analog data from r...

W. H. Mints A. Pomerance

1975-01-01

340

Avian reproductive physiology  

USGS Publications Warehouse

Knowledge of the many physiological factors associated with egg production , fertility, incubation, and brooding in nondomestic birds is limited. Science knows even less about reproduction in most of the 238 endangered or threatened birds. This discussion uses studies of nondomestic and, when necessary, domestic birds to describe physiological control of reproduction. Studies of the few nondomestic avian species show large variation in physiological control of reproduction. Aviculturists, in order to successfully propagate an endangered bird, must understand the bird's reproductive peculiarities. First, investigators can do studies with carefully chosen surrogate species, but eventually they need to confirm the results in the target endangered bird. Studies of reproduction in nondomestic birds increased in the last decade. Still, scientists need to do more comparative studies to understand the mechanisms that control reproduction in birds. New technologies are making it possible to study reproductive physiology of nondomestic species in less limiting ways. These technologies include telemetry to collect information without inducing stress on captives (Howey et al., 1987; Klugman, 1987), new tests for most of the humoral factors associated with reproduction, and the skill to collect small samples and manipulate birds without disrupting the physiological mechanisms (Bercovitz et al., 1985). Managers are using knowledge from these studies to improve propagation in zoological parks, private and public propagation facilities, and research institutions. Researchers need to study the control of ovulation, egg formation, and oviposition in the species of nondomestic birds that lay very few eggs in a season, hold eggs in the oviduct for longer intervals, or differ in other ways from the more thoroughly studied domestic birds. Other techniques that would enhance propagation for nondomestlc birds include tissue culture of cloned embryonic cells, cryopreservation of embryos and gametes, embryo transplant, DNA analysis and manipulation, disease screening and control, and improved release conditioning methods.

Gee, G.F.

1995-01-01

341

Event-Related Potentials and Electroencephalograms in Adaptive Operator Training: Rationale and Annotated Bibliography.  

National Technical Information Service (NTIS)

This report presents summaries of research on physiological metrics of learning and memory, task performance, attention, imagery, mental workload, and adaptive training. The focus of the report is on the potential for physiological metrics such as electro...

L. J. Trejo M. Mullane J. Stewart

1995-01-01

342

Phagocytosis by somatic cells from dry cow secretion.  

PubMed

Independently of medium in which the process occurred, serum or PBS, phagocytosis and killing of Staphylococcus aureus by somatic cells from dry cow secretion were significantly higher at the early dry period than at the steady state period. Total bacterial survival was highly correlated with phagocytosis and with intracellular survival. Correlations between phagocytosis and intracellular survival were much lower. Percentage of S. aureus phagocytosed after incubation in bovine blood serum showed highly significant variation among samples of cells isolated from secretion of different cows at the early dry period and significant variation among samples of cells isolated from different cows at the steady state period. PMID:2462334

Bassalik-Chabielska, L; Smuda, P; Zieba, G; Kostrzy?ski, S

1988-01-01

343

Risk factors associated with colostrum quality in Norwegian dairy cows.  

PubMed

The objectives of the present study were to evaluate colostrum quality in Norwegian dairy cows based on IgG content, and to identify associations between possible risk factors and low colostral IgG. A longitudinal cross-sectional survey on calf health in Norway was performed between June 2004 and December 2006. The participating dairy herds were randomly selected among herds registered in the Norwegian Dairy Herd Recording System as having at least 15 cow years. The participating farmers were requested to sample 10 mL of colostrum from the first milking after calving from 12 cows that had calved during the defined project period of 365 d. Colostrum samples from 1,250 cows from 119 herds were collected. The material consisted of 451, 337, 213, and 249 samples collected from cows in their first, second, third, and fourth parity or more, respectively. Analysis was performed on IgG content by using single radial immunodiffusion. Mixed models with herd as a cluster were fit by using grams of IgG per liter of colostrum as the dependent variable for the statistical analyses. The IgG content in the colostrum sampled ranged from 4 to 235 g/L, with a median of 45.0 g of IgG/L, with the 10th, 25th, 75th, and 90th percentiles being 23.1, 31.4, 63.6, and 91.6 g of IgG/L, respectively. Altogether, 57.8% of the samples contained less than the desired 50 g of IgG/L of colostrum. Cows in their fourth parity or more were found to have significantly higher levels of IgG per liter of colostrum than cows in their first or second parity. Colostrum from cows in their second parity had the lowest level of IgG. Cows calving during the winter months (December, January, and February) produced colostrum with a significantly lower IgG content compared with cows calving in any other season of the year. Somatic cell count, measured after calving, was significantly higher in cows producing colostrum of inferior quality compared with those producing high-quality colostrum. Of the total variation in colostrum quality, 13.7% could be explained by cluster effects within herd. The variation in IgG content in colostrum produced by Norwegian dairy cows indicates a need for improved colostrum quality control and subsequent adjustment of the colostrum feeding regimen to ensure a protective immunological status for newborn calves. PMID:18218758

Gulliksen, S M; Lie, K I; Sølverød, L; Østerås, O

2008-02-01

344

Whither adaptation?  

Microsoft Academic Search

The two authors of this paper have diametrically opposed views of the prevalence and strength of adaptation in nature. Hendry\\u000a believes that adaptation can be seen almost everywhere and that evidence for it is overwhelming and ubiquitous. Gonzalez believes\\u000a that adaptation is uncommon and that evidence for it is ambiguous at best. Neither author is certifiable to the knowledge\\u000a of

Andrew P. Hendry; Andrew Gonzalez

2008-01-01

345

Effects of duration of zilpaterol hydrochloride supplementation on growth performance, carcass traits and meat quality of grain-fed cull cows.  

PubMed

Several studies have shown that feeding of an energy-dense diet over short periods to cull cows could be profitable in terms of increased saleable yield and improved carcass conditions. Although the application of growth promoters, such as anabolic implants and beta agonists, in finishing of cull cows have been recorded, there is no conclusive evidence as to the timing and duration of beta agonists in cull cow production. In this study, 288 cull cows with four or more permanent incisors and varying weights and body conditions were divided into four treatment groups so that variation in age, weight and body condition were equally distributed among groups. One group received concentrate feed without any beta agonist (C), whereas the other three groups also received concentrate feed with zilpaterol hydrochloride (6 p.p.m.) for 20 (Z20), 30 (Z30) or 40 (Z40) days, respectively, followed by a 2-day withdrawal. Animals were adapted for 10 days on a grain-based diet and fed an additional 40 days before slaughter. Growth rate and efficiency (live and carcass), trimmed meat yield and meat tenderness (Warner Bratzler shear force and sensory) of the aged (10 days) m. longissimus thoracis (LT) and m. semitendinosus (ST) were recorded. In general, Z cows had higher carcass gains and efficiency of gain than C cows (P < 0.05). In addition, Z carcasses showed higher proportional trimmed meat yields than C carcasses (P < 0.05). No significant differences in tenderness measurements were recorded for LT or ST. In general, supplementation of zilpaterol for 30 days showed better growth performance and higher trimmed meat yield than 20 and 40 days supplementation. PMID:22444052

Strydom, P E; Smith, M F

2010-04-01

346

Fertilization and early embryonic development in heifers and lactating cows in summer and lactating and dry cows in winter.  

PubMed

Two experiments in two seasons evaluated fertilization rate and embryonic development in dairy cattle. Experiment 1 (summer) compared lactating Holstein cows (n = 27; 97.3 +/- 4.1 d postpartum [dppl; 40.0 +/- 1.5 kg milk/d) to nulliparous heifers (n = 28; 11 to 17 mo old). Experiment 2 (winter) compared lactating cows (n = 27; 46.4 +/- 1.6 dpp; 45.9 +/- 1.4 kg milk/d) to dry cows (n = 26). Inseminations based on estrus included combined semen from four high-fertility bulls. Embryos and oocytes recovered 5 d after ovulation were evaluated for fertilization, embryo quality (1 = excellent to 5 = degenerate), nuclei/embryo, and accessory sperm. In experiment 1, 21 embryos and 17 unfertilized oocytes (UFO) were recovered from lactating cows versus 32 embryos and no UFO from heifers (55% vs. 100% fertilization). Embryos from lactating cows had inferior quality scores (3.8 +/- 0.4 vs. 2.2 +/- 0.3), fewer nuclei/embryo (19.3 +/- 3.7 vs. 36.8 +/- 3.0) but more accessory sperm (37.3 +/- 5.8 vs. 22.4 +/- 5.5/embryo) than embryos from heifers. Sperm were attached to 80% of UFO (17.8 +/- 12.1 sperm/UFO). In experiment 2, lactating cows yielded 36 embryos and 5 UFO versus 34 embryos and 4 UFO from dry cows (87.8 vs. 89.5% fertilization). Embryo quality from lactating cows was inferior to dry cows (3.1 +/- 0.3 vs. 2.2 +/- 0.3), but embryos had similar numbers of nuclei (27.2 +/- 2.7 vs. 30.6 +/- 2.1) and accessory sperm (42.0 +/- 9.4 vs. 36.5 +/- 6.3). From 53% of the flushings from lactating cows and 28% from dry cows, only nonviable embryos were collected. Thus, embryos of lactating dairy cows were detectably inferior to embryos from nonlactating females as early as 5 d after ovulation, with a surprisingly high percentage of nonviable embryos. In addition, fertilization rate was reduced only in summer, apparently due to an effect of heat stress on the oocyte. PMID:12487447

Sartori, R; Sartor-Bergfelt, R; Mertens, S A; Guenther, J N; Parrish, J J; Wiltbank, M C

2002-11-01

347

Relationship between the milk yield response to short-term bovine somatotropin treatment and the lipolytic response to adrenaline in dairy cows.  

PubMed

The aim of this experiment was to determine if the milk yield response of dairy cows to short-term treatment with bovine somatotropin (bST) was correlated with the non-esterified fatty-acid (NEFA) response to an adrenaline challenge. Twenty-six multiparous Holstein cows (58+/-5.4 days postpartum) received daily sub-cutaneous injections of saline for 7 days followed by sub-cutaneous injections of 20mg/day of bST for 14 days. On day 7 of the saline treatment and day 14 of the bST treatment the cows were given an intravenous injection of adrenaline (1.4 microg/kg body weight). Blood samples were taken before and after the adrenaline challenge. The difference in milk yield between the saline and the second week of bST treatment (MYR) varied considerably between animals (from -0.4 to +8.0 kg/day). MYR was positively correlated with the change in the basal concentration of NEFA between the saline and second week of bST treatment, as well as with the change in the area under the profile of NEFA above basal values following the adrenaline challenge. It remains to be established whether the greater lipolytic responses to adrenaline of the cows with the greater MYR reflects the deeper negative energy that these animals also experienced or a fundamental difference in the physiology of their adipose tissue. PMID:18952396

Rose, M T; Weekes, T E C; Rowlinson, P

2009-01-01

348

Obesity and Asthma: Physiological Perspective  

PubMed Central

Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC). Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma.

Brashier, Bill; Salvi, Sundeep

2013-01-01

349

Obesity and asthma: physiological perspective.  

PubMed

Obesity induces some pertinent physiological changes which are conducive to either development of asthma or cause of poorly controlled asthma state. Obesity related mechanical stress forces induced by abdominal and thoracic fat generate stiffening of the lungs and diaphragmatic movements to result in reduction of resting lung volumes such as functional residual capacity (FRC). Reduced FRC is primarily an outcome of decreased expiratory reserve volume, which pushes the tidal breathing more towards smaller high resistance airways, and consequentially results in expiratory flow limitation during normal breathing in obesity. Reduced FRC also induces plastic alteration in the small collapsible airways, which may generate smooth muscle contraction resulting in increased small airway resistance, which, however, is not picked up by spirometric lung volumes. There is also a possibility that chronically reduced FRC may generate permanent adaptation in the very small airways; therefore, the airway calibres may not change despite weight reduction. Obesity may also induce bronchodilator reversibility and diurnal lung functional variability. Obesity is also associated with airway hyperresponsiveness; however, the mechanism of this is not clear. Thus, obesity has effects on lung function that can generate respiratory distress similar to asthma and may also exaggerate the effects of preexisting asthma. PMID:23970905

Brashier, Bill; Salvi, Sundeep

2013-01-01

350

Physiology of prolonged bed rest  

NASA Technical Reports Server (NTRS)

Bed rest has been a normal procedure used by physicians for centuries in the treatment of injury and disease. Exposure of patients to prolonged bed rest in the horizontal position induces adaptive deconditioning responses. While deconditioning responses are appropriate for patients or test subjects in the horizontal position, they usually result in adverse physiological responses (fainting, muscular weakness) when the patient assume the upright posture. These deconditioning responses result from reduction in hydrostatic pressure within the cardiovascular system, virtual elimination of longitudinal pressure on the long bones, some decrease in total body metabolism, changes in diet, and perhaps psychological impact from the different environment. Almost every system in the body is affected. An early stimulus is the cephalic shift of fluid from the legs which increases atrial pressure and induces compensatory responses for fluid and electrolyte redistribution. Without countermeasures, deterioration in strength and muscle function occurs within 1 wk while increased calcium loss may continue for months. Research should also focus on drug and carbohydrate metabolism.

Greenleaf, J. E.

1988-01-01

351

Influence of energy and nutrient supply pre and post partum on performance of multiparous Simmental, Brown Swiss and Holstein cows in early lactation.  

PubMed

A study was conducted to evaluate the effects of pre partum (PRE) and post partum (POST) dietary energy and nutrient supply (E) and their interactions on feed intake, performance and energy status in dairy cows of three breeds. In this experiment, the effects of three energy and nutrient supply levels (low (L), medium (M), high (H)), both pre-calving and post-calving, were investigated, using a 3×3 factorial arrangement of treatments. In both phases (84 days pre- and 105 days post-calving) E levels applied to a total of 81 multiparous cows of breeds Simmental (SI), Brown Swiss (BS) and Holstein-Friesian (HF; n=27 for each breed), were 75%, 100% and 125% of recommendations of the German Society of Nutrition Physiology (GfE). Dry matter intake (DMI) was restricted, if energy intake exceeded target values. Pre partum DMI and energy intake were different as designed, liveweight and body condition score (BCS) of SI cows were higher, but EB was lower, compared to BS and HF cows. Milk yield and composition were influenced by all three main experimental factors (EPRE, EPOST, breed). Energy-corrected milk yield was 25.6, 28.6 and 30.1 kg/day for LPRE, MPRE and HPRE as well as 21.5, 30.1 and 32.6 kg/day for LPOST, MPOST and HPOST, respectively. Numerically, only for milk protein content the interactions EPRE×EPOST and EPRE×breed reached significance. Impact of energy supply pre-calving was more pronounced when cows had lower energy supply post-calving and vice versa. On the other hand, milk yield response of cows to energy supply above requirements was greater for cows that were fed on a low energy level pre partum. Impact of energy level pre partum was higher for HF cows, showing that their milk production relies to a greater extent on mobilization of body reserves. Increasing energy supply pre partum led to a more negative energy balance post partum, mainly by increasing milk yield and content, whereas feed intake was slightly reduced. Increasing energy supply post partum enhanced milk yield as well as milk protein and lactose content. Calculated energy balance corresponded well with liveweight and BCS change. Response of milk yield to increasing energy supply followed the principle of diminishing returns, since energy was increasingly partitioned to body retention. Increasing energy supply pre partum enhances milk yield and content post partum, but exacerbates negative energy balance and its consequences. PMID:24229715

Gruber, L; Urdl, M; Obritzhauser, W; Schauer, A; Häusler, J; Steiner, B

2014-01-01

352

Physiology for High School - Human Physiological Limits to Exploring Mars  

NSDL National Science Digital Library

The keynote presentation from EB 2008's Physiology for Life Science High School Teachers and Students Workshop. This powerpoint presentation discusses the possibility of human exploration on Mars, specifically, how space flight and life on mars would effect human physiology.

PhD James A Pawelczyk (Pennsylvania State University)

2008-04-05

353

Adaptive People for Adaptive Management  

Microsoft Academic Search

Adaptive management needs people within organizations that can learn flexibly and be adaptive. Unfortunately, people are not\\u000a generally very good at changing thinking or understanding or translating such change into doing things differently. Insights\\u000a into the sorts of characteristics that make people adaptive can be found in educational psychology, including work on how\\u000a people improve performance and the personal beliefs

Ioan Fazey; Lisen Schultz

354

Neuropeptide Physiology in Insects  

Microsoft Academic Search

\\u000a \\u000a In a search for more environmentally benign alternatives to chemical pesticides, insect neuropeptides have been suggested as\\u000a ideal candidates. Neuropeptides are neuromodulators and\\/or neurohormones that regulate most major physiological and behavioral\\u000a processes in insects. The major neuropeptide structures have been identified through peptide purification in insects (peptidomics)\\u000a and insect genome projects. Neuropeptide receptors have been identified and characterized in Drosophila

William G. Bendena

355

BEEF SPECIES SYMPOSIUM: Difficulties associated with predicting forage intake by grazing beef cows.  

PubMed

The current NRC model to estimate DMI is based on a single equation related to metabolic size and net energy density of the diet; this equation was a significant improvement over previous models. However, observed DMI by grazing animals can be conceptualized by a function that includes animal demand, largely determined by metabolic or linear size, physiological state, genetics, or any combination of these. Even in the database used to generate the current NRC equation, DMI by cows is poorly predicted at the extremes. In fact, across a wide range of actual DMI, predicted DMI is rather flat, indicating an insensitivity of prediction, so the model requires further refinement. A broad-based database was developed that includes pasture and confinement studies with growing, nonlactating, and lactating cattle. New equations are presented for consideration in the new model. It was found that the premise behind earlier NRC equations based on diet digestibility and BW are sound but that for cows, additional drivers based on milk production or calf performance were stronger than BW. Future models should be based on multiple variables, including functions for physiological state, animal suitability to the environment, and activity to modify the predicted DMI. Further, the model could possibly account for imbalances of protein to energy, particularly as they relate to ruminal function. Further, the issue of how reference data were collected (pen vs. pasture) and how the methods or constraints influence DMI must be evaluated. Overall, the new NRC model needs to be more robust in its ability to account for the wide variation in the environment, dietary characteristics, and metabolic demands. PMID:24398834

Coleman, S W; Gunter, S A; Sprinkle, J E; Neel, J P S

2014-07-01

356

Adaptive Hypermedia  

Microsoft Academic Search

Adaptive hypermedia is a relatively new direction of research on the crossroads of hypermedia anduser modeling. Adaptivehypermedia systemsbuild a model ofthe goals, prefer- ences and knowledge ofeach individual user, and use this model throughoutthe interactionwith the user, in order to adapt to the needs of that user.The goal of this paper is to present the state of the art in

Peter Brusilovsky

2001-01-01

357

Isoelectric focusing and ELISA for detecting adulteration of donkey milk with cow milk.  

PubMed

Donkey milk has been recently revalued intensely due to its nutritional properties. Moreover, donkey milk has been proposed as an effective alternative food for some infants with cow milk allergy. Two fast analytical methods were proposed to detect the fraudulent practice of blending cow milk to donkey milk. Detection of cow ?s1-casein bands along the profiles of experimental donkey-cow milk mixtures analyzed by isoelectric focusing was adequate to estimate cow milk used as adulterant of donkey milk starting from 5% (v/v). An ELISA-based method using the antipeptide antibodies raised against the 1-28 sequence stretch of cow ?-casein was also developed for an accurate definition of composition of donkey-cow milk mixtures. The presence of cow milk at levels as low as 0.5% (v/v) was detected in donkey-cow milk mixtures prepared at laboratory scale and assayed by ELISA. PMID:24892189

Pizzano, Rosa; Salimei, Elisabetta

2014-06-25

358

Correlator optical wavefront sensor 'COWS,' Task 6. Final report.  

National Technical Information Service (NTIS)

This report documents the significant upgrades and improvements made to the COWS optical bench during this phase of the program. Software for the experiment was reviewed and documented. Flowcharts showing the program flow are included as well as documenta...

1991-01-01

359

Milk Cows and Production: Final Estimates 1993-97.  

National Technical Information Service (NTIS)

This bulletin presents final estimates, including revisions made by the Agricultural Statistics Board (ASB), for the production years 1993 through 1997. Number of milk coes, production per cow, total production, and annual estimates of number of operation...

1999-01-01

360

Grape marc reduces methane emissions when fed to dairy cows.  

PubMed

Grape marc (the skins, seeds, stalk, and stems remaining after grapes have been pressed to make wine) is currently a by-product used as a feed supplement by the dairy and beef industries. Grape marc contains condensed tannins and has high concentrations of crude fat; both these substances can reduce enteric methane (CH4) production when fed to ruminants. This experiment examined the effects of dietary supplementation with either dried, pelleted grape marc or ensiled grape marc on yield and composition of milk, enteric CH4 emissions, and ruminal microbiota in dairy cows. Thirty-two Holstein dairy cows in late lactation were offered 1 of 3 diets: a control (CON) diet; a diet containing dried, pelleted grape marc (DGM); and a diet containing ensiled grape marc (EGM). The diet offered to cows in the CON group contained 14.0kg of alfalfa hay dry matter (DM)/d and 4.3kg of concentrate mix DM/d. Diets offered to cows in the DGM and EGM groups contained 9.0kg of alfalfa hay DM/d, 4.3kg of concentrate mix DM/d, and 5.0kg of dried or ensiled grape marc DM/d, respectively. These diets were offered individually to cows for 18d. Individual cow feed intake and milk yield were measured daily and milk composition measured on 4d/wk. Individual cow CH4 emissions were measured by the SF6 tracer technique on 2d at the end of the experiment. Ruminal bacterial, archaeal, fungal, and protozoan communities were quantified on the last day of the experiment. Cows offered the CON, DGM, and EGM diets, ate 95, 98, and 96%, respectively, of the DM offered. The mean milk yield of cows fed the EGM diet was 12.8kg/cow per day and was less than that of cows fed either the CON diet (14.6kg/cow per day) or the DGM diet (15.4kg/cow per day). Feeding DGM and EGM diets was associated with decreased milk fat yields, lower concentrations of saturated fatty acids, and enhanced concentrations of mono- and polyunsaturated fatty acids, in particular cis-9,trans-11 linoleic acid. The mean CH4 emissions were 470, 375, and 389g of CH4/cow per day for cows fed the CON, DGM, and EGM diets, respectively. Methane yields were 26.1, 20.2, and 21.5g of CH4/kg of DMI for cows fed the CON, DGM, and EGM diets, respectively. The ruminal bacterial and archaeal communities were altered by dietary supplementation with grape marc, but ruminal fungal and protozoan communities were not. Decreases of approximately 20% in CH4 emissions and CH4 yield indicate that feeding DGM and EGM could play a role in CH4 abatement. PMID:24952778

Moate, P J; Williams, S R O; Torok, V A; Hannah, M C; Ribaux, B E; Tavendale, M H; Eckard, R J; Jacobs, J L; Auldist, M J; Wales, W J

2014-08-01

361

Investigation of Chlamydophila spp. in dairy cows with reproductive disorders  

PubMed Central

Background Reports worldwide indicate high prevalence of Chlamydophila spp. infection in cattle. To assess the prevalence in Sweden, 525 cows in 70 dairy herds with reproductive disorders was investigated. Methods To detect antibodies two commercially available kits were used. Moreover, 107 specimens, including vaginal swabs, organ tissues and milk were analysed by Polymerase Chain Reaction (PCR). Results Two (0.4%) cows were seropositive in the Pourquier Cp. abortus ELISA. The seroprevalence with the Chekit ELISA was 28% with no difference between cases and controls. Five specimens were positive in real-time PCR and further analysed by nested PCR. Cp. pecorum was confirmed by partial omp1 DNA sequencing of the nested PCR product of vaginal swabs from control cows. Conclusion The results suggest that Cp. abortus infection is absent or rare in Swedish cows whereas Cp. pecorum is probably more spread. They also suggest that Chlamydophila spp. are not related to reproduction disorders in Swedish cattle.

Godin, Ann-Charlotte; Bjorkman, Camilla; Englund, Stina; Johansson, Karl-Erik; Niskanen, Rauni; Alenius, Stefan

2008-01-01

362

PBS Learning Media: Cow's Eye Dissection  

NSDL National Science Digital Library

This video-based interactive activity gives users a close-up and fascinating view of the anatomy of a real cow eye as it is dissected by a teenage narrator. You'll get a view of the cornea, watch light refract through the extracted lens, see the retina from the inside, and more. The Flash movies are divided into 12 segments which may be stopped/started interactively. Each segment contains text information with vocabulary definitions in hover-over format. The resource also provides a diagram of the eye and detailed illustrations of how the eye refracts light and sends messages to the optic nerve. PBS Learning Media is a growing collection of 10,000+ free educational resources compiled by researchers and experienced teachers to promote the use of digital resources in the classroom.

2009-06-12

363

Bioavailability of vitamin B?? in cows' milk.  

PubMed

The natural source of vitamin B?? in human diets comes from animal products. For example, one glass (250 ml) of milk provides approximately 50 % of the RDA (2·4 ?g/d). It was hypothesised that the provision of vitamin B?? from milk is more efficiently absorbed than the synthetic form used in vitamin supplements. Pigs (n 10) were used as a model for intestinal absorption of vitamin B?? in humans to compare the net fluxes of vitamin B?? across the portal-drained viscera (PDV; an indicator of intestinal absorption) after ingestion of meals complemented with conventional and vitamin B??-enriched (via injections to cows) milk (raw, pasteurised or microfiltrated) or with equivalent amounts of cyanocobalamin, the synthetic form used in supplements or unsupplemented. Net flux of vitamin B?? across PDV after the ingestion of milk was positive, though not influenced by milk enrichment (P>0·3) or technological processes (P = 0·8) and was greater than after ingestion of equivalent amounts of cyanocobalamin (cyanocobalamin v. all milk, P ? 0·003). In fact, net fluxes of this vitamin were not different from 0 after either cyanocobalamin or the meal devoid of vitamin B?? (unsupplemented v. cyanocobalamin, P = 0·7). The cumulative PDV fluxes during the 24 h following ingestion of meals complemented with milk varied from 5·5 to 6·8 ?g. These values correspond to an efficiency of intestinal absorption of vitamin B?? from milk varying between 8 and 10 %. Therefore, vitamin B??, which is abundant in cows' milk, is also substantially more available than the most commonly used synthetic form of this vitamin. PMID:21733330

Matte, J Jacques; Guay, Frédéric; Girard, Christiane L

2012-01-01

364

Anxiety Reduction through Detachment: Subjective, Physiological, and Neural Effects  

Microsoft Academic Search

The ability to volitionally regulate emotions helps to adapt behavior to changing environmental demands and can alleviate subjective distress. We show that a cognitive strategy of detachment attenuates subjective and physiolog- ical measures of anticipatory anxiety for pain and reduces reactivity to receipt of pain itself. Using functional magnetic resonance imaging, we locate the potential site and source of this

Raffael Kalisch; Katja Wiech; Hugo D. Critchley; Ben Seymour; John P. O'Doherty; David A. Oakley; Philip Allen; Raymond J. Dolan

2005-01-01

365

Is cow's milk harmful to a child's health?  

PubMed

Discussions and debates have recently emerged on the potential positive and negative effects of cow's milk in the paediatric community, also under the pressure of public opinion. The negative effects of cow's-milk consumption seem to be limited to iron status up to 9 to 12 months; then no negative effects are observed, provided that cow's milk, up to a maximum daily intake of 500?mL, is adequately complemented with iron-enriched foods. Lactose intolerance can be easily managed and up to 250?mL/day of milk can be consumed. Allergy to cow's-milk proteins is usually transient. Atopic children may independently be at risk for poor growth, and the contribution of dairy nutrients to their diet should be considered. The connection of cow's milk to autistic spectrum disorders is lacking, and even a cause-effect relation with type 1 diabetes mellitus has not been established because many factors may concur. Although it is true that cow's milk stimulates insulin-like growth factor-1 and may affect linear growth, association with chronic degenerative, noncommunicable diseases has not been established. Finally, fat-reduced milk, if needed, should be considered after 24 to 36 months. Cow's milk represents a major source of high nutritional quality protein as well as of calcium. Moreover, it has growth-promoting effects independent of specific compounds. Its protein and fat composition, together with the micronutrient content, is suggestive of a functional food, whose positive effects are emphasised by regular consumption, particularly under conditions of diets poor in some limiting nutrients, although in industrialised countries cow's milk's optimal daily intake should be around 500?mL, adequately complemented with other relevant nutrients. PMID:21921812

Agostoni, Carlo; Turck, Dominique

2011-12-01

366

Cardiovascular Responses of Cows Given Electrical Current During Milking  

Microsoft Academic Search

Six Holstein cows in late Iactation were used to determine effects of 4-mA square wave alternating current on mammary gland blood flow rate, heart rate, and blood pressure. Current to the lumbar-sacral region of the cows' back was applied 10 s prior to udder massage and throughout milking. Heart rate was measured from systolic pulses (beats\\/min) off strip chart recordings.

R. C. Gorewit; N. R. Scott

1986-01-01

367

Corn silage hybrid type and quality of alfalfa hay affect dietary nitrogen utilization by early lactating dairy cows.  

PubMed

This experiment was conducted to determine the effects of corn silage (CS) hybrids and quality of alfalfa hay (AH) in high-forage dairy diets on N utilization, ruminal fermentation, and lactational performance by early-lactating dairy cows. Eight multiparous Holstein cows were used in a duplicated 4 × 4 Latin square experiment with a 2 × 2 factorial arrangement of dietary treatments. The 8 cows (average days in milk = 23 ± 11.2) were surgically fitted with ruminal cannula, and the 2 squares were conducted simultaneously. Within square, cows were randomly assigned to a sequence of 4 diets: conventional CS (CCS) or brown midrib CS (BMR) was combined with fair-quality AH [FAH: 46.7% neutral detergent fiber (NDF) and 18.4% crude protein (CP)] or high-quality AH (HAH: 39.2% NDF and 20.7% CP) to form 4 treatments: CCS with FAH, CCS with HAH, BMR with FAH, and BMR with HAH. Diets were isonitrogenous across treatments, averaging 15.9% CP. Each period lasted a total of 21 d, with 14 d for treatment adaptation and 7d for data collection and sampling. Intake of DM and milk yield did not differ in response to CS hybrids or AH quality. Although feeding BMR-based diets decreased urinary N output by 24%, it did not affect fecal N output. Feeding HAH decreased urinary N output by 15% but increased fecal N output by 20%. Nitrogen efficiency [milk N (g/d)/intake N (g/d)] tended to increase for BMR treatments. Ruminal ammonia-N concentration was lower for cows fed BMR-based diets than for those fed CCS-based diets but was not affected by quality of AH. Feeding BMR-based diets or HAH decreased milk urea N concentration by 23 or 15%, respectively, compared with CCS-based diets or FAH. Total volatile fatty acid concentration increased with HAH but was not influenced by CS hybrids. Feeding BMR-based diets decreased urinary N-to-fecal N ratio (UN:FN), and it was further reduced by feeding HAH. Although cows fed the BMR-based diets tended to increase milk N-to-manure N ratio, the quality of AH did not affect the ratio. The lower ratio of UN:FN with a higher ratio of milk N-to-manure N ratio for the BMR-based diets indicates that feeding BMR may reduce manure ammonia-N by reducing excretion of urinary N and increasing secretion of milk N per unit of manure N excreted. PMID:23958019

Holt, M S; Neal, K; Eun, J-S; Young, A J; Hall, J O; Nestor, K E

2013-10-01

368

Effect of Feeding Bacillus subtilis natto on Hindgut Fermentation and Microbiota of Holstein Dairy Cows.  

PubMed

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with 0.5×10(11) cfu as DMF1 group and B. subtilis natto with 1.0×10(11) cfu as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, NH3-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal NH3-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance. PMID:25049979

Song, D J; Kang, H Y; Wang, J Q; Peng, H; Bu, D P

2014-04-01

369

[Tool of nutrition education for allergic to egg and cow's milk protein in pediatric age®].  

PubMed

Introduction: Food allergy affects a large part of the population and their numbers are increasing. Although the knowing of this pathology is growing, allergic patients have really difficulties to lead a normal life, especially with food. Until now,this group hadn t practical tools that would help them in the development of a balanced daily diet, as there are for the general population in the form of pyramids and dietary guidelines . This work has covered this need for two of the most prevalent allergies in early life. Aims: gather information on the allergy of cow's milk protein and egg, to design a food pyramid for these patients, based on the consensus, recommendations and scientific guidance. Results: After confirming the absence of a similar work, food pyramids allergy to egg and cow's milk protein, adapted to each, and a joint pyramid is designed to both allergies. Besides basic recommendations for healthy eating were included in general and in particular individuals, with special interest for the collective (food hygiene, food additives, cosmetics, medicines, etc). Conclusions: Due to the importance of nutrition in childhood and acquires the underlying difficulties this group, to properly plan the diet is very important as it can prevent accidents and long-term nutritional deficiencies. Therefore provide graphical tools and practices to this goal, is importance for population and medical and scientific community, and is the result of this work. PMID:24951986

San Mauro Martín, Ismael

2014-05-01

370

Effect of Feeding Bacillus subtilis natto on Hindgut Fermentation and Microbiota of Holstein Dairy Cows  

PubMed Central

The effect of Bacillus subtilis natto on hindgut fermentation and microbiota of early lactation Holstein dairy cows was investigated in this study. Thirty-six Holstein dairy cows in early lactation were randomly allocated to three groups: no B. subtilis natto as the control group, B. subtilis natto with 0.5×1011 cfu as DMF1 group and B. subtilis natto with 1.0×1011 cfu as DMF2 group. After 14 days of adaptation period, the formal experiment was started and lasted for 63 days. Fecal samples were collected directly from the rectum of each animal on the morning at the end of eighth week and placed into sterile plastic bags. The pH, NH3-N and VFA concentration were determined and fecal bacteria DNA was extracted and analyzed by DGGE. The results showed that the addition of B. subtilus natto at either treatment level resulted in a decrease in fecal NH3-N concentration but had no effect on fecal pH and VFA. The DGGE profile revealed that B. subtilis natto affected the population of fecal bacteria. The diversity index of Shannon-Wiener in DFM1 decreased significantly compared to the control. Fecal Alistipes sp., Clostridium sp., Roseospira sp., beta proteobacterium were decreased and Bifidobacterium was increased after supplementing with B. subtilis natto. This study demonstrated that B. subtilis natto had a tendency to change fecal microbiota balance.

Song, D. J.; Kang, H. Y.; Wang, J. Q.; Peng, H.; Bu, D. P.

2014-01-01

371

A study of helminth parasites in culled cows from Ireland.  

PubMed

The objective of this study was to determine the prevalence and intensity of gastrointestinal nematode, lungworm and liver fluke infection in culled cows in Ireland. Abomasa, colorectal contents and livers were collected from 30 to 68 culled beef and dairy cows during autumn 2002 and summer 2003, respectively. Ostertagia ostertagi were found in the abomasa of only three (10%) cows sampled in autumn and in 38 (57%) cows examined in summer. The majority of positive animals had low burdens of O. ostertagi but a few individuals in the group sampled during the summer had a moderate infection (5000-10,000 adult worms). A proportion of the cows in the summer group were also co-infected with small numbers of Trichostrongylus axei. Cooperia oncophora predominated in the recoveries from the larval cultures although O. ostertagi were also recovered. The overall prevalence of Dictyocaulus viviparus was 14%, based on larval identification in faecal samples. Liver fluke, or varying degrees of pathology attributable to Fasciola hepatica, were present in 65% of the livers. The results of this study extend those of previous workers, which were largely limited to dairy cows alone and which focussed on gastrointestinal nematodes and did not include simultaneous infections with lungworm and liver fluke. It was concluded, from the level of polyparasitism evident in this study, that adult cattle should be considered in preventative approaches to bovine helminthosis. PMID:16777251

Murphy, T M; Fahy, K N; McAuliffe, A; Forbes, A B; Clegg, T A; O'Brien, D J

2006-09-15

372

Physiological and molecular adaptations to drought in Andean potato genotypes  

PubMed Central

The drought stress tolerance of two Solanum tuberosum subsp. andigena landraces, one hybrid (adg×tbr) and Atlantic (S. tuberosum subsp. tuberosum) has been evaluated. Photosynthesis in the Andigena landraces during prolonged drought was maintained significantly longer than in the Tuberosum (Atlantic) line. Among the Andigena landraces, ‘Sullu’ (SUL) was more drought resistant than ‘Negra Ojosa’ (NOJ). Microarray analysis and metabolite data from leaf samples taken at the point of maximum stress suggested higher mitochondrial metabolic activity in SUL than in NOJ. A greater induction of chloroplast-localized antioxidant and chaperone genes in SUL compared with NOJ was evident. ABA-responsive TFs were more induced in NOJ compared with SUL, including WRKY1, mediating a response in SA signalling that may give rise to increased ROS. NOJ may be experiencing higher ROS levels than SUL. Metabolite profiles of NOJ were characterized by compounds indicative of stress, for example, proline, trehalose, and GABA, which accumulated to a higher degree than in SUL. The differences between the Andigena lines were not explained by protective roles of compatible solutes; hexoses and complex sugars were similar in both landraces. Instead, lower levels of ROS accumulation, greater mitochondrial activity and active chloroplast defences contributed to a lower stress load in SUL than in NOJ during drought.

Vasquez-Robinet, Cecilia; Mane, Shrinivasrao P.; Ulanov, Alexander V.; Watkinson, Jonathan I.; Stromberg, Verlyn K.; De Koeyer, David; Schafleitner, Roland; Willmot, David B.; Bonierbale, Merideth; Bohnert, Hans J.; Grene, Ruth

2008-01-01

373

Obesity, a Disease of Adaptation to Environmental & Physiological Stressors  

ERIC Educational Resources Information Center

Background: The educational intervention of this Applied Dissertation consisted of a presentation during which self-selected volunteers were introduced to relevant literature focusing on less known factors causing the disease of obesity and contrasting from behavior. Purpose: The workshop was structured to address the problem statement: "The…

Bijaoui, Nadia Judith

2012-01-01

374

Ultraviolet radiation stress: molecular and physiological adaptations in trees  

Microsoft Academic Search

The ozone layer acts like a giant sunshade, protecting forests and other life forms on the Earth's surface from much of the Sun's harmful ultraviolet radiation. The depletion in stratospheric ozone layer due to anthropogenically released pollutants such as CFCs during the last few decades has resulted in increased UV radiation at ground level. UV radiation (100-400 nm) consists of

S. S. SINGH; PANKAJ KUMAR; ASHWANI K. RAI

375

Levels of PCDDs, PCDFs and dioxin-like PCBs in raw cow’s milk collected in France in 2006  

Microsoft Academic Search

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD\\/Fs) as well as polychlorinated biphenyls (PCBs) are widespread environmental contaminants. A French national survey was carried out in April 2006 to assess the concentrations of PCDD\\/Fs and dioxin-like PCBs (DL-PCBs) in raw cow’s milk. A random sampling scheme stratified by region was applied to collect 239 raw milk samples from 93 plants belonging to 17

Benoit Durand; Barbara Dufour; Daniel Fraisse; Stéphanie Defour; Koenraad Duhem; Karine Le-Barillec

2008-01-01

376

Dietary Cation-Anion Difference and the Health and Production of Pasture-Fed Dairy Cows 2. Nonlactating Periparturient Cows  

Microsoft Academic Search

Anecdotal observations of reduced hypocalcemia due to small reductions in the precalving dietary cation- anion difference (DCAD) are widely reported in Austra- liaandNewZealand.Dietsofferedtononlactating,peri- parturient dairy cows in pasture-based dairy systems insoutheasternAustraliacanvaryintheircation-anion difference from 0 to +76 mEq\\/100 g. The effects of such a range in the DCAD on the health and production of cows, on a pasture-based diet, were examined

J. R. Roche; D. Dalley; P. Moate; C. Grainger; M. Rath; F. O’Mara

2003-01-01

377

Effects of dietary amylase and sucrose on productivity of cows fed low-starch diets.  

PubMed

Recent studies have observed positive effects of both sucrose and exogenous amylase on the productivity of dairy cattle. Our objective was to evaluate direct effects and interactions of amylase and sucrose on dry matter intake (DMI), milk production, and milk components. Forty-eight multiparous Holstein cows between 70 and 130d in milk were randomly assigned to each of 4 pens (12 cows/pen). Pens were randomly assigned to treatment sequence in a 4×4 Latin square design, balanced for carryover effects. Treatment periods were 28d, with 24d for diet adaptation and 4d for sample and data collection. The treatments were a control diet (36% NDF and 21% starch), the control diet with amylase [0.5g/kg of DM; Ronozyme RumiStar 600 (CT); DSM Nutritional Products Ltd., Basel, Switzerland], a diet with sucrose replacing corn grain at 2% of DM, and the sucrose diet with amylase (0.5g/kg of DM). All data were analyzed with mixed models, including the fixed effects of sugar, amylase, and their interaction, and the random effects of period and pen. Milk data included the random effects of cow nested within pen and pen × period to provide the error term for the pen-level analysis. Dry matter intake was not affected by treatments. Milk yield and milk composition were not altered by the inclusion of sucrose or amylase; however, a tendency for an amylase × sucrose interaction was observed for milk protein content, reflecting slightly lower milk protein concentrations for amylase and sucrose treatments (3.00 and 2.99±0.03%) compared with the control and amylase + sucrose treatments (3.02 and 3.03±0.03%). Solids-corrected and fat-corrected milk yields were not significantly altered by treatment, although the direct effect of amylase approached significance for both variables, suggesting possible small increases with amylase supplementation (~0.5kg/d). Feed efficiency (energy-corrected milk divided by dry matter intake) numerically increased with either amylase (1.57±0.12) or sucrose (1.60±0.12) treatment, but the combination of the 2 resulted in feed efficiency similar to the control treatment (both 1.50±0.12). The inclusion of amylase or sucrose did not affect DMI, productivity, or feed efficiency in mid-lactation cows fed low-starch, high-fiber diets. PMID:24792809

Vargas-Rodriguez, C F; Engstrom, M; Azem, E; Bradford, B J

2014-07-01

378

Effect of a high-palmitic acid fat supplement on milk production and apparent total-tract digestibility in high- and low-milk yield dairy cows.  

PubMed

The effect of a high-palmitic acid fat supplement was tested in 12 high-producing (mean=42.1kg/d) and 12 low-producing (mean=28.9kg/d) cows arranged in a replicated 3×3 Latin square design. Experimental periods were 21d, with 18d of diet adaptation and 3 d of sample collection. Treatments were (1) control (no supplemental fat), (2) high-palmitic acid (PA) supplement (84% C16:0), and (3) Ca salts of palm fatty acid (FA) supplement (Ca-FA). The PA supplement had no effect on milk production, but decreased dry matter intake by 7 and 9% relative to the control in high- and low-producing cows, respectively, and increased feed efficiency by 8.5% in high-producing cows compared with the control. Milk fat concentration and yield were not affected by PA relative to the control in high- or low-producing cows, although PA increased the yield of milk 16-C FA by more than 85g/d relative to the control. The Ca-FA decreased milk fat concentration compared with PA in high-, but not in low-producing cows. In agreement, Ca-FA dramatically increased milk fat concentration of trans-10 C18:1 and trans-10, cis-12 conjugated linoleic acid (>300%) compared with PA in high-producing cows, but not in low-producing cows. No effect of treatment on milk protein concentration or yield was detected. The PA supplement also increased 16-C FA apparent digestibility by over 10% and increased total FA digestibility compared with the control in high- and low-producing cows. During short-term feeding, palmitic acid supplementation did not increase milk or milk fat yield; however, it was efficiently absorbed, increased feed efficiency, and increased milk 16-C FA yield, while minimizing alterations in ruminal biohydrogenation commonly observed for other unsaturated fat supplements. Longer-term experiments will be necessary to determine the effects on energy balance and changes in body reserves. PMID:24731645

Rico, D E; Ying, Y; Harvatine, K J

2014-06-01

379

Immunodiagnostic identification of dairy cows infected with Prototheca zopfii at various clinical stages and discrimination between infected and uninfected cows.  

PubMed

Protothecosis is a severe form of mastitis in cattle that is caused by colorless algae of the genus Prototheca. So far, no suitable serological test for the identification of infected animals is available for routine diagnosis. In this study an indirect enzyme-linked immunosorbent assay (ELISA) for the identification of infected cows and for discriminating among infected cows at various clinical stages was developed. Immunoglobulin G (IgG) in serum and IgA and IgG1 in whey were used as antibody isotypes. The ELISA was evaluated using serum and whey from animals at different clinical stages of infection. A total of 12 cows with acute clinical manifestation of protothecal mastitis, 22 cows with clinical signs of chronic mastitis, 40 Prototheca zopfii-negative cows, and 18 cows with chronic clinical signs and earlier cultures positive for P. zopfii but with presently negative culturing results were investigated. A sensitivity of 96% and a specificity of 94% were calculated for the ELISA based on IgA levels. Intra-assay and interassay variations were calculated to be 6.08 and 6.32%, respectively. Based on these data, this ELISA was found to be suitable for discrimination between infected and uninfected animals and might therefore be useful for screening affected herds. PMID:11158103

Roesler, U; Scholz, H; Hensel, A

2001-02-01

380

Immunodiagnostic Identification of Dairy Cows Infected with Prototheca zopfii at Various Clinical Stages and Discrimination between Infected and Uninfected Cows  

PubMed Central

Protothecosis is a severe form of mastitis in cattle that is caused by colorless algae of the genus Prototheca. So far, no suitable serological test for the identification of infected animals is available for routine diagnosis. In this study an indirect enzyme-linked immunosorbent assay (ELISA) for the identification of infected cows and for discriminating among infected cows at various clinical stages was developed. Immunoglobulin G (IgG) in serum and IgA and IgG1 in whey were used as antibody isotypes. The ELISA was evaluated using serum and whey from animals at different clinical stages of infection. A total of 12 cows with acute clinical manifestation of protothecal mastitis, 22 cows with clinical signs of chronic mastitis, 40 Prototheca zopfii-negative cows, and 18 cows with chronic clinical signs and earlier cultures positive for P. zopfii but with presently negative culturing results were investigated. A sensitivity of 96% and a specificity of 94% were calculated for the ELISA based on IgA levels. Intra-assay and interassay variations were calculated to be 6.08 and 6.32%, respectively. Based on these data, this ELISA was found to be suitable for discrimination between infected and uninfected animals and might therefore be useful for screening affected herds.

Roesler, Uwe; Scholz, Holger; Hensel, Andreas

2001-01-01

381

Physiology of Iron Metabolism  

PubMed Central

Summary A revolution occurred during the last decade in the comprehension of the physiology as well as in the physiopathology of iron metabolism. The purpose of this review is to summarize the recent knowledge that has accumulated, allowing a better comprehension of the mechanisms implicated in iron homeostasis. Iron metabolism is very fine tuned. The free molecule is very toxic; therefore, complex regulatory mechanisms have been developed in mammalian to insure adequate intestinal absorption, transportation, utilization, and elimination. ‘Ironomics’ certainly will be the future of the understanding of genes as well as of the protein-protein interactions involved in iron metabolism.

Waldvogel-Abramowski, Sophie; Waeber, Gerard; Gassner, Christoph; Buser, Andreas; Frey, Beat M.; Favrat, Bernard; Tissot, Jean-Daniel

2014-01-01

382

Aging, physiology, and vision.  

PubMed

This article provides an overview of the normal, physiologic changes in vision that are a part of the aging process. Associated symptoms noted by and worrisome to many patients also are discussed. Clear explanations of the rationale and cause of these concerning complaints reduces anxiety and enables people to function more safely in environments in which visual loss is likely to have a deleterious effect. Likewise, accurate understanding of normal versus pathological vision symptoms assists health care providers, such as nurse practitioners, to better triage, assess, and treat ophthalmic-related problems. PMID:9624972

Smith, S C

1998-03-01

383

Cholesterol oxidase: physiological functions  

PubMed Central

An important aspect of catalysis by cholesterol oxidase (3?-hydroxysteroid oxidase) is the nature of its association with the lipid bilayer that contains the sterol substrate. Efficient catalytic turnover is affected by the association of the protein with the membrane as well as the solubility of the substrate in the lipid bilayer. In this review, the binding of cholesterol oxidase to the lipid bilayer, its turnover of substrates presented in different physical environments, and how these conditions affect substrate specificity are discussed. The physiological functions of the enzyme in bacterial metabolism, pathogenesis, and macrolide biosynthesis are reviewed in this context.

Kreit, Joseph; Sampson, Nicole S.

2009-01-01

384

Adaptive arrays  

Microsoft Academic Search

A method for adaptively optimizing the signal-to-noise ratio of an array antenna is presented. Optimum element weights are derived for a prescribed environment and a given signal direction. The derivation is extended to the optimization of a \\

S. Applebaum

1976-01-01

385

Vitamins A, E and Selenium Blood Levels in the Fat Cow Syndrome  

PubMed Central

Blood plasma analyses for vitamins A, E and selenium were performed from calving to five weeks of lactation in 29 cows. Twelve of the 29 cows had fat cow syndrome. The healthy cows had significantly higher (P<0.01) plasma vitamin A (40 ?g/dL) and vitamin E (5 ?g/mL) levels than the cows with fat cow syndrome (29 ?g vitamin A/dL and 3 ?g vitamin E/mL). At parturition, vitamin A level in plasma was low (25 ?g/dL) but increased progressively thereafter (up to 51 ?g/dL) in healthy cows, whereas cows with fat cow syndrome had lower levels of vitamin A, bordering on deficiency. The possible role of vitamin E in the alleviation of fat cow syndrome by affecting oxidation-reduction reactions in the liver is discussed. Significant (P<0.01) difference was not observed in selenium blood plasma level (35 ng/mL) between the two groups of cows or in another random group of 12 cows clinically affected by fat cow syndrome. ImagesFigures 1-6.

Hidiroglou, M.; Hartin, K. E.

1982-01-01

386

Hemorrhagic shock: The "physiology approach".  

PubMed

A shift of approach from 'clinics trying to fit physiology' to the one of 'physiology to clinics', with interpretation of the clinical phenomena from their physiological bases to the tip of the clinical iceberg, and a management exclusively based on modulation of physiology, is finally surging as the safest and most efficacious philosophy in hemorrhagic shock. ATLS(®) classification and recommendations on hemorrhagic shock are not helpful because antiphysiological and potentially misleading. Hemorrhagic shock needs to be reclassified in the direction of usefulness and timing of intervention: in particular its assessment and management need to be tailored to physiology. PMID:23248495

Bonanno, Fabrizio Giuseppe

2012-10-01

387

Hemorrhagic shock: The "physiology approach"  

PubMed Central

A shift of approach from ‘clinics trying to fit physiology’ to the one of ‘physiology to clinics’, with interpretation of the clinical phenomena from their physiological bases to the tip of the clinical iceberg, and a management exclusively based on modulation of physiology, is finally surging as the safest and most efficacious philosophy in hemorrhagic shock. ATLS® classification and recommendations on hemorrhagic shock are not helpful because antiphysiological and potentially misleading. Hemorrhagic shock needs to be reclassified in the direction of usefulness and timing of intervention: in particular its assessment and management need to be tailored to physiology.

Bonanno, Fabrizio Giuseppe

2012-01-01

388

Hepatic lipid metabolism in transition dairy cows fed flaxseed.  

PubMed

Thirty-three Holstein cows averaging 687 kg of body weight were allotted 6 wk before the expected date of parturition to 11 groups of 3 cows blocked within parity for similar calving dates to determine the effects of feeding different sources of fatty acids on blood parameters related to fatty liver and profile of fatty acids in plasma and liver. Cows were fed lipid supplements from 6 wk before the expected date of parturition until d 28 of lactation. Cows within each block were assigned to 1 of 3 isonitrogenous and isoenergetic dietary supplements: control with no added lipids (CO); unsaturated lipids supplied as whole flaxseed (FL; 3.3 and 11.0% of the dry matter in prepartum and postpartum diets, respectively); and saturated lipids supplied as Energy Booster (EB; 1.7 and 3.5% of the DM in prepartum and postpartum diets, respectively). Diets EB and FL had similar ether extract concentrations. Multiparous cows fed EB had lower dry matter intake and milk production, higher concentrations of nonesterified fatty acids and beta-hydroxybutyrate in plasma and triglycerides (TG) and total lipids in liver, and lower concentrations of plasma glucose and liver glycogen than those fed FL and CO. Production of 4% fat-corrected milk was similar among treatments. Multiparous cows fed FL had the highest liver concentrations of glycogen on wk 2 and 4 after calving and lowest concentrations of TG on wk 4 after calving. Liver C16:0 relative percentages in multiparous cows increased after calving whereas those of C18:0 decreased. Relative percentages of liver C16:0 were higher in wk 2 and 4 postpartum for multiparous cows fed EB compared with those fed CO and FL; those of C18:0 were lower in wk 4 postpartum for cows fed EB compared with those fed CO and FL. Liver C18:1 relative percentages of multiparous cows increased after calving and were higher in wk 4 for cows fed EB compared with those fed CO and FL. The inverse was observed for liver C18:2 relative percentages. In general, diets had more significant effects on plasma concentrations of nonesterified fatty acids, beta-hydroxybutyrate, and glucose and liver profiles of fatty acids, TG, total lipids, and glycogen of multiparous than primiparous cows. These data suggest that feeding a source of saturated fatty acids increased the risk of fatty liver in the transition cow compared with feeding no lipids or whole flaxseed. Feeding flaxseed compared with no lipids or a source of saturated fatty acids from 6 wk before calving could be a useful strategy to increase liver concentrations of glycogen and decrease liver concentrations of TG after calving, which may prevent the development of fatty liver in the transition dairy cow. PMID:17881701

Petit, H V; Palin, M F; Doepel, L

2007-10-01

389

Photrodes for physiological sensing  

NASA Astrophysics Data System (ADS)

This paper describes a paradigm shift in the technology for sensing electro-physiological signals. In recent years, SRICO has been developing small lithium niobate photonic electrodes, otherwise called "Photrodes" for measuring EEG and ECG signals. These extrinsic fiber-optic sensing devices exploit the extremely high electrical input impedance of Mach-Zehnder Intensity (MZI) electro-optic modulators to detect microvolt and millivolt physiological signals. Voltage levels associated with electrocardiograms are typically on the order of several millivolts, and such signals can be detected by capacitive pickup through clothing, i.e., the Photrode may be used in a non-contact mode. Electroencephalogram signals, which typically have an amplitude of several microvolts, require direct contact with the skin. However, this contact may be dry, eliminating the need for conductive gels. The electrical bandwidth of this photonic electrode system stretches from below 0.1 Hz to many tens of kHz and is constrained mainly by the signal processing electronics, not by the Photrode itself. The paper will describe the design and performance of Photrode systems and the challenging aspects of this new technology.

Kingsley, Stuart A.; Sriram, Sriram; Pollick, Andrea; Marsh, John

2004-06-01

390

Physiology of bile secretion  

PubMed Central

The formation of bile depends on the structural and functional integrity of the bile-secretory apparatus and its impairment, in different situations, results in the syndrome of cholestasis. The structural bases that permit bile secretion as well as various aspects related with its composition and flow rate in physiological conditions will first be reviewed. Canalicular bile is produced by polarized hepatocytes that hold transporters in their basolateral (sinusoidal) and apical (canalicular) plasma membrane. This review summarizes recent data on the molecular determinants of this primary bile formation. The major function of the biliary tree is modification of canalicular bile by secretory and reabsorptive processes in bile-duct epithelial cells (cholangiocytes) as bile passes through bile ducts. The mechanisms of fluid and solute transport in cholangiocytes will also be discussed. In contrast to hepatocytes where secretion is constant and poorly controlled, cholangiocyte secretion is regulated by hormones and nerves. A short section dedicated to these regulatory mechanisms of bile secretion has been included. The aim of this revision was to set the bases for other reviews in this series that will be devoted to specific issues related with biliary physiology and pathology.

Esteller, Alejandro

2008-01-01

391

The evolution of evolutionary physiology.  

PubMed

Studies on comparative and ontogenetic physiology appeared in the 19th and the beginning of the 20th centuries, and the view that these two methods are important for developing the bases of the evolution of functions was formulated. The term "evolutionary physiology" was proposed by Severtsov in 1914. At the beginning of the 1930s, the Laboratory for the Development of Problems in Evolutionary Physiology was established in the USSR and a review of these studies was published. The I. M. Sechenov Institute of Evolutionary Physiology was set up in Leningrad in 1956 under the direction of Orbeli, who formulated the main study areas and methods of evolutionary physiology. This field of physiology was actively developed over the following half century. Evolutionary physiology addresses problems of the evolution of functions and functional evolution, often recruiting methods from allied scientific fields, including biochemistry, morphology, and molecular biology. PMID:19629702

Natochin, Yu V

2009-09-01

392

Metabolic Adaptation to Muscle Ischemia  

NASA Technical Reports Server (NTRS)

Although all tissues in the body can adapt to varying physiological/pathological conditions, muscle is the most adaptable. To understand the significance of cellular events and their role in controlling metabolic adaptations in complex physiological systems, it is necessary to link cellular and system levels by means of mechanistic computational models. The main objective of this work is to improve understanding of the regulation of energy metabolism during skeletal/cardiac muscle ischemia by combining in vivo experiments and quantitative models of metabolism. Our main focus is to investigate factors affecting lactate metabolism (e.g., NADH/NAD) and the inter-regulation between carbohydrate and fatty acid metabolism during a reduction in regional blood flow. A mechanistic mathematical model of energy metabolism has been developed to link cellular metabolic processes and their control mechanisms to tissue (skeletal muscle) and organ (heart) physiological responses. We applied this model to simulate the relationship between tissue oxygenation, redox state, and lactate metabolism in skeletal muscle. The model was validated using human data from published occlusion studies. Currently, we are investigating the difference in the responses to sudden vs. gradual onset ischemia in swine by combining in vivo experimental studies with computational models of myocardial energy metabolism during normal and ischemic conditions.