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1

Physiological Adaptation in Desert Birds  

NSDL National Science Digital Library

This peer-reviewed article from BioScience journal is about adaptations desert birds. We call into question the idea that birds have not evolved unique physiological adaptations to desert environments. The rate at which desert larks metabolize energy is lower than in mesic species within the same family, and this lower rate of living translates into a lower overall energy requirement in the wild. We argue that selection has reduced oxygen consumption at the tissue level under basal conditions for birds living in deserts. We document that total evaporative water loss--the sum of cutaneous water loss (CWL) and respiratory water loss--is reduced in desert birds, and present evidence that changes in CWL are responsible for this pattern. The diminution in CWL is attributable to changes in the lipid structure of the stratum corneum of the skin, the physical barrier to diffusion of water vapor. Finally, we show linkages between physiology and life-history attributes of larks along an aridity gradient; birds from deserts have not only a reduced rate of metabolism but also a small clutch size and slow nestling development. Hence, attributes of physiology are correlated with traits that directly affect reproductive success. Our hope is that we will prompt students to question the notion that birds do not possess physiological adaptations to the desert environment, and raise the specter of doubt about "preadaptation" in birds living in deserts.

JOSEPH B. WILLIAMS and B. IRENE TIELEMAN (;)

2005-05-01

2

An adaptive interface based on physiological indices  

Microsoft Academic Search

In this paper, we are concerned with an adaptive interface which controls a mental task according to the changes of human mental condition. Many studies in the field of physiology indicate that the physiological indices extracted from electroencephalogram (EEG), electrocardiogram (EGG) and skin potential response reflect human mental condition related to the comfort aspect. The system measures and analyzes such

Naoki SAIWAKI; Hiroyuki TOGASHI; Hiroaki TSUJIMOTO; Shogo NISHIDA

1996-01-01

3

Physiologic adaptation to space - Space adaptation syndrome  

NASA Technical Reports Server (NTRS)

The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

Vanderploeg, J. M.

1985-01-01

4

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

5

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

6

Adaptive filtering of physiological tremor for real-time compensation  

Microsoft Academic Search

Physiological tremor is one of the main cause for human imprecision during micro surgery. Accurate filtering of physiological tremor is extremely important for compensation in robotics assisted micro-surgical instruments\\/procedures. A study on surgeon's tremor is conducted and the characteristics of the tremor band and its nature are analyzed. An adaptive filtering approach is developed to estimate the modulated signals with

K. C. Veluvolu; U.-X. Tan; W. T. Latt; C. Y. Shee; W. T. Ang

2009-01-01

7

PHYSIOLOGICAL ADAPTATION TO THE ENVIRONMENT 1  

Microsoft Academic Search

The ability of an animal to cope with new environments arises from its capacity to respond to environmental variables and maintain body equilibrium (homeostasis). Each compensating mechanism depends on, and is a part of, a physiological feedback process. The severity (intensity and duration) of an environmental change relative to the animal's capacity to respond determines the potential disruption to the

B. A. Young; B. Walker; A. E. Dixon; V. A. Walker

2010-01-01

8

Some physiological and biochemical methods for acute and chronic stress evaluation in dairy cows  

Microsoft Academic Search

Stress factors are so numerous and so diverse in their strength and duration that the consequences on animal welfare can be quite varied. The first important distinction concerns the characterization of acute and chronic stress conditions. Acute stress is a short-lived negative situation that allows a quick and quite complete recovery of the physiological balance (adaptation), while chronic stress is

Erminio Trevisi; Giuseppe Bertoni

2010-01-01

9

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

10

Plasticity of physiology in Lobelia: testing for adaptation and constraint.  

PubMed

Phenotypic plasticity is thought to be a major mechanism allowing sessile organisms such as plants to adapt to environmental heterogeneity. However, the adaptive value of many common plastic responses has not been tested by linking these responses to fitness. Even when plasticity is adaptive, costs of plasticity, such as the energy necessary to maintain regulatory pathways for plastic responses, may constrain its evolution. We used a greenhouse experiment to test whether plastic physiological responses to soil water availability (wet vs. dry conditions) were adaptive and/or costly in the congeneric wildflowers Lobelia cardinalis and L. siphilitica. Eight physiological traits related to carbon and water uptake were measured. Specific leaf area (SLA), photosynthetic rate (A), stomatal conductance (gs), and photosynthetic capacity (Amax) responded plastically to soil water availability in L. cardinalis. Plasticity in Amax was maladaptive, plasticity in A and g(s) was adaptive, and plasticity in SLA was adaptively neutral. The nature of adaptive plasticity in L. cardinalis, however, differed from previous studies. Lobelia cardinalis plants with more conservative water use, characterized by lower g(s), did not have higher fitness under drought conditions. Instead, well-watered L. cardinalis that had higher g(s) had higher fitness. Only Amax responded plastically to drought in L. siphilitica, and this response was adaptively neutral. We detected no costs of plasticity for any physiological trait in either L. cardinalis or L. siphilitica, suggesting that the evolution of plasticity in these traits would not be constrained by costs. Physiological responses to drought in plants are presumed to be adaptive, but our data suggest that much of this plasticity can be adaptively neutral or maladaptive. PMID:16817538

Caruso, Christina M; Maherali, Hafiz; Sherrard, Mark

2006-05-01

11

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

12

Exploring the use of physiology in adaptive game design  

Microsoft Academic Search

This paper explores the use of human physiology in adaptive game mechanics. The study shows evidence that galvanic skin response (GSR) can react to stress changes caused by game difficulties and that GSR positively and significantly correlates with negative game events (frustration events) rather than positive events (success events); moreover, continuous failures during game playing can trigger distress (negative stress),

Shaomei Wu; Tao Lin

2011-01-01

13

Functional Genomics of Physiological Plasticity and Local Adaptation in Killifish  

PubMed Central

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

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

2011-01-01

14

Morpho-physiological traits characterizing environmental adaptation of Avena barbata  

Microsoft Academic Search

Seventeen morphological and physiological characteristics of three Avena barbata L. populations from Israel were measured\\u000a in order to define possible combinations explaining adaptation of these populations to different precipitation, temperature\\u000a and altitude regimes. Five genotypes from each A. barbata populations were collected from Ashqelon (31°63?N, low annual precipitation),\\u000a En Hamifraz (32°46?N, high temperature), and Mount Carmel (32°73?N, high altitude), Israel.

Susanne Somersalo; Pirjo Mäkelä; Ari Rajala; Eviatar Nevo; Pirjo Peltonen-Sainio

1998-01-01

15

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

16

Physiological adaptations of small mammals to desert ecosystems.  

PubMed

Adaptations of animals to the xeric environment have been studied in various taxonomic groups and across several deserts. Despite the impressive data that have been accumulated, the focus in most of these studies is mainly on the significance of one variable at a time. Here, we attempt to integrate between responses of several physiological systems, challenged by increasing diet and water salinity and extreme temperatures, acquired in different studies of thermo and osmo-regulatory adaptations, of small rodents, to the xeric environment. Studies have shown differential thermoregulatory responses to increased dietary salinity, which were attributed to habitat and habits of the relevant species. In the thermoregulatory studies, a potential adaptive significance of low metabolic rate was demonstrated. From an evolutionary point of view, the most important adaptation is in the timing of reproduction, as it enables the transfer of genetic properties to the next generation in an unpredictable ecosystem, where reproduction might not occur every year. Results in this aspect show that increased dietary salinity, through an increase in vasopressin plasma levels, plays an important role as a regulator of the reproductive system. We assume that the amount of food existing in the habitat and the amount of reserves in the animal in the form of white adipose tissue are important for reproduction. Photoperiod affects all studied physiological responses, emphasizing the importance of pre-acclimation to seasonal characteristics. We summarize the existing data and suggest neuro-endocrine pathways, which have a central role in these adaptations by affecting thermoregulation, osmoregulation and reproduction to create the optimal response to xeric conditions. These hypotheses can be used as the basis for future studies. PMID:21392308

Schwimmer, Hagit; Haim, Abraham

2009-12-01

17

Cytokine hypothesis of overtraining: a physiological adaptation to excessive stress?  

PubMed

Overtraining syndrome (OTS) is a condition wherein an athlete is training excessively, yet performance deteriorates. This is usually accompanied by mood/behavior changes and a variety of biochemical and physiological alterations. Presently, there is no global hypothesis to account for OTS. The present paper will attempt to provide a unifying paradigm that will integrate previous research under the rubric of the cytokine hypothesis of overtraining. It is argued that high volume/intensity training, with insufficient rest, will produce muscle and/or skeletal and/or joint trauma. Circulating monocytes are then activated by injury-related cytokines, and in turn produce large quantities of proinflammatory IL-1beta, and/or IL-6, and/or TNF-alpha, producing systemic inflammation. Elevated circulating cytokines then co-ordinate the whole-body response by: a) communicating with the CNS and inducing a set of behaviors referred to as "sickness" behavior, which involves mood and behavior changes that support resolution of systemic inflammation: b) adjusting liver function, to support the up-regulation of gluconeogenesis, as well as de novo synthesis of acute phase proteins, and a concomitant hypercatabolic state; and c) impacting on immune function. Theoretically, OTS is viewed as the third stage of Selye's general adaptation syndrome, with the focus being on recovery/survival, and not adaptation, and is deemed to be "protective," occurring in response to excessive physical/physiological stress. Recommendations are made for potential markers of OTS, based on a systemic inflammatory condition. PMID:10694113

Smith, L L

2000-02-01

18

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

19

Eccentric action of muscles: physiology, injury, and adaptation.  

PubMed

Eccentric muscle action deserves special consideration from the standpoint of physiology, adaptation, and training. The function of muscles as shock absorbers or springs seems to be quite different from other actions described in classical descriptions of muscle biology. This uniqueness certainly requires a more careful understanding of muscle as a unit consisting of myofibers and fascia which may work together or in opposition in response to chronic or acute stimuli. In addition, the stretch-shortening cycle is a special case of its own. However, from the standpoint of maximum human performance, there remain tremendous gaps in our understanding of the role of eccentric muscle action and its use in athletic training. How much is good? Does microfibrosis represent a problem of overtraining and eventually limit performance, or is it advantageous for success? Is the body-builder really developing muscle or connective tissue separating muscles? How does eccentric muscle action sometimes produce pain but not always? It would appear that much work is needed before a complete understanding of eccentric muscle action is obtained. This brief review has been designed to encourage research, argument, and discussion. PMID:2676546

Stauber, W T

1989-01-01

20

Adapting APSIM to model the physiology and genetics of complex adaptive traits in field crops.  

PubMed

Progress in molecular plant breeding is limited by the ability to predict plant phenotype based on its genotype, especially for complex adaptive traits. Suitably constructed crop growth and development models have the potential to bridge this predictability gap. A generic cereal crop growth and development model is outlined here. It is designed to exhibit reliable predictive skill at the crop level while also introducing sufficient physiological rigour for complex phenotypic responses to become emergent properties of the model dynamics. The approach quantifies capture and use of radiation, water, and nitrogen within a framework that predicts the realized growth of major organs based on their potential and whether the supply of carbohydrate and nitrogen can satisfy that potential. The model builds on existing approaches within the APSIM software platform. Experiments on diverse genotypes of sorghum that underpin the development and testing of the adapted crop model are detailed. Genotypes differing in height were found to differ in biomass partitioning among organs and a tall hybrid had significantly increased radiation use efficiency: a novel finding in sorghum. Introducing these genetic effects associated with plant height into the model generated emergent simulated phenotypic differences in green leaf area retention during grain filling via effects associated with nitrogen dynamics. The relevance to plant breeding of this capability in complex trait dissection and simulation is discussed. PMID:20400531

Hammer, Graeme L; van Oosterom, Erik; McLean, Greg; Chapman, Scott C; Broad, Ian; Harland, Peter; Muchow, Russell C

2010-05-01

21

Adaptive latitudinal shifts in the thermal physiology of a terrestrial isopod  

Microsoft Academic Search

ABSTRACT Temperature is the most important abiotic factor affecting physiology, ecology and evolution inectotherms.,Do organisms ,broadly ,distributed along a latitudinal ,gradient adapt to local differences in temperature? In ectotherms this question has played a central role in evolutionary physiology. By means of an extensive field study and laboratory experiments, we tested the existence of local adaptations,in thermal traits along 10of

Luis E. Castañeda; A. Lardies; Francisco Bozinovic

22

Journal of Plant Physiology 162 (2005) 151--160 Apple flavonols during fruit adaptation to solar  

E-print Network

Journal of Plant Physiology 162 (2005) 151--160 Apple flavonols during fruit adaptation to solar of an inversion technique developed for non-destructive leaf pigment assessment. The model for flavonol content) are an abundant group of phenolic compounds involved in a number of physiological functions in higher plants

Gitelson, Anatoly

23

Physiological, Productive, and Economic Benefits of Shade, Spray, and Fan System Versus Shade for Holstein Cows During Summer Heat  

Microsoft Academic Search

During the 1984 summer, effects of spray and fan in freestall areas and feed- ing areas on milk yield, plasma growth hormone and prolactin, freestall utiliza- tion, and economic significance for Hol- stein cows were studied. Weekly milk and rectal temperatures at morning and after- noon milkings were higher for cows in shade than in shade with spray and fan

M. O. Igono; H. D. Johnson; B. J. Steevens; G. F. Krause; M. D. Shanklin

1987-01-01

24

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

25

Adaptive estimation of bandlimited physiological signals in real-time  

Microsoft Academic Search

Accurate estimation of physiological bandlimited signal is extremely important in various biomedical applications. This paper focuses on developing a single stage robust algorithm for accurate bandlimited signal estimation in real-time applications. In this paper, the existing method bandlimited multiple Fourier linear combiner(BMFLC) with least-mean square(LMS) is improved by replacing LMS with recursive leat square (RLS). A comparative study is conducted

Zhe Fan; Yubo Wang; Kalyana C. Veluvolu

2011-01-01

26

Cardiac adaptation in athletes of black ethnicity: differentiating pathology from physiology.  

PubMed

Cardiac adaptation to intense physical exercise is determined by factors including age, gender, body size, sporting discipline and ethnicity. Differentiating physiology from pathological conditions such as hypertrophic cardiomyopathy (HCM) is challenging, but relevant, as HCM remains the commonest cause of sudden death in young athletes. Marked electrocardiographic repolarisation changes and echocardiographic left ventricular hypertrophy have been demonstrated in athletes of black ethnicity. Such changes highlight the overlap between 'athlete's heart' and morphologically mild HCM with potential for false-positive diagnoses and disqualification from competitive sport. The focus of this article is to provide practical considerations in differentiating physiological adaptation to exercise from cardiac pathology in athletes of black ethnicity. PMID:22773610

Chandra, Navin; Papadakis, Michael; Sharma, Sanjay

2012-08-01

27

Physiological adaptations of Saccharomyces cerevisiae evolved for improved butanol tolerance  

PubMed Central

Background Butanol is a chemical with potential uses as biofuel and solvent, which can be produced by microbial fermentation. However, the end product toxicity is one of the main obstacles for developing the production process irrespective of the choice of production organism. The long-term goal of the present project is to produce 2-butanol in Saccharomyces cerevisiae. Therefore, unraveling the toxicity mechanisms of solvents such as butanol and understanding the mechanisms by which tolerant strains of S. cerevisiae adapt to them would be an important contribution to the development of a bio-based butanol production process. Results A butanol tolerant S. cerevisiae was achieved through a series of sequential batch cultures with gradual increase of 2-butanol concentration. The final mutant (JBA-mut) tolerates all different alcohols tested at higher concentrations compared to the wild type (JBA-wt). Proteomics analysis of the two strains grown under mild butanol-stress revealed 46 proteins changing their expression by more than 1.5-fold in JBA-mut, 34 of which were upregulated. Strikingly, 21 out of the 34 upregulated proteins were predicted constituents of mitochondria. Among the non-mitochondrial up-regulated proteins, the minor isoform of Glycerol-3-phosphatase (Gpp2) was the most notable, since it was the only tested protein whose overexpression was found to confer butanol tolerance. Conclusion The study demonstrates several differences between the butanol tolerant mutant and the wild type. Upregulation of proteins involved in the mitochondrial ATP synthesizing machinery constituents and glycerol biosynthesis seem to be beneficial for a successful adaptation of yeast cells to butanol stress. PMID:23855998

2013-01-01

28

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

29

The adaptation of digestive enzymes to the diet : Its physiological significance  

E-print Network

The adaptation of digestive enzymes to the diet : Its physiological significance T. CORRING Laboratoire de Physiologie de la Nutrition, LN.R.A. 78350 Jouy en Josas, France. Summary. Digestive enzymes that this process includes many enzymes. The intestinal step of digestion is the most important in the enzyme

Paris-Sud XI, Université de

30

Biomaterials 28 (2007) 671679 Cell adaptation to a physiologically relevant ECM mimic with different  

E-print Network

Biomaterials 28 (2007) 671­679 Cell adaptation to a physiologically relevant ECM mimic bioactivity and mechanical strength. This is because cell interaction with the extracellular matrix (ECM on ECM biological stimuli, and traction-induced signaling, which depends on ECM mechanical stimuli

Nakamura, Toshio

31

Our ancestral physiological phenotype: An adaptation for hypoxia tolerance and for endurance performance?  

Microsoft Academic Search

There are well known mechanistic similari- ties in human physiology between adaptations for endurance performance and hypoxia tolerance. By using background principles arising from recent studies of the evolution of the diving response in marine mammals, here we analyze human responses to hypobaric hypoxia based on studies with several different low and high altitude human lineages. As in the evolution

PETER W. HOCHACHKA; HANNS CHRISTIAN GUNGA; KARL KIRSCH

1998-01-01

32

The strengths of in vivo magnetic resonance imaging (MRI) to study environmental adaptational physiology in fish  

Microsoft Academic Search

Adaptational physiology studies how animals cope with their environment, even if this environment is subject to permanent fluctuations such as tidal or seasonal variations. Aquatic organisms are generally more prone to be exposed to osmotic, hypoxic and temperature challenges than terrestrial animals. Some of these challenges are more restraining in an aquatic environment. To date, very few studies have used

A. Van der Linden; M. Verhoye; H. O. Pörtner; C. Bock

2004-01-01

33

The adaptive significance of ontogenetic changes in physiology: a test in Avena barbata.  

PubMed

Physiological changes with ontogeny are common in plants. Although ontogenetic changes are hypothesized to improve plant function, their adaptive significance has rarely been tested. Here, we estimated phenotypic selection on ontogenetic change in photosynthesis (A) and stomatal conductance (g(s)) of Avena barbata. We tested whether ontogenetic changes in A and g(s) increased fitness in wet and dry soil environments. To determine whether evolution in response to this selection would be constrained, we estimated the heritability of ontogenetic change in physiology, as well as cross-environment genetic correlations. Ontogenetic change in A, but not g(s), was adaptive in the wet soil environment; plants that maintained or increased A from the prereproductive to the reproductive phase had higher fitness. In the dry soil environment, ontogenetic change in A and g(s) was adaptively neutral. We detected significant genetic variation for ontogenetic change in A and g(s), but no cross-environment genetic correlations, suggesting that the evolution of these traits would not be genetically constrained. We demonstrate that ontogenetic changes in physiological traits can increase fitness but the adaptive value of these changes varies among traits and environments. PMID:19402881

Maherali, Hafiz; Caruso, Christina M; Sherrard, Mark E

2009-08-01

34

Allosteric Regulation of PKM2 Allows Cellular Adaptation to Different Physiological States  

NSDL National Science Digital Library

Pyruvate kinase isoform M2 (PKM2) activity is subject to complex allosteric regulation. Recently, serine and SAICAR (succinylaminoimidazolecarboxamide ribose-5′-phosphate) were identified as previously unrecognized activators of PKM2. These findings add additional complexity to how PKM2 is regulated in cells and support the notion that modulating PKM2 activity enables cells to adapt their metabolic state to specific physiological contexts.

Dan Y. Gui (Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology; REV); Caroline A. Lewis (Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology; REV); Matthew G. Vander Heiden (Koch Institute for Integrative Cancer Research at Massachusetts Institute of Technology; REV)

2013-02-19

35

Physiological responses and adaptive strategies of wheat seedlings to salt and alkali stresses  

Microsoft Academic Search

Effects of salt (NaCl?:?Na2SO4) and alkali (NaHCO3?:?Na2CO3) stresses on the contents of inorganic ions and organic solutes in wheat shoots were compared to explore the physiological responses and adaptive strategies of wheat to these stresses. Wheat significantly accumulated Na and simultaneously accumulated Cl, soluble sugars and proline to maintain osmotic and ionic balance under salt stress. Compared with salt stress,

Xiaoyu Li; Jiaju Liu; Yuting Zhang; Jixiang Lin; Chunsheng Mu

2009-01-01

36

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. PMID:22566674

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

2012-01-01

37

Physiological and proteomic analysis of Lactobacillus casei in response to acid adaptation.  

PubMed

The aim of this study was to investigate the acid tolerance response (ATR) in Lactobacillus casei by a combined physiological and proteomic analysis. To optimize the ATR induction, cells were acid adapted for 1 h at different pHs, and then acid challenged at pH 3.5. The result showed that acid adaptation improved acid tolerance, and the highest survival was observed in cells adapted at pH 4.5 for 1 h. Analysis of the physiological data showed that the acid-adapted cells exhibited higher intracellular pH (pHi), intracellular NH4 (+) content, and lower inner permeability compared with the cells without adaptation. Proteomic analysis was performed upon acid adaptation to different pHs (pH 6.5 vs. pH 4.5) using two-dimensional electrophoresis. A total of 24 proteins that exhibited at least 1.5-fold differential expression were identified. Four proteins (Pgk, LacD, Hpr, and Galm) involved in carbohydrate catabolism and five classic stress response proteins (GroEL, GrpE, Dnak, Hspl, and LCAZH_2811) were up-regulated after acid adaptation at pH 4.5 for 1 h. Validation of the proteomic data was performed by quantitative RT-PCR, and transcriptional regulation of all selected genes showed a positive correlation with the proteomic patterns of the identified proteins. Results presented in this study may be useful for further elucidating the acid tolerance mechanisms and may help in formulating new strategies to improve the industrial performance of this species during acid stress. PMID:25062817

Wu, Chongde; He, Guiqiang; Zhang, Juan

2014-10-01

38

Ash, calcium, phosphorus and magnesium content of the metacarpus of hereford cows under different nutritional and physiological conditions  

E-print Network

fulfillment of the requirements for the degree of MASTER OF SCIENCE May, 1967 Major Subject: Animal Science ASII, CAT Clbtl, PIIOSI. 'IIORUS AND NAGNES LIPtI COiITENT OF TIIE tlETACt&RPIRS OF IIKREFORD COIIS UNDER DIFFERENT tNV'i'RTTIOiNAI. ANID PIIYS... of this lost weight from various areas of the body of the anima], in it's different stales of productive life. Calcium& phosphorus nul magnesium are the major mineral el et c ots of. bone in beef cows. When the. essential dietary mineraLs are not available...

Haque, Mozammel

2012-06-07

39

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. PMID:22936840

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

2012-01-01

40

Adaptation to altitude as a vehicle for experiential learning of physiology by university undergraduates  

NSDL National Science Digital Library

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. Here, teams of three to four students measured the maximal rate of oxygen uptake, cognitive function, hand and foot volume changes, reticulocyte count and hematocrit, urinary pH and 24-h urine volume, athletic performance, and nocturnal blood oxygen saturation. Their data allowed the students to quantify the effect of altitude on the oxygen cascade and to demonstrate the following altitude-related changes: 1) impaired performance on selected cognitive function tests, 2) mild peripheral edema, 3) rapid reticulocytosis, 4) urinary alkalinization and diuresis, 5) impaired aerobic but not anaerobic exercise performance, 6) inverse relationship between blood oxygen saturation and resting heart rate, and 7) regular periodic nocturnal oxygen desaturation events accompanied by heart rate accelerations. The students learned and applied basic statistical techniques to analyze their data, and each team summarized its results in the format of a scientific paper. The students were uniformly enthusiastic about the use of self-directed experimentation to explore the physiology of altitude adaptation and felt that they learned more from this course format than a control group of students felt that they learned from a physiology course taught by the same instructor in the standard classroom/laboratory format.

David S Weigle (University of Washington Medicine); Amelia Buben (University of Washington Arts and Sciences); Caitlin C Burke (University of Washington Arts and Sciences); Nels D Carroll (University of Washington Arts and Sciences); Brett M Cook (University of Washington Arts and Sciences); Benjamin S Davis (University of Washington Arts and Sciences)

2007-05-16

41

Global transcriptional, physiological, and metabolite analyses of the responses of Desulfovibrio vulgaris hildenborough to salt adaptation.  

PubMed

The response of Desulfovibrio vulgaris Hildenborough to salt adaptation (long-term NaCl exposure) was examined by performing physiological, global transcriptional, and metabolite analyses. Salt adaptation was reflected by increased expression of genes involved in amino acid biosynthesis and transport, electron transfer, hydrogen oxidation, and general stress responses (e.g., heat shock proteins, phage shock proteins, and oxidative stress response proteins). The expression of genes involved in carbon metabolism, cell growth, and phage structures was decreased. Transcriptome profiles of D. vulgaris responses to salt adaptation were compared with transcriptome profiles of D. vulgaris responses to salt shock (short-term NaCl exposure). Metabolite assays showed that glutamate and alanine accumulated under salt adaptation conditions, suggesting that these amino acids may be used as osmoprotectants in D. vulgaris. Addition of amino acids (glutamate, alanine, and tryptophan) or yeast extract to the growth medium relieved salt-related growth inhibition. A conceptual model that links the observed results to currently available knowledge is proposed to increase our understanding of the mechanisms of D. vulgaris adaptation to elevated NaCl levels. PMID:20038696

He, Zhili; Zhou, Aifen; Baidoo, Edward; He, Qiang; Joachimiak, Marcin P; Benke, Peter; Phan, Richard; Mukhopadhyay, Aindrila; Hemme, Christopher L; Huang, Katherine; Alm, Eric J; Fields, Matthew W; Wall, Judy; Stahl, David; Hazen, Terry C; Keasling, Jay D; Arkin, Adam P; Zhou, Jizhong

2010-03-01

42

Global Transcriptional, Physiological, and Metabolite Analyses of the Responses of Desulfovibrio vulgaris Hildenborough to Salt Adaptation ? †  

PubMed Central

The response of Desulfovibrio vulgaris Hildenborough to salt adaptation (long-term NaCl exposure) was examined by performing physiological, global transcriptional, and metabolite analyses. Salt adaptation was reflected by increased expression of genes involved in amino acid biosynthesis and transport, electron transfer, hydrogen oxidation, and general stress responses (e.g., heat shock proteins, phage shock proteins, and oxidative stress response proteins). The expression of genes involved in carbon metabolism, cell growth, and phage structures was decreased. Transcriptome profiles of D. vulgaris responses to salt adaptation were compared with transcriptome profiles of D. vulgaris responses to salt shock (short-term NaCl exposure). Metabolite assays showed that glutamate and alanine accumulated under salt adaptation conditions, suggesting that these amino acids may be used as osmoprotectants in D. vulgaris. Addition of amino acids (glutamate, alanine, and tryptophan) or yeast extract to the growth medium relieved salt-related growth inhibition. A conceptual model that links the observed results to currently available knowledge is proposed to increase our understanding of the mechanisms of D. vulgaris adaptation to elevated NaCl levels. PMID:20038696

He, Zhili; Zhou, Aifen; Baidoo, Edward; He, Qiang; Joachimiak, Marcin P.; Benke, Peter; Phan, Richard; Mukhopadhyay, Aindrila; Hemme, Christopher L.; Huang, Katherine; Alm, Eric J.; Fields, Matthew W.; Wall, Judy; Stahl, David; Hazen, Terry C.; Keasling, Jay D.; Arkin, Adam P.; Zhou, Jizhong

2010-01-01

43

Adaptation and response of Bifidobacterium animalis subsp. lactis to bile: a proteomic and physiological approach.  

PubMed

Bile salts are natural detergents that facilitate the digestion and absorption of the hydrophobic components of the diet. However, their amphiphilic nature makes them very inhibitory for bacteria and strongly influences bacterial survival in the gastrointestinal tract. Adaptation to and tolerance of bile stress is therefore crucial for the persistence of bacteria in the human colonic niche. Bifidobacterium animalis subsp. lactis, a probiotic bacterium with documented health benefits, is applied largely in fermented dairy products. In this study, the effect of bile salts on proteomes of B. animalis subsp. lactis IPLA 4549 and its bile-resistant derivative B. animalis subsp. lactis 4549dOx was analyzed, leading to the identification of proteins which may represent the targets of bile salt response and adaptation in B. animalis subsp. lactis. The comparison of the wild-type and the bile-resistant strain responses allowed us to hypothesize about the resistance mechanisms acquired by the derivative resistant strain and about the bile salt response in B. animalis subsp. lactis. In addition, significant differences in the levels of metabolic end products of the bifid shunt and in the redox status of the cells were also detected, which correlate with some differences observed between the proteomes. These results indicate that adaptation and response to bile in B. animalis subsp. lactis involve several physiological mechanisms that are jointly dedicated to reduce the deleterious impact of bile on the cell's physiology. PMID:17827318

Sánchez, Borja; Champomier-Vergès, Marie-Christine; Stuer-Lauridsen, Birgitte; Ruas-Madiedo, Patricia; Anglade, Patricia; Baraige, Fabienne; de los Reyes-Gavilán, Clara G; Johansen, Eric; Zagorec, Monique; Margolles, Abelardo

2007-11-01

44

Adaptation and Response of Bifidobacterium animalis subsp. lactis to Bile: a Proteomic and Physiological Approach?  

PubMed Central

Bile salts are natural detergents that facilitate the digestion and absorption of the hydrophobic components of the diet. However, their amphiphilic nature makes them very inhibitory for bacteria and strongly influences bacterial survival in the gastrointestinal tract. Adaptation to and tolerance of bile stress is therefore crucial for the persistence of bacteria in the human colonic niche. Bifidobacterium animalis subsp. lactis, a probiotic bacterium with documented health benefits, is applied largely in fermented dairy products. In this study, the effect of bile salts on proteomes of B. animalis subsp. lactis IPLA 4549 and its bile-resistant derivative B. animalis subsp. lactis 4549dOx was analyzed, leading to the identification of proteins which may represent the targets of bile salt response and adaptation in B. animalis subsp. lactis. The comparison of the wild-type and the bile-resistant strain responses allowed us to hypothesize about the resistance mechanisms acquired by the derivative resistant strain and about the bile salt response in B. animalis subsp. lactis. In addition, significant differences in the levels of metabolic end products of the bifid shunt and in the redox status of the cells were also detected, which correlate with some differences observed between the proteomes. These results indicate that adaptation and response to bile in B. animalis subsp. lactis involve several physiological mechanisms that are jointly dedicated to reduce the deleterious impact of bile on the cell's physiology. PMID:17827318

Sanchez, Borja; Champomier-Verges, Marie-Christine; Stuer-Lauridsen, Birgitte; Ruas-Madiedo, Patricia; Anglade, Patricia; Baraige, Fabienne; de los Reyes-Gavilan, Clara G.; Johansen, Eric; Zagorec, Monique; Margolles, Abelardo

2007-01-01

45

Match and mismatch: conservation physiology, nutritional ecology and the timescales of biological adaptation  

PubMed Central

Conservation physiology (CP) and nutritional ecology (NE) are both integrative sciences that share the fundamental aim of understanding the patterns, mechanisms and consequences of animal responses to changing environments. Here, we explore the high-level similarities and differences between CP and NE, identifying as central themes to both fields the multiple timescales over which animals adapt (and fail to adapt) to their environments, and the need for integrative models to study these processes. At one extreme are the short-term regulatory responses that modulate the state of animals in relation to the environment, which are variously considered under the concepts of homeostasis, homeorhesis, enantiostasis, heterostasis and allostasis. In the longer term are developmental responses, including phenotypic plasticity and transgenerational effects mediated by non-genomic influences such as parental physiology, epigenetic effects and cultural learning. Over a longer timescale still are the cumulative genetic changes that take place in Darwinian evolution. We present examples showing how the adaptive responses of animals across these timescales have been represented in an integrative framework from NE, the geometric framework (GF) for nutrition, and close with an illustration of how GF can be applied to the central issue in CP, animal conservation. PMID:22566672

Raubenheimer, David; Simpson, Stephen J.; Tait, Alice H.

2012-01-01

46

What Has Natural Variation Taught Us about Plant Development, Physiology, and Adaptation?  

PubMed Central

Nearly 100 genes and functional polymorphisms underlying natural variation in plant development and physiology have been identified. In crop plants, these include genes involved in domestication traits, such as those related to plant architecture, fruit and seed structure and morphology, as well as yield and quality traits improved by subsequent crop breeding. In wild plants, comparable traits have been dissected mainly in Arabidopsis thaliana. In this review, we discuss the major contributions of the analysis of natural variation to our understanding of plant development and physiology, focusing in particular on the timing of germination and flowering, plant growth and morphology, primary metabolism, and mineral accumulation. Overall, functional polymorphisms appear in all types of genes and gene regions, and they may have multiple mutational causes. However, understanding this diversity in relation to adaptation and environmental variation is a challenge for which tools are now available. PMID:19574434

Alonso-Blanco, Carlos; Aarts, Mark G.M.; Bentsink, Leonie; Keurentjes, Joost J.B.; Reymond, Matthieu; Vreugdenhil, Dick; Koornneef, Maarten

2009-01-01

47

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. PMID:24885261

2014-01-01

48

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. PMID:22004364

2011-01-01

49

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

50

Genetic variance and covariance for physiological traits in Lobelia: are there constraints on adaptive evolution?  

PubMed

Physiological traits that control the uptake of carbon dioxide and loss of water are key determinants of plant growth and reproduction. Variation in these traits is often correlated with environmental gradients of water, light, and nutrients, suggesting that natural selection is the primary evolutionary mechanism responsible for physiological diversification. Responses to selection, however, can be constrained by the amount of standing genetic variation for physiological traits and genetic correlations between these traits. To examine the potential for constraint on adaptive evolution, we estimated the quantitative genetic basis of physiological trait variation in one population of each of two closely related species (Lobelia siphilitica and L. cardinalis). Restricted maximum likelihood analyses of greenhouse-grown half-sib families were used to estimate genetic variances and covariances for seven traits associated with carbon and water relations. We detected significant genetic variation for all traits in L. siphilitica, suggesting that carbon-gain and water-use traits could evolve in response to natural selection in this population. In particular, narrow-sense heritabilities for photosynthetic rate (A), stomatal conductance (gs), and water-use efficiency (WUE) in our L. siphilitica population were high relative to previous studies in other species. Although there was significant narrow-sense heritability for A in L. cardinalis, we detected little genetic variation for traits associated with water use (gs and WUE), suggesting that our population of this species may be unable to adapt to drier environments. Despite being tightly linked functionally, the genetic correlation between A and gs was not strong and significant in either population. Therefore, our L. siphilitica population would not be genetically constrained from evolving high A (and thus fixing more carbon for growth and reproduction) while also decreasing gs to limit water loss. However, a significant negative genetic correlation existed between WUE and plant size in L. siphilitica, suggesting that high WUE may be negatively associated with high fecundity. In contrast, our results suggest that any constraints on the evolution of photosynthetic and stomatal traits of L. cardinalis are caused primarily by a lack of genetic variation, rather than by genetic correlations between these functionally related traits. PMID:15926692

Caruso, Christina M; Maherali, Hafiz; Mikulyuk, Alison; Carlson, Kjarstin; Jackson, Robert B

2005-04-01

51

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. PMID:23308206

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

2013-01-01

52

Antepartal insulin-like growth factor concentrations indicating differences in the metabolic adaptive capacity of dairy cows  

PubMed Central

Cows with different Insulin-like Growth Factor-I (IGF-I) concentrations showed comparable expression levels of hepatic growth hormone receptor (GHR). Suppressor of cytokine signaling 2 (SOCS2), could be responsible for additional inhibition of the GHR signal cascade. The aims were to monitor cows with high or low antepartal IGF-I concentrations (IGF-Ihigh or IGF-Ilow), evaluate the interrelationships of endocrine endpoints, and measure hepatic SOCS2 expression. Dairy cows (n = 20) were selected (240 to 254 days after artificial insemination (AI)). Blood samples were drawn daily (day -17 until calving) and IGF-I, GH, insulin, thyroid hormones, estradiol, and progesterone concentrations were measured. Liver biopsies were taken (day 264 ± 1 after AI and postpartum) to measure mRNA expression (IGF-I, IGFBP-2, IGFBP-3, IGFBP-4, acid labile subunit (ALS), SOCS2, deiodinase1, GHR1A). IGF-I concentrations in the two groups were different (p < 0.0001). However, GH concentrations and GHR1A mRNA expression were comparable (p > 0.05). Thyroxine levels and ALS expression were higher in the IGF-Ihigh cows compared to IGF-Ilow cows. Estradiol concentration tended to be greater in the IGF-Ilow group (p = 0.06). It was hypothesized that low IGF-I levels are associated with enhanced SOCS2 expression although this could not be decisively confirmed by the present study. PMID:24962413

Holzhausen, Lars; Araujo, Marcelo Gil; Heppelmann, Maike; Sipka, Anja; Pfarrer, Chistiane; Schuberth, Hans-Joachim; Bollwein, Heinrich

2014-01-01

53

[Adaptation of Mycoplasma gallisepticum to unfavorable growth conditions: changes in morphological and physiological characteristics].  

PubMed

Adaptation of Mycoplasma gallisepticum to unfavorable growth conditions results in altered morphological and physiological characteristics of the cells. M. gallisepticum populations in a complete nutrient medium contain pear-shaped vegetative cells (d approximately 0.3 microm; l approximately 0.8 microm) with pronounced polar and cytoskeleton-like structures. Such mycoplasma cells are able to induce damage in a bacterial genome, causing an SOS response of the test strain (Escherichia coli PQ37). In a starvation medium, M. gallisepticum produces nanoforms, small coccoid cells (d approximately 0.15-0.2 microm) without either polar or cytoskeleton-like structures. Unlike vegetative cells, nanoforms do not induce genome damage. Alleviation of unfavorable growth conditions results in a reversion of nanoforms to typical vegetative cells. PMID:19137716

Chernov, V M; Chernova, O A; Gorshkov, O V; Muzykantov, A A; Sha?mardarova, G F; Pel'nikevich, A D; Margulis, A B; Kolpakov, A I; Il'inskaia, O N

2008-01-01

54

Eco-physiological adaptation of dominant tree species at two contrasting karst habitats in southwestern China  

PubMed Central

The purpose of this study was to investigate the eco-physiological adaptation of indigenous woody species to their habitats in karst areas of southwestern China. Two contrasting forest habitats were studied: a degraded habitat in Daxiagu and a well-developed habitat in Tianlongshan, and the eco-physiological characteristics of the trees were measured for three growth seasons. Photosynthetic rate (Pn), stomatal conductance (gs), and transpiration rate (Tr) of the tree species in Daxiagu were 2-3 times higher than those in Tianlongshan under ambient conditions. However, this habitat effect was not significant when measurements were taken under controlled conditions. Under controlled conditions, Pn, gs, and Tr of the deciduous species were markedly higher than those for the evergreen species. Habitat had no significant effect on water use efficiency (WUE) or photochemical characteristics of PSII. The stomatal sensitivity of woody species in the degraded habitat was much higher than that in the well-developed habitat. Similarly, the leaf total nitrogen (N) and phosphorus (P) contents expressed on the basis of either dry mass or leaf area were also much higher in Daxiagu than they were in Tianlongshan. The mass-based leaf total N content of deciduous species was much higher than that of evergreen species, while leaf area-based total N and P contents of evergreens were significantly higher than those of deciduous species. The photosynthetic nitrogen- and phosphorus-use efficiencies (PNUE and PPUE) of deciduous species were much higher than those of evergreens. Further, the PPUE of the woody species in Tianlongshan was much higher than that  of the woody species in Daxiagu. The results from three growth seasons imply that the tree species were able to adapt well to their growth habitats. Furthermore, it seems that so-called “temporary drought stress” may not occur, or may not be severe for most woody plants in karst areas of southwestern China. PMID:24555059

2013-01-01

55

Seasonal variation in coat characteristics, tick loads, cortisol levels, some physiological parameters and temperature humidity index on Nguni cows raised in low- and high-input farms  

NASA Astrophysics Data System (ADS)

Seasonal variations in hair length, tick loads, cortisol levels, haematological parameters (HP) and temperature humidity index (THI) in Nguni cows of different colours raised in two low-input farms, and a commercial stud was determined. The sites were chosen based on their production systems, climatic characteristics and geographical locations. Zazulwana and Komga are low-input, humid-coastal areas, while Honeydale is a high-input, dry-inland Nguni stud farm. A total of 103 cows, grouped according to parity, location and coat colour, were used in the study. The effects of location, coat colour, hair length and season were used to determine tick loads on different body parts, cortisol levels and HP in blood from Nguni cows. Highest tick loads were recorded under the tail and the lowest on the head of each of the animals (P < 0.05). Zazulwana cows recorded the highest tick loads under the tails of all the cows used in the study from the three farms (P < 0.05). High tick loads were recorded for cows with long hairs. Hair lengths were longest during the winter season in the coastal areas of Zazulwana and Honeydale (P < 0.05). White and brown-white patched cows had significantly longer (P < 0.05) hair strands than those having a combination of red, black and white colour. Cortisol and THI were significantly lower (P < 0.05) in summer season. Red blood cells, haematoglobin, haematocrit, mean cell volumes, white blood cells, neutrophils, lymphocytes, eosinophils and basophils were significantly different (P < 0.05) as some associated with age across all seasons and correlated to THI. It was concluded that the location, coat colour and season had effects on hair length, cortisol levels, THI, HP and tick loads on different body parts and heat stress in Nguni cows.

Katiyatiya, C. L. F.; Muchenje, V.; Mushunje, A.

2014-08-01

56

Effect of farm and simulated laboratory cold environmental conditions on the performance and physiological responses of lactating dairy cows supplemented with bovine somatotropin (BST)  

NASA Astrophysics Data System (ADS)

A study was conducted to evaluate the effect of bovine somatotropin (BST) supplementation in twelve lactating dairy cows maintained in cold environmental conditions. Six cows were injected daily with 25 mg of BST; the other six were injected with a control vehicle. Cows were maintained under standard dairy management during mid-winter for 30 days. Milk production was recorded twice daily, and blood samples were taken weekly. Animals were then transferred to environmentally controlled chambers and exposed to cycling thermoneutral (15° to 20° C) and cycling cold (-5° to +5° C) temperatures for 10 days in a split-reversal design. Milk production, feed and water intake, body weights and rectal temperatures were monitored. Blood samples were taken on days 1, 3, 5, 8 and 10 of each period and analyzed for plasma triiodothyronine (T3), thyroxine (T4), cortisol, insulin and prolactin. Under farm conditions, BST-treated cows produced 11% more milk than control-treated cows and in environmentally controlled chambers produced 17.4% more milk. No differences due to BST in feed or water intake, body weights or rectal temperatures were found under laboratory conditions. Plasma T3 and insulin increased due to BST treatment while no effect was found on cortisol, prolactin or T4. The results showed that the benefits of BST supplementation in lactating dairy cows were achieved under cold environmental conditions.

Becker, B. A.; Johnson, H. D.; Li, R.; Collier, R. J.

1990-09-01

57

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 PMID:25075311

2014-01-01

58

Physiological Adaptations Involved in Alkane Assimilation at a Low Temperature by Rhodococcus sp. Strain Q15†  

PubMed Central

We examined physiological adaptations which allow the psychrotroph Rhodococcus sp. strain Q15 to assimilate alkanes at a low temperature (alkanes are contaminants which are generally insoluble and/or solid at low temperatures). During growth at 5°C on hexadecane or diesel fuel, strain Q15 produced a cell surface-associated biosurfactant(s) and, compared to glucose-acetate-grown cells, exhibited increased cell surface hydrophobicity. A transmission electron microscopy examination of strain Q15 grown at 5°C revealed the presence of intracellular electron-transparent inclusions and flocs of cells connected by an extracellular polymeric substance (EPS) when cells were grown on a hydrocarbon and morphological differences between the EPS of glucose-acetate-grown and diesel fuel-grown cells. A lectin binding analysis performed by using confocal scanning laser microscopy (CSLM) showed that the EPS contained a complex mixture of glycoconjugates, depending on both the growth temperature and the carbon source. Two glycoconjugates [?-d-Gal-(1-3)-d-GlcNAc and ?-l-fucose] were detected only on the surfaces of cells grown on diesel fuel at 5°C. Using scanning electron microscopy, we observed strain Q15 cells on the surfaces of octacosane crystals, and using CSLM, we observed strain Q15 cells covering the surfaces of diesel fuel microdroplets; these findings indicate that this organism assimilates both solid and liquid alkane substrates at a low temperature by adhering to the alkane phase. Membrane fatty acid analysis demonstrated that strain Q15 adapted to growth at a low temperature by decreasing the degree of saturation of membrane lipid fatty acids, but it did so to a lesser extent when it was grown on hydrocarbons at 5°C; these findings suggest that strain Q15 modulates membrane fluidity in response to the counteracting influences of low temperature and hydrocarbon toxicity. PMID:10388690

Whyte, L. G.; Slagman, S. J.; Pietrantonio, F.; Bourbonnière, L.; Koval, S. F.; Lawrence, J. R.; Inniss, W. E.; Greer, C. W.

1999-01-01

59

Physiological cellular responses and adaptations of Rhodococcus erythropolis IBBPo1 to toxic organic solvents.  

PubMed

A new Gram-positive bacterium, Rhodococcus erythropolis IBBPo1 (KF059972.1) was isolated from a crude oil-contaminated soil sample by enrichment culture method. R. erythropolis IBBPo1 was able to tolerate a wide range of toxic compounds, such as antibiotics (800-1000?g/mL), synthetic surfactants (50-200?g/mL), and organic solvents (40%-100%). R. erythropolis IBBPo1 showed good tolerance to both alkanes (cyclohexane, n-hexane, n-decane) and aromatics (toluene, styrene, ethylbenzene) with logPOW (logarithm of the partition coefficient of the solvent in octanol-water mixture) values between 2.64 and 5.98. However, alkanes were less toxic for R. erythropolis IBBPo1 cells, compared with aromatics. The high organic solvent tolerance of R. erythropolis IBBPo1 could be due to the presence in their large genome of some catabolic (alkB, alkB1, todC1, todM, xylM), transporter (HAE1) and trehalose-6-phosphate synthase (otsA1, KF059973.1) genes. Numerous and complex physiological cellular responses and adaptations involved in organic solvent tolerance were revealed in R. erythropolis IBBPo1 cells exposed 1 and 24hr to 1% organic solvents. R. erythropolis IBBPo1 cells adapt to 1% organic solvents by changing surface hydrophobicity, morphology and their metabolic fingerprinting. Considerable modifications in otsA1 gene sequence were also observed in cells exposed to organic solvents (except ethylbenzene). PMID:25288551

Stancu, Mihaela Marilena

2014-10-01

60

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. PMID:23716056

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

2013-01-01

61

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. PMID:12839748

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

2003-01-01

62

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

63

Adaptation and evaluation of the GrazeIn model of grass dry matter intake and milk yield prediction for grazing dairy cows.  

PubMed

The prediction of grass dry matter intake (GDMI) and milk yield (MY) are important to aid sward and grazing management decision making. Previous evaluations of the GrazeIn model identified weaknesses in the prediction of GDMI and MY for grazing dairy cows. To increase the accuracy of GDMI and MY prediction, GrazeIn was adapted, and then re-evaluated, using a data set of 3960 individual cow measurements. The adaptation process was completed in four additive steps with different components of the model reparameterised or altered. These components were: (1) intake capacity (IC) that was increased by 5% to reduce a general GDMI underprediction. This resulted in a correction of the GDMI mean and a lower relative prediction error (RPE) for the total data set, and at all stages of lactation, compared with the original model; (2) body fat reserve (BFR) deposition from 84 days in milk to next calving that was included in the model. This partitioned some energy to BFR deposition after body condition score nadir had been reached. This reduced total energy available for milk production, reducing the overprediction of MY and reducing RPE for MY in mid and late lactation, compared with the previous step. There was no effect on predicted GDMI; (3) The potential milk curve was reparameterised by optimising the rate of decrease in the theoretical hormone related to secretory cell differentiation and the basal rate of secretory cell death to achieve the lowest possible mean prediction error (MPE) for MY. This resulted in a reduction in the RPE for MY and an increase in the RPE for GDMI in all stages of lactation compared with the previous step; and (4) finally, IC was optimised, for GDMI, to achieve the lowest possible MPE. This resulted in an IC correction coefficient of 1.11. This increased the RPE for MY but decreased the RPE for GDMI compared with the previous step. Compared with the original model, modifying this combination of four model components improved the prediction accuracy of MY, particularly in late lactation with a decrease in RPE from 27.8% in the original model to 22.1% in the adapted model. However, testing of the adapted model using an independent data set would be beneficial and necessary to make definitive conclusions on improved predictions. PMID:24438821

O'Neill, B F; Ruelle, E; O'Donovan, M; Shalloo, L; Mulligan, F J; Boland, T M; Delaby, L; Delagarde, R; Lewis, E

2014-04-01

64

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

65

Relation between QT interval and heart rate. New design of physiologically adaptive cardiac pacemaker  

Microsoft Academic Search

The relation between QT interval and heart rate has been studied in a group of patients undergoing physiological exercise, in a group undergoing atrial pacing without exercise, and in a group with complete heart block undergoing exercise at a fixed ventricular rate controlled by cardiac pacing. The expected shortening in QT interval during physiological exercise is only in part the

A F Rickards; J Norman

1981-01-01

66

SIRT1 is a Highly Networked Protein That Mediates the Adaptation to Chronic Physiological Stress  

PubMed Central

SIRT1 is a NAD+-dependent protein deacetylase that has a very large number of established protein substrates and an equally impressive list of biological functions thought to be regulated by its activity. Perhaps as notable is the remarkable number of points of conflict concerning the role of SIRT1 in biological processes. For example, evidence exists suggesting that SIRT1 is a tumor suppressor, is an oncogene, or has no effect on oncogenesis. Similarly, SIRT1 is variably reported to induce, inhibit, or have no effect on autophagy. We believe that the resolution of many conflicting results is possible by considering recent reports indicating that SIRT1 is an important hub interacting with a complex network of proteins that collectively regulate a wide variety of biological processes including cancer and autophagy. A number of the interacting proteins are themselves hubs that, like SIRT1, utilize intrinsically disordered regions for their promiscuous interactions. Many studies investigating SIRT1 function have been carried out on cell lines carrying undetermined numbers of alterations to the proteins comprising the SIRT1 network or on inbred mouse strains carrying fixed mutations affecting some of these proteins. Thus, the effects of modulating SIRT1 amount and/or activity are importantly determined by the genetic background of the cell (or the inbred strain of mice), and the effects attributed to SIRT1 are synthetic with the background of mutations and epigenetic differences between cells and organisms. Work on mice carrying alterations to the Sirt1 gene suggests that the network in which SIRT1 functions plays an important role in mediating physiological adaptation to various sources of chronic stress such as calorie restriction and calorie overload. Whether the catalytic activity of SIRT1 and the nuclear concentration of the co-factor, NAD+, are responsible for modulating this activity remains to be determined. However, the effect of modulating SIRT1 activity must be interpreted in the context of the cell or tissue under investigation. Indeed, for SIRT1, we argue that context is everything. PMID:24020004

Clark-Knowles, Katherine V.; Caron, Annabelle Z.; Gray, Douglas A.

2013-01-01

67

Physiological adaptations of the gut in the Lake Magadi tilapia, Alcolapia grahami, an alkaline- and saline-adapted teleost fish  

Microsoft Academic Search

We describe the gut physiology of the Lake Magadi tilapia (Alcolapia grahami), specifically those aspects associated with feeding and drinking while living in water of unusually high carbonate alkalinity (titratable base=245 mequiv l?1) and pH (9.85). Drinking of this highly alkaline lake water occurs at rates comparable to or higher than those seen in marine teleosts. Eating and drinking take

Annie Narahara Bergman; Pierre Laurent; George Otiang'a-Owiti; Harold L. Bergman; Patrick J. Walsh; Paul Wilson; Chris M. Wood

2003-01-01

68

HEMOGLOBIN FUNCTION AND PHYSIOLOGICAL ADAPTATION TO HYPOXIA IN HIGH-ALTITUDE MAMMALS  

E-print Network

polymorphism in North American deer mice (Peromyscus maniculatus) that illustrates how integrative studies, evolutionary physiology, hemoglobin, hypoxia, natural selection, oxygen transport, Peromyscus maniculatus High a case study involving a complex hemoglobin polymorphism in deer mice (Peromyscus maniculatus

Storz, Jay F.

69

Adaptability of buffaloes to climatic stress, as assessed by physiological reactions.  

PubMed

Among the physiological reactions to climate, the haematocrit value had a tendency to increase in the hotter months, though the increase observed was within physiological limits. Rectal temperature did not change to significantly higher levels, during the months with average ambient temperatures in the region of 25.1-31.6 degrees C. Similarly, pulse rates, too, increased in parallel to rising ambient temperatures. PMID:2241491

Garg, S K; Nangia, O P

1990-01-01

70

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. PMID:22973220

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

2012-01-01

71

Eco-physiological adaptations that favour freshwater cyanobacteria in a changing climate.  

PubMed

Climate change scenarios predict that rivers, lakes, and reservoirs will experience increased temperatures, more intense and longer periods of thermal stratification, modified hydrology, and altered nutrient loading. These environmental drivers will have substantial effects on freshwater phytoplankton species composition and biomass, potentially favouring cyanobacteria over other phytoplankton. In this Review, we examine how several cyanobacterial eco-physiological traits, specifically, the ability to grow in warmer temperatures; buoyancy; high affinity for, and ability to store, phosphorus; nitrogen-fixation; akinete production; and efficient light harvesting, vary amongst cyanobacteria genera and may enable them to dominate in future climate scenarios. We predict that spatial variation in climate change will interact with physiological variation in cyanobacteria to create differences in the dominant cyanobacterial taxa among regions. Finally, we suggest that physiological traits specific to different cyanobacterial taxa may favour certain taxa over others in different regions, but overall, cyanobacteria as a group are likely to increase in most regions in the future. PMID:22217430

Carey, Cayelan C; Ibelings, Bas W; Hoffmann, Emily P; Hamilton, David P; Brookes, Justin D

2012-04-01

72

Adaptive value and costs of physiological plasticity to soil moisture limitation in recombinant inbred lines of Avena barbata.  

PubMed

Costs are hypothesized to constrain the evolution of adaptive phenotypic plasticity, but they have been difficult to quantify because strong selection should eliminate costly genotypes from natural populations. However, recent studies suggest that crosses between natural populations can recover these genotypes. We determined the adaptive value and costs of, as well as the genetic variation for, physiological and morphological plasticity to soil water limitation in Avena barbata recombinant inbred lines (RILs) created by crossing mesic and xeric ecotypes. All traits were plastic, and plasticity in stomatal limitation of photosynthesis and photosynthetic rate before and at reproduction was adaptive. However, we detected a significant cost of plasticity only for stomatal conductance at reproduction, and the mean cost for all traits of A. barbata RILs was at least 50% smaller than costs previously estimated using RILs. In addition, heritabilities for plasticity were <0.1 and were significant only for photosynthesis at reproduction and leaf mass per unit area. Our results suggest that costs are less likely to constrain the evolution of adaptive plasticity in A. barbata than genetic variation for plasticity. PMID:20039799

Maherali, Hafiz; Caruso, Christina M; Sherrard, Mark E; Latta, Robert G

2010-02-01

73

Physiological adaptation to 6 weeks of specific training of intercollegiate soccer players  

Microsoft Academic Search

The purpose of this study was first to examine selected anthropometric and physiological characteristics of the outfield players of a soccer team according to playing position, and secondly to study the effects of a six week soccer training regimen on peak aerobic power (VO2peak), treadmill run?time to exhaustion (TTE), percent body fat (%BF), and sum of skinfold thicknesses (SST). Twenty

H. Silverman; D. J. McCann; P. A. Molé

2001-01-01

74

Ecological adaptation in Lolium : morphologi-cal and physiological parameters at early stages  

E-print Network

on persistence of the two varieties. Additional key words : Lolium perenne, Mediterranean climate, physiological morphologiques et physiologiques de deux variétés de Lolium perenne L., de niveau diffé- rent de persistance en jeunes de croissance sur la persistance des deux variétés. Mots clés additionnels : Lolium perenne

Paris-Sud XI, Université de

75

PhysioNet 2010 Challenge: A Robust Multi-Channel Adaptive Filtering Approach to the Estimation of Physiological Recordings.  

PubMed

The 2010 PhysioNet Challenge was to predict the last few seconds of a physiological waveform given its previous history and M-1 different concurrent physiological recordings. A robust approach was implemented by using a bank of adaptive filters to predict the desired channel. In all, M channels (the M-1 original signals, and 1 signal derived from the previous history of the target signal) were used to estimate the missing data. For each channel, a Gradient Adaptive Lattice Laguerre filter (GALL) was trained to estimate the desired channel. The GALL filter was chosen because of its fast convergence, stability, and ability to model a long response using relatively few parameters. The prediction of each of the channels (the output of each of the GALL filters) was then linearly combined using time-varying weights determined through a Kalman filter. This approach is extensible to recordings with any number of signals, other types of signals, and other problem domains. The code for the algorithm is freely available at PhysioNet under the GPL. PMID:22708118

Silva, Ikaro

2010-01-01

76

Individual Differences in Behavioral, Physiological, and Genetic Sensitivities to Contexts: Implications for Development and Adaptation  

Microsoft Academic Search

Although exposure to adversity places children at high risk for developmental problems, there is considerable variation in the adaptation of children exposed to both low and high levels of adversity. In recent years, researchers have made significant progress in understanding how social environments shape children’s development. Studies indicate that not all children are equally susceptible to environmental effects. In this

W. Thomas Boyce

2009-01-01

77

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

PubMed Central

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 product otoacoustic emission onset adaptation and contralateral suppression had predictable changes in direction of magnitude and phase that were dependent on the input–output function. After sectioning of the middle-ear muscles (MEMs), DPOAE onset adaptation and contralateral suppression were greatly reduced, and there were little, if any, changes in phase. These “residual” changes were interpreted as a result of the MOC reflex. The results suggest that what appears to be DPOAE onset adaptation and contralateral suppression can be mediated primarily by MEM reflexes. When studying MOC effects on otoacoustic emissions (OAEs) using acoustic stimulation, it is necessary to make recordings over a span of stimulus levels. In addition, looking at both magnitude and phase of the OAE may help separate what is due to the MOC reflex from MEM reflex. PMID:15952049

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

2005-01-01

78

Adaptations and Resistance of Zooplankton to Stress: Effects of Genetic, Environmental, and Physiological Factors  

Microsoft Academic Search

The ability of a species to adapt to stress factors such as exposure to toxicants depends to a large extent on the presence of individuals that are able to respond to the exposure in a successful way. Several strategies can be employed to cope with different stress factors. Investments on growth and reproduction, for instance, can be varied to meet

Marko Reinikainen; Jaana Hietala; Mari Walls

1998-01-01

79

From Physiology to Fitness: The Costs of a Defensive Adaptation in Rattlesnakes  

Microsoft Academic Search

The costs of using and maintaining presumed adaptations are unknown for most animals. Energetically expensive traits, such as some agonistic and antipredator behaviors in animals, may incur trade-offs with other aspects of an animal's life history, such as feeding and reproduction. However, infrequent and brief use may reduce the costs of vigorous behaviors. The shaker muscles in the tails of

Brad R. Moon

2006-01-01

80

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

81

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. PMID:23536375

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

2013-01-01

82

Influence of gender and endogenous sex steroids on catecholaminergic structures involved in physiological adaptation to hypoxia  

Microsoft Academic Search

Mechanisms underlying sex-related differences in adaptation to high altitude were investigated by assessing the turnover\\u000a of dopamine and noradrenaline in structures of the chemoafferent pathway, i.e. carotid body and brainstem noradrenergic cell\\u000a groups (A1, A5, A6, A2 to which chemosensory fibres project). The influence of gender was assessed in male and female rats reared at an altitude\\u000a of 3600 m,

J. M. Pequignot; H. Spielvogel; E. Caceres; A. Rodriguez; B. Semporé; R. Favier

1997-01-01

83

Physiological adaptation to the humid tropics with special reference to the West African Dwarf (WAD) goat  

Microsoft Academic Search

West African Dwarf (WAD) goats are widely distributed in the subhumid and humid zones of Africa but are particularly associated\\u000a with less favourable environments. Adaptive features such as feeding behaviour, efficiency of feed use and disease tolerance\\u000a enable WAD goats to thrive on natural resources left untouched by other domestic ruminants. In marginal environments this\\u000a goat remains the only domestic

J. O. Daramola; A. A. Adeloye

2009-01-01

84

Physiological elevation of endogenous hormones results in superior strength training adaptation  

Microsoft Academic Search

The purpose of this study was to determine the influence of transiently elevated endogenous hormone concentrations during\\u000a exercise on strength training adaptations. Nine subjects performed four unilateral strength training session per week on the\\u000a elbow flexors for 11 weeks. During two of the weekly sessions, leg exercises were performed to acutely increase the systemic\\u000a anabolic hormone concentration immediately before the exercises

Bent R. RønnestadHa; Håvard Nygaard; Truls Raastad

85

Physiological fitness and health adaptations from purposeful training using off-road vehicles  

Microsoft Academic Search

The purpose of this study was to evaluate fitness and health adaptations from a training program riding all-terrain vehicles\\u000a (ATV) and off-road motorcycles (ORM) as the exercise stimulus. Participants (n = 58) were randomized to a control group (n = 12) or one of four experimental groups; 2 days\\/week ATV (n = 11), 2 days\\/week ORM (n = 12), 4 days\\/week ATV (n = 11), or 4 days\\/week ORM (n = 12). Aerobic fitness, musculoskeletal fitness,

J. F. Burr; V. K. Jamnik; N. Gledhill

86

Possible involvement of oxytocin in modulating the stress response in lactating dairy cows  

PubMed Central

Oxytocin can attenuate the physiological and behavioral response to stress in animals. In this study we investigated the relationship between plasma oxytocin concentrations and the behavioral and physiological response of dairy cows to a repeated psychological stressor (novel environment). Twenty lactating multi-parous dairy cows were milked in a familiar milking parlor and in a novel environment. Blood samples were collected before and after milking in the familiar parlor (baseline) and on the second and fifth day in the novel parlor to measure plasma cortisol and oxytocin concentrations. Heart rate was recorded on all cows during milking in the familiar and novel environment. On all test days, the behavioral response of cows to milk cluster attachment was scored. On day 2 in the novel parlor, the oxytocin response, cortisol concentrations and heart rate were greater, and heart rate variability was lower than baseline values recorded in the familiar parlor. The results from this study suggest that oxytocin release is increased in response to exposure to a psychological stressor (novel environment) and that cows adapt to this stressor over time. After initial suppression, oxytocin levels increased over days of milking in a novel environment, whereas indicators of stress simultaneously decreased. Furthermore, the oxytocin increase was associated with habituation of the cortisol response in anticipation of milking in a novel environment, suggesting that oxytocin may be involved in habituation to a novel environment in dairy cows. This mechanism of habituation to novel environments may reflect an association between oxytocin and a “familiarization-habituation response” to repeated exposure to an initially novel environment that has previously been reported in humans.

Sutherland, Mhairi A.; Tops, Mattie

2014-01-01

87

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

88

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. PMID:22232765

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

2012-01-01

89

Behaviorally mediated, warm adaptation: a physiological strategy when mice behaviorally thermoregulate.  

PubMed

Laboratory mice housed under standard vivarium conditions with an ambient temperature (Ta) of ~22°C are likely to be cold stressed because this Ta is below their thermoneutral zone (TNZ). Mice raised at Tas within the TNZ adapt to the warmer temperatures, developing smaller internal organs and longer tails compared to mice raised at 22°C. Since mice prefer Tas equal to their TNZ when housed in a thermocline, we hypothesized that mice reared for long periods (e.g., months) in a thermocline would undergo significant changes in organ development and tail length as a result of their thermoregulatory behavior. Groups of three female BALB/c mice at an age of 37 days were housed together in a thermocline consisting of a 90cm long aluminum runway with a floor temperature ranging from 23 to 39°C. Two side-by-side thermoclines allowed for a total of 6 mice to be tested simultaneously. Control mice were tested in isothermal runways maintained at a Ta of 22°C. All groups were given cotton pads for bedding/nest building. Mass of heart, lung, liver, kidney, brain, and tail length were assessed after 73 days of treatment. Mice in the thermocline and control (isothermal) runways were compared to cage control mice housed 3/cage with bedding under standard vivarium conditions. Mice in the thermocline generally remained in the warm end throughout the daytime with little evidence of nest building, suggesting a state of thermal comfort. Mice in the isothermal runway built elaborate nests and huddled together in the daytime. Mice housed in the thermocline had significantly smaller livers and kidneys and an increase in tail length compared to mice in the isothermal runway as well as when compared to the cage controls. These patterns of organ growth and tail length of mice in the thermocline are akin to warm adaptation. Thus, thermoregulatory behavior altered organ development, a process we term behaviorally mediated, warm adaptation. Moreover, the data suggest that the standard vivarium conditions are likely a cold stress that alters normal organ development relative to mice allowed to select their thermal preferendum. PMID:25086972

Gordon, Christopher J; Aydin, Cenk; Repasky, Elizabeth A; Kokolus, Kathleen M; Dheyongera, Geoffrey; Johnstone, Andrew F M

2014-08-01

90

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. PMID:23613590

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

2013-01-01

91

Physiological and metabolic adaptations of Potamogeton pectinatus L. tubers support rapid elongation of stem tissue in the absence of oxygen.  

PubMed

Tubers of Potamogeton pectinatus L., an aquatic pondweed, over-winter in the anoxic sediments of rivers, lakes and marshes. Growth of the pre-formed shoot that emerges from the tuber is remarkably tolerant to anoxia, with elongation of the stem occurring faster when oxygen is absent. This response, which allows the shoot to reach oxygenated waters, occurs despite a 69-81% reduction in the rate of ATP production, and it is underpinned by several physiological and metabolic adaptations that contribute to efficient energy usage. First, extension of the pre-formed shoot is the result of cell expansion, without the accumulation of new cellular material. Secondly, after over-wintering, the tuber and pre-formed shoot have the enzymes necessary for a rapid fermentative response at the onset of growth under anoxia. Thirdly, the incorporation of [(35)S]methionine into protein is greatly reduced under anoxia. The majority of the anoxically synthesized proteins differ from those in aerobically grown tissue, implying an extensive redirection of protein synthesis under anoxia. Finally, anoxia-induced cytoplasmic acidosis is prevented to an unprecedented degree. The adaptations of this anoxia-tolerant plant tissue emphasize the importance of the mechanisms that balance ATP production and consumption in the absence of oxygen. PMID:16284407

Dixon, M H; Hill, S A; Jackson, M B; Ratcliffe, R G; Sweetlove, L J

2006-01-01

92

Physiological adaptations of microorganisms to high oxygen in two oligotrophic lakes  

SciTech Connect

Dissolved oxygen at four times normal saturation inhibited growth and metabolism of summer planktobacteria in surface waters of alpine oligotrophic Mountain Lake (Giles County, Virginia). Data included viable colony counts, D-(U-/sup 14/C)glucose incorporation into extractable lipid of colonies, and respiration-assimilation of D-(U-/sup 14/C)glucose by lake water samples. Significant differences were not detected in either colony counts or /sup 14/C-lipid when superoxide dismutase or catalase were added to the medium. The upper waters of Lake Hoare, Antarctica, contain dissolved oxygen at greater than or equal to42 mg liter/sup -1/ (=HDO). HDO did inhibit D-(U-/sup 14/C)glucoses assimilation-respiration compared with normal atmospheric dissolved oxygen (=ADO) in Lake Hoare water. D-(U-/sup 14/C)glucose was assimilated and respired optimally at 12/sup 0/C in Lake Hoare. Colony formation was inhibited in both lakes. Five microbial isolated were selected from Lake Hoare by growth under very high oxygen. Isolates were examined for physiological characteristics which might enhance their survival in the HDO environment. Bacterial isolates were motile Gram negative rods, catalase and oxidase positive, differing in their growth response to temperature and nutrient concentration. Four of five bacterial isolates demonstrated HDO inducible superoxide dismutase (SOD). Microorganisms in the high oxygen Lake Hoare waters may be protected from oxygen toxicity by the lake's oligotrophic nature as well as a combination of cellular defenses.

Mikell, A.T. Jr.

1985-01-01

93

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

94

Physiological and genetic control mechanisms for plant adaptation to high temperature and elevated CO2  

SciTech Connect

Acclimations of the stomatal response to CO2 were characterized. Stomata from the model plant used, Vicia faba, are very sensitive to ambient CO2 when grown in growth chambers as compared to stomata from green house grown leaves. The different CO2 sensitivities of growth chamber and green house grown guard cells was confirmed by reciprocal transfer experiments. Stomata acclimated to their new environment and acquired the CO2 sensitivity typical of that environment. A mechanism for CO2 sensing was also characterized. Results show that CO2 concentration alters the concentration of zeaxanthin in the guard cell chloroplast, thus modifying the light response of the guard cells. This mechanism accounts for the well characterized interactions of light and CO2 in the stomatal responses. The xanthophyll cycle in the stomata of the facultative CAM plant, Mesembryanthemum crystallinum, was characterized. In the C3 mode, zeaxanthin is formed in the light and stomata open. Upon induction of the CAM mode, zeaxanthin synthesis is blocked and stomata no longer respond to light. These results implicate the regulation of the xanthophyll cycle of guard cells in the CAM adaptation.

Zeiger, Eduardo

2001-02-01

95

Cortical response to psycho-physiological changes in auto-adaptive robot assisted gait training.  

PubMed

Robot-assisted treadmill training improves motor function and walking ability in neurologically impaired patients. However, despite attention having been shown to play a role in training success, psychological responsiveness to task difficulty and motivational levels at task onset have not been measured. Seven healthy subjects participated in a robot-assist treadmill training task. Subjects engaged in a virtual task with varying difficulty levels that was shown to induce a feeling of being bored, excited and over-stressed. The participants' mental engagement was measured using the ECG-based heart rate variability in real time, during gait training as a proxy for EEG and psychological test batteries. Heart rate variability (HRV), which has been shown to reflect cortical engagement for both cognitive and physical tasks, was measured using nonlinear measures obtained from the Poincaré plot. We show that the cortical response to the task measured with HRV varies in relation to the level of mental engagement in response to the difficulty level of the virtual task. From these results we propose that nonlinear measures quantify cortical response / motivational level to robot-assist motor learning tasks and that the adaptation to the task is dependent on the level of motivation. PMID:22256051

Jelinek, Herbert F; August, Katherine G; Imam, Md Hasan; Khandoker, Ahsan H; Koenig, Alexander; Riener, Robert

2011-01-01

96

Space Physiology within an Exercise Physiology Curriculum  

ERIC Educational Resources Information Center

Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of…

Carter, Jason R.; West, John B.

2013-01-01

97

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

98

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

PubMed Central

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

2014-01-01

99

Zearalenone (ZEN) metabolism and residue concentrations in physiological specimens of dairy cows exposed long-term to ZEN-contaminated diets differing in concentrate feed proportions.  

PubMed

A long-term feeding experiment with dairy cows was performed to investigate the effects of feeding a Fusarium toxin contaminated (FUS) and a background-contaminated control (CON) ration with a mean concentrate feed proportion of 50% during the first 11 weeks after parturition (Groups FUS-50, CON-50, Period 1), and with concentrate feed proportions of 30% or 60% during the remaining 17 weeks (Groups CON-30, CON-60, FUS-30 and FUS-60, Period 2), on zearalenone (ZEN) residue levels in blood serum, milk, urine and bile. ZEN, ?-zearalenol (?-ZEL) and ?-zearalenol (?-ZEL), zearalanone (ZAL), ?-zearalanol (?-ZAL) and ?-zearalanol (?-ZAL) were determined by HPLC with fluorescence detection. The ZEN concentrations of the rations fed to Groups CON-50, FUS-50 (Period 1), CON-30, CON-60, FUS-30 and FUS-60 (Period 2) amounted to 53.1, 112.7, 35.0, 24.4, 73.8 and 72.5 µg/kg dry matter, respectively. The concentrations of ZEN, ?-ZEL, ?-ZEL, ZAN, ?-ZAL and ?-ZAL in serum, urine and milk were lower than 1, 1, 4, 100, 50 and 200 ng/g, respectively, while ZEN, ?-ZEL and ?-ZEL were detected in bile. Their levels changed with oral ZEN exposure in the course of the experiment and in a similar direction with concentrate feed proportion (Period 2 only). Thus the proportions of the individual ?-ZEL, ?-ZEL and ZEN concentrations of their sum varied only in narrow ranges of 68-76%, 6-13% and 12-20%, respectively. Interestingly, the bile concentrations of ?-ZEL, ?-ZEL and ZEN of Groups CON-60 and FUS-60 amounted to only approximately 50%, 45% and 62%, respectively, of those of Groups CON-30 and FUS-30 despite a similar or even lower ZEN exposure. The results indicate that conversion of ZEN to its detectable metabolites was not changed by different dietary concentrate feed proportions while their absolute levels were decreased. These findings might suggest concentrate feed proportion-dependent and rumen fermentation-mediated alterations in ZEN/metabolite degradation, and/or liver associated alterations in bile formation and turnover. PMID:25348458

Dänicke, Sven; Keese, Christina; Meyer, Ulrich; Starke, Alexander; Kinoshita, Asako; Rehage, Jürgen

2014-12-01

100

Physiological and health-related adaptations to low-volume interval training: influences of nutrition and sex.  

PubMed

Interval training refers to the basic concept of alternating periods of relatively intense exercise with periods of lower-intensity effort or complete rest for recovery. Low-volume interval training refers to sessions that involve a relatively small total amount of exercise (i.e. ?10 min of intense exercise), compared with traditional moderate-intensity continuous training (MICT) protocols that are generally reflected in public health guidelines. In an effort to standardize terminology, a classification scheme was recently proposed in which the term 'high-intensity interval training' (HIIT) be used to describe protocols in which the training stimulus is 'near maximal' or the target intensity is between 80 and 100 % of maximal heart rate, and 'sprint interval training' (SIT) be used for protocols that involve 'all out' or 'supramaximal' efforts, in which target intensities correspond to workloads greater than what is required to elicit 100 % of maximal oxygen uptake (VO2max). Both low-volume SIT and HIIT constitute relatively time-efficient training strategies to rapidly enhance the capacity for aerobic energy metabolism and elicit physiological remodeling that resembles changes normally associated with high-volume MICT. Short-term SIT and HIIT protocols have also been shown to improve health-related indices, including cardiorespiratory fitness and markers of glycemic control in both healthy individuals and those at risk for, or afflicted by, cardiometabolic diseases. Recent evidence from a limited number of studies has highlighted potential sex-based differences in the adaptive response to SIT in particular. It has also been suggested that specific nutritional interventions, in particular those that can augment muscle buffering capacity, such as sodium bicarbonate, may enhance the adaptive response to low-volume interval training. PMID:25355187

Gibala, Martin J; Gillen, Jenna B; Percival, Michael E

2014-11-01

101

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. PMID:25049937

Kim, Jin Wook

2014-01-01

102

Physiological basis for high CO2 tolerance in marine ectothermic animals: pre-adaptation through lifestyle and ontogeny?  

NASA Astrophysics Data System (ADS)

Future ocean acidification has the potential to adversely affect many marine organisms. A growing body of evidence suggests that many species could suffer from reduced fertilization success, decreases in larval- and adult growth rates, reduced calcification rates, and even mortality when being exposed to near-future levels (year 2100 scenarios) of ocean acidification. Little research focus is currently placed on those organisms/taxa that might be less vulnerable to the anticipated changes in ocean chemistry; this is unfortunate, as the comparison of more vulnerable to more tolerant physiotypes could provide us with those physiological traits that are crucial for ecological success in a future ocean. Here, we attempt to summarize some ontogenetic and lifestyle traits that lead to an increased tolerance towards high environmental pCO2. In general, marine ectothermic metazoans with an extensive extracellular fluid volume may be less vulnerable to future acidification as their cells are already exposed to much higher pCO2 values (0.1 to 0.4 kPa, ca. 1000 to 3900 ?atm) than those of unicellular organisms and gametes, for which the ocean (0.04 kPa, ca. 400 ?atm) is the extracellular space. A doubling in environmental pCO2 therefore only represents a 10% change in extracellular pCO2 in some marine teleosts. High extracellular pCO2 values are to some degree related to high metabolic rates, as diffusion gradients need to be high in order to excrete an amount of CO2 that is directly proportional to the amount of O2 consumed. In active metazoans, such as teleost fish, cephalopods and many brachyuran crustaceans, exercise induced increases in metabolic rate require an efficient ion-regulatory machinery for CO2 excretion and acid-base regulation, especially when anaerobic metabolism is involved and metabolic protons leak into the extracellular space. These ion-transport systems, which are located in highly developed gill epithelia, form the basis for efficient compensation of pH disturbances during exposure to elevated environmental pCO2. Compensation of extracellular acid-base status in turn may be important in avoiding metabolic depression. So far, maintained "performance" at higher seawater pCO2 (>0.3 to 0.6 kPa) has only been observed in adults/juveniles of active, high metabolic species with a powerful ion regulatory apparatus. However, while some of these taxa are adapted to cope with elevated pCO2 during their regular embryonic development, gametes, zygotes and early embryonic stages, which lack specialized ion-regulatory epithelia, may be the true bottleneck for ecological success - even of the more tolerant taxa. Our current understanding of which marine animal taxa will be affected adversely in their physiological and ecological fitness by projected scenarios of anthropogenic ocean acidification is quite incomplete. While a growing amount of empirical evidence from CO2 perturbation experiments suggests that several taxa might react quite sensitively to ocean acidification, others seem to be surprisingly tolerant. However, there is little mechanistic understanding on what physiological traits are responsible for the observed differential sensitivities (see reviews of Seibel and Walsh, 2003; Pörtner et al., 2004; Fabry et al., 2008; Pörtner, 2008). This leads us to the first very basic question of how to define general CO2 tolerance on the species level.

Melzner, F.; Gutowska, M. A.; Langenbuch, M.; Dupont, S.; Lucassen, M.; Thorndyke, M. C.; Bleich, M.; Pörtner, H.-O.

2009-10-01

103

Physiological adaptations of anaerobic bacteria to low pH: metabolic control of proton motive force in Sarcina ventriculi.  

PubMed Central

Detailed physiological studies were done to compare the influence of environmental pH and fermentation end product formation on metabolism, growth, and proton motive force in Sarcina ventriculi. The kinetics of end product formation during glucose fermentation in unbuffered batch cultures shifted from hydrogen-acetate production to ethanol production as the medium pH dropped from 7.0 to 3.3. At a constant pH of 3.0, the production of acetate ceased when the accumulation of acetate in the medium reached 40 mmol/liter. At a constant pH of 7.0, acetate production continued throughout the entire growth time course. The in vivo hydrogenase activity was much higher in cells grown at pH 7.0 than at pH 3.0. The magnitude of the proton motive force increased in relation to a decrease of the medium pH from 7.5 to 3.0. When the organism was grown at pH 3.0, the cytoplasmic pH was 4.25 and the organism was unable to exclude acetic acid or butyric acid from the cytoplasm. Addition of acetic acid, but not hydrogen or ethanol, inhibited growth and resulted in proton motive force dissipation and the accumulation of acetic acid in the cytoplasm. The results indicate that S. ventriculi is an acidophile that can continue to produce ethanol at low cytoplasmic pH values. Both the ability to shift to ethanol production and the ability to continue to ferment glucose while cytoplasmic pH values are low adapt S. ventriculi for growth at low pH. PMID:3571164

Goodwin, S; Zeikus, J G

1987-01-01

104

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

PubMed

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: 565-588) 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. PMID:18334562

Tansey, Etain A

2008-03-01

105

Heart-rate-adapted image reconstruction in multidetector-row cardiac CT: influence of physiological and technical prerequisite on image quality  

Microsoft Academic Search

.   The purpose of this study was to develop strategies for optimal image reconstruction in multidetector-row cardiac CT and\\u000a to discuss the results in the context of individual heart rate, cardiac physiology, and technical prerequisite. Sixty-four\\u000a patients underwent multidetector-row cardiac CT. Depending on the heart rate either a single-segmental reconstruction (SSR)\\u000a or an adaptive two-segmental reconstruction (ASR) was applied. Image

Christopher Herzog; Nasreddin Abolmaali; Joern O. Balzer; Sabine Baunach; Hanns Ackermann; Selami Dogan; Martina B. Britten; Thomas J. Vogl

2002-01-01

106

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. PMID:21601097

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

2013-01-01

107

How to reintroduce cow's milk?  

PubMed

In a child that is allergic to milk, the natural next step, following the elimination diet, is the reintroduction of cow's milk. Several questions may arise. When feasible, this reintroduction has many benefits for the child and his family. However, the disease needs to be well defined by physicians and explained to parents. They need to understand that there are different types of allergy to cow's milk, specifically IgE- and non-IgE-mediated, and each of these may exhibit both a variable duration and frequently an incomplete recovery. Deciding where to first reintroduce cow's milk to a child who has previously followed a milk-free diet, whether it be at home or in a hospital, also frequently presents an issue. Following this first reintroduction, the progressive increase of milk into the diet needs to be managed properly, as not all children will go back to a normal dairy products intake. Recent studies show that most children with milk allergy tolerate products containing baked milk and that their consumption might speed up recovery. Hence, the purpose of the milk challenge in a child on a milk-free diet is becoming, even in a child still reactive to milk, the first step of gradual and individually adapted reintroduction of milk or dairy products. When reintroduction of cow's milk does not work, immunotherapy becomes an option, and this is carried out in specialized centers. PMID:24112424

Dupont, Christophe

2013-11-01

108

Cows Causing Global Warming  

E-print Network

Broadcast Transcript: Remember when President Reagan blamed trees for air pollution? Well now the Japanese are blaming cows for global warming. Apparently, the methane emissions from burping cows account for 5% of all global greenhouse gases. Simple...

Hacker, Randi

2008-08-06

109

Physiological basis for high CO2 tolerance in marine ectothermic animals: pre-adaptation through lifestyle and ontogeny?  

NASA Astrophysics Data System (ADS)

Future ocean acidification has the potential to adversely affect many marine organisms. A growing body of evidence suggests that many species could suffer from reduced fertilization success, decreases in larval- and adult growth rates, reduced calcification rates, metabolic depression and even mortality when being exposed to near-future levels (year 2100 scenarios) of ocean acidification. Little research focus is currently placed on those organisms/taxa that might be less vulnerable to the anticipated changes in ocean chemistry; this is unfortunate, as the comparison of more vulnerable to more tolerant physiotypes could provide us with those physiological traits that are crucial for ecological success in a future ocean. Here, we attempt to summarize some ontogenetic and lifestyle traits that lead to an increased tolerance towards high environmental pCO2. In general, marine ectothermic metazoans with an extensive extracellular fluid volume may be less vulnerable to future acidification as their cells are already exposed to much higher pCO2 values (0.1 to 0.4 kPa, 1000 to 4000 ?atm) than those of unicellular organisms and gametes, for which the ocean (0.04 kPa, 400 ?atm) is the extracellular space. A doubling in environmental pCO2 therefore only represents a 10% change in extracellular CO2 in some marine teleosts. High extracellular pCO2 values are to some degree related to high metabolic rates, as diffusion gradients need to be high in order to excrete an amount of CO2 that is directly proportional to the amount of O2 consumed. In active metazoans, such as teleost fish, cephalopods and many brachyuran crustaceans, exercise induced increases in metabolic rate require an efficient ion-regulatory machinery for CO2 excretion and acid-base regulation, especially when anaerobic metabolism is involved and metabolic protons leak into the extracellular space. These ion-transport systems, which are located in highly developed gill epithelia, form the basis for efficient compensation of pH disturbances during exposure to elevated environmental pCO2. Compensation of extracellular acid-base status in turn may be extremely important in avoiding metabolic depression. So far, maintained "performance" at higher seawater pCO2 (>0.3 to 0.6 kPa) has only been observed in adults/juveniles of active, high metabolic species with a powerful ion regulatory apparatus. However, while some of these taxa are adapted to cope with elevated pCO2 during their regular embryonic development, unicellular gametes, which lack specialized ion-regulatory epithelia, may be the true bottleneck for ecological success - even of the more tolerant taxa.

Melzner, F.; Gutowska, M. A.; Langenbuch, M.; Dupont, S.; Lucassen, M.; Thorndyke, M. C.; Bleich, M.; Pörtner, H.-O.

2009-05-01

110

Feeding the Transition Dairy Cow  

E-print Network

. Ketosis Low energy intake Dextrose IV, oral Close-up dry cow and fresh cow propylene glycol ration management. Milk fever Drop in blood Calcium Close-up dry cow and fresh cow calcium gluconate IV ration management. Oral calcium gel at calving. Far-off cow.... Ketosis Low energy intake Dextrose IV, oral Close-up dry cow and fresh cow propylene glycol ration management. Milk fever Drop in blood Calcium Close-up dry cow and fresh cow calcium gluconate IV ration management. Oral calcium gel at calving. Far-off cow...

Stokes, Sandra R.

1999-09-20

111

Morphology and Physiology of Methanomonas Methanooxidans.  

National Technical Information Service (NTIS)

Pure cultures of methane-oxidizing bacteria isolated from soil, from the rumen of a fistulated cow, and from coalmine water were found to be identical in morphological, cultural, and physiological characteristics with Methanomanas methanooxidans of Brown ...

P. K. Stocks, C. S. McCleskey

1964-01-01

112

Physiological and biochemical adaptations of Cynodon dactylon (L.) Pers. from the Salt Range (Pakistan) to salinity stress  

Microsoft Academic Search

Naturally adapted salt tolerant populations provide a valuable material for exploring the adaptive components of salt tolerance. Under this aspect, two populations of Cynodon dactylon (L.) Pers. were subjected to salt stress in hydroponics. One was collected from a heavily salt-affected soil in the vicinity of a natural salt lake, Uchhali Lake, in the Salt Range of the Punjab province

Mansoor Hameed; Muhammad Ashraf

2008-01-01

113

Physiological Observations and Omics to Develop Personalized Sensormotor Adaptability Countermeasures Using Bed Rest and Space Flight Data  

NASA Technical Reports Server (NTRS)

Astronauts experience sensorimotor disturbances during the initial exposure to microgravity and during the re-adapation phase following a return to an earth-gravitational environment. These alterations may disrupt the ability to perform mission critical functional tasks requiring ambulation, manual control and gaze stability. Interestingly, astronauts who return from space flight show substantial differences in their abilities to readapt to a gravitational environment. The ability to predict the manner and degree to which individual astronauts would be affected would improve the effectiveness of countermeasure training programs designed to enhance sensorimotor adaptability. For such an approach to succeed, we must develop predictive measures of sensorimotor adaptability that will allow us to foresee, before actual space flight, which crewmembers are likely to experience the greatest challenges to their adaptive capacities. The goals of this project are to identify and characterize this set of predictive measures that include: 1) behavioral tests to assess sensory bias and adaptability quantified using both strategic and plastic-adaptive responses; 2) imaging to determine individual brain morphological and functional features using structural magnetic resonance imaging (MRI), diffusion tensor imaging, resting state functional connectivity MRI, and sensorimotor adaptation task-related functional brain activation; 3) genotype markers for genetic polymorphisms in Catechol-O-Methyl Transferase, Dopamine Receptor D2, Brain-derived neurotrophic factor and genetic polymorphism of alpha2-adrenergic receptor that play a role in the neural pathways underlying sensorimotor adaptation. We anticipate these predictive measures will be significantly correlated with individual differences in sensorimotor adaptability after long-duration space flight and an analog bed rest environment. We will be conducting a retrospective study leveraging data already collected from relevant ongoing/completed bed rest and space flight studies. These data will be combined with predictor metrics that will be collected prospectively - behavioral, brain imaging and genomic measures; from these returning subjects to build models for predicting post-mission (bed rest - non-astronauts or space flight - astronauts) adaptive capability as manifested in their outcome measures. Comparisons of model performance will allow us to better design and implement sensorimotor adaptability training countermeasures that are customized for each crewmember's sensory biases, adaptive capacity, brain structure and functional capacities, and genetic predispositions against decrements in post-mission adaptive capability. This ability will allow more efficient use of crew time during training and will optimize training prescriptions for astronauts to ensure expected outcomes.

Mulavara, A. P.; Seidler, R. D.; Feiveson, A.; Oddsson, L.; Zanello, S.; Oman, C. M.; Ploutz-Snyder, L.; Peters, B.; Cohen, H. S.; Reschke, M.; Wood, S.; Bloomberg, J. J.

2014-01-01

114

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

115

Design and rationale of the assessment of proper physiologic response with rate adaptive pacing driven by minute ventilation or accelerometer (APPROPRIATE) trial.  

PubMed

Rate-adaptive sensors are designed to restore a physiologic heart rate response to activity, in particular for patients that have chronotropic incompetence (CI). Limited data exist comparing two primary types of sensors; an accelerometer (XL) sensor which detects activity or motion and a minute ventilation (MV) sensor, which detects the product of respiration rate and tidal volume. The APPROPRIATE study will evaluate the MV sensor compared with the XL sensor for superiority in improving functional capacity (peak VO(2)) in pacemaker patients that have CI. This study is a double-blind, randomized, two-arm trial that will enroll approximately 1,000 pacemaker patients. Patients will complete a 6-min walk test at the 2-week visit to screen for potential CI. Those projected to have CI will advance to a 1-month visit. At the 1-month visit, final determination of CI will be done by completing a peak exercise treadmill test while the pacemaker is programmed to DDDR with the device sensors set to passive. Patients failing to meet the study criteria for CI will not continue further in the trial. Patients that demonstrate CI will be randomized to program their rate-adaptive sensors to either MV or XL in a 1:1 ratio. The rate-adaptive sensor will be optimized for each patient using a short walk to determine the appropriate response factor. At a 2-month visit, patients will complete a CPX test with the rate-adaptive sensors in their randomized setting. PMID:21104046

Gilliam, F Roosevelt; Giudici, Michael; Benn, Andrew; Koplan, Bruce; Berg, Kellie Jean Chase; Kraus, Stacia Merkel; Stolen, Kira Q; Alvarez, Guy E; Hopper, Donald L; Wilkoff, Bruce L

2011-02-01

116

Alkanols and chlorophenols cause different physiological adaptive responses on the level of cell surface properties and membrane vesicle formation in Pseudomonas putida DOT-T1E.  

PubMed

In order to cope with the toxicity imposed by the exposure to environmental hydrocarbons, many bacteria have developed specific adaptive responses such as modifications in the cell envelope. Here we compared the influence of n-alkanols and chlorophenols on the surface properties of the solvent-tolerant bacterium Pseudomonas putida DOT-T1E. In the presence of toxic concentrations of n-alkanols, this strain significantly increased its cell surface charge and hydrophobicity with changes depending on the chain length of the added n-alkanols. The adaptive response occurred within 10 min after the addition of the solvent and was demonstrated to be of physiological nature. Contrary to that, chlorophenols of similar hydrophobicity and potential toxicity as the corresponding alkanols caused only minor effects in the surface properties. To our knowledge, this is the first observation of differences in the cellular adaptive response of bacteria to compound classes of quasi equal hydrophobicity and toxicity. The observed adaptation of the physico-chemical surface properties of strain DOT-T1E to the presence of alkanols was reversible and correlated with changes in the composition of the lipopolysaccharide content of the cells. The reaction is explained by previously described reactions allowing the release of membrane vesicles that was demonstrated for cells affected by 1-octanol and heat shock, whereas no membrane vesicles were released after the addition of chlorophenols. PMID:21732242

Baumgarten, Thomas; Vazquez, José; Bastisch, Christian; Veron, Wilfried; Feuilloley, Marc G J; Nietzsche, Sandor; Wick, Lukas Y; Heipieper, Hermann J

2012-01-01

117

Surgical Motion Adaptive Robotic Technology (S.M.A.R.T): Taking the Motion out of Physiological Motion  

Microsoft Academic Search

In precision computer and robotic assisted minimally invasive surgical procedures, such as retinal microsurgery or cardiac\\u000a bypass surgery, physiological motion can hamper the surgeon’s ability to effectively visualize and approach the target site.\\u000a Current day stabilizers used for minimally invasive cardiac surgery often stretch or pull at the tissue, causing subsequent\\u000a tissue damage. In this study, we investigated novel means

Anshul Thakral; Jeffrey Wallace; Damian Tomlin; Nikesh Seth; Nitish V. Thakor

2001-01-01

118

Hunting for sacred cows.  

PubMed

"Sacred cows" are behavioral patterns that we continue to use even though they may no longer be effective. Their continued use tramples creativity, reduces innovative thought, limits the ability to respond quickly to change, and ultimately becomes costly to individuals and organizations. In less turbulent times, sacred cows were a source of irritation that managers worked around. There is no longer time available for managers to "work around" sacred cows. They must be rounded up and dealt with. It is only by confronting their own sacred cows that nurse managers will find the energy to maintain a caring environment for patients' families and staff. PMID:10418419

Muller-Smith, P

1999-04-01

119

Dissecting the COW  

SciTech Connect

The COW, or Console On Wheels, is the primary operator interface to the SLC accelerator control system. A hardware and software description of the COW, a microcomputer based system with a color graphics display output and touch-panel and knob inputs, is given. The ease of development and expandability, due to both the modular nature of the hardware and the multitasking, interrupt driven software running in the COW, are described. Integration of the COW into the SLCNET communications network and SLC Control system is detailed.

Linstadt, E.

1985-04-01

120

The nervous system has the remarkable ability to adapt and respond to various stimuli, ranging from physiologi-  

E-print Network

The nervous system has the remarkable ability to adapt and respond to various stimuli, ranging from to regenerate beyond the lesion site, in contrast to those in the PNS or embryonic nervous system. Recent evi of glial inhibition in the intact nervous system, and their implications for the development of strategies

Cai, Long

121

Fasting in the American marten ( Martes americana ): a physiological model of the adaptations of a lean-bodied animal  

Microsoft Academic Search

The American marten (Martes americana) is a boreal forest marten with low body adiposity throughout the year. The aim of this study was to investigate the adaptations\\u000a of this lean-bodied species to fasting for an ecologically relevant duration (48 h) by exposing eight farm-bred animals to\\u000a total food deprivation with seven control animals. Selected morphological and hematological parameters, plasma and serum

Petteri Nieminen; Kirsti Rouvinen-Watt; Seppo Saarela; Anne-Mari Mustonen

2007-01-01

122

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

123

Cows and Sheep  

NSDL National Science Digital Library

Solvers of this problem apply number sense and logical reasoning to determine the numbers of cows and sheep in each of five fields by using clues about how many cows and sheep can be seen by each animal. The problem includes questions for getting started, suggestions for implementation and differentiation, a printable student page, and sample solutions.

2014-01-01

124

Physiological Adaptation of a Nitrate-Storing Beggiatoa sp. to Diel Cycling in a Phototrophic Hypersaline Mat?  

PubMed Central

The aim of this study was to investigate the supposed vertical diel migration and the accompanying physiology of Beggiatoa bacteria from hypersaline microbial mats. We combined microsensor, stable-isotope, and molecular techniques to clarify the phylogeny and physiology of the most dominant species inhabiting mats of the natural hypersaline Lake Chiprana, Spain. The most dominant morphotype had a filament diameter of 6 to 8 ?m and a length varying from 1 to >10 mm. Phylogenetic analysis by 16S rRNA gene comparison revealed that this type appeared to be most closely related (91% sequence identity) to the narrow (4-?m diameter) nonvacuolated marine strain MS-81-6. Stable-isotope analysis showed that the Lake Chiprana species could store nitrate intracellularly to 40 mM. The presence of large intracellular vacuoles was confirmed by fluorescein isothiocyanate staining and subsequent confocal microscopy. In illuminated mats, their highest abundance was found at a depth of 8 mm, where oxygen and sulfide co-occurred. However, in the dark, the highest Beggiatoa densities occurred at 7 mm, and the whole population was present in the anoxic zone of the mat. Our findings suggest that hypersaline Beggiatoa bacteria oxidize sulfide with oxygen under light conditions and with internally stored nitrate under dark conditions. It was concluded that nitrate storage by Beggiatoa is an optimal strategy to both occupy the suboxic zones in sulfidic sediments and survive the dark periods in phototrophic mats. PMID:17766448

Hinck, Susanne; Neu, Thomas R.; Lavik, Gaute; Mussmann, Marc; de Beer, Dirk; Jonkers, Henk M.

2007-01-01

125

Space physiology within an exercise physiology curriculum.  

PubMed

Compare and contrast strategies remain common pedagogical practices within physiological education. With the support of an American Physiological Society Teaching Career Enhancement Award, we have developed a junior- or senior-level undergraduate curriculum for exercise physiology that compares and contrasts the physiological adaptations of chronic terrestrial exercise (TEx) and microgravity (?G). We used a series of peer-reviewed publications to demonstrate that many of the physiological adaptations to TEx and ?G are opposite. For example, TEx typically improves cardiovascular function and orthostatic tolerance, whereas ?G can lead to declines in both. TEx leads to muscle hypertrophy, and ?G elicits muscle atrophy. TEx increases bone mineral density and red blood cell mass, whereas ?G decreases bone mineral density and red blood cell mass. Importantly, exercise during spaceflight remains a crucial countermeasure to limit some of these adverse physiological adaptations to ?G. This curriculum develops critical thinking skills by dissecting peer-reviewed articles and discussing the strengths and weaknesses associated with simulated and actual ?G studies. Moreover, the curriculum includes studies on both animals and humans, providing a strong translational component to the curriculum. In summary, we have developed a novel space physiology curriculum delivered during the final weeks of an exercise physiology course in which students gain critical new knowledge that reinforces key concepts presented throughout the semester. PMID:24022767

Carter, Jason R; West, John B

2013-09-01

126

Physiological adaptations in the lichens Peltigera rufescens and Cladina arbuscula var. mitis, and the moss Racomitrium lanuginosum to copper-rich substrate.  

PubMed

Two lichen species (Peltigera rufescens and Cladina arbuscula subsp. mitis) and one moss species (Racomitrium lanuginosum) growing on a copper mine heaps (probably 200-300yr old) in the village of Spania dolina (Slovak Republic) were assessed for selected physiological parameters, including composition of assimilation pigments, chlorophyll a fluorescence, soluble proteins and free amino acid content. The lichen C. arbuscula subsp. mitis was collected also at a control locality where total copper concentration in the soil was approximately 3% that of the waste heaps. Concentrations of Al, Co, Cu, Ni, Sb and Zn were highest in thalli of Peltigera, while the moss Racomitrium contained the highest content of Fe and Pb. Thalli of Cladina contained less metals than the cyanolichen Peltigera, and except for Zn metal concentrations in Cladina from the control locality were lower than in thalli of the same species from copper mine heaps. Regardless of the species or locality, the composition of assimilation pigments and chlorophyll a fluorescence showed that the tested lichens and moss were in good physiological condition and adapted to increased copper levels in the soil. There were significantly different amounts of total free amino acids in Peltigera, Cladina and Racomitrium from the Cu-polluted field. However, differences in amount of free amino acids in control, as well as Cu-polluted thalli of Cladina were less pronounced. PMID:19595434

Backor, Martin; Klejdus, Borivoj; Vantová, Ivana; Kovácik, Jozef

2009-09-01

127

Fasting in the American marten (Martes americana): a physiological model of the adaptations of a lean-bodied animal.  

PubMed

The American marten (Martes americana) is a boreal forest marten with low body adiposity throughout the year. The aim of this study was to investigate the adaptations of this lean-bodied species to fasting for an ecologically relevant duration (48 h) by exposing eight farm-bred animals to total food deprivation with seven control animals. Selected morphological and hematological parameters, plasma and serum biochemistry, endocrinological variables and liver and white adipose tissue (WAT) enzyme activities were determined. After 48 h without food, the marten were within phase II of fasting with depleted liver and muscle glycogen stores, but with active lipid mobilization indicated by the high lipase activities in several WAT depots. The plasma ghrelin concentrations were higher due to food deprivation, possibly increasing appetite and enhancing foraging behavior. The lower plasma insulin and higher cortisol concentrations could mediate augmented lipolysis and the lower triiodothyronine levels could suppress the metabolic rate. Fasting did not affect the plasma levels of stress-associated catecholamines or variables indicating tissue damage. In general, the adaptations to short-term fasting exhibited some differences compared to the related farm-bred American mink (Mustela vison), an example of which was the better ability of the marten to hydrolyze lipids despite its significantly lower initial fat mass. PMID:17605015

Nieminen, Petteri; Rouvinen-Watt, Kirsti; Saarela, Seppo; Mustonen, Anne-Mari

2007-10-01

128

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

PubMed

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. PMID:23516239

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

2013-05-22

129

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. PMID:23516239

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

2013-01-01

130

Photosynthetic Adaptation of Solanum dulcamara L. to Sun and Shade Environments: II. Physiological Characterization of Phenotypic Response to Environment.  

PubMed

Photosynthetic and growth properties of Solanum dulcamara L. were studied under controlled environments. The 200 experimentally tested plants were clonal replicates of five field-collected individuals, three from fully exposed habitats and two from deeply shaded habitats. After 4 weeks of growth in one of eight environmental treatments, each plant was measured for leaf adaxial and abaxial conductance to water vapor, specific leaf weight, chlorophyll per square decimeter of leaf, photosynthetic unit size, light-saturated photosynthetic rate, total leaf area, and total leaf, stem, and root dry weights. Changes in light level influenced photosynthesis and growth of each plant more than changes in water availability or temperature. It is strongly suggested that the primary adaptive response of the tested individuals to changes in levels of light involves the regulation of leaf thickness. PMID:16660909

Clough, J M; Alberte, R S; Teeri, J A

1979-07-01

131

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

132

Six weeks of a polarized training-intensity distribution leads to greater physiological and performance adaptations than a threshold model in trained cyclists.  

PubMed

This study was undertaken to investigate physiological adaptation with two endurance-training periods differing in intensity distribution. In a randomized crossover fashion, separated by 4 wk of detraining, 12 male cyclists completed two 6-wk training periods: 1) a polarized model [6.4 (±1.4 SD) h/wk; 80%, 0%, and 20% of training time in low-, moderate-, and high-intensity zones, respectively]; and 2) a threshold model [7.5 (±2.0 SD) h/wk; 57%, 43%, and 0% training-intensity distribution]. Before and after each training period, following 2 days of diet and exercise control, fasted skeletal muscle biopsies were obtained for mitochondrial enzyme activity and monocarboxylate transporter (MCT) 1 and 4 expression, and morning first-void urine samples were collected for NMR spectroscopy-based metabolomics analysis. Endurance performance (40-km time trial), incremental exercise, peak power output (PPO), and high-intensity exercise capacity (95% maximal work rate to exhaustion) were also assessed. Endurance performance, PPOs, lactate threshold (LT), MCT4, and high-intensity exercise capacity all increased over both training periods. Improvements were greater following polarized rather than threshold for PPO [mean (±SE) change of 8 (±2)% vs. 3 (±1)%, P < 0.05], LT [9 (±3)% vs. 2 (±4)%, P < 0.05], and high-intensity exercise capacity [85 (±14)% vs. 37 (±14)%, P < 0.05]. No changes in mitochondrial enzyme activities or MCT1 were observed following training. A significant multilevel, partial least squares-discriminant analysis model was obtained for the threshold model but not the polarized model in the metabolomics analysis. A polarized training distribution results in greater systemic adaptation over 6 wk in already well-trained cyclists. Markers of muscle metabolic adaptation are largely unchanged, but metabolomics markers suggest different cellular metabolic stress that requires further investigation. PMID:23264537

Neal, Craig M; Hunter, Angus M; Brennan, Lorraine; O'Sullivan, Aifric; Hamilton, D Lee; De Vito, Giuseppe; Galloway, Stuart D R

2013-02-15

133

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

134

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

Microsoft Academic Search

The effects of feeding transgenic (Bt) whole cottonseed (WCS) were studied in lactating cows. Twenty multiparous crossbred\\u000a cows (Karan Swiss × Karan Fries) in early lactation were given a concentrate mixture containing 40% crushed delinted non-transgenic\\u000a (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

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

2010-01-01

135

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

136

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

137

Calving Time Management for Beef Cows  

E-print Network

Calving Time Management for Beef Cows and Heifers Calving Time Management for Beef Cows and Heifers;#12;Calving Time Management for Beef Cows and HeifersCalving Time Management for Beef Cows and Heifers Glenn

Balasundaram, Balabhaskar "Baski"

138

Ruminant Metabolic Systems Biology: Reconstruction and Integration of Transcriptome Dynamics Underlying Functional Responses of Tissues to Nutrition and Physiological Statea  

PubMed Central

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

139

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

140

Using physiologically based pharmacokinetic modeling to address nonlinear kinetics and changes in rodent physiology and metabolism due to aging and adaptation in deriving reference values for propylene glycol methyl ether and propylene glycol methyl ether acetate.  

SciTech Connect

Reference values, including an oral reference dose (RfD) and an inhalation reference concentration (RfC), were derived for propylene glycol methyl ether (PGME), and an oral RfD was derived for its acetate (PGMEA). These values were based upon transient sedation observed in F344 rats and B6C3F1 mice during a two-year inhalation study. The dose-response relationship for sedation was characterized using internal dose measures as predicted by a physiologically based pharmacokinetic (PBPK) model for PGME and its acetate. PBPK modeling was used to account for changes in rodent physiology and metabolism due to aging and adaptation, based on data collected during weeks 1, 2, 26, 52, and 78 of a chronic inhalation study. The peak concentration of PGME in richly perfused tissues was selected as the most appropriate internal dose measure based upon a consideration of the mode of action for sedation and similarities in tissue partitioning between brain and other richly perfused tissues. Internal doses (peak tissue concentrations of PGME) were designated as either no-observed-adverse-effect levels (NOAELs) or lowest-observed-adverse-effect levels (LOAELs) based upon the presence or absence of sedation at each time-point, species, and sex in the two year study. Distributions of the NOAEL and LOAEL values expressed in terms of internal dose were characterized using an arithmetic mean and standard deviation, with the mean internal NOAEL serving as the basis for the reference values, which was then divided by appropriate uncertainty factors. Where data were permitting, chemical-specific adjustment factors were derived to replace default uncertainty factor values of ten. Nonlinear kinetics are were predicted by the model in all species at PGME concentrations exceeding 100 ppm, which complicates interspecies and low-dose extrapolations. To address this complication, reference values were derived using two approaches which differ with respect to the order in which these extrapolations were performed: (1) uncertainty factor application followed by interspecies extrapolation (PBPK modeling); and (2) interspecies extrapolation followed by uncertainty factor application. The resulting reference values for these two approaches are substantially different, with values from the former approach being 7-fold higher than those from the latter approach. Such a striking difference between the two approaches reveals an underlying issue that has received little attention in the literature regarding the application of uncertainty factors and interspecies extrapolations to compounds where saturable kinetics occur in the range of the NOAEL. Until such discussions have taken place, reference values based on the latter approach are recommended for risk assessments involving human exposures to PGME and PGMEA.

Kirman, C R.; Sweeney, Lisa M.; Corley, Rick A.; Gargas, M L.

2005-04-01

141

[Female physiology during exercise].  

PubMed

Physiological responses and adaptations of women to exercise are influenced by her genetically determined morphological and functional characteristics, and by her level of physical fitness. Physiological responses of women during submaximal and maximal exercise differ quantitatively from those of men but adaptations to training are qualitatively similar in both. Studies demonstrate that differences between the sexes in performance of athletic events that require high aerobic or anaerobic capacity are due, to a large extent, to differences in body structure and composition: the average woman is smaller and lighter and has less muscle mass than the average man. These characteristics influence physiologic responses of the musculoskeletal, cardiovascular and respiratory systems during exercise. This article describes physiological responses of women during exercise in relation to her sex related morphological characteristics, and the adaptations that occur with physical training. PMID:2270262

Rivera Brown, A M

1990-04-01

142

Disruption of hypothalamic leptin signaling in mice leads to early-onset obesity, but physiological adaptations in mature animals stabilize adiposity levels  

PubMed Central

Distinct populations of leptin-sensing neurons in the hypothalamus, midbrain, and brainstem contribute to the regulation of energy homeostasis. To assess the requirement for leptin signaling in the hypothalamus, we crossed mice with a floxed leptin receptor allele (Leprfl) to mice transgenic for Nkx2.1-Cre, which drives Cre expression in the hypothalamus and not in more caudal brain regions, generating LeprNkx2.1KO mice. From weaning, LeprNkx2.1KO mice exhibited phenotypes similar to those observed in mice with global loss of leptin signaling (Leprdb/db mice), including increased weight gain and adiposity, hyperphagia, cold intolerance, and insulin resistance. However, after 8 weeks of age, LeprNkx2.1KO mice maintained stable adiposity levels, whereas the body fat percentage of Leprdb/db animals continued to escalate. The divergence in the adiposity phenotypes of Leprdb/db and LeprNkx2.1KO mice with age was concomitant with increased rates of linear growth and energy expenditure in LeprNkx2.1KO mice. These data suggest that remaining leptin signals in LeprNkx2.1KO mice mediate physiological adaptations that prevent the escalation of the adiposity phenotype in adult mice. The persistence of severe adiposity in LeprNkx2.1KO mice, however, suggests that compensatory actions of circuits regulating growth and energy expenditure are not sufficient to reverse obesity established at an early age. PMID:20592471

Ring, Laurence E.; Zeltser, Lori M.

2010-01-01

143

PHYSIOLOGICAL ADAPTATION IN LABORATORY ENVIRONMENTS  

E-print Network

environment that is changed. In nature, thermodynamic variables such as temperature, pressure, and chemical is the most important and common physical variable affecting the distribution and abundance of organisms.g., overwintering plants and insects, hot springs bacteria). Thus, selection experiments using temperature may

Ahmad, Sajjad

144

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

145

[Intolerance to cow's milk].  

PubMed

The authors report results of allergological history, of passive haemagglutination reaction, lymphocytes blast transformation and leucocytes migration inhibition tests in 100 patients suffering from affections involving the gastro-intestinal tract. Control investigations were carried out in 20 practically healthy individuals. From these results the authors conclude that the data of the allergological history and clinical symptoms of the cow milk intolerance are determined, above all, by the immuno-allergic mechanisms, this being confirmed by the results of the "in vitro" methods characterizing the humoral and cellular types of the immunological reactivity. PMID:988940

Martynov, S M; Fedorenko, T A

1976-01-01

146

Normal bacterial flora from vaginas of Criollo Limonero cows.  

PubMed

In order to describe the normal bacterial flora in vaginas of Criollo Limonero cows, 51 healthy multiparous cows, at least 90-day postpartum, were selected. Duplicated swabs (N = 102) were taken from the vaginal fornix of cows to perform aerobic and anaerobic cultures as well as conventional biochemical tests. Out of 102 swabs, bacterial growth was obtained in 55 (53.9%) while the remaining 47 (46.1%) did not exhibited any bacterial growth. Of the 55 bacterial growths, 23 (41.8%) were aerobic whereas 32 (58.1%) were anaerobic. Likewise, 29 (52.72%) of bacterial growths were pure and 26 (47.27%) were mixed. Under both aerobic and anaerobic conditions, Gram positive bacteria were predominant (81.82% and 73.08%, respectively) over Gram negative bacteria (18.18% and 26.92%, respectively). Isolated bacteria were Arcanobacterium pyogenes (22.92%), Staphylococcus aureus (15.63%), Staphylococcus coagulase negative (17.71%), Erysipelothrix rhusiopathiae (6.25%), Bacteroides spp. (13.54%), and Peptostreptococcus spp. (7.29%). In conclusion, normal vaginal bacterial flora of Criollo Limonero cows was predominantly Gram positive and included A. pyogenes, S. aureus, coagulase negative Staphylococcus, E. rhusiopathiae, Bacteroides spp., and Peptostreptococcus spp. In Criollo Limonero cattle, adaptive aspects such as development of humoral and physical mechanisms for defense, and bacterial adaptation to host deserve research attention. PMID:21082249

Zambrano-Nava, Sunny; Boscán-Ocando, Julio; Nava, Jexenia

2011-02-01

147

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

148

Mad Cow Disease  

NSDL National Science Digital Library

BioEd Online is an âÂÂeducational resource for educators, students, and parentsâ from the Baylor College of Medicine. This is an excellent place to find educational materials and current information in the field of biology. The âÂÂHot Topicsâ section of this site focus on current events and issues in biology that are âÂÂreceiving national attention.â Mad Cow Disease has remained a challenge to scientists and regulatory commissions since its discovery in 1986. This âÂÂHot Topicâ on Mad Cow Disease was compiled by Sonia Clayton, PhD, James Denk, MA, and Nancy Moreno, PhD, and contains a brief discussion of the how the disease effects cattle and humans, as well as prevention information. Also included are references and links for further reading at the bottom of the page. On the right hand side of the page a related slide set is available for viewing as well as several links to related news stories.

Clayton, Sonia; Denk, James; Moreno, Nancy

2004-01-22

149

Physiological adaptations in the lichens Peltigera rufescens and Cladina arbuscula var. mitis, and the moss Racomitrium lanuginosum to copper-rich substrate  

Microsoft Academic Search

Two lichen species (Peltigera rufescens and Cladina arbuscula subsp. mitis) and one moss species (Racomitrium lanuginosum) growing on a copper mine heaps (probably 200–300yr old) in the village of Špania dolina (Slovak Republic) were assessed for selected physiological parameters, including composition of assimilation pigments, chlorophyll a fluorescence, soluble proteins and free amino acid content. The lichen C. arbuscula subsp. mitis

Martin Ba?kor; Bo?ivoj Klejdus; Ivana Vantová; Jozef Ková?ik

2009-01-01

150

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

151

Evolution of Human Hypoxia Tolerance Physiology  

Microsoft Academic Search

Analysis of human responses to hypobaric hypoxia in different lineages (lowlanders, Andean natives, Himalayan natives, and East Africans) indicates ‘conservative’ and ‘adaptablephysiological characters involved in human responses to hypoxia. Conservative characters, arising by common descent, dominant and indeed define human physiology, but in five hypoxia response systems analyzed, we also found evidence for ‘adaptable’ characters at all levels of

Peter W. Hochachka; C. Carlos Monge

152

Consider a Cylindrical Cow  

NASA Astrophysics Data System (ADS)

Cylindrical Cow will help students achieve a whole new level of environmental modeling and problem solving. Featuring a new core set of 25 fully worked-out problems, this book uses real problems in environmental science rather than relying on the more traditional cookbook problems found in textbooks. It is organized according to five thematic sections on probability, optimization, scaling, differential equations, and stability & feedback. Each section begins with a general treatment of the relevant mathematical concepts, and concludes with a range of homework exercises to help students sharpen their modeling skills. Like its predecessor, this book will empower students with the mathematical skills needed to cut through the complexity of real-world problems.

Harte, John

153

Physiological Networks: towards systems physiology  

NASA Astrophysics Data System (ADS)

The human organism is an integrated network where complex physiologic systems, each with its own regulatory mechanisms, continuously interact, and where failure of one system can trigger a breakdown of the entire network. Identifying and quantifying dynamical networks of diverse systems with different types of interactions is a challenge. Here, we develop a framework to probe interactions among diverse systems, and we identify a physiologic network. We find that each physiologic state is characterized by a specific network structure, demonstrating a robust interplay between network topology and function. Across physiologic states the network undergoes topological transitions associated with fast reorganization of physiologic interactions on time scales of a few minutes, indicating high network flexibility in response to perturbations. The proposed system-wide integrative approach may facilitate new dimensions to the field of systems physiology.

Bartsch, Ronny P.; Bashan, Amir; Kantelhardt, Jan W.; Havlin, Shlomo; Ivanov, Plamen Ch.

2012-02-01

154

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 ...

155

Physiological Genomics  

NSDL National Science Digital Library

Five journals with free (or recently extended) online trial periods were recently announced; online content includes full text, figures, and tables. The American Physiological Society has announced free, online access to Physiological Genomics through December 31, 2001; full text and abstracts are available from 1999. The journal is published in conjunction with Stanford University's HighWire Press.

1969-12-31

156

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.

157

Crop Physiology  

SciTech Connect

In this chapter, we review the physiology of switchgrass from seed dormancy till the effects of water and nutrients stress on grown plants. These characteristics are presented and discussed mainly at the canopy and whole-plant level with emphasis on the agro-physiology of the species in view of the possible contribution of crop physiology to agricultural development. Switchgrass is noted for the variable degrees of seed dormancy regulated by endogenous and exogenous factors that determine the successful seedling establishment. Plant growth rates are determined by temperature while the reproductive phase is controlled mainly by photoperiod. There is also evidence that some physiological attributes, such as photosynthesis, transpiration, and water use efficiency differ between tetraploid, hexaploid and octaploid ecotypes. But despite these differences, in general switchgrass combines important attributes of efficient use of nutrients and water with high yields thanks to its ability to acquire resources from extended soil volumes, especially at deep layers. Moreover at canopy level, resources capture and conservation are determined by morpho-physiological characteristics (C{sub 4} photosynthetic pathway, stomatal control of transpiration, high leaf area index, low light extinction coefficient) that enhance radiation use efficiency and reduce carbon losses. However, specific information on switchgrass physiology is still missing, in particular deeper understanding of physiological principles controlling the water and nutrients acquisition mechanisms and allocation under suboptimal growing conditions. The physiology of tillering and root respiration are also factors that need further investigation.

Zegada-Lizarazu, Walter [University of Bologna; Wullschleger, Stan D [ORNL; Nair, S. Surendran [University of Tennessee, Knoxville (UTK); Monti, Andrea [University of Bologna

2013-01-01

158

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. 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.

2013-01-01

159

Developmental Physiology  

NSDL National Science Digital Library

This Web portal offered through the University of North Texas aims to "promote a sense of identity and connectivity among interested scientists and students active in the burgeoning field of developmental physiology." Users will find a wide array of useful features and services, including developmental physiology news, career and funding information, regularly updated links to related publications, a searchable database of developmental physiology researchers worldwide, op-ed pieces, hundreds of related links, and more. A helpful intra-site search engine has been recently added.

160

Characteristics of temporal patterns of cortisol and luteinizing hormone in primiparous, postpartum, anovular, suckled, beef cows exposed acutely to bulls  

Microsoft Academic Search

BACKGROUND: The physiological mechanism by which bulls stimulate resumption of ovarian cycling activity in postpartum, anovular, suckled cows after calving may involve the concurrent activation of the hypothalamic-hypophyseal-ovarian (HPO) axis and hypothalamic-hypophyseal-adrenal (HPA) axis. Thus, the objectives of this experiment were to determine if characteristics of temporal patterns of cortisol and luteinizing hormone (LH) in postpartum, anovular, beef cows are

Shaun A Tauck; Jesse R Olsen; Jarrod RC Wilkinson; Riley J Wedlake; Kathleen C Davis; James G Berardinelli

2010-01-01

161

Interrelationship of endogenous and exogenous prostaglandins with uterine involution and postpartum interval in beef cows and heifers  

E-print Network

INTERRELATIONSHIP OF ENDOGENOUS AND EXOGENOUS PROSTAGLANDINS WITH UTERINE INVOLUTION AND POSTPARTUM INTERVAL IN BEEF COWS AND HEIFERS A Thesis by DOUGLAS RAY TOLLESON Submitted to the Graduate College of Texas A8M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1986 Major Subject: Physiology of Reproduction INTERRELATIONSHIP OF ENDOGENOUS AND EXOGENOUS PROSTAGLANDINS WITH UTERINE INVOLUTION AND POSTPARTUM INTERVAL IN BEEF COWS...

Tolleson, Douglas Ray

2012-06-07

162

The cis–trans isomerase of unsaturated fatty acids in Pseudomonas and Vibrio: biochemistry, molecular biology and physiological function of a unique stress adaptive mechanism  

Microsoft Academic Search

Isomerization of cis to trans unsaturated fatty acids is a mechanism enabling Gram-negative bacteria belonging to the genera Pseudomonas and Vibrio to adapt to several forms of environmental stress. The extent of the isomerization apparently correlates with the fluidity effects caused, i.e. by an increase in temperature or the accumulation of membrane-toxic organic compounds. Trans fatty acids are generated by

Hermann J Heipieper; Friedhelm Meinhardt; Ana Segura

2003-01-01

163

The physiological effects of IGF-1 (class 1:Ea transgene) over-expression on exercise-induced damage and adaptation in dystrophic muscles of mdx mice  

Microsoft Academic Search

Duchenne muscular dystrophy (DMD) is a genetic disorder in which muscle weakness and fragility contribute to ongoing muscle\\u000a degeneration. Although exercise-induced muscle damage is associated with adaptation that protects normal muscle from further\\u000a damage, exploiting this process to protect dystrophic muscle has been avoided for fear of inducing excessive muscle degeneration.\\u000a However, muscle-specific over-expression of the class 1:Ea isoform of

James A. Ridgley; Gavin J. Pinniger; Peter W. Hamer; Miranda D. Grounds

2009-01-01

164

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. PMID:25002754

Garssen, Johan

2014-01-01

165

Blood plasma magnesium, potassium, glucose, and immunoreactive insulin changes in cows moved abruptly from barn feeding to early spring pasture  

SciTech Connect

Cations and immunoreactive insulin in plasma were measured in 35 lactating cows moved abruptly to early spring pasture. After change of cows from grass-clover hay to fescue-bluegrass pasture containing 22 to 31 g potassium/kg dry matter, immunoreactive insulin of 5 Holstein cows increased 30% in 5 days and averaged 45% above prepasture concentrations for 40 days. Magnesium averaged 44% below prepasture content of plasma during this period and was correlated negatively with potassium -.17 and immunoreactive insulin -.37. Thirty Hereford cows were changed from corn silage and grass-clover hay to wheat-rye pasture containing 3.06% potassium in the dry matter. Each day on pasture, 10 cows each were fed 2.3 kg cornmeal, 10 were given 30 g magnesium oxide by capsule, and 10 were given no supplement. After unsupplemented cows were moved to pasture, immunoreactive insulin rose 51% in 8 days and plasma magnesium fell 24%. Both supplements reduced immunoreactive insulin, but magnesium was maintained higher by magnesium oxide than by cornmeal. Injection of two Holstein cows with insulin (2 IU/kg body weight) reduced plasma concentrations of both potassium and mgnesium 20% below that of two cows injected with only physiological saline. Whether elevated plasma insulin may accelerate development of hypomagnesemia in cattle on spring pasture with relatively high potassium content has not been established.

Miller, J.K. (Comparative Animal Research Lab., Oak Ridge, TN); Madsen, F.C.; Lentz, D.E.; Wong, W.O.; Ramsey, N.; Tysinger, C.E.; Hansard, S.L.

1980-07-01

166

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

167

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. PMID:22873405

2012-01-01

168

Predictive Models for Regional Hepatic Function Based on 99mTc-IDA SPECT and Local Radiation Dose for Physiologic Adaptive Radiation Therapy  

SciTech Connect

Purpose: High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT. Methods and Materials: Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF dose–response functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT. Results: The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=?0.80, P<.0001), for all time points. Linear correlations between local doses and regional HEFs 1 month after RT were significant in 12 patients. In the priori model, regional HEF after RT was predicted by the planned dose and regional HEF assessed before RT (R=0.71, P<.0001). In the adaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, P<.0001). Conclusions: 99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies to maximize tumor control and minimize the risk of liver damage.

Wang, Hesheng, E-mail: hesheng@umich.edu [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Feng, Mary [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Frey, Kirk A. [Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Ten Haken, Randall K.; Lawrence, Theodore S. [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Cao, Yue [Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan (United States); Department of Radiology, University of Michigan, Ann Arbor, Michigan (United States); Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan (United States)

2013-08-01

169

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

170

Virtual Fences for Controlling Cows  

Microsoft Academic Search

We describe a moving virtual fence algorithm for herding cows. Each animal in the herd is given a smart collar consisting of a GPS, PDA, wireless networking and a sound amplifier. Using the GPS, the animal's location can be verified relative to the fence boundary. When approaching the perimeter, the animal is presented with a sound stimulus whose effect is

Zack J. Butler; Peter I. Corke; Ronald A. Peterson; Daniela Rust

2004-01-01

171

Transition Cow: Interaction with Fertility  

Microsoft Academic Search

In recent years a progressive worsening of fertility indices in dairy cow herds has been observed. Several factors (genetic, dietary and management) seem to be more related to poor fertility than milk yield level. The degree and the length of the energy deficit during the transition period are inversely related to reproductive indices (e.g. conception rate is < 30% for

A. Formigoni; E. Trevisi

2003-01-01

172

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

173

Effect of somatic cell count and mastitis pathogens on milk composition in Gyr cows  

PubMed Central

Background Gyr cows are well adapted to tropical conditions, resistant to some tropical diseases and have satisfactory milk production. However, Gyr dairy herds have a high prevalence of subclinical mastitis, which negatively affects their milk yield and composition. The objectives of this study were (i) to evaluate the effects of seasonality, mammary quarter location (rear x front), mastitis-causing pathogen species, and somatic cell count (SCC) on milk composition in Gyr cows with mammary quarters as the experimental units and (ii) to evaluate the effects of seasonality and somatic cell count (SCC) on milk composition in Gyr cows with cows as the experimental units. A total of 221 lactating Gyr cows from three commercial dairy farms were selected for this study. Individual foremilk quarter samples and composite milk samples were collected once a month over one year from all lactating cows for analysis of SCC, milk composition, and bacteriological culture. Results Subclinical mastitis reduced lactose, nonfat solids and total solids content, but no difference was found in the protein and fat content between infected and uninfected quarters. Seasonality influenced milk composition both in mammary quarters and composite milk samples. Nevertheless, there was no effect of mammary quarter position on milk composition. Mastitis-causing pathogens affected protein, lactose, nonfat solids, and total solids content, but not milk fat content. Somatic cell count levels affected milk composition in both mammary quarters and composite samples of milk. Conclusions Intramammary infections in Gyr cows alter milk composition; however, the degree of change depends on the mastitis-causing pathogen. Somatic cell count is negatively associated with reduced lactose and nonfat solids content in milk. Seasonality significantly affects milk composition, in which the concentration of lactose, fat, protein, nonfat solids and total solids differs between dry and wet seasons in Gyr cows. PMID:23566405

2013-01-01

174

Exercise Physiology Ethnic Differences in Physiological Cardiac Adaptation to  

E-print Network

males; these frequently overlap with those observed in cardiomyopathy and have important implications with manifestations observed in individuals with hypertrophic cardiomyopathy (HCM).4 In contrast, white female

Boyer, Edmond

175

INTRODUCTION Morphology and physiology of the gastrointestinal tract show several  

E-print Network

3981 INTRODUCTION Morphology and physiology of the gastrointestinal tract show several adaptations digestive capacity could allow some energy and nutrients to escape the gastrointestinal tract unutilized

Mladenoff, David

176

The monitoring, prevention, and treatment of milk fever and subclinical hypocalcemia in dairy cows.  

PubMed

The periparturient cow undergoes a transition from non-lactating to lactating at calving. The animal is tremendously challenged to maintain calcium homeostasis. Those that fail can develop milk fever, a clinical disorder that is life threatening to the cow and predisposes the animal to a variety of other disorders. Guidelines for monitoring the incidence of hypocalcemia and methods for treating milk fever are reviewed. The physiological factors that cause milk fever and strategies for prevention of milk fever are discussed, focusing on the effects diet cation-anion difference can have on tissue sensitivity to parathyroid hormone. Another major risk factor for milk fever is hypomagnesemia, which is observed when animals are fed inadequate amounts of magnesium, or some factor is present in the diet that prevents adequate absorption of magnesium. Moderate hypomagnesemia impairs the ability of the cow to maintain calcium homeostasis and hypocalcemia occurs. PMID:18342555

Goff, Jesse P

2008-04-01

177

Feeding Milk Cows. - Four Feeding Experiments With Milk Cows.  

E-print Network

. HARRINGTON, 11. SC.. Chemist. ........................................ M. FRANCIS, D. V. M.. Veterinarian. ............................................. R. H. PRICE, B. S Horticulturist. ....................... D. ADRIANCE, 3f. S.. Meteorologist..., cornmeal and cotton seed meal.) Ans. Cotton seed meal. (See pages 510 and 515. Experiments 3 and 4.) FEEDING MILK COWS. 501 EXPERIMENT NO. 1-TEST OF FORAGE STUFFS. (Fed ad libitum ration of grain and forage.) most cotto do th the bL ex'' tair uar...

Connell, J. H.; Clayton, Jas. (James)

1894-01-01

178

Human Physiology Department of Neurobiology, Physiology,  

E-print Network

Human Physiology Minor Department of Neurobiology, Physiology, and Behavior College of Biological Sciences (530) 752 - 0410 Human Physiology Minor Requirements: Total and Development in Human Performance EXB 116 Nutrition for Physically Active Persons EXB 117 Exercise and Aging

Wainwright, Peter C.

179

[Aviation physiology].  

PubMed

Aviation physiology should be known at least in parts by the physicians advising air travellers. Due to reducing atmospheric pressure at altitude gas volume in body cavities expands (Boyle's law). This might not be a problem during ascend since air can disappear easily through natural ways. However, air must return to body cavities during descend and a person with a cold may suffer from painful barotitis. Hypoxia is mostly due to a reduced pO2 in high altitude (Daltons's Law). This may be prevented by an aircraft cabin or supplemented oxygen. Decompression sickness is very rare in aviation but divers should comply to a dive free interval before flying. PMID:10568247

Frank, P W

1999-10-01

180

The Cow Gait Recognition Using CHLAC  

Microsoft Academic Search

This paper reports the preliminary experiments on the cow identification via gait recognition of motion images. The eight cows walking under two different situations have been precisely identified by Cubic Higher-order Lo- cal Auto-Correlation (CHLAC). The cow gait recognition using CHLAC is expected to be a landmark achievement for realizing cost-effective dairy cattle breeding management systems which do not use

Shu Mimura; Keichi Itoh; Takumi Kobayashi; Tomohiro Takigawa; Atsushi Tajima; Atsushi Sawamura; Nobuyuki Otsu

2008-01-01

181

Induction of parturition in cows using betamethasone  

Microsoft Academic Search

To avoid dystocia and calf mortality two groups of cows were induced to calve six or seven days prematurely. Group I consisted of none Hereford cross Friesian two-and-a-half-year-old recipient cows carrying Continental beef breed fetuses. Group 2 consisted of 10 four-year-old Continental beef breed cows carrying pure or crossbred fetuses of the same breeds. On day 280 of gestation a

MG Diskin; PG Box; JM Sreenan

1982-01-01

182

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 19.55 d 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 >90 d 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 150 d 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

183

Survey of mycotic mastitis in dairy cows from Heilongjiang Province, China.  

PubMed

A survey of the prevalence rate, pathogenic subspecies, and risk factors of mycotic mastitis in dairy cows from Heilongjiang Province, China, was conducted. Milk samples from 412 cows with chronic mastitis were collected and cultured on 8 % sheep blood agar, MacConkey agar, and Sabouraud agar with chloramphenicol. Counting of the morphologically distinct colonies was performed, as well as the isolation and identification of organisms through phenotypical and physiological criteria. Four hundred seventy-eight aerobic microorganisms were isolated. Yeasts and yeast-like fungi 35.6 % (170/478) and bacteria 64.4 % (308/478) were isolated. The fungal isolates were identified as Candida (79.4 %), Trichosporon (5.9 %), Aspergillus (7.1 %), Cryptococcus (2.4 %), and Rhodotorula (4.1 %). More than ten species of yeast were isolated including Candida krusei 50/135 (37 %), Candida rugosa 16/135 (11.9 %), and Candida lusitaniae 15/135 (11.1 %). A higher positivity (18.5 and 56.3 %) (P ?0.05) was observed in cows from environmental temperatures of 0-15 and 15-35 °C than those at <0 °C and in cows affected by the disease for >45 and 30-45 days compared with cows suffering 10-30 days. Meanwhile, a statistically significant difference (44.9 vs. 31.4 %) (P ?0.05) was observed under extensive raising systems vs. intensive raising systems. It appears that Candida is a major pathogen of mycotic mastitis of dairy cows. Extensive raising system, high environmental temperature (15-35 °C), and the duration of the disease (>30 days) were important risk factors of the incidence of mycotic mastitis. Here, we provide a theoretical foundation for research into preventing and treating mycotic mastitis of dairy cows in China. PMID:23813119

Zhou, Yulong; Ren, Yachao; Fan, Chunling; Shao, Hong; Zhang, Zecai; Mao, Wenbin; Wei, Chunbo; Ni, Hongbo; Zhu, Zhanbo; Hou, Xilin; Piao, Fanze; Cui, Yudong

2013-11-01

184

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

185

Genome-wide scans for candidate genes involved in the aquatic adaptation of dolphins.  

PubMed

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. PMID:23246795

Sun, Yan-Bo; Zhou, Wei-Ping; Liu, He-Qun; Irwin, David M; Shen, Yong-Yi; Zhang, Ya-Ping

2013-01-01

186

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

187

Glycerol Supplementation in Dairy Cows and Calves  

E-print Network

Glycerol Supplementation in Dairy Cows and Calves Anna Werner Omazic Faculty of Veterinary Medicine Nordqvist #12;Glycerol Supplementation in Dairy Cows and Calves Abstract The production of biodiesel from-product and a promising feed supplement for farm animals. This thesis provides information about the supplemental feeding

188

Egg and cows' milk allergy in children  

Microsoft Academic Search

The relationships between a history of egg or cows' milk allergy, positive skin tests to these allergens, and atopic illness were examined in a sample of 126 children. Positive skin tests were found more often in children with a history of egg or cows' milk allergy than in children with no such history. 40 children suspected of being allergic to

R P Ford; D M Fergusson

1980-01-01

189

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

190

Feeding the Cow and Calf.  

E-print Network

and calves varies greatly. The digest- ible protein in very young grasses is nearly 15 per- cent and decreases to less than 2 percent in the mature and weathered grasses. This reduction ir! percent protein along with reduced forage avail- able, results... demonstrates the importance of a high percentage calf crop. The icngth of productive life shows that feed efficiency changes rapidly during the first three or four calves ;mtl tends to level out if the cows stay in production lor six or eight calves...

Maddox, L. A. Jr.

1965-01-01

191

[Cow-milk's protein allergy].  

PubMed

Milk contains more than 40 proteins and all of them may act like human species antigens. The main allergens are beta lactoglobulin, casein, alpha lactoalbumin and seroalbumin; beta lactoglobulin is a protein not existing in human species and is found in maternal milk in minimal quantities (mcg) due to milky products ingested by the mother, these small quantities are responsible of the highest number of sensitizations to this protein. This article reviews the allergy to the cow-milk's protein, also, a critical route to its diagnosis and management is planted. PMID:16579184

Avila Castañón, Lourdes; Hidalgo Castro, E M; del Río Navarro, Blanca Estela; Sienra Monge, Juan José Luis

2005-01-01

192

Bone physiology of tooth movement, ankylosis, and osseointegration  

Microsoft Academic Search

Tooth movement is a highly conserved physiologic mechanism for continuous adaptation of the dentition. Physiologic drift of teeth is essential for maintaining appropriate stomatognathic function over a lifetime. Orthodontics is a therapeutic exploitation of this physiologic mechanism. The relative position of a tooth is dictated by the equilibrium of forces acting on it. The periodontium is an “organ” of functionally

W. Eugene Roberts

2000-01-01

193

Associations of udder-health indicators with cow factors and with intramammary infection in dairy cows.  

PubMed

The objective of this study was to investigate if and how cow factors and intramammary infection (IMI) are associated with 4 different udder-health indicators in dairy cows as a first step in investigating whether the diagnostic performance of these indicators can be improved. The investigated indicators were somatic cell count (SCC), lactate dehydrogenase (LDH), N-acetyl-?-d-glucosaminidase (NAGase), and alkaline phosphatase (AP) measured in milk. In this cross-sectional study, approximately 1,000 cows from 25 dairy herds were sampled for bacteriology (quarter milk samples) during 3 consecutive days: the day before test milking, at the day of test milking, and at the day after test milking. The whole-udder test milking sample was analyzed for milk composition, SCC, LDH, NAGase, and AP. Cow data (parity, breed, milk yield, percentage of milk fat and protein, milk urea concentration, and days in milk from the sampled test milking) were collected from the Swedish milk-recording scheme. Of the sampled cows 485 were considered IMI negative and were used in multivariable mixed-effect linear regression models to investigate associations between cow factors and the udder-health indicators. A second modeling including all cows, both IMI negative and IMI positive (256 cows), was also performed. The results showed that all udder-health indicators were affected by cow factors but that different cow factors were associated with different indicators. Intramammary-infection status was significantly associated with all udder-health indicators except AP. Parity and milk urea concentration were the only cow factors associated with all indicators in all models. The significant cow factors explained 23% of the variation in SCC and >30% of the variation in LDH, NAGase, and AP in IMI-negative cows, showing that LDH, NAGase, and AP are more affected than SCC by cow factors. The IMI status explained 23% of the variation in SCC in the model with all cows but only 7% of the variation in LDH and 2% of the variation in NAGase, indicating that SCC has the best potential as a diagnostic tool in finding cows with IMI. However, further studies are needed to investigate whether the diagnostic properties of these udder-health indicators will improve with adjustment according to their associations with different cow factors when used as a diagnostic tool for finding cows with IMI. PMID:24997662

Nyman, A-K; Persson Waller, K; Bennedsgaard, T W; Larsen, T; Emanuelson, U

2014-09-01

194

21 CFR 1210.12 - Physical examination of cows.  

Code of Federal Regulations, 2013 CFR

...examination of cows. 1210.12...OF HEALTH AND HUMAN SERVICES (CONTINUED...FEDERAL IMPORT MILK ACT Inspection...examination of cows. (a) Physical...in which such milk or cream is produced...whether such cow or cows are in a healthy...

2013-04-01

195

21 CFR 1210.12 - Physical examination of cows.  

...examination of cows. 1210.12...OF HEALTH AND HUMAN SERVICES (CONTINUED...FEDERAL IMPORT MILK ACT Inspection...examination of cows. (a) Physical...in which such milk or cream is produced...whether such cow or cows are in a healthy...

2014-04-01

196

RUMINAL ADAPTATION TO INCREASING LEVELS OF CONCENTRATES  

E-print Network

Research Institute for Livestock Feeding and Nutrition, Lelystad, the Netherlands Dairy cows, even if in good condition, are often fed concentrates during late pregnancy. This is then assumed to result pregnancy does not improve adaptation and is therefore unne- cessary. The question which then remains is how

Paris-Sud XI, Université de

197

[Homeopathic prophylaxis in dairy cows on an organic farm part 1--fertility].  

PubMed

The objective of the study was to assess the efficacy of different prophylactically applied homeopathic compounds on health and fertility during the periparturient period on an organic dairy farm. In a randomised double blinded study 146 dairy cows were enrolled in two treatment groups. The average milk yield was about 5100 kg per cow per lactation. The treatment group received the homeopathic compounds Carduus comp. and Coenzyme comp. at drying off, Traumeel on the day of calving, Lachesis comp. on day 7 post partum (p.p.) and Carduus comp. and Coenzyme comp. on day 14 days p.p. The control group followed the same protocol with a placebo (physiological saline solution). Each drug was administered subcutaneously in a dosage of 5 ml. At drying off, the day of calving and in weekly intervals until day 35 p.p. clinical examinations as well as blood sampling were performed. The effect of treatment was measured by clinical parameters, reproductive performance and serum profiles (Ca, P, AST, Urea, Bilirubin). Data of reproductive performance (days to first service, days open, conception rate) were compared between treatment groups and to those in the previous lactation. There was no significant difference between both treatment groups. Cows of the treatment group had an earlier onset of cyclic activity, especially when milk yield was considered as an influencing factor (82% vs. 57%, P < 0,05). In contrast the cows of the treatment group had a significant lower submission rate. The prophylactic treatment of all cows did not have an effect in general, but in cows with increased milk yield, especially in the current lactation. The reproductive performance in the previous lactation did not have any effects on the success of the homeopathic treatment. Reproductive performance in the herd could be enhanced slightly compared to the previous lactation. PMID:17724935

Fidelak, Ch; Klocke, P; Heuwieser, W

2007-07-01

198

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

199

Markers of gut mucosal inflammation and cow’s milk specific immunoglobulins in non-IgE cow’s milk allergy  

PubMed Central

Background Allergy to cow’s milk protein (CMP) may cause gastrointestinal (GI) symptoms in the absence of CMP specific IgE. The immunological mechanisms involved in such disease are not fully understood. Therefore we examined markers of gut mucosal inflammation and the immunoglobulin profiles in children with Gl symptoms suspected of cow’s milk protein allergy (CMPA). Patients and methods We prospectively recruited infants and young children (n?=?57; median age 8.7 months) with gastrointestinal complaints suspected of CMPA. The diagnosis of CMPA was made using the double-blind, placebo-controlled food challenge. Serum and stool samples were collected during CMP-free diet and after both placebo and active challenges. We analyzed the stool samples for calprotectin, human ?-defensin 2 and IgA. In serum, we analyzed the levels of ?-lactoglobulin and ?-casein specific IgA, and IgG antibodies (total IgG and subclasses IgG1 and IgG4). Control group included children with e.g. dermatological or pulmonary problems, consuming normal diets. Results Fecal calprotectin levels were higher in the challenge positive group (n?=?18) than in the negative (n?=?37), with respective geometric means 55 ?g/g [95% confidence interval 38–81] and 29 [24–36] ?g/g (p?=?0.0039), during cow’s milk free diet. There were no significant inter-group differences in the fecal ?-defensin and IgA levels. The CMP specific IgG and IgA were not elevated in patients with CMPA, but the levels of ?-lactoglobulin-IgG4 (p?=?0.0118) and ?-casein-IgG4 (p?=?0.0044), and total ?-casein-IgG (p?=?0.0054) and -IgA (p?=?0.0050) in all patient samples (regardless of CMPA diagnosis) were significantly lower compared to the control group using dairy products. Conclusions Despite cow’s milk elimination in children intolerant to cow’s milk there might be ongoing low-grade inflammation in the gut mucosa. CMP specific IgG or IgA should not be used to diagnose non-IgE CMPA. The observed frequency of impaired CMP specific total IgA, IgG and IgG4 production in patients following cow’s milk free diet warrants further studies. PMID:24598281

2014-01-01

200

Productivity of F b1 sAngus-Jersey cows compared with Hereford cows under intensive and extensive management conditions  

E-print Network

the younger Angus-Jersey cows at parturition, during the lactation and postlactation periods. Hereford cows consumed an average of 10. 8 kg of feed during the lactation period while the Angus-Jersey cows consumed 9. 5 kg of feed daily during this period.... Average weight change was positive during both the lactation and post- lactation periods. The Herefords gained more weight during the lactation period while the Angus-Jersey cows gained more weight during the postlactation period. Breed of cow...

Ellison, Daniel Richard

2012-06-07

201

Factors and Feeds for Supplementing Beef Cows  

E-print Network

decreases, and so does diet quality. Then, supple- mentation may become necessary even if animal numbers are reduced. Factors and Feeds for Supplementing Beef Cows Stephen P. Hammack and Ronald J. Gill* *Extension Beef Cattle Specialist and Extension Live... decreases, and so does diet quality. Then, supple- mentation may become necessary even if animal numbers are reduced. Factors and Feeds for Supplementing Beef Cows Stephen P. Hammack and Ronald J. Gill* *Extension Beef Cattle Specialist and Extension Live...

Hammack, Stephen P.; Gill, Ronald J.

2000-05-03

202

Cow-Calf Enterprise Standardized Performance Analysis  

E-print Network

. After they have done so they will have a clearer under- standing of data requirements and will be able Stan Bevers and Dean McCorkle* 2 to improve the accuracy of the SPA analysis with better data over time. Most producers complete the cow-calf SPA... for Texas cow-calf producers, is available on the Internet at http://agrisk.tamu.edu. Texas producers who desire more informa- tion should contact Stan Bevers at (940) 552-9941 ext. 231. ...

McCorkle, Dean; Bevers, Stan

2009-03-02

203

Assessment of Cardiac Functions in Infants with Cow's Milk Allergy  

PubMed Central

Background Cow’s milk allergy is the most common food allergy in children, with rates estimated at 1.9% to 4.9%. Clinical phenotypes of cow’s milk allergy are varied and involve 1 or more target organs, with the main targets being the skin, respiratory system, and gastrointestinal tract. To date, no studies have investigated detailed cardiac function in children with cow’s milk allergy. The current study aimed to investigate cardiac function in infants with cow’s milk allergy. Material/Methods We studied 42 infants with cow’s milk allergy and 30 age- and sex-matched healthy subjects. Cardiac functions were evaluated by M-mode, pulsed-wave, and tissue Doppler echocardiography. Results There were no significant differences in ejection fraction or mitral and tricuspid annular plane systolic excursion between the 2 groups. Pulsed-wave Doppler-derived E/A ratios in mitral and tricuspid valves were similar in both groups. Ea/Aa ratios in the left ventricle posterior wall and right ventricle free wall were lower in patients with cow’s milk allergy than in the control group. The E/Ea ratio in the left ventricle, isovolumic relaxation time, deceleration time, and right and left ventricular myocardial performance indices were higher in patients in the study group. Conclusions Our study identified reduced early diastolic tissue Doppler velocities in infants with cow’s milk allergy. PMID:25098395

Ece, Ibrahim; Demiroren, Kaan; Demir, Nihat; Uner, Abdurrahman; Balli, Sevket

2014-01-01

204

Liver functional genomics in beef cows on grazing systems: novel genes and pathways revealed.  

PubMed

The adaptation of the liver to periods of negative energy balance is largely unknown in beef cattle on grazing systems. We evaluated liver transcriptome throughout gestation and early lactation of purebred and crossbred beef cows [Angus, Hereford, and their F1 crossbreeds (CR)], grazing high or low herbage allowances (HA) of native grasslands (4 and 2.5 kg dry matter/kg body wt annual mean; n = 16) using an Agilent 4 × 44k bovine array. A total of 4,661 transcripts were affected by days [272 ? 2.5-fold difference, false discovery rate (FDR) ? 0.10] and 47 pathways were altered during winter gestation (-165 to -15 days relative to calving), when cows experienced decreased body condition score, decreased insulin, and increased nonesterified fatty acid concentrations. Gluconeogenesis and fatty acid oxidation pathways were upregulated, while cell growth, DNA replication, and transcription pathways were downregulated (FDR ? 0.25). We observed only small changes in the liver transcriptome during early lactation (+15 to +60 days). A total of 225 genes were differentially expressed (47 ? 2-fold difference, FDR ? 0.10) between HA. The majority of those were related to glucose and pyruvate metabolism and were upregulated in high HA, reflecting their better metabolic status. Two genes were upregulated in CR cows, but 148 transcripts (74 ? 2-fold change difference, FDR ? 0.10) were affected by the HA and cow genotype interaction. The transcriptional changes observed indicated a complex and previously unrecognized, hepatic adaptive program of grazing beef cows in different nutritional environments. Novel target candidate genes, metabolic pathways, and regulatory mechanisms were reported. PMID:24326346

Laporta, Jimena; Rosa, Guilherme J M; Naya, Hugo; Carriquiry, Mariana

2014-02-15

205

Effects of different feeding time and frequency on metabolic conditions and milk production in heat-stressed dairy cows  

NASA Astrophysics Data System (ADS)

The aim of this paper was to evaluate the effects of three different feeding management (FM) schedules on physiological markers of heat stress (HS), metabolic conditions, milk yield and quality during the hot season in dairy cows. The study involved 27 mid-lactating cows, subdivided in three homogeneous groups differing in feeding time and frequency: total mixed ration (TMR) delivered once daily in the morning (M); twice daily, half in the morning and half in the evening (ME); once daily in the evening (E). During the trial, blood samples were collected in the morning (a.m.) and in the evening (p.m.), breathing rate (BR), rectal temperature (RT), and milk yield were recorded and individual milk samples were collected. Microclimate data indicated that cows were subjected to mild-moderate HS. During the hotter days, cows receiving M treatment showed higher values of RT (38.97 °C vs 38.68 °C and 38.62 °C, in ME and E) and BR (71.44 vs 66.52 and 65.26 breaths min-1, in ME and E), a.m. plasma glucose was lower in M (3.69 vs 3.83 and 3.83 mmol L-1, in ME and E) and a.m. plasma urea was lower in E (4.82 vs 5.48 and 5.35 mmol L-1, in M and ME). Milk yield was unaffected by FM, as well as milk composition and cheese-making properties. Only milk protein content and yield were higher in M (3.42 vs 3.36 and 3.27 g 100 mL-1; and 1.11 vs 1.08 and 1.02 kg day-1, for ME and E). Our results on cow physiology indicate that M seems a less suitable FM to match cow welfare during the summer season.

Calamari, L.; Petrera, F.; Stefanini, L.; Abeni, F.

2013-09-01

206

A case of galactosemia misdiagnosed as cow’s milk intolerance  

PubMed Central

We report on a female patient affected by galactosemia in whom the diagnosis was obscured by the concomitant presence of manifestations suggesting a cow’s milk intolerance. This case exemplifies the problems in reaching a correct diagnosis in patients with metabolic diseases. PMID:22992216

2012-01-01

207

Alterations in physiology and anatomy during pregnancy.  

PubMed

Pregnant women undergo profound anatomical and physiological changes so that they can cope with the increased physical and metabolic demands of their pregnancies. The cardiovascular, respiratory, haematological, renal, gastrointestinal and endocrine systems all undergo important physiological alterations and adaptations needed to allow development of the fetus and to allow the mother and fetus to survive the demands of childbirth. Such alterations in anatomy and physiology may cause difficulties in interpreting signs, symptoms, and biochemical investigations, making the clinical assessment of a pregnant woman inevitably confusing but challenging. Understanding these changes is important for every practicing obstetrician, as the pathological deviations from the normal physiological alterations may not be clear-cut until an adverse outcome has resulted. Only with a sound knowledge of the physiology and anatomy changes can the care of an obstetric parturient be safely optimized for a better maternal and fetal outcome. PMID:24012425

Tan, Eng Kien; Tan, Eng Loy

2013-12-01

208

Plasma thiobarbituric acid reactive substances, vitamin A and vitamin E levels and resumption of postpartum ovarian activity in dairy cows.  

PubMed

Vitamins with antioxidative functions are commonly used as supplements to improve fertility in dairy cows. However, according to field test results uncertainty exists about the effect of these vitamins, especially in vitamin A and vitamin E, on ovarian functional activity. This study was performed to reveal the physiological characteristics of cows receiving enough feed and the ovaries of which were activated in the early postpartum period. Six of 12 primiparous cows showing the corpus luteum on 25 to 27 days after parturition were classified as early responders (PER); the remaining six were classified as late responders (PLR). Among 11 multiparous cows, nine were early responders (MER), and the remaining two were late responders (MLR). Plasma concentration of thiobarbituric acid reactive substances (TBARS) in the PER were lower than those in the PLR (P<0.01). The ratio of plasma all-trans-retinol to intake ?-tocopherol or ?-carotene were increased in the following order: MERcows which were able to utilize antioxidants and energy from the feed efficiently may have earlier resumption of ovaries postpartum. PMID:24506096

Aoki, Mari; Ohshita, Tomoko; Aoki, Yasuhiro; Sakaguchi, Minoru

2014-05-01

209

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

210

Cardiovascular physiology. Effects of microgravity.  

PubMed

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. PMID:1402772

Convertino, V; Hoffler, G W

1992-08-01

211

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

212

Leukotriene B4 in cows with normal calving, and in cows with retained fetal membranes and/or uterine subinvolution.  

PubMed Central

Two experiments were performed to study the relationship between leukotriene B4 (LTB4) synthesis and placental separation and uterine involution in the cow. In experiment I, the concentration and synthesis of LTB4 by caruncular tissue was lower in cows with retained fetal membranes (RFM cows, n = 11) than in cows that expelled the fetal membranes normally (NFM cows, n = 19). The presence of bacterial cell wall, especially of alpha-hemolytic streptococci and coagulase positive staphylococci enhanced LTB4 synthesis by allantochorion only in NFM cows. In the RFM group, Escherichia coli lipopolysaccharide decreased allantochorionic LTB4 synthesis. With caruncle, only epidermal growth factor increased LTB4 production in NFM cows. In experiment II, the caruncular and endometrial secretion of LTB4 was lower in cows with subuterine involution (SUI cows, n = 5) or cows with SUI and RFM (SUI+RFM cows, n = 4) than in cows with normal uterine involution (NUI cows, n = 8). This decrease was especially noticeable in the previously gravid horn. In the three uterine involution groups, there were no differences in LTB4 synthesis by caruncular tissue taken from the previously gravid horn. However, progesterone and a bacterial suspension of E. coli reduced the synthesis of LTB4. Estradiol had no effect on LTB4 synthesis at the end of the postpartum period. These results suggest that LTB4 may play an important role in both placental separation and uterine involution in cattle and LTB4 synthesis may be modulated by endocrine and bacterial factors. PMID:8269369

Slama, H; Vaillancourt, D; Goff, A K

1993-01-01

213

Beef Cow/Calf Herd Health Program and Calendar  

E-print Network

Beef Cow/Calf Herd Health Program and Calendar W. Dee Whittier, Extension Specialist and Professor represent a major obstacle to the profitability of many cow/calf beef operations. Disease results in animal

Liskiewicz, Maciej

214

A Model for Poor Fertility in Dairy Cows  

E-print Network

A Model for Poor Fertility in Dairy Cows SW Walsh, EJ Williams, ACO Evans University College Dublin, Ireland From A review of the causes of poor fertility in high milk producing dairy cows (2011) Animal

215

BSE (Bovine Spongiform Encephalopathy, or Mad Cow Disease)  

MedlinePLUS

... an ear-tag identification number and subsequent genetic testing confirmed that the BSE-infected cow was imported into the United States from Canada in August 2001. Because the animal was non-ambulatory (a "downer cow") at slaughter, ...

216

Cow's milk proteins in human milk.  

PubMed

Cow's milk proteins (CMPs) are among the best characterized food allergens. Cow's milk contains more than twenty five different proteins, but only whey proteins alpha-lactalbumin, beta-lactoglobulin, bovine serum albumin (BSA), and lactoferrin, as well as the four caseins, have been identified as allergens. Aim of this study was to investigate by proteomics techniques cow's milk allergens in human colostrum of term and preterm newborns' mothers, not previously detected, in order to understand if such allergens could be cause of sensitization during lactation. Term colostrum samples from 62 healthy mothers and preterm colostrum samples from 11 healthy mothers were collected for this purpose. The most relevant finding was the detection of the intact bovine alpha-S1-casein in both term and preterm colostrum. Using this method, which allows direct proteins identification, beta-lactoglobulin was not detected in any of colostrum samples. According to our results bovine alpha 1 casein that is considered a major cow's milk allergen is readily secreted in human milk: further investigations are needed in order to clarify if alpha-1-casein has a major role in sensitization or tolerance to cow's milk of exclusively breastfed predisposed infants. PMID:23158513

Coscia, A; Orrù, S; Di Nicola, P; Giuliani, F; Rovelli, I; Peila, C; Martano, C; Chiale, F; Bertino, E

2012-01-01

217

Type 1 and type 2 immune response profiles of commercial dairy cows in 4 regions across Canada  

PubMed Central

Diseases of dairy cattle have adverse implications for both the dairy industry and animal welfare. Understanding adaptive immune response profiles of cattle on a national scale will provide insight into the potential for improving health and decreasing disease. The objectives of the present study were to evaluate immune response phenotypes of Holstein cows outside the peripartum period and to determine if antibody isotype bias to putative type 1 and type 2 test antigens is maintained. The cows, housed on commercial farms in 4 key dairy regions across Canada, were immunized with test antigens to measure their ability to mount cell-mediated immune responses (CMIR) and antibody-mediated immune responses (AMIR). Delayed-type hypersensitivity (DTH) was used as an indicator of CMIR and primary and secondary serum antibodies of the immunoglobulin (Ig) G1 and IgG2 isotypes were used to determine AMIR to the test antigens. Immune response phenotypes varied significantly among regions, herds, and cows. Cows in Alberta had significantly higher DTH responses and secondary responses to the type 2 test antigen than those in other regions. However, cows in Alberta had significantly lower primary antibody responses. It was found that Alberta had the lowest incidence of mastitis caused by Escherichia coli and Staphylococcus aureus compared with other regions. The IgG1/IgG2 antibody isotype ratio confirmed the nature of the test antigens. This was the first study to evaluate adaptive immune response profiles and disease incidence of dairy cows on a national scale and it therefore provides a glimpse of the current situation in Canada. PMID:23024454

Thompson-Crispi, Kathleen A.; Mallard, Bonnie A.

2012-01-01

218

Production Efficiency of Beef Cows through Mathematical Modeling and Genomics  

E-print Network

Production Efficiency of Beef Cows through Mathematical Modeling and Genomics For decades cows reside. With recent advances in genomics, the identification of intrinsic genetic factors Develop and evaluate the individual-based model· for production efficiency of beef cows using genomic

219

Ruminal fermentation and forestomach digestion of peas by dairy cows  

E-print Network

Ruminal fermentation and forestomach digestion of peas by dairy cows GR Khorasani E Okine R Corbett Protein feeds commonly used in dairy cow rations in Western Canada include soybean meal, canola meal %) and starch (48 %), but information on the digestion and utilization of peas by lactating dairy cows

Boyer, Edmond

220

Anthropometric and physiological predispositions for elite soccer  

Microsoft Academic Search

This review is focused on anthropometric and physiological characteristics of soccer players with a view to establishing their roles within talent detection, identification and development programmes. Top-class soccer playershave to adapt to the physical demandsof the game, which are multifactorial. Players may not need to have an extraordinary capacity within any of the areas of physical performance but must possess

T. Reilly; J. Bangsbo; A. Franks

2000-01-01

221

Dopamine or thyrotropin-releasing hormone effects on luteinizing hormone secretion in heifers and on the postpartum interval in cows  

E-print Network

DOPAMINE OR THYROTROPIN-RELEASING HORMONE EFFECTS ON LUTEINIZING HORMONE SECRETION IN HEIFERS AND ON THE POSTPARTUM INTERVAL IN COWS A Thesis by Jeffrey Clay Lovin Submitted to the Graduate College of Texas ASM University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1984 Major Subject: Physiology of Reproduction DOPAMINE OR THYROTROPIN-RELEASING HORMONE EFFECTS ON LUTEINIZING HORMONE SECRETION IN HEIFERS AND ON THE POSTPARTUM INTERVAL...

Lovin, Jeffrey Clay

2012-06-07

222

Physiological Bases of Acoustic LRT in Nonstutterers, Mild  

E-print Network

physiologically-based models of the disorder (Adams. 1974. 1978; Schwartz. 1974; Van Riper. 1982;Wyke. 1971 frequency of dysfluency and less adaptation when reading aloud passages containing both voiced and voiceless

223

Regulation of Adult Physiology and Behavior in Drosophila melanogaster  

E-print Network

The physiological responses involved in mediating adaptive change due to varying environmental conditions or social interactions are complex and involve integration of numerous signaling pathways. With Drosophila melanogaster, I can investigate...

Schwedes, Christoph 1980-

2012-10-26

224

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

225

Comparison of F1 cows sired by Brahman, Boran and Tuli bulls for reproductive, maternal, and cow longevity traits  

E-print Network

LITERATURE REVIEW...................................................................................................4 The Importance of Crossbreeding in Beef Cattle...........................................................4 Bos Indicus / Bos Taurus... and produces heavy calves at weaning (Sanders et al., 2005). Crossbreeding research has consistently documented higher levels of heterosis or hybrid vigor in Bos indicus x Bos taurus cows compared to Bos taurus x Bos taurus cows, and the F1 Brahman cow...

Maiga, Assalia Hassimi

2007-04-25

226

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

227

Physiological requirements of cricket  

Microsoft Academic Search

Despite its long history and global appeal, relatively little is known about the physiological and other requirements of cricket. It has been suggested that the physiological demands of cricket are relatively mild, except in fast bowlers during prolonged bowling spells in warm conditions. However, the physiological demands of cricket may be underestimated because of the intermittent nature of the activity

T. D. Noakes; J. J. Durandt

2000-01-01

228

Wheat Versus Milo for Dairy Cows.  

E-print Network

BULLE -, -1' CAA~ AGRICULTURAL ciiPERIMER~5dTFl A. B. CONNOR, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS DIVISION OF DAIRY HUSBANDRY Wheat Versus Milo For Dairy Cows IT, 1933 4ND ME , 0. WAI ZAL COLLEGE 0 resident IF TEXA STATION...BULLE -, -1' CAA~ AGRICULTURAL ciiPERIMER~5dTFl A. B. CONNOR, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS DIVISION OF DAIRY HUSBANDRY Wheat Versus Milo For Dairy Cows IT, 1933 4ND ME , 0. WAI ZAL COLLEGE 0 resident IF TEXA STATION...

Copeland, O. C. (Orlin Cephas)

1933-01-01

229

The Vitamin A Requirements of Dairy Cows.  

E-print Network

BULLE A 8 CO XAS AfiRICULTURAL LLLUL, CAMPU EXPERIMENT 7%" A. R. CONNER, DIRECTOR COLLEGE STATION, BRAZOS COUNTY, TEXAS TIN NO. 495 AUGUST, 193g :3= -a c 3 DIVISION OF CHEMISTRY I'HE VITAMIN A REQUIREMENTS OF DAIRY COWS GRICULTURAL... of Veterinary Medicine. TAs of Augnst 1, 1934 **In cooperation with U. S. Department of Agriculture. $In cooperation with Texas Extension Service. Dairy cows must have feed high in vitamin A potency in order to continue to produce butter high in vitamin A...

Fraps, G. S. (George Stronach); Copeland, O. C. (Orlin Cephas); Treichler, Ray

1934-01-01

230

The relationship between evolutionary and physiological variation in hemoglobin  

E-print Network

The relationship between evolutionary and physiological variation in hemoglobin Ron Milo , Jennifer, 2007) Physiological and evolutionary adaptations operate at very differ- ent time scales. Nevertheless, there are reasons to believe there should be a strong relationship between the two, as together they modify

Kirschner, Marc W.

231

Bacterial and fungal organisms in the vagina of normal cows and cows with vaginitis  

E-print Network

frequent aerobic isolates included Acinetobacter lwoffii, Arcanobacterium pyogenes, Escherichia coli, Corynebacterium spp., and Streptococcus spp. These organisms were isolated from both groups of cows, but more frequently from the vaginitis group...

Husted, James Ross

2005-02-17

232

Priming the cow for mobilization in the periparturient period: effects of supplementing the dry cow with saturated fat or linseed.  

PubMed

High-producing dairy cows experience negative energy balance in early lactation. Dry-cow feeding management will affect the performance and metabolic status of dairy cows in the following early lactation. The present study evaluates dry-cow feeding strategies for priming lipid metabolism in the dairy cow to overcome the metabolic challenges in the following early lactation. Five weeks before expected calving, 27 cows were assigned to 1 of 3 isonitrogenous and isoenergetic dietary treatments: a low-fat control diet (dry-control); a high saturated fat diet (dry-HSF); and a high linseed diet (dry-HUF). The cows were fed the same TMR lactation diet after calving. The treatments were evaluated by performance and metabolic parameters in blood and liver. The cows fed dry-HSF and dry-HUF had significantly greater plasma nonesterified fatty acid concentrations compared with dry-control, and the dry-HUF cows had the greatest C18:3 concentrations in plasma in the prepartum period. Further, the cows fed dry-HSF and dry-HUF diets had a tendency for the greatest capacity for incomplete beta-oxidation of fatty acids in the liver in wk 3 prepartum. The plasma cholesterol concentration was greatest for cows fed dry-HSF in the prepartum period compared with those fed dry-control and dry-HUF. The cows fed dry-HSF had the lowest plasma nonesterified fatty acid and liver fat concentrations in early lactation compared with the cows fed dry-control and dry-HUF. Data in the literature and the present experiment indicate that supplementing dry cows with a saturated fatty acid source is a positive strategy for priming dairy cows for body fat mobilization in the following early lactation. PMID:18292259

Andersen, J B; Ridder, C; Larsen, T

2008-03-01

233

Prion diseases: transmission from mad cows?  

PubMed

Prion diseases in humans show considerable clinical and pathological heterogeneity. The identification of a new variant of Creutzfeldt-Jakob disease, and its interpretation as evidence of transmission of mad cow disease to man, rely critically on our understanding of the epidemiology of prion diseases. PMID:8939557

Roberts, G W; James, S

1996-10-01

234

Identifying and managing cow's milk protein allergy  

Microsoft Academic Search

Cow's milk protein (CMP) is usually one of the first complementary foods to be introduced into the infant's diet and is commonly consumed throughout childhood as part of a balanced diet. CMP is capable of inducing a multitude of adverse reactions in children, which may involve organs like the skin, gastrointestinal (GI) tract or respiratory system. The diagnosis of CMP-induced

George du Toit; Rosan Meyer; Neil Shah; Ralf G Heine; Michael A Thomson; Gideon Lack; Adam T Fox

2010-01-01

235

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

236

Digestive adaptation: A new surgical proposal to treat obesity based on physiology and evolution Adaptação digestiva: Uma nova proposta cirúrgica para tratar a obesidade com base em fisiologia e evolução  

Microsoft Academic Search

Objective: To report on a new surgical technique to treat obesity - Digestive Adaptation - and to present its preliminary results. Method: The technique includes a vertical (sleeve) gastrectomy, omentectomy and enterectomy maintaining the initial 150-cm- portion of the jejunum and the final 150-cm-portion of the ileum. The three first obese patients operated on are described. Results: With a minimum

Sérgio Santoro; Manoel Carlos; Prieto Velhote; Carlos Eduardo Malzoni; Alexandre Sérgio Gracia Mechenas; Victor Strassmann; Morton Scheinberg

237

Cow attributes, herd management, and reproductive history events associated with abortion in cow-calf herds from Western Canada.  

PubMed

The primary objective of this study was to identify herd management and cow characteristics that are associated with abortion in cow-calf herds in Western Canada. Reproductive events were closely monitored in 29,713 cows in 203 herds from the beginning of the breeding season in 2001 through the calving season in 2002. Herd management and cow-level risk factors such as age, body condition score, and previous reproductive history were measured through a series of herd visits by project personnel and detailed individual animal records maintained by the herd owner. Pregnancy status was assessed in fall of 2001 by the herd veterinarian. Cows most likely to abort were replacement heifers, cows that were more than 10 years of age, cows with a body condition score of less than or equal to or 5 of 9 at pregnancy testing, or with twin pregnancies. Cows vaccinated for bovine viral diarrhea virus and infectious bovine rhinotracheitis and bred on community pastures were less likely to abort than cows from community pastures that were not vaccinated. Cows bred on community pastures that were not vaccinated were also more likely to abort than cows that were not on community pastures regardless of vaccination status. Adverse calving-associated events such as severe dystocia, problems such as uterine prolapse or retained placentas, abortion or calf death within 1 hour of birth were also associated with an increased risk of abortion the subsequent calving season after accounting for all other factors. PMID:24472651

Waldner, C L

2014-04-01

238

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

239

Ultrasonography of the rumen of dairy cows  

PubMed Central

Background This study describes the ultrasonographic findings of the rumen in 45 healthy dairy cows. Results The cows were scanned on both sides using a 5.0 MHz transducer. The dorsal visible margin of the rumen ran parallel to the lung from cranioventral to caudodorsal. It was furthest from the dorsal midline at the 9th intercostal space (48.3?±?9.24 cm) and closest at the 12th intercostal space (22.4?±?3.27 cm). The longitudinal groove, which could be clearly identified at all examination sites because it appeared as a triangular notch, formed the ventral margin of the dorsal sac of the rumen. The dorsal sac of the rumen was largest at the caudal flank (40.3?±?6.33 cm), where it was adjacent to the abdominal wall. The ventral sac of the rumen extended across the ventral midline into the right hemiabdomen and its ventral margin had a largely horizontal craniocaudal course. The height of the ventral sac of the rumen exceeded that of the dorsal sac at all examination sites; the maximum height was measured at the 12th intercostal space (62.6?±?9.53 cm). The dorsal gas cap, characterised ultrasonographically by typical reverberation artifacts, was visible in all cows from the 12th intercostal space to the caudal flank. It was largest at the 12th intercostal space (20.5?±?7.03 cm). The transition from the gas cap to the fibre mat was marked by the abrupt cessation of the reverberation artifacts. It was not possible to differentiate a fibre mat and a ventral fluid phase. The rumen could be imaged from the right side in 21 cows (47%). Conclusions Ultrasonography is well suited for the detailed examination of the rumen of cows. The reference values obtained from this study add to the diagnostic tools that are available for the assessment of bovine patients. PMID:23497545

2013-01-01

240

Residues in colostrum following antibiotic dry cow therapy.  

PubMed

Cows from five dairy herds were used to determine persistence of antibiotic residues in colostrum and milk following dry cow therapy. Cows were treated in all quarters at drying off with antibiotics approved for use for nonlactating cows. Antibiotics procaine penicillin G plus dihydrostreptomycin, novobiocin, cloxacillin, or cephapirin were compared with no treatment. Composite colostrum samples were collected from each cow at first milking after parturition. Samples were screened for residues by Delvotest P. Colostrum samples positive by Delvotest also were tested by Bacillus stearothermophilus disc assay. Four of 186 colostrum samples from cows treated with antibiotics at drying off were positive for residues by Delvotest. Only one was confirmed positive by disc assay following heat treatment. All colostrum samples from 48 cows not treated were negative. Samples of first marketable milk also were collected. Over 96% of milk samples from cows treated at drying off and 100% of milk samples from cows not treated were negative for residues by Delvotest. If manufacturer's recommendations are followed, antibiotic residues in colostrum and milk following dry cow therapy with products in our study should not be a significant problem. PMID:6530498

Oliver, S P; Duby, R T; Prange, R W; Tritschler, J P

1984-12-01

241

Comparison of metabolic, hematological, and peripheral blood leukocyte cytokine profiles of dairy cows and heifers during the periparturient period.  

PubMed

The periparturient period presents major physiological challenges for the dairy cow. It is a period that is affected by metabolic stressors, major changes in endocrine status, and altered immune function, which together result in an increased risk of disease. Immunological, hematological, and metabolic profiles from the periparturient period of heifers (primipara) were compared with those of cows (pluripara) to test the hypothesis that at the time of calving they have qualitatively different peripheral blood profiles. Blood samples were collected from 22 Holstein-Friesian animals on 3 occasions: approximately 2 wk before calving, within 24h after calving, and approximately 2 wk after calving. Quantitative PCR was used to measure the expression of a selected set of cytokines and receptors by peripheral blood leukocytes. Additional analyses included hemoglobin concentration, red cell, platelet and white cell counts (total and differentiated), and clinical diagnostic biochemical profiles. Total leukocyte counts, neutrophils, and lymphocytes were higher in heifers than cows before calving and within 24h after calving. Alkaline phosphatase was consistently higher in heifers than cows and several significant differences were observed between the 2 groups with regards to cytokine and cytokine-receptor mRNA expression. The results warrant further investigation from the perspective of identifying risk factors for metabolic and parturient disease in dairy cattle. PMID:23462170

Jonsson, N N; Fortes, M R S; Piper, E K; Vankan, D M; de Cisneros, J Prada J; Wittek, T

2013-04-01

242

Animal Physiology Course Description  

E-print Network

Chapters The physiology of neuronal function Nerve impulses and neurotransmission Sensory reception Organization of the nervous system Glands and hormones Skeletal muscles and movement Behavior Circulation Gas

243

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. PMID:25049874

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

2013-01-01

244

Lecture 14: Adaptation Adaptation  

E-print Network

, larger testes in bats that roost in large groups (Fig 9.11) Fruit bats Flying foxes Small group, small as an adaptation · Flying foxes, fruit bats · Males compete to fertilize females · Larger testes, more sperm · H1

245

Dynamical Adaptation in Photoreceptors  

PubMed Central

Adaptation is at the heart of sensation and nowhere is it more salient than in early visual processing. Light adaptation in photoreceptors is doubly dynamical: it depends upon the temporal structure of the input and it affects the temporal structure of the response. We introduce a non-linear dynamical adaptation model of photoreceptors. It is simple enough that it can be solved exactly and simulated with ease; analytical and numerical approaches combined provide both intuition on the behavior of dynamical adaptation and quantitative results to be compared with data. Yet the model is rich enough to capture intricate phenomenology. First, we show that it reproduces the known phenomenology of light response and short-term adaptation. Second, we present new recordings and demonstrate that the model reproduces cone response with great precision. Third, we derive a number of predictions on the response of photoreceptors to sophisticated stimuli such as periodic inputs, various forms of flickering inputs, and natural inputs. In particular, we demonstrate that photoreceptors undergo rapid adaptation of response gain and time scale, over ? 300 ms—i. e., over the time scale of the response itself—and we confirm this prediction with data. For natural inputs, this fast adaptation can modulate the response gain more than tenfold and is hence physiologically relevant. PMID:24244119

Clark, Damon A.; Benichou, Raphael; Meister, Markus; Azeredo da Silveira, Rava

2013-01-01

246

Evaluation of the impacts of spaying by either the dropped ovary technique or ovariectomy via flank laparotomy on the welfare of Bos indicus beef heifers and cows.  

PubMed

The welfare outcomes for Bos indicus cattle (100 heifers and 50 cows) spayed by either the dropped ovary technique (DOT) or ovariectomy via flank laparotomy (FL) were compared with cattle subjected to physical restraint (PR), restraint by electroimmobilization in conjunction with PR (EIM), and PR and mock AI (MAI). Welfare assessment used measures of morbidity, mortality, BW change, and behavior and physiology indicative of pain and stress. One FL heifer died at d 5 from peritonitis. In the 8-h period postprocedures, plasma bound cortisol concentrations of FL, DOT, and EIM cows were not different and were greater (P<0.05) than PR and MAI. Similarly, FL and DOT heifers had greater (P<0.05) concentrations than PR and MAI, with EIM intermediate. Creatine kinase and aspartate aminotransferase concentrations were greater (P<0.05) in FL and EIM heifers compared with the other treatments, with a similar pattern seen in the cows. Haptoglobin concentrations were significantly (P<0.05) increased in the FL heifers compared with other treatments in the 8- to 24-h and 24- to 96-h periods postprocedures, and in cows were significantly (P<0.05) increased in the FL and DOT compared with PR in the 24- to 96-h period. Behavioral responses complemented the physiological responses; standing head down was shown by more (P<0.05) FL cows and heifers to 3 d postprocedures compared with other treatments, although there was no difference between FL and DOT heifers at the end of the day of procedures. At this same time, fewer (P<0.05) FL and DOT heifers and cows were observed feeding compared with other treatments, although in cows there was no difference between FL, DOT, and EIM. There were no significant differences (P>0.05) between treatments in BW changes. For both heifers and cows, FL and DOT spaying caused similar levels of acute pain, but FL had longer-lasting adverse impacts on welfare. Electroimmobilization during FL contributed to the pain and stress of the procedure. We conclude that: i) FL and DOT spaying should not be conducted without measures to manage the associated pain and stress; ii) DOT spaying is preferable to FL spaying; iii) spaying heifers is preferable to spaying cows; and iv) electroimmobilization causes pain and stress and should not be routinely used as a method of restraint. PMID:23048132

Petherick, J C; McCosker, K; Mayer, D G; Letchford, P; McGowan, M

2013-01-01

247

Toward building the cow folliculome.  

PubMed

One of the goals of the EmbryoGENE network was to gather information on the conditions leading to competent oocytes. Using a combination of transcriptomic analyses we are building the foundation of the folliculome, which will take the form of a virtual follicle with gene expression profiling data spanning small to ovulatory or atretic follicles. The different models currently being established not only provide information on the follicular conditions leading to good outcome but also intermediary steps, including evolution towards atresia. The physiology of very few species has been covered to the extent of our database, which is the only one for mono-ovulatory species. The first interesting observation extracted from our data is related to the plateau phase of follicular development, which is not a linear intermediate between growth and ovulation but rather an important modification step of tissue ontogenesis during which growth switches to differentiation or atresia. The markers of cell division, matrix rearrangement, mesenchymal differentiation, oxidation, steroidogenesis and ovulatory changes identified confirm known changes but also several others are now hinting to a more complex picture of this dynamic tissue. In addition to biomarkers, we have insight into the multiple pathways involved during the last few days before ovulation. Our new ability to validate these networks in vitro using primary granulosa cells culture also contributes to the construction of a follicular blueprint. The amazing list of gene responding to FSH alone is a good start but a complete meta-analysis will provide the foundation of the bovine folliculome. PMID:25018044

Sirard, Marc-André

2014-09-01

248

Phun Week: Understanding Physiology  

ERIC Educational Resources Information Center

Topics such as sports, exercise, health, and nutrition can make the science of physiology relevant and engaging for students. In addition, many lessons on these topics, such as those on the cardiovascular, respiratory, and digestive systems, align with national and state life science education standards. Physiology Understanding Week (PhUn…

Limson, Mel; Matyas, Marsha Lakes

2009-01-01

249

Normal bacterial flora from vaginas of Criollo Limonero cows  

Microsoft Academic Search

In order to describe the normal bacterial flora in vaginas of Criollo Limonero cows, 51 healthy multiparous cows, at least\\u000a 90-day postpartum, were selected. Duplicated swabs (N?=?102) were taken from the vaginal fornix of cows to perform aerobic and anaerobic cultures as well as conventional biochemical\\u000a tests. Out of 102 swabs, bacterial growth was obtained in 55 (53.9%) while the

Sunny Zambrano-Nava; Julio Boscán-Ocando; Jexenia Nava

2011-01-01

250

Breed and heterotic effects on productive longevity of beef cows  

E-print Network

DIFFERENCES BY BREEDTYPE 54 11 AGE COMPOSITION OF THE HERDS BY BREEDTYPE, PERCENT 12 PERCENT OF COWS REMOVED THAT WERE CULLED OR DIED BY BREEDTYPE 61 62 1X LIST OF TABLES TABLE Page 13 AGE SPECIFIC PROBABILITIES OF ATTRITION AND SURVIVAL RATESi... PROBABILITY OF SURVIVING TO A SPECIFIC AGE AND THE AGE DISTRIBUTION OF CULLED COWS AND THE COWS IN THE HERD FOR THE ANGUS BREEDTYPE . . . . . . . . . , ~ ~ ~ ~ ~ ~ ~ ~ ~ 69 14 AGE SPECIFIC PROBABILITIES OF ATTRITION AND SURVIVAL RATES, PROBABILITY...

Rohrer, Gary Alan

2012-06-07

251

Fatal jejunal haemorrhage syndrome in cows.  

PubMed

Jejunal haemorrhage syndrome in a four-year-old Holstein Friesian cow Umbilical cord accident in a stillborn calf Cerebellar abiotrophy/dysgenesis in a three-day-old calf Congenital swayback in a three-week-old lamb Louping ill in a two-week-old lamb These are among matters discussed in the disease surveillance report for June from SAC Consulting: Veterinary Services (SAC C VS). PMID:25344042

2014-10-25

252

Maxillary osteosarcoma in a beef suckler cow  

PubMed Central

A ten-year-old beef suckler cow was referred to the Scottish Centre for Production Animal Health & Food Safety of the University of Glasgow, because of facial swelling in the region of the right maxilla. The facial swelling was first noticed three months earlier and was caused by a slow growing oral mass which contained displaced, loosely embedded teeth. The radiographic, laboratory and clinicopathological findings are described. Necropsy, gross pathology and histological findings confirmed the mass as a maxillary osteosarcoma. PMID:22788782

2012-01-01

253

Abnormal regurgitation in three cows caused by intrathoracic perioesophageal lesions  

PubMed Central

Background Three Brown Swiss cows with abnormal regurgitation because of a perioesophageal disorder are described. Case presentation The cows were ill and had poor appetite, salivation and regurgitation of poorly-chewed feed. Collection of rumen juice was successful in one cow, and in another, the tube could be advanced to the level of the 7th intercostal space, and in the third, only saliva could be collected. In one cow, oesophagoscopy revealed a discoloured 10-cm mucosal area with fibrin deposits. Thoracic radiographs were normal. The cows were euthanased and examined postmortem. Cow 1 had a large perioesophageal abscess containing feed material at the level of the thoracic inlet, believed to be the result of a healed oesophageal injury. Cow 2 had an abscess between the oesophagus and trachea 25 cm caudal to the epiglottis with the same presumed aetiology as in cow 1. Cow 3 had a mediastinal carcinoma that enclosed and constricted the oesophagus. Conclusions Abnormal regurgitation in cattle is usually the result of an oesophageal disorder. Causes of oesophageal disorders vary widely and their identification can be difficult. PMID:24629042

2014-01-01

254

High altitude living: genetic and environmental adaptation.  

PubMed

High altitude (HA) living produces physiological changes for adaptation to chronic hypobaric-hypoxemic conditions. Although much is known about these physiologic adaptations, no clear separation has been made regarding what is "native" or "genetic" adaptation and what is "acquired." In this review, we describe the genetic vs. acquired adaptation and only include studies performed in a population native to HA and not in an acclimatized population or trekkers. The changes encountered in animals and humans living at HA in terms of hematology, muscular, respiratory, cerebral, cardiovascular, hormonal, fluid and electrolytes and reproduction, strongly suggest that genetics play a very important role in HA adaptation. Unfortunately, the characteristic physiology of HA natives has not been systematically defined to established specific measurable parameters of adaptation in comparison to the acquired ambient adaptation of the non-native population. Once the parameters are established, we can compare non-native populations exposed to HA that must emulate the HA physiology for a definite adaptation to be present. With measurable parameters, especially in the management of fluids and electrolytes, we can define how long it will take for a sea level native to adapt to an HA altitude. Until these studies are performed, speculation will continue and no rational medical intervention can be offered to HA newcomers who may experience HA difficulties. PMID:9895025

Ramirez, G; Bittle, P A; Rosen, R; Rabb, H; Pineda, D

1999-01-01

255

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. PMID:24772083

Costantine, Maged M.

2014-01-01

256

Genetics and the physiological ecology of conifers  

SciTech Connect

Natural selection acts on the diversity of genotypes, adapting populations to their specific environments and driving evolution in response to changes in climate. Genetically based differences in physiology and demography adapt species to alternate environments and produce, along with historical accidents, the present distribution of species. The sorting of conifer species by elevation is so marked that conifers help to define plant communities arranged in elevational bands in the Rocky Mountains. For these reasons, a genetic perspective is necessary to appreciate the evolution of ecophysiological patterns in the coniferous forests of the Rocky Mountains. The fascinating natural history and the economic importance of western conifers have stimulated numerous studies of their ecology, ecological genetics, and geographic variation. These studies yield some generalizations, and present some puzzling contradictions. This chapter focuses on the genetic variability associated with the physiological differences among genotypes in Rocky Mountain conifers. Variation among genotypes in survival, growth, and resistance to herbivores is used to illustrate genetically based differences in physiology, and to suggest the mechanistic studies needed to understand the relationships between genetic and physiological variation.

Mitton, J.B.

1995-07-01

257

Photosynthesis: Physiological and  

E-print Network

Photosynthesis: Physiological and Ecological Considerations Chapter 9 THE CONVERSION OF SOLAR reactions of photosynthesis should not overshadow the fact that, under natural condi- tions. The impact of the environment on photosynthesis is of interest to plant physiologists, ecologists

Ehleringer, Jim

258

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

259

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

260

PHYSIOLOGICAL AND NONSPECIFIC BIOMARKERS  

EPA Science Inventory

This chapter summarizes the advantages and disadvantages of physiological and non specific biomarkers. t lists the criteria to be used in selecting biomarkers to address specific ecological questions. fter a general discussion of this topic, several specific biomarkers of possibl...

261

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

262

Animal Physiology Summer 2014  

E-print Network

. Topics Textbook Chapters The physiology of neuronal function Nerve impulses and neurotransmission Sensory Circulation Gas exchange and acid-base balance Osmoregulation Digestion 5 6 7 8 9 10 11 12 13 14 15 Attendance

263

Why Physiology Matters in Medicine  

NSDL National Science Digital Library

Editorial, April 2011. The author advocates for increased utilization of physiology in the biomedical field with examples of medical research in which physiology and doctors with physiological training played a crucial role.

Michael J Joyner (Mayo Clinic Anesthesiology)

2011-04-01

264

Adaptive density propagation in pharmacokinetics  

E-print Network

: TRAIL (Horenko & Weiser 2004) ­ Linearized propagation ­ Assign new coefficients ­ Estimate time error" Computational Physiology, Dept. of Mathematics & Informatics, FU Berlin Summary · TRAIL: ­ Representation Adaptive Propagation of the Quantum-Classical Liouville Equation", J. Chem. Physics, 120 (19), 2004

Spang, Rainer

265

Gluconeogenesis in dairy cows: the secret of making sweet milk from sour dough.  

PubMed

Gluconeogenesis is a crucial process to support glucose homeostasis when nutritional supply with glucose is insufficient. Because ingested carbohydrates are efficiently fermented to short-chain fatty acids in the rumen, ruminants are required to meet the largest part of their glucose demand by de novo genesis after weaning. The qualitative difference to nonruminant species is that propionate originating from ruminal metabolism is the major substrate for gluconeogenesis. Disposal of propionate into gluconeogenesis via propionyl-CoA carboxylase, methylmalonyl-CoA mutase, and the cytosolic form of phosphoenolpyruvate carboxykinase (PEPCK) has a high metabolic priority and continues even if glucose is exogenously supplied. Gluconeogenesis is regulated at the transcriptional and several posttranscriptional levels and is under hormonal control (primarily insulin, glucagon, and growth hormone). Transcriptional regulation is relevant for regulating precursor entry into gluconeogenesis (propionate, alanine and other amino acids, lactate, and glycerol). Promoters of the bovine pyruvate carboxylase (PC) and PEPCK genes are directly controlled by metabolic products. The final steps decisive for glucose release (fructose 1,6-bisphosphatase and glucose 6-phosphatase) appear to be highly dependent on posttranscriptional regulation according to actual glucose status. Glucogenic precursor entry, together with hepatic glycogen dynamics, is mostly sufficient to meet the needs for hepatic glucose output except in high-producing dairy cows during the transition from the dry period to peak lactation. Lactating cows adapt to the increased glucose requirement for lactose production by mobilization of endogenous glucogenic substrates and increased hepatic PC expression. If these adaptations fail, lipid metabolism may be altered leading to fatty liver and ketosis. Increasing feed intake and provision of glucogenic precursors from the diet are important to ameliorate these disturbances. An improved understanding of the complex mechanisms underlying gluconeogenesis may further improve our options to enhance the postpartum health status of dairy cows. PMID:21171012

Aschenbach, Jörg R; Kristensen, Niels B; Donkin, Shawn S; Hammon, Harald M; Penner, Gregory B

2010-12-01

266

Metaanalysis of Input\\/Output Kinetics in Lactating Dairy Cows  

Microsoft Academic Search

The kinetics of dry matter intake, raw milk yield, milk fat yield, and body weight of 140 treatment groups of cows reported in 37 articles published between 1959 and 1999 were collected in a database. The majority of these experiments were performed with Holstein- Friesian cows (primiparous: n = 51, multiparous: n = 89). Animals were fed with forages and

O. Martin; D. Sauvant

2002-01-01

267

Clinical reactivity to beef in children allergic to cow's milk  

Microsoft Academic Search

Background: Cow's milk is one of the most common food allergens in children. Limited information is available on the prevalence of reactivity to a related food source, beef. The purposes of this study were to examine the prevalence of symptomatic sensitivity to beef in a selected pediatric population and to determine the frequency of concomitant reactivity to cow's milk and

Sabine J. Werfel; Sara K. Cooke; Hugh A. Sampson

1997-01-01

268

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2013 CFR

...System on Tank Vessels Design, Equipment, and Installation...each tank must have sufficient nozzles with the proper diameter...bulkheads. (g) Each single nozzle COW machine that is mounted...operations. (h) Each multi-nozzle COW machine that is...

2013-07-01

269

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2010 CFR

...System on Tank Vessels Design, Equipment, and Installation...each tank must have sufficient nozzles with the proper diameter...bulkheads. (g) Each single nozzle COW machine that is mounted...operations. (h) Each multi-nozzle COW machine that is...

2010-07-01

270

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2011 CFR

...System on Tank Vessels Design, Equipment, and Installation...each tank must have sufficient nozzles with the proper diameter...bulkheads. (g) Each single nozzle COW machine that is mounted...operations. (h) Each multi-nozzle COW machine that is...

2011-07-01

271

33 CFR 157.124 - COW tank washing machines.  

Code of Federal Regulations, 2012 CFR

...System on Tank Vessels Design, Equipment, and Installation...each tank must have sufficient nozzles with the proper diameter...bulkheads. (g) Each single nozzle COW machine that is mounted...operations. (h) Each multi-nozzle COW machine that is...

2012-07-01

272

Calf Removal: A Way to Stimulate Reproduction in Cows  

E-print Network

Cows that are slow to breed or fail to breed are costly to producers. One of the factors that delays the resumption of estrous activity in a cow--and subsequent breeding--is nursing stress. Removing a calf from a dam, either short...

Sprott, L. R.

2003-10-08

273

Impact of udder disorders on culling of dairy cows  

E-print Network

Impact of udder disorders on culling of dairy cows F Beaudeau C Fourichon K Frankena2 B Faye H com- mercial Holstein dairy herds from western France were used to quantify the effects of udder, respectively. dairy cow / culling / disease / udder I risk Résumé ― Impact des troubles de santé de la

Paris-Sud XI, Université de

274

RAPID GLUTARALDEHYDE FIXATION FOR COW MILK CELL COUNT  

E-print Network

of milk ; a ratio of 2.5 : 1000 (V/V). Samples were homogenized and then kept at laboratory temperatureRAPID GLUTARALDEHYDE FIXATION FOR COW MILK CELL COUNT BY COULTER COUNTER B. POUTREL G. DUBRAY INRA) is regarded as the reference method for counting somatic cells in cow milk. The use of an electronic particle

Paris-Sud XI, Université de

275

Risk factors for infertility in nursing cows linked to calving  

E-print Network

Risk factors for infertility in nursing cows linked to calving C Ducrot I Cimarosti F Bugnard with 3 590 cows in order to study the risk factors for infertility linked to calving. Based upon an analy infertility, breed factors, parity, fattening, comfort, calf characteristics (number, sex, weight

Paris-Sud XI, Université de

276

Automatic observation of cow leg health using load sensors  

Microsoft Academic Search

The milking robot offers a unique possibility for dynamic measurements of the leg health of dairy cows. Four strain gauge scales were installed into a milking robot. The sensors were connected to an amplifier and the data were collected into a PC using dedicated computer programs. The measurement was automatically started and ended based on the cow ID acquired from

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

2008-01-01

277

PurpleCowClinicsLLC Williamstown,MA01267  

E-print Network

at the Cole Field House at Williams College 9:30 AM: Fun with a Soccer Ball 10 AM: Attacking 10:30 AMPurpleCowClinicsLLC P.O.Box804 Williamstown,MA01267 PURPLE COW SOCCER CLINIC FOR BOYS & GIRLS at Williams College with Williams Soccer Players and Coaches WHO Students going into Grades K­8 WHEN June 30

Aalberts, Daniel P.

278

Mortality (including euthanasia) among Danish dairy cows (1990–2001)  

Microsoft Academic Search

Mortality among Danish dairy cows was examined using data from the Danish Cattle Database (DCD) and a questionnaire survey. Mortality risk has increased from approximately 2% in 1990 to approximately 3.5% in 1999. The increased mortality was seen for all dairy breeds and all age groups. Mortality among older dairy cows (parity 3 and older) was approximately twice the mortality

Peter T Thomsen; Anne Mette Kjeldsen; Jan Tind Sørensen; Hans Houe

2004-01-01

279

Adaptation of the rumen microbial population to native potato starch degradation determined with the gas production technique and the nylon bag technique.  

PubMed

Experiments were conducted to investigate the influence of the adaptation of rumen micro-organisms on the degradation of native potato starch (PS) in the rumen. Cows were fed with rations used for gas production (GP) analysis (dry cows, 1.6% starch) and for the nylon bag (NB) technique (lactating cows, 23% starch, mainly maize starch) and a ration containing 19% native PS (lactating cows). Fermentation characteristics of 13 samples were investigated with the GP technique using rumen fluid from cows fed each of the three rations. The same samples were investigated with the NB technique in the cows obtaining the NB ration and the PS ration. The results showed that the rate of GP was influenced by the source of the rumen fluid. The fermentation rate of PS was considerably enhanced by using rumen fluid adapted to the fermentation of native PS instead of using the other rumen fluids. Incubating in cows fed the PS ration, the rate of PS degradation determined with the NB technique, was higher compared with cows fed other rations. Using the PS ration the observed lag period for PS was shorter. The results show a clear influence of ration on the degradation characteristics of starch, determined with both the GP technique and the NB technique. However, these changes in behaviour did not explain observed differences in amounts of rumen escape PS measured in vivo in animal experiments and in situ, using the NB technique. PMID:17083432

Cone, J W; van Gelder, A H

2006-12-01

280

Technical note: quantification of plasma 1- and 3-methylhistidine in dairy cows by high-performance liquid chromatography-tandem mass spectrometry.  

PubMed

To improve monitoring of protein mobilization in dairy cows, we developed and evaluated a method to quantify 1-methylhistidine and 3-methylhistidine in plasma by HPLC-tandem mass spectrometry. The analytical method described is (1) sensitive: both histidine derivates can be detected in the picomole range; (2) accurate: intra- and interassay coefficients of variation were < 5% for all standard solutions of 1-methylhistidine and 3-methylhistidine measured (31 to 500 pmol); (3) specific: 1-methylhistidine is clearly separated from 3-methyl-histidine in plasma samples from dairy cows; and (4) flexible: can be easily adapted to measure other amino acids or compounds containing a primary amine. 1-Methylhistidine is present in plasma of dairy cows at concentrations of 5.0 ± 1.7 ?M, similar to concentrations of 3-methylhistidine (4.4 ± 2.4 ?M). Analytical separation of both histidine metabolites is essential when plasma 3-methylhistidine is used as indicator for muscle breakdown in dairy cows. Specific quantification of the concentration of 3-methylhistidine in bovine plasma samples by HPLC tandem mass spectrometry can improve monitoring of protein mobilization in dairy cows. PMID:22612948

Houweling, M; van der Drift, S G A; Jorritsma, R; Tielens, A G M

2012-06-01

281

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

282

Winter-annual pasture as a supplement for beef cows.  

PubMed

In each of two experiments, 120 pregnant beef cows were stratified by body condition score, BW, breed, and age, randomly divided into six groups of 20, and assigned to one of six 5.1-ha bermudagrass (Cynodon dactylon [L.] Pers.) pastures (two replicates/ treatment) in early January to evaluate the use of winter-annual pasture as a supplement. All cows in Exp. 1 and 2 had ad libitum access to bermudagrass/dallisgrass (Paspalum dilatatum Poir.) hay plus three treatments: 1) a concentrate-based supplement fed 3 d/wk, 2) limit grazing on winter-annual pasture 2 d/wk (7 hr/ d; 0.04 ha x cow(-1) x grazing d(-1)), or 3) limit grazing on winter-annual pasture 3 d/wk (7 hr/d; 0.04 ha x cow(-1) x grazing d(-1)) sod-seeded into a portion of the pasture until mid-May. The seeded portion of pastures in Exp. 1 was planted with a mixture of wheat (Triticum aestivum L.) and rye (Secale cereale L.), but annual ryegrass (Lolium multiflorum Lam.) was added to the seed mixture in Exp. 2. In mid-May, cows were blocked by treatment and the previous sorting factors, randomly assigned to six new groups of 20, and placed on the six perennial pastures until calves were weaned. Groups of cows were exposed to a bull for 60 d beginning in mid-May. In Exp. 1 and 2, limit-grazing winter-annual pasture compared to the concentrate-based supplement or limit grazing 2 vs 3 d/wk did not affect (P > 0.15) cow BW. In Exp. 1, cows limit grazed on winter-annual pasture had a lower (P = 0.05) body condition score than cows fed the concentrate-based supplement in the early spring. However, in Exp. 2, cows limit grazed on winter-annual pasture had higher (P < or = 0.07) body condition score than cows fed the concentrate-based supplement. The conception rate of cows in Exp. 1 and 2 did not differ (P > 0.22) between cows fed concentrate-based supplements and cows limit grazed on winter-annual pasture. In Exp. 2, cows limit grazed 2 d/wk tended to have a greater (P = 0.10) conception rate than cows limit grazed 3 d/wk. In Exp. 1 and 2, birth weight, total gain, BW, and ADG of calves were not affected (P > 0.15) by treatment. We conclude that wheat and rye pasture is a marginal supplement for lactating beef cows. However, cows limit grazed 2 d/wk on winter-annual pasture of wheat, rye, and annual ryegrass as a supplement maintained BW and body condition score as well as cows fed the concentrate-based supplement. But, grazing pasture 3 vs 2 d/wk did not seem to affect performance of cows. PMID:12019601

Gunter, S A; Cassida, K A; Beck, P A; Phillips, J M

2002-05-01

283

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

284

Neuropeptide physiology in helminths.  

PubMed

Parasitic worms come from two distinct, distant phyla, Nematoda (roundworms) and Platyhelminthes (flatworms). The nervous systems of worms from both phyla are replete with neuropeptides and there is ample physiological evidence that these neuropeptides control vital aspects of worm biology. In each phyla, the physiological evidence for critical roles for helminth neuropeptides is derived from both parasitic and free-living members. In the nematodes, the intestinal parasite Ascaris suum and the free-living Caenorhabditis elegans have yielded most of the data; in the platyhelminths, the most physiological data has come from the blood fluke Schistosoma mansoni. FMRFamide-like peptides (FLPs) have many varied effects (excitation, relaxation, or a combination) on somatic musculature, reproductive musculature, the pharynx and motor neurons in nematodes. Insulin-like peptides (INSs) play an essential role in nematode dauer formation and other developmental processes. There is also some evidence for a role in somatic muscle control for the somewhat heterogeneous grouping ofpeptides known as neuropeptide-like proteins (NLPs). In platyhelminths, as in nematodes, FLPs have a central role in somatic muscle function. Reports of FLP physiological action in platyhelminths are limited to a potent excitation of the somatic musculature. Platyhelminths are also abundantly endowed with neuropeptide Fs (NPFs), which appear absent from nematodes. There is not yet any data linking platyhelminth NPF to any particular physiological outcome, but this neuropeptide does potently and specifically inhibit cAMP accumulation in schistosomes. In nematodes and platyhelminths, there is an abundance of physiological evidence demonstrating that neuropeptides play critical roles in the biology of both free-living and parasitic helminths. While it is certainly true that there remains a great deal to learn about the biology of neuropeptides in both phyla, physiological evidence presently available points to neuropeptidergic signaling as a very promising field from which to harvest future drug targets. PMID:21189675

Mousley, Angela; Novozhilova, Ekaterina; Kimber, Michael J; Day, Tim A

2010-01-01

285

Utilization of Vitamin A by Dairy Cows.  

E-print Network

pasture, the vitamin A potency of the butter :ased from 12 units per gram to 40 or 58 units per gram thin three days. \\\\Then other depleted corns were placed upon pasture, there was ewise a rapid increase in the vitamin A potency of the butter. e... (13) reported that 2.5 to 3.4% of the vitamin A value of dried alfalfa and corn silage usually appeared in the m-ilk on a daily intake of 1,213,500 to 946,700 U. S. P. 1934 units per cow. Peterson et a1 (12) stated that only about 2% of the carotene...

Fraps, G. S. (George Stronach)

1937-01-01

286

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

287

Physiological Computing: Interfacing with the Human Nervous System  

Microsoft Academic Search

\\u000a This chapter describes the physiological computing paradigm where electrophysiological changes from the human nervous system\\u000a are used to interface with a computer system in real time. Physiological computing systems are categorized into five categories:\\u000a muscle interfaces, brain-computer interfaces, biofeedback, biocybernetic adaptation and ambulatory monitoring. The differences\\u000a and similarities of each system are described. The chapter also discusses a number of

Stephen H. Fairclough

288

Assessing Cognitive State with Multiple Physiological Measures: A Modular Approach  

Microsoft Academic Search

The purpose of this effort is to introduce a novel approach which can be used to determine how multiple minimally intrusive\\u000a physiological sensors can be used together and validly applied to areas such as Augmented Cognition and Neuroergonomics. While\\u000a researchers in these fields have established the utility of many physiological measures for informing when to adapt systems,\\u000a the use of

Lee W. Sciarini; Denise M. Nicholson

2009-01-01

289

Rapid adaptation: a new dimension for evolutionary perspectives in ecology  

Microsoft Academic Search

Although the study of adaptation is central to biology, two types of adaptation are recognized in the biological field: physiological\\u000a adaptation (accommodation or acclimation; an individual organism’s phenotype is adjusted to its environment) and evolutionary–biological\\u000a adaptation (adaptation is shaped by natural selection acting on genetic variation). The history of the former concept dates\\u000a to the late nineteenth and early twentieth

Masakazu Shimada; Yumiko Ishii; Harunobu Shibao

2010-01-01

290

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

291

Vitamin E Status of Dairy Cows Fed Stored Feeds Continuously or Pastured during Summer1  

Microsoft Academic Search

Parameters indicative of vitamin E status were monitored for over 4 yr in dairy cows to determine if feeding cows only stored feeds could cause deficiency of vitamin E. Low-E cows were fed stored feeds all year whereas the pastured cows grazed during summer. A third group pastured only while dry also was moni- tored the 4th yr. There were

D. J. Schingoethe; J. G. Parsons; F. C. Ludens; W. L. Tucker; H. J. Shave

1978-01-01

292

Effects of Corn Processing on the Site and Extent of Digestion in Lactating Cows  

Microsoft Academic Search

Three multiparous Holstein cows in midlactation were fitted with ruminal and duodenal cannulas. Cows were used in an experiment with a 3 × 3 Latin square design to study the effect of corn processing on nutrient flow from the rumen to the duodenum and on ruminal fermentation in lactating cows. Cows were fed diets consisting of 40% forage and 60%

M. T. Joy; E. J. DePeters; J. G. Fadel; R. A. Zinn

1997-01-01

293

Effect of grass maturity and starch supplementation on nutrient digestibility in dairy cows  

E-print Network

Effect of grass maturity and starch supplementation on nutrient digestibility in dairy cows AM van from young grass, due to increased cell-wall lignification. Starch in diets for dairy cows can reduce forage maturity and starch supplementation in dairy cows. Four lactating cows were fed totally mixed

Paris-Sud XI, Université de

294

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

295

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

296

Effect of Recombinant Bovine Somatotropin on Milk Production and Composition of Cows with Streptococcus uberis Mastitis  

Microsoft Academic Search

The protective effect of bovine somatotropin (bST) during experimental Streptococcus uberis mastitis in cows was studied. The left quarters of 10 cows were infected with 500 cfu of S. uberis O140J. Five cows were subcutaneously treated with 500 mg of recom- binant bST 7 d before and after infection, and 5 control cows received the excipient. In the treated cows,

D. Hoeben; C. Burvenich; P. J. Eppard; D. L. Hard

1999-01-01

297

Renal adaptation during hibernation  

PubMed Central

Hibernators periodically undergo profound physiological changes including dramatic reductions in metabolic, heart, and respiratory rates and core body temperature. This review discusses the effect of hypoperfusion and hypothermia observed during hibernation on glomerular filtration and renal plasma flow, as well as specific adaptations in renal architecture, vasculature, the renin-angiotensin system, and upregulation of possible protective mechanisms during the extreme conditions endured by hibernating mammals. Understanding the mechanisms of protection against organ injury during hibernation may provide insights into potential therapies for organ injury during cold storage and reimplantation during transplantation. PMID:24049148

Martin, Sandra L.; Jain, Swati; Keys, Daniel; Edelstein, Charles L.

2013-01-01

298

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

299

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

300

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.

301

Renal physiology of pregnancy.  

PubMed

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. PMID:23928384

Cheung, Katharine L; Lafayette, Richard A

2013-05-01

302

Psychology 260 Physiological Psychology  

E-print Network

of the brain as well as nervous system development. 3) To introduce the different physiological systems decrements from the top score on each exam. · Extra Credit There will be 4 extra credit pop quizzes given Parscore scantrons. Scantrons will be used for exams and pop quizzes, so you will be expected to have

Gallo, Linda C.

303

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

304

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

305

Physiological requirements of cricket.  

PubMed

Despite its long history and global appeal, relatively little is known about the physiological and other requirements of cricket. It has been suggested that the physiological demands of cricket are relatively mild, except in fast bowlers during prolonged bowling spells in warm conditions. However, the physiological demands of cricket may be underestimated because of the intermittent nature of the activity and the generally inadequate understanding of the physiological demands of intermittent activity. Here, we review published studies of the physiology of cricket. We propose that no current model used to analyse the nature of exercise fatigue (i.e. the cardiovascular-anaerobic model, the energy supply-energy depletion model, the muscle power-muscle recruitment model) can adequately explain the fatigue experienced during cricket. A study of players in the South African national cricket team competing in the 1999 Cricket World Cup revealed that, in a variety of measures of explosive ('anaerobic') power and aerobic endurance capacity, they were as 'fit' as South African national rugby players competing in the 1999 Rugby World Cup. Yet, outwardly, the physiological demands of rugby would seem to be far greater than those of cricket. This poses the question: 'Why are these international cricketers so fit if the physiological demands of cricket are apparently so mild?' One possibility is that this specific group of athletes are unusually proficient in a variety of sports; many achieved high standards of performance in other sports, including rugby, before choosing to specialize in cricket. Hence their apparently high fitness may simply reflect a superior genetic physical endowment, necessary to achieve success in modern international sports, including cricket. Alternatively, it could be hypothesized that superior power and endurance fitness may be required to cope with the repeated eccentric muscle contractions required in turning and in bowling and which may account for fatigue and risk of injury in cricket. If this is the case, the fitness of cricketers may be increased and their risk of injury reduced by more specific eccentric exercise training programmes. PMID:11138982

Noakes, T D; Durandt, J J

2000-12-01

306

Survey of aflatoxin M1 in cows' milk from free-grazing cows in Abeokuta, Nigeria.  

PubMed

Aflatoxin M1 (AFM1) in milk from 100 different herds of free-grazing cows in Abeokuta, Nigeria, was analysed by immunoaffinity column cleanup and HPLC with fluorescence detection. AFM1 was found in 75 % of the samples, the toxin levels in positive samples ranged from 9.0 to 456.0 ng/l. The mean AFM1 level in positive samples was 108.15 ng/l, exceeding, for example, the European Union maximum level by a factor of two. These results indicated that there is an urgent need to more closely control the milk of free-grazing cows for AFM1 in order to protect the health of humans consuming milk and milk products. PMID:25033991

Oluwafemi, F; Badmos, A O; Kareem, S O; Ademuyiwa, O; Kolapo, A L

2014-11-01

307

[Ultrasonographic finding and treatment of a cow with pyelonephrosis].  

PubMed

Ultrasonography of a six-year-old Simmental cow revealed an abscess like structure, approximately 15 cm in diameter, in place of the right kidney. The cow had a history of colic for 4 days and was referred to our clinic with a tentative diagnosis of caecal dilatation. The cow voided dark opaque urine with white floccules. Laboratory examination yielded increased haematocrit, leukocytosis with left shift, hyperbilirubinaemia and azotaemia. The diagnosis was confirmed, the caecum emptied surgically and the pus-filled structure at the site of the right kidney removed. A diagnosis of pyonephrosis was made after pathological examination of the pus-filled structure. PMID:24973321

Lesser; Krüger; Nuss; Sydler; Braun

2014-07-01

308

Lymphocyte functions in dairy cows in hot environment  

NASA Astrophysics Data System (ADS)

This study was carried out to ascertain the effects of intense high environmental temperatures (HET) on lymphocyte functions in periparturient dairy cows. The study was undertaken from the beginning of March through the end of July 2003 in a commercial dairy unit located approximately 40 km north of Rome. Thirty-four Holstein cows were utilised in the study. Twenty-two of these cows gave birth in spring (SP cows), from 28 March to 30 April. The remaining 12 cows gave birth in summer (SU cows), between 15 June and 2 July. The two groups of cows were balanced for parity and were fed the same rations. Blood samples were taken 4, 3, 2 and 1 week before calving, and 1, 2 and 4 weeks after calving, in order to evaluate peripheral blood mononuclear cell (PBMC) function in vitro, and to determine plasma cortisol concentrations. After isolation, the PBMC were stimulated with mitogens and their response in terms of DNA synthesis and IgM secretion was measured. During spring, either the day (9 20 h) or the night (21 8 h) temperature humidity index (THI) was below the upper critical THI (72) established for dairy cows. During summer, the mean daily THI values were 79.5±2.9 during the day and 70.1±4.7 during the night. Furthermore, during summer, three heat waves (a period of at least 3 consecutive days during which there were less than 10 recovery hours) occurred. Recovery hours were intended hours with a THI below 72. The first heat wave lasted 5 days, the second 6 days, and the third 15 days. Compared to the SP cows, over the entire periparturient period the extent of DNA synthesis and IgM secretion levels were lower (P ranging from <0.01 to 0.0001) and higher (P<0.01) respectively, in the SU cows. Before calving, the SU cows also presented higher (P<0.01) concentrations of plasma cortisol compared to the SP cows. This study indicates that the effects of HET on the immune response depend on the specific immune function under consideration, and that neuroendocrinal changes due to HET may play a role in the perturbation of immune functions.

Lacetera, Nicola; Bernabucci, Umberto; Scalia, Daniela; Ronchi, Bruno; Kuzminsky, Giorgina; Nardone, Alessandro

2005-11-01

309

A mathematical model for the dynamics and synchronization of cows  

NASA Astrophysics Data System (ADS)

We formulate a mathematical model for the daily activities of a cow (eating, lying down, and standing) in terms of a piecewise linear dynamical system. We analyze the properties of this bovine dynamical system representing the single animal and develop an exact integrative form as a discrete-time mapping. We then couple multiple cow “oscillators” together to study synchrony and cooperation in cattle herds. We comment on the relevant biology and discuss extensions of our model. With this abstract approach, we not only investigate equations with interesting dynamics but also develop biological predictions. In particular, our model illustrates that it is possible for cows to synchronize less when the coupling is increased.

Sun, Jie; Bollt, Erik M.; Porter, Mason A.; Dawkins, Marian S.

2011-09-01

310

Adaptive SPECT  

PubMed Central

Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

2008-01-01

311

The influence of cow and management factors on reproductive performance of Irish seasonal calving dairy cows.  

PubMed

Herd management record analysis facilitates accurate assessment of the current herd reproductive status; a crucial decision making tool to implement effective change. To determine the relative importance of cow and management factors on reproductive indices in moderate-yielding Irish seasonal-calving dairy herds, breeding records of 1173 cows were collected from 10 seasonal calving herds between 2007 and 2009. Backward-stepwise multivariable logistic regression analysis was utilised to determine the effect of cow factors including parity, calving timing, days post partum, heat detection accuracy and herd factors including herd size and heat detection efficiency on key reproductive indices. Mean farm six-week pregnancy and end of season not-in-calf rate were 46% (range 14-72%) and 22% (range 3-40%), respectively. Oestrous detection efficiency (P<0.001), timing of calving (P<0.001) relative to start of breeding, history of abnormal repeat intervals (P<0.001) and length of post partum interval (P<0.001) were each associated with lower six-week pregnancy rates. Timing of calving (P<0.001) and history of abnormal repeat intervals (P<0.001) were associated with higher not-in-calf rates. Herd size and cow parity were not associated (P>0.05) with either outcome when factors including existing calving pattern and heat detection accuracy and efficiency were accounted for. The existing spread in calving pattern, heat detection quality and length of voluntary waiting period were the most influential factors that reduced fertility performance in seasonal-calving herds. PMID:23928154

Lane, Elizabeth A; Crowe, Mark A; Beltman, Marijke E; More, Simon J

2013-09-01

312

Adaptive Information Systems: From Adaptive Hypermedia to  

E-print Network

technologies can be applied? · How we can model the user in adaptive hypertext? #12;1/5/11 5 Do we need adaptation Adaptive hypermedia technologies Adaptive presentation Adaptive navigation support Direct guidance1/5/11 1 Adaptive Information Systems: From Adaptive Hypermedia to the Adaptive Web Peter

Brusilovsky, Peter

313

Adaptive Hypermedia  

Microsoft Academic Search

Adaptive hypermedia makes it possible to author learning material once and generate a personalized learning experience for\\u000a every user. The information that is presented, the way in which it is presented and the possible ways for the user to navigate\\u000a through it can all be adapted. This chapter presents the most common adaptive hypermedia methods and techniques and shows\\u000a examples

PME De Bra

2008-01-01

314

Adaptive Computing.  

ERIC Educational Resources Information Center

Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)

Harrell, William

1999-01-01

315

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

316

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

317

Metabolomics in plant environmental physiology.  

PubMed

Changes in plant metabolism are at the heart of plant developmental processes, underpinning many of the ways in which plants respond to the environment. As such, the comprehensive study of plant metabolism, or metabolomics, is highly valuable in identifying phenotypic effects of abiotic and biotic stresses on plants. When study is in reference to analysing samples that are relevant to environmental or ecologically based hypotheses, it is termed 'environmental metabolomics'. The emergence of environmental metabolomics as one of the latest of the omics technologies has been one of the most critically important recent developments in plant physiology. Its applications broach the entire landscape of plant ecology, from the understanding of plant plasticity and adaptation through to community composition and even genetic modification in crops. The multitude of novel studies published utilizing metabolomics methods employ a variety of techniques, from the initial stages of tissue sampling, through to sample preservation, transportation, and analysis. This review introduces the concept and applications of plant environmental metabolomics as an ecologically important investigative tool. It examines the main techniques used in situ within field sites, with particular reference to sampling and processing, and those more appropriate for use in laboratory-based settings with emphasis on secondary metabolite analysis. PMID:23922358

Brunetti, Cecilia; George, Rachel M; Tattini, Massimiliano; Field, Katie; Davey, Matthew P

2013-10-01

318

Physiology and psychology of dreams.  

PubMed

The discovery of the close association between rapid eye movement (REM) sleep and dreaming and development of sleep laboratory techniques ushered in a new era in the study of dreams. For the first time, direct and systematic investigation could be made of such topics as the occurrence, qualities, recollection, and childhood development of dreaming. Experimental methodologies permitted investigation of the responsiveness of dreams to external stimulation and the effects of deprivation of REM sleep. Much effort was devoted to searching for parallels between physiological aspects of REM sleep and characteristics of associated dreams, with modest results. The leading theory of dreaming in the early decades of this research was the psychoanalytic, which views dreams as highly meaningful reflections of unconscious mental functioning. With developments in understanding of the neurophysiology of REM sleep, new theories of dreaming were proposed. The most prominent, the activation-synthesis hypothesis, derived its view of dreaming directly from the neurophysiology of REM sleep, in particular the role of the brain stem, and in its original form regarded dreams as not essentially meaningful. Further developments in neurobiological research, including lesion and brain imaging studies, have established a clearer view of the functional neuroanatomy of REM sleep and dreaming. To what degree, and in what way, implications can be drawn from these findings for the psychology of dreaming is controversial. Some more recent theories of dreaming emphasize an adaptive function related to emotion and a role in learning and memory consolidation. PMID:15798942

Eiser, Alan S

2005-03-01

319

Physiology of the hormetic effect  

SciTech Connect

Beneficial (hormetic) effects of ionizing radiation have been largely ignored in developing radiobiological theory, chiefly because a suitable explanatory hypothesis is lacking. Examination of the relevant literature has revealed that food restriction effects in animals resemble those of low-level, low-LET, whole-body ionizing radiation exposure (without food restriction) in two major respects: increased longevity and change in the variance of longevity. These physiological changes can be interpreted as resulting from alteration of the steady-state flux of oxygen radicals which affect the endocrine balance. Oxy-radical-producing, low-level ionizing radiation exposure (whole body) is interpreted by the body as excess food intake, thus lowering the appetite and reducing caloric intake which, in turn, increases longevity. The greater variance in longevity accompanying increases in the median age at death with food restriction alters the ratio of long-lived to short-lived descendants and hastens the population's adaptation to semi-permanently diminished rates of food supply. Less variance and earlier mean ages at death result from an increased rate of food supply. Whole-body ionizing radiation exposure results in a mixed response, because it reduces caloric intake while signaling that an increase has occurred.

Totter, J.R.

1987-05-01

320

An examination of the prevalence of and risk factors for shedding of Cryptosporidium spp. and Giardia spp. in cows and calves from western Canadian cow–calf herds  

Microsoft Academic Search

The primary objectives of this study were to describe the prevalence and risk factors for Cryptosporidium spp. and Giardia spp. infection in cows and calves during the calving season in western Canadian cow–calf herds. Through the calving season of 2002, fresh fecal samples were collected from 560 beef cows and 605 calves in western Canada. Feces were examined for the

Sheryl Gow; Cheryl Waldner

2006-01-01

321

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. PMID:18822135

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

2008-01-01

322

Detection of cow milk adulteration in yak milk by ELISA.  

PubMed

In the current study, a simple, sensitive, and specific ELISA assay using a high-affinity anti-bovine ?-casein monoclonal antibody was developed for the rapid detection of cow milk in adulterated yak milk. The developed ELISA was highly specific and could be applied to detect bovine ?-casein (10-8,000?g/mL) and cow milk (1:1,300 to 1:2 dilution) in yak milk. Cross-reactivity was <1% when tested against yak milk. The linear range of adulterant concentration was 1 to 80% (vol/vol) and the minimum detection limit was 1% (vol/vol) cow milk in yak milk. Different treatments, including heating, acidification, and rennet addition, did not interfere with the assay. Moreover, the results were highly reproducible (coefficient of variation <10%) and we detected no significant differences between known and estimated values. Therefore, this assay is appropriate for the routine analysis of yak milk adulterated with cow milk. PMID:25151876

Ren, Q R; Zhang, H; Guo, H Y; Jiang, L; Tian, M; Ren, F Z

2014-10-01

323

Body Condition, Nutrition and Reproduction of Beef Cows  

E-print Network

Producers must be able to evaluate beef cows' body reserves and to relate the evaluation to reproductive and nutritional management. Topics discussed include the practical importance of body condition scoring and various BCS suggestions....

Herd, Dennis B.; Sprott, L. R.

1998-03-16

324

Fall and Winter Health Problems in Cow-Calf Herds  

E-print Network

Producers can prevent or minimize health problems in cow-calf herds in fall and winter by reducing the stresses caused by inadequate nutrition, sudden feeding changes and unsanitary conditions. This publication describes common health problems...

Faries Jr., Floron C.

2005-09-09

325

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

326

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

327

Calm temperament improves reproductive performance of beef cows.  

PubMed

Profitability of a beef operation is determined by the proportion of cows attaining pregnancy early in the breeding season and those that are pregnant at the end of breeding season. Many factors, including temperament, contribute to those reproductive parameters. The objective of this study was to evaluate effects of temperament on reproductive performance of beef cows. In Experiment 1, Angus and Angus-cross beef cows (n = 1546) from eight locations were assigned a body condition score (BCS; 1 = emaciated; 9 = obese) and chute exit and gait score (1 = slow exit, walk; calm temperament; 2 = jump, trot or run; excitable temperament). Cows were grouped with bulls (1 : 25 to 1 : 30; with satisfactory breeding potential and free of venereal disease) for an 85-day breeding season. Pregnancy status and stage of gestation were determined (transrectal palpation) 35 days after the end of the breeding season. Controlling for BCS (p < 0.01) and handling facility (p < 0.0001) and handling facility by temperament score interaction (p < 0.001), breeding season pregnancy rate was lower in excited versus calm cows [88.6% (798/901) vs 94.1% (607/645); p < 0.001]. Cows with an excitable temperament took 24 more days to become pregnant compared to calm cows (median days to pregnancy, 35 vs 59 days; p < 0.0001). In Experiment 2, Angus and Angus-cross beef cows (n = 1407) from 8 locations were assigned scores for body condition and chute exit and gait (as described in Experiment 1) and assigned to bulls (breeding sound and free of venereal disease; 1 : 25 to 1 : 30) for 85 days. Pregnancy status was determined by transrectal palpation at 2 and 6 months after the onset of the breeding season. Controlling for BCS (p < 0.05), pregnancy loss was higher in excited versus calm cows [5.5% (36/651) vs 3.2% (20/623), p < 0.0001]. In conclusion, beef cows with an excitable temperament had significantly lower reproductive performance than calmer cows. The modified two-point chute exit-gait scoring method was repeatable and identified cattle with an excitable temperament. PMID:25293406

Kasimanickam, R; Asay, M; Schroeder, S; Kasimanickam, V; Gay, Jm; Kastelic, Jp; Hall, Jb; Whittier, Wd

2014-12-01

328

Glucocorticoid receptor physiology  

Microsoft Academic Search

Glucocorticoid action in cells is mediated by a specific receptor protein, the glucocorticoid receptor (GR). GR is a member\\u000a of a superfamily of ligand-inducible transcription factors that control a variety of physiological functions; such as, metabolism,\\u000a development, and reproduction. Unliganded GR is predominantly localized within the cytoplasm but rapidly and efficiently translocates\\u000a to the nucleus following hormone binding. This review

Marjet D. Heitzer; Irene M. Wolf; Edwin R. Sanchez; Selma F. Witchel; Donald B. DeFranco

2007-01-01

329

Pavlov and integrative physiology.  

PubMed

Ivan Petrovich Pavlov was the first physiologist to win the Nobel Prize. The Prize was given in 1904 for his research on the neural control of salivary, gastric, and pancreatic secretion. A major reason for the success and novelty of his research was the use of unanesthetized dogs surgically prepared with chronic fistulas or gastric pouches that permitted repeated experiments in the same animal for months. Pavlov invented this chronic method because of the limitations he perceived in the use of acute anesthetized animals for investigating physiological systems. By introducing the chronic method and by showing its experimental advantages, Pavlov founded modern integrative physiology. This paper reviews Pavlov's journey from his birthplace in a provincial village in Russia to Stockholm to receive the Prize. It begins with childhood influences, describes his training and mentors, summarizes the major points of his research by reviewing his book Lectures on the Work of the Digestive Glands, and discusses his views on the relationship between physiology and medicine. PMID:10956230

Smith, G P

2000-09-01

330

Molecular biology in physiology  

SciTech Connect

The aim of this symposium on molecular biology in physiology was to introduce molecular biology to physiologists who had relatively little exposure to the new developments in this field, so that they can become conversant on this topic and contribute to the advancement of physiology by incorporating molecular biological approaches as a part of their research arsenal. This report is a review of the symposium, which consisted of two four-part sessions. Each session had four papers. After the discussion of the basic concepts, terminology, and methodology used in molecular biology, it was shown how these basic principles have been applied to the study of the genes encoding two membrane proteins that have important transport functions (band 3 and ATPase). The second half of the symposium consisted of papers on the state-of-the-art developments in the application of molecular biology to the studies of the atrial natriuretic factor and renin genes, adenylate cyclase-coupled adrenergic receptors, acetylcholine receptors and sodium channel, and long-term and short-term memories. The ultimate goal is that these examples will provide an impetus for the opening of new frontiers of research in physiology by taking advantage of the tools developed from recent advances in molecular biology.

Chien, S.; Gargus, J.J.

1987-08-01

331

Mammary Transfer of Vitamin E in Dairy Cows1  

Microsoft Academic Search

Milk vitamin E from eight dairy cows was analyzed for vitamin E by HPLC during the 1st mo of lactation. Colostrum gave a mean value of 1.9 gg a-tocoph- erol\\/ml while concentrations of fresh milk averaged .3 ktg ~-tocopherol\\/ml. D-~ tocopherol concentrations were observed in very small amounts. When six cows at the end of the 1st mo of lactation

M. Hidiroglou

1989-01-01

332

The environmental physiology of Antarctic terrestrial nematodes: a review  

Microsoft Academic Search

The environmental physiology of terrestrial Antarctic nematodes is reviewed with an emphasis on their cold-tolerance strategies. These nematodes are living in one of the most extreme environments on Earth and face a variety of stresses, including low temperatures and desiccation. Their diversity is low and declines with latitude. They show resistance adaptation, surviving freezing and desiccation in a dormant state

D. A. Wharton

2003-01-01

333

MPTrain: A Mobile, Music and Physiology-Based Personal Trainer  

E-print Network

, 1, 12]. The overwhelming majority of previous research points to very positive effects of music, performance perception and perceived exertion levels are positively influenced by music versus non-music of music on physiology and physical ac- tivity in an adaptive and real-time manner. During our background

Jepson, Allan D.

334

A Physiologically-based Model for Methylmercury Uptake and Accumulation in Female American Kestrels  

EPA Science Inventory

A physiologically-based model was developed to describe the uptake, distribution, and elimination of methylmercury in female American Kestrels (Falco sparverius). The model was adapted from established models for methylmercury in rodents. Features unique to the model include meth...

335

Dye marked antibiotics in dry cow mastitis therapy.  

PubMed

Eight dry cow dye/antibiotic preparations were used to determine dye and antibiotic excretion endpoints. Formulations contained 400 mg of novobiocin with 25 or 250 mg Food Drug and Cosmetic Blue No. 1 per infusion or 400 mg novobiocin plus 200,000 IU penicillin with 25, 125, or 250 mg Blue No. 1 or 2 dye per infusion. Fifty-two cows entering their second or later lactations were treated in two or four quarters. Milk was sampled postpartum and tested for residues. Dye content was determined visually and subvisually. Antibiotic content was analyzed by the cylinder plate, or Delvotest-P, or by both methods. One sample contained penicillin residues. Three samples had visual dye content of Blue No. 1. Blue No. 2 was not detected. Subvisual dye was detected for one to four milkings in most cows treated with preparations containing Blue No. 1. Cows were treated within 1 to 7 d prepartum with novobiocin plus penicillin containing 250 mg Blue No. 1. Visual dye persisted from 3 to 15 milkings postpartum and subvisual dye for one to two milkings longer. Penicillin was present in postpartum milk in five of seven cows. Novobiocin persisted in three of seven cows. PMID:3722533

Gilmore, T M; Ellefson, R A; Parsons, J G

1986-04-01

336

Determinants of estrous behavior in lactating Holstein cows.  

PubMed

The objective was to determine factors that affect the expression of estrus. Thirteen lactating Holstein cows were ovariectomized about 4 to 6 wk postpartum and then challenged repeatedly with progesterone and estradiol benzoate to induce estrus six times during the postpartum period. Each challenge included 5 d when the cow was primed with progesterone through insertion of a progesterone-impregnated, foam rubber pessary. Estradiol benzoate (1 mg) was injected intramuscularly 36 h after removal of the pessary. Groups of two to three cows each began the experiment at 3-mo intervals to avoid confounding treated simultaneously. Observations for estrous behavior were at 8-h intervals following each challenge. A minimum of three sexually active cows were always observed together to avoid differences in estrous behavior caused by having too few sexually active animals in the group. Observations for estrous behavior were at 8-h intervals following each challenge. During each observation, cows were observed for 30 min on dirt and for 30 min on concrete. Standing behavior was not influenced by postpartum interval, season of year, or milk yield. Mounting behavior increased from the first to the sixth postpartum challenge, but it was not affected by season of year or milk yield. Duration of estrus, mounting activity, and standing activity were greater on dirt than on concrete. These results indicate that the surface on which cows were observed had a profound effect on sexual behavior; however, postpartum interval, season of year, and milk yield were of minor importance. PMID:3760306

Britt, J H; Scott, R G; Armstrong, J D; Whitacre, M D

1986-08-01

337

Serum zinc concentration in exclusively breast-fed infants and in infants fed an adapted formula  

Microsoft Academic Search

Serum zinc concentrations have been determined in 28 healthy full-term Italian infants of both sexes at birth, as well as at 3 and at 5 months of age. Fourteen exclusively breast-fed infants who served as a control group were compared with 14 infants fed a cow's milk based adapted infant formula. No significant differences in serum zinc concentration between the

V. Vigi; R. Chierici; L. Osti; F. Fagioli; R. Reseazzi

1984-01-01

338

Water salinity effects on performance and rumen parameters of lactating grazing Holstein cows  

NASA Astrophysics Data System (ADS)

Eighteen multiparous lactating grazing Holstein cows, 9 ruminally cannulated, average 136.1 ± 14.6 days in milk, were randomly assigned to three treatments consisting of water containing different levels of total dissolved solids (TDS; mg/l): Treatment 1 = 1,000; Treatment 2 = 5,000 and Treatment 3 = 10,000, at the Experimental Dairy Unit at Rafaela Experimental Station (31°11'S latitude) during summer 2005. Animals were arranged in a randomized complete block design with three 28-day experimental periods, with 3 weeks for water adaptation and 1 week for measurements. Feed and water intake, milk production and composition, body weight and condition score and rumen parameters were evaluated. No treatment effects were observed in any of the variables evaluated, with the exception of water intake, which was higher for animals receiving 10,000 mg/l TDS in the drinking water (189 l/day vs. 106 and 122 l/day for cows receiving water with 1,000 and 5,000 mg/l TDS, respectively). Water intake was significantly higher for animals in treatment 10,000 ( P < 0.05). It was concluded that the rumen presents a surprising buffer capacity and that consideration of TDS alone is insufficient to characterize drinking water quality.

Valtorta, Silvia E.; Gallardo, Miriam R.; Sbodio, Oscar A.; Revelli, Germán R.; Arakaki, Cristina; Leva, Perla E.; Gaggiotti, Mónica; Tercero, Esteban J.

2008-01-01

339

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. PMID:25049979

Song, D. J.; Kang, H. Y.; Wang, J. Q.; Peng, H.; Bu, D. P.

2014-01-01

340

Age-related shifts in the density and distribution of genetic marker water quality indicators in cow and calf feces.  

PubMed

Calves make up about 16% of the current bovine population in the United States and can excrete high levels of human pathogens in their feces. We describe the density and distribution of genetic markers from 9 PCR- and real-time quantitative PCR-based assays, including CF128, CF193, CowM2, CowM3, GenBac3, Entero1, EC23S857, CampF2, and ttr-6, commonly used to help assess ambient surface water quality. Each assay was tested against a collection of 381 individual bovine fecal samples representing 31 mother and calf pairings collected over a 10-month time period from time of birth through weaning. Genetic markers reported to be associated with ruminant and/or bovine fecal pollution were virtually undetected in calves for up to 115 days from birth, suggesting that physiological changes in calf ruminant function impact host-associated genetic marker shedding. In addition, general fecal indicator markers for Bacteroidales, Escherichia coli, and Enterococcus spp. exhibited three separate trends across time, indicating that these bacteria respond differently to age-related physiological and dietary changes during calf development. The results of this study suggest that currently available PCR-based water quality indicator technologies can under- or overestimate fecal pollution originating from calves and identify a need for novel calf-associated source identification methods. PMID:24362434

Shanks, Orin C; Kelty, Catherine A; Peed, Lindsay; Sivaganesan, Mano; Mooney, Thomas; Jenkins, Michael

2014-03-01

341

Fertilization and Early Embryonic Development in Heifers and Lactating Cows in Summer and Lactating and Dry Cows in Winter  

Microsoft Academic Search

Two experiments in two seasons evaluated fertiliza- tion rate and embryonic development in dairy cattle. Experiment 1 (summer) compared lactating Holstein cows (n = 27; 97.3 ± 4.1 d postpartum (dpp); 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;

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

2002-01-01

342

PHYSIOLOGY BY ACTING OUT CONCEPTS  

Microsoft Academic Search

ypically, classes in anatomy and physiology are taught via lecture and visual aids. This seems to work well for students who are primarily auditory and visual learners but not for those who learn better through kinesthetic experiences. This is the first report describing the use of improvisation to act out physiological concepts within an anatomy and physiology course. Improvisational techniques

Carolyn B. Yucha

343

Physiological Adaptation of the Cardiovascular System to High Altitude  

Microsoft Academic Search

Altitude exposure is associated with major changes in cardiovascular function. The initial cardiovascular response to altitude is characterized by an increase in cardiac output with tachycardia, no change in stroke volume, whereas blood pressure may temporarily be slightly increased. After a few days of acclimatization, cardiac output returns to normal, but heart rate remains increased, so that stroke volume is

Robert Naeije

2010-01-01

344

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. PMID:18535297

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

345

Physiology, metabolism Adaptation of Lactobacillus sakei to meat  

E-print Network

sakei is a lactic acid bacterium commonly found on meat and meat products. Meat is a rich substrate is then metabolized through the pentose-P pathway involving xylulose-5P phosphoketolase and acetate kinase. Whereas phosphoketolase and acetate kinase activities remained unchanged in L. sakei ptsI mutants, ribose kinase activity

Boyer, Edmond

346

Physiological effects of melatonin: Role of melatonin receptors and signal transduction pathways  

Microsoft Academic Search

Melatonin, an endogenous signal of darkness, is an important component of the body's internal time-keeping system. As such it regulates major physiological processes including the sleep wake cycle, pubertal development and seasonal adaptation. In addition to its relevant antioxidant activity, melatonin exerts many of its physiological actions by interacting with membrane MT1 and MT2 receptors and intracellular proteins such as

Seithikurippu R. Pandi-Perumal; Ilya Trakht; Venkataramanujan Srinivasan; D. Warren Spence; Georges J. M. Maestroni; Nava Zisapel; Daniel P. Cardinali

2008-01-01

347

Animals must use physiological mechanisms to cope with novel toxins in the environment when behavioral avoidance  

E-print Network

a novel food source). There are four possible ways to adapt physiologically to a novel toxin the chemical into something less harmful or that can be handled by physiological systems already in place in their larval food. This system mimics natural circumstances in which toxins are unavoidable, because fruitfly

Ahmad, Sajjad

348

In vitro and Lactation Responses in Mid-lactating Dairy Cows Fed Protected Amino Acids and Fat  

PubMed Central

The objective of this study was to evaluate the effect of ruminally protected amino acids (RPAAs) and ruminally protected fat (RPF) supplementation on ruminal fermentation characteristics (in vitro) and milk yield and milk composition (in vivo). Fourteen mid-lactating Holstein dairy cows (mean weight 653±62.59 kg) were divided into two groups according to mean milk yield and number of days of postpartum. The cows were then fed a basal diet during adaptation (2 wk) and experimental diets during the treatment period (6 wk). Dietary treatments were i) a basal diet (control) and ii) basal diet containing 50 g of RPAAs (lysine and methionine, 3:1 ratio) and 50 g of RPF. In rumen fermentation trail (in vitro), RPAAs and RPF supplementation had no influence on the ruminal pH, dry matter digestibility, total volatile fatty acid production and ammonia-N concentration. In feeding trial (in vivo), milk yield (p<0.001), 4% fat corrected milk (p<0.05), milk fat (p<0.05), milk protein (p<0.001), and milk urea nitrogen (p<0.05) were greater in cows fed RPAAs and RPF than the corresponding values in the control group. With an index against as 0%, the rates of decrease in milk yield and milk protein were lower in RPAAs and RPF treated diet than those of basal diet group (p<0.05). In conclusion, diet supplemented with RPAAs and RPF can improve milk yield and milk composition without negatively affecting ruminal functions in Holstein dairy cows at mid-lactating. PMID:25358363

Nam, I. S.; Choi, J. H.; Seo, K. M.; Ahn, J. H.

2014-01-01

349

Physiology of iron metabolism.  

PubMed

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. PMID:25053935

Waldvogel-Abramowski, Sophie; Waeber, Gérard; Gassner, Christoph; Buser, Andreas; Frey, Beat M; Favrat, Bernard; Tissot, Jean-Daniel

2014-06-01

350

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. PMID:19843168

Kreit, Joseph; Sampson, Nicole S.

2009-01-01

351

Pioneering in gravitational physiology  

NASA Technical Reports Server (NTRS)

Gravity affects biology at almost all levels above that of the cell organelle. Attention is presently given to progress made in the understanding of gravitational effects through studies employing centrifuges, clinostats, inverted preparations, linear devices, water immersion, free fall, and short- and long-term spaceflight. The cardiovascular changes which cause malaise and illness during the first few days of extended space missions are the direct result of fluid translocation from the lower extremities. Upon reentry, there is hypovolumnia and a cardiovascular deconditioning that can include tachycardia, changes in arterial blood pressure, narrow pulse pressure, and syncope. Attention is also given to NASA's gravitational physiology reseach program.

Soffen, G. A.

1983-01-01

352

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.

Cabrera, Marco E.; Coon, Jennifer E.; Kalhan, Satish C.; Radhakrishnan, Krishnan; Saidel, Gerald M.; Stanley, William C.

2000-01-01

353

Network Physiology: Mapping Interactions Between Networks of Physiologic Networks  

NASA Astrophysics Data System (ADS)

The human organism is an integrated network of interconnected and interacting organ systems, each representing a separate regulatory network. The behavior of one physiological system (network) may affect the dynamics of all other systems in the network of physiologic networks. Due to these interactions, failure of one system can trigger a cascade of failures throughout the entire network. We introduce a systematic method to identify a network of interactions between diverse physiologic organ systems, to quantify the hierarchical structure and dynamics of this network, and to track its evolution under different physiologic states. We find a robust relation between network structure and physiologic states: every state is characterized by specific network topology, node connectivity and links strength. Further, we find that transitions from one physiologic state to another trigger a markedly fast reorganization in the network of physiologic interactions on time scales of just a few minutes, indicating high network flexibility in response to perturbations. This reorganization in network topology occurs simultaneously and globally in the entire network as well as at the level of individual physiological systems, while preserving a hierarchical order in the strength of network links. Our findings highlight the need of an integrated network approach to understand physiologic function, since the framework we develop provides new information which can not be obtained by studying individual systems. The proposed system-wide integrative approach may facilitate the development of a new field, Network Physiology.

Ivanov, Plamen Ch.; Bartsch, Ronny P.

354

Short communication: Lameness impairs feeding behavior of dairy cows.  

PubMed

The automated, reliable, and early detection of lameness is an important aim for the future development of modern dairy operations. One promising indicator of lameness is a change in the feeding behavior of a cow. In this study, the associations between feeding behavior and lameness were evaluated. A herd of 50 cows was investigated during the winter season in a freestall barn. Feeding behavior, feed intake, milk yield, and body weight were monitored using electronic feeding troughs and an automated milking system. Gait scoring every second week was used as a measure of lameness. To analyze the effect of lameness on feeding behavior and milk yield, linear mixed models were used. Cows with more severe lameness spent less time feeding per day (104 ± 4, 101 ± 4, and 91 ± 4 min/d for lameness scores 2, 3, and 4, respectively). An interaction between parity and lameness score was detected, with severely lame primiparous cows spending the least time feeding. Severely lame cows fed faster; however, their body weights were lower than for less-lame cows. Increase in lactation stage was associated with longer daily feeding time, longer duration of feeding bouts, and lower feeding rate. Worsening of gait was associated with lower silage intake and less time spent feeding even before severe lameness was scored. The results indicate that lameness is associated with changes in feeding behavior and that such changes could be considered in the future development of remote monitoring systems. It should also be noted that impaired feeding behavior along with lameness can put the welfare of especially early lactating primiparous cows at risk. PMID:24792807

Norring, M; Häggman, J; Simojoki, H; Tamminen, P; Winckler, C; Pastell, M

2014-07-01

355

Social interactions affecting caste development through physiological actions in termites  

PubMed Central

A colony of social insects is not only an aggregation of individuals but also a functional unit. To achieve adaptive social behavior in fluctuating environmental conditions, in addition to coordination of physiological status in each individual, the whole colony is coordinated by interactions among colony members. The study on the regulation of social-insect colonies is termed “social physiology.” Termites, a major group of social insects, exhibit many interesting phenomena related to social physiology, such as mechanisms of caste regulation in a colony. In their colonies, there are different types of individuals, i.e., castes, which show distinctive phenotypes specialized in specific colony tasks. Termite castes comprise reproductives, soldiers and workers, and the caste composition can be altered depending on circumstances. For the regulation of caste compositions, interactions among individuals, i.e., social interactions, are thought to be important. In this article, we review previous studies on the adaptive meanings and those on the proximate mechanisms of the caste regulation in termites, and try to understand those comprehensively in terms of social physiology. Firstly, we summarize classical studies on the social interactions. Secondly, previous studies on the pheromone substances that mediate the caste regulatory mechanisms are overviewed. Then, we discuss the roles of a physiological factor, juvenile hormone (JH) in the regulation of caste differentiation. Finally, we introduce the achievements of molecular studies on the animal sociality (i.e., sociogenomics) in terms of social physiology. By comparing the proximate mechanisms of social physiology in termites with those in hymenopterans, we try to get insights into the general principles of social physiology in social animals. PMID:24782780

Watanabe, Dai; Gotoh, Hiroki; Miura, Toru; Maekawa, Kiyoto

2014-01-01

356

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. PMID:18837079

Esteller, Alejandro

2008-01-01

357

A dual adaptive control theory inspired by Hebbian associative learning  

E-print Network

Hebbian associative learning is a common form of neuronal adaptation in the brain and is important for many physiological functions such as motor learning, classical conditioning and operant conditioning. Here we show that ...

Poon, Chi-Sang

358

Hyperplastic goiter in two adult dairy cows.  

PubMed

Iodine excess and resultant hyperplastic goiter are well documented in neonatal ruminants, but little is reported on iodine excess in adult ruminants and associated histological changes of the thyroid gland. Two adult Holstein cows from a Michigan dairy herd that had lost several other animals had nonspecific clinical signs of illness and were submitted for necropsy. Thyroid glands of one of these 2 animals were grossly and markedly enlarged, and histologically, thyroid glands from both animals had regions of cystic nodular hyperplasia and follicular atrophy. Thyroid glands from both animals had markedly elevated iodine concentrations. Investigation into the potential source of excessive iodine on the farm revealed multiple sources of supplemental dietary iodine and probable uneven feed and mineral mixing. Based on the findings of this investigation, adult cattle could be susceptible to excessive doses of iodine. Possibility of previous iodine deficiency before supplementation period, with subsequent development and persistence of thyroid hyperplasia and cystic change, cannot be completely excluded. Current findings suggested that iodine excess in adult cattle can result in nodular hyperplastic goiter. Use of iodized salt in mineral supplements in adult dairy herds is common practice, and accidental excessive iodine supplement may be more common than reported. Recognizing gross and histological thyroid gland changes, consisting of concurrent cystic follicular hyperplasia, atrophy, and fibrosis should raise suspicion of iodine excess and/or prior deficiency in a cattle herd, and ancillary tests such as serum iodine measurements should be part of the diagnostic workup in suspected cases. PMID:25292195

Ong, Chee Bing; Herdt, Thomas H; Fitzgerald, Scott D

2014-11-01

359

Slaughterhouse survey of pyelonephritis in dairy cows.  

PubMed

Twenty-one rejected kidneys from 2426 slaughtered dairy cows (0.87 per cent) had gross signs of pyelonephritis that were confirmed by histopathology. In all the kidneys the findings were consistent with a chronic rather than an acute infection. One species of bacteria was cultured from 12 of the kidneys and two species of bacteria were cultured from six. The most commonly isolated bacteria were Escherichia coli, from eight kidneys, Arcanobacterium pyogenes, from seven kidneys and Corynebacterium renale, from five kidneys. The other bacteria cultured were Corynebacterium cystitidis, Corynebacterium species, Streptococcus species group G and Enterococcus faecalis. E. coli was cultured from all the kidneys from which two species were isolated; the accompanying bacteria were A. pyogenes in three kidneys, C. renale in two and C. cystitidis in one. No bacteria were cultured from two of the kidneys and no significant bacteria were cultured from another. The kidneys with pyelonephritis were slightly larger than a comparison group of 72 kidneys without nephritis. PMID:16299366

Rosenbaum, A; Guard, C L; Njaa, B L; McDonagh, P L; Schultz, C A; Warnick, L D; White, M E

2005-11-19

360

A regional analysis of U.S. utility slaughter cows prices  

E-print Network

This study investigated the effects of Utility slaughter cow supply, lagged prices, per capita disposable personal income, prime interest rates, price of wholesale Utility beef, seasonality and yearly effects on the price of Utility slaughter cows...

Rogers, Toby Gale

2012-06-07

361

Induced hyperketonemia affects the mammary immune response during lipopolysaccharide challenge in dairy cows.  

PubMed

Metabolic adaptations during negative energy and nutrient balance in dairy cows are thought to cause impaired immune function and hence increased risk of infectious diseases, including mastitis. Characteristic adaptations mostly occurring in early lactation are an elevation of plasma ketone bodies and free fatty acids (nonesterified fatty acids, NEFA) and diminished glucose concentration. The aim of this study was to investigate effects of elevated plasma ?-hydroxybutyrate (BHBA) at simultaneously even or positive energy balance and thus normal plasma NEFA and glucose on factors related to the immune system in liver and mammary gland of dairy cows. In addition, we investigated the effect of elevated plasma BHBA and intramammary lipopolysaccharide (LPS) challenge on the mammary immune response. Thirteen dairy cows were infused either with BHBA (HyperB, n=5) to induce hyperketonemia (1.7 mmol/L) or with a 0.9% saline solution (NaCl, n=8) for 56 h. Two udder quarters were injected with 200 ?g of LPS after 48 h of infusion. Rectal temperature (RT) and somatic cell counts (SCC) were measured before, at 48 h after the start of infusions, and hourly during the LPS challenge. The mRNA abundance of factors related to the immune system was measured in hepatic and mammary tissue biopsies 1 wk before and 48 h after the start of the infusion, and additionally in mammary tissue at 56 h of infusion (8h after LPS administration). At 48 h of infusion in HyperB, the mRNA abundance of serum amyloid A (SAA) in the mammary gland was increased and that of haptoglobin (Hp) tended to be increased. Rectal temperature, SCC, and mRNA abundance of candidate genes in the liver were not affected by the BHBA infusion until 48 h. During the following LPS challenge, RT and SCC increased in both groups. However, SCC increased less in HyperB than in NaCl. Quarters infused with LPS showed a more pronounced increase of mRNA abundance of IL-8 and IL-10 in HyperB than in NaCl. The results demonstrate that an increase of plasma BHBA upregulates acute phase proteins in the mammary gland. In response to intramammary LPS challenge, elevated BHBA diminishes the influx of leukocytes from blood into milk, perhaps by via modified cytokine synthesis. Results indicate that increased ketone body plasma concentrations may play a crucial role in the higher mastitis susceptibility in early lactation. PMID:24239080

Zarrin, M; Wellnitz, O; van Dorland, H A; Bruckmaier, R M

2014-01-01

362

Supplemental methionine and urea for gestating beef cows consuming low quality forage diets.  

PubMed

A study was conducted to evaluate Met requirements of late-gestation beef cows consuming low quality forages on the premise that inadequate supply of metabolizable AA may limit protein accretion during pregnancy. Five ruminally cannulated, multiparous late-gestation beef cows (490 +/- 27 kg), of predominantly Angus (> or =75%) with Hereford and Simmental breeding, were used in a 5 x 5 Latin square experiment to evaluate the effects of postruminal dl-Met supplementation on N retention, serum metabolites, and plasma AA concentrations during the third trimester of pregnancy. The basal diet was fed individually, and weights of refusals were recorded for N intake determination. Treatments consisted of no urea, urea (0.053 +/- 0.002 g/kg of BW daily), urea + 5 g of Met/d, urea + 10 g of Met/d, and urea + 15 g of Met/d. Cows were adapted to the experimental diet 30 d before the beginning of the study, with periods lasting for 14 d; 4 d to allow for clearance of the previous treatment effects, 4 d for adaptation to the treatments, and 6 d for total fecal and urine collection. Blood samples were collected every 4 h on d 13 of each period for analysis of serum metabolites and plasma AA. Inclusion of urea increased DM and OM intakes (urea vs. no urea; P = 0.05), but no further improvement in intake was observed with inclusion of Met. Serum urea concentrations increased with inclusion of urea (P = 0.03) and responded quadratically (P = 0.06) when Met was added, with the lowest concentration observed in the urea + 5 g of Met/d treatment. More N was retained with the inclusion of urea (P = 0.04), and N retention increased linearly (P = 0.07) with inclusion of Met. Plasma Met concentration increased linearly (P < 0.01) with inclusion of Met. These data suggest that Met was a limiting AA and that supplementation of a combination of urea and 5 g/d of rumen-protected Met to low quality, forage diets will improve N retention and promote protein accretion during late pregnancy. PMID:17060412

Waterman, R C; Löest, C A; Bryant, W D; Petersen, M K

2007-03-01

363

Quarter, cow, and farm risk factors for intramammary infections with major pathogens relative to minor pathogens in Thai dairy cows.  

PubMed

A cross-sectional study was carried out from May to September 2011 on 35 smallholder dairy farms in Chiang Mai, Thailand, to identify the quarter, cow, and farm factors that relate to intramammary infections (IMI) from major specified pathogens, compared to infections from minor pathogens. Data on general farm management, milking management, and dry cow management were recorded for each herd. Quarter milk samples were collected from either clinical or subclinical mastitis quarters. Dependent variables were binary data defining the specified major pathogens, including Streptococcus agalactiae (7.1 %), Streptococcus uberis (9.4 %), Streptococcus dysgalactiae (4.0 %), and other streptococci (16.7 %), as a case, and all minor pathogens as a control, in each dependent variable. The occurrence of S. agalactiae IMI was lower in first-parity cows and cows with short milking time. Cows with body condition score (BCS) <2.5 had higher occurrence of S. agalactiae IMI. The occurrence of S. uberis IMI was higher in quarters with California mastitis test (CMT) score 2, score 3, and having clinical mastitis and in farms with increasing age of vacuum system. Quarters with CMT score 3, having clinical mastitis, cow with manual milking after detaching milking cluster, and farms with high bulk milk somatic cell counts (BMSCC >500,000 cells/ml) had higher occurrence of S. dysgalactiae IMI. For other streptococci, quarters having clinical mastitis, BCS <2.5, and pulling down of milking cluster while milking increased occurrence of other streptococci IMI relative to minor pathogen IMI. These results highlight the importance of individual cow factors, milking characteristics, and BMSCC in determining the risk of IMI from major pathogens. PMID:24823898

Leelahapongsathon, Kansuda; Schukken, Ynte Hein; Suriyasathaporn, Witaya

2014-08-01

364

Heterosis and heterosis retention for reproductive and maternal traits in Brahman - British crossbred cows  

E-print Network

.............................................. 50 Table 22. Unadjusted means, standard deviations, and numbers of observations for calf survival by breed group and age of cow.................................... 52 Table 23. Least squares means and standard errors for calf survival by cow... crossbred females that exceeded those of first generation cows. Morris et al. (1986) concluded that epistatic effects for birth weight, weaning weight, and preweaning gain were not significant in a group of Angus x Hereford cows in New Zealand. Much...

Key, Kelli Loren

2005-02-17

365

[Physiological changes in microgravity].  

PubMed

Microgravity affects the different organ systems to various degrees. In particular, a thoracocephalic fluid shift occurs through suppression of the hydrostatic gradient. Sensory conflict leads to space motion sickness, which is frequent early in the flight, and the musculo-skeletal system is perturbed by the lack of stimuli. The respiratory system seems to be less affected. These changes do not seem to impair health or performance. Humans seem able to adapt to long-term exposure to microgravity, but disorders can occur on return to Earth. In-flight preventive measures need be developed. PMID:20669641

Riviere, Daniel

2009-10-01

366

Invited Review: Production and Digestion of Supplemented Dairy Cows on Pasture  

Microsoft Academic Search

Literature with data from dairy cows on pasture was reviewed to evaluate the effects of supplementation on intake, milk production and composition, and ruminal and postruminal digestion. Low dry matter intake (DMI) of pasture has been identified as a major factor limiting milk production by high producing dairy cows. Pasture DMI in grazing cows is a function of grazing time,

F. Bargo; L. D. Muller; E. S. Kolver; J. E. Delahoy

2003-01-01

367

A SILENT HYPOCUPREMIC CONDITION IN BEEF COWS FED GRASS SILAGE AND THE EFFICACY OF SEQUESTERED COPPER  

E-print Network

A SILENT HYPOCUPREMIC CONDITION IN BEEF COWS FED GRASS SILAGE AND THE EFFICACY OF SEQUESTERED advantages over hay- making, its use exclusively as a maintenance diet for beef cows has been associated in pregnant beef cows fed grass silage was also evaluated in the present study. Materials and Methods Three

Paris-Sud XI, Université de

368

Influence of Corn Processing and Frequency of Feeding on Cow Performance1,2  

Microsoft Academic Search

Twenty cows, including five fitted with rumen cannu- lae, were used to study the influence of corn processing and frequency of feeding on milk yield and ruminal fermentation characteristics. Cows were assigned to five treatments in a 5 × 5 Latin square experiment. Each period was 3 wk. Cows were fed 45% forage and 55% grain in a total mixed

T. R. Dhiman; M. S. Zaman; I. S. MacQueen; R. L. Boman

2002-01-01

369

Improving Energy Supply to Late Gestation and Early Postpartum Dairy Cows  

Microsoft Academic Search

Sixty-five multiparous Holstein cows were used to test the effects of feeding diets of varied ruminal carbohydrate availability during the transition period on dry matter intake, blood metabolites, and lacta- tional performance. Cows received total mixed rations containing either cracked corn or steam-flaked corn beginning 28 d prior to expected calving date. At parturition, cows were assigned to a postpartum

H. M. Dann; G. A. Varga; D. E. Putnam

1999-01-01

370

Heterosis for Lifetime Production in Hereford, Angus, Shorthorn, and Crossbred Cows  

Microsoft Academic Search

The effects of maternal heterosis and maternal and grandmaternal breed effects on cumulative lifetime number and weight of calves weaned per cow entering the breeding herd were evaluated for 172 reciprocal crossbred and 156 straightbred cows of the Hereford, Angus, and Shorthorn breeds. Cows born in 1960 and 1961 were developed and mated to calve first at 3 yr of

Larry V. Cundiff; R. Nuiiez-Dorninguezft; Gordon E. Dickerson; Keith E. Gregory; Robert M. Koch; Roman L. Hruska

2010-01-01

371

Detection of cow milk in cooked buffalo Mozzarella used as Pizza topping  

Microsoft Academic Search

One of the most popular worldwide meals is Pizza. Among the main ingredients, buffalo or cow Mozzarella are the cheeses most widely used. Different prices between buffalo and cow Mozzarella can stimulate frauds but it is unknown whether the European official method can differentiate Mozzarella from cow or buffalo milk after oven cooking when used as a Pizza topping. Preliminary

F. Locci; R. Ghiglietti; S. Francolino; R. Iezzi; V. Oliviero; A. Garofalo; G. Mucchetti

2008-01-01

372

Minerals to Dairy Cows with Focus on Calcium and Magnesium Balance  

E-print Network

Minerals to Dairy Cows with Focus on Calcium and Magnesium Balance Cecilia Kronqvist Faculty;Minerals to Dairy Cows with Focus on Calcium and Magnesium Balance Abstract Both clinical and subclinical deficiency of calcium and magnesium may cause problems in dairy cows. Clinical hypocalcaemia most commonly

373

MODELLING RADIOIODINE DYNAMICS Modelling the Dynamics of Radioiodine in Dairy Cows  

E-print Network

MODELLING RADIOIODINE DYNAMICS Modelling the Dynamics of Radioiodine in Dairy Cows N. M. J. CROUT, dairy cows)15 16 17 Abbreviation Key: ECF = Extra Cellular Fluid.18 19 #12;INTRODUCTION1 Isotopes if they are to be used in any aspect of radiological8 protection.9 In the case of radioiodine transfer within dairy cows

Crout, Neil

374

Antigenicity for Humans of Cow Milk Caseins, Casein Hydrolysate and Casein Hydrolysate Fractions  

Microsoft Academic Search

Nentwich I., Szépfalusi Zs., Kunz C., Spuergin P., Urbanek R.: Antigenicity for Humans of Cow Milk Caseins, Casein Hydrolysate and Casein Hydrolysate Fractions. Acta Vet. Brno 2004, 73: 291-298. Cow milk casein consists of several fractions each of which have different structure and differing antigenicity. The aim of the study was to investigate the capacity of cow milk casein, casein

I. NENTWICH; Z. S. SZÉPFALUSI; C. KUNZ; P. SPUERGIN; R. URBANEK

2004-01-01

375

Effect of level of nitrogen fertilization and protein supplementation on herbage utilization by grazing dairy cows.  

E-print Network

by grazing dairy cows. I. Herbage intake and feeding behaviour JL Peyraud, L Astigarraga, P Faverdin, L meal (1 kg pro- tected cake) (SBM) supplementation when cows grazed the LN sward (LN + S treatment). The sward was strip grazed at a high daily herbage allowance of 28 kg OM/cow (cut by motor scythe). Each

Paris-Sud XI, Université de

376

Effects of herbage allowance on performances of dairy cows grazing alfalfa swards  

E-print Network

Effects of herbage allowance on performances of dairy cows grazing alfalfa swards E Comer�n L sward, herbage allowance (HA) greatly affect milk production and herbage intake by grazing dairy cows of HA when cows grazed pure alfalfa swards. Three levels of daily herbage allowance : 100 (SG10), 20 (SG

Paris-Sud XI, Université de

377

Short communication: Genetic relationships between the Holstein cow populations of three European dairy countries  

Microsoft Academic Search

The degree of relatedness was studied in 3 dairy cow populations from Great Britain (GBR), Italy (ITA), and Ireland (IRL) by using cows born from 2003 to 2006. Effective population size, inbreeding coefficient (F), and average relationship in the top and bottom 4,000 cows ranked on a profit index value (PIV) or milk yield evaluations were studied. Average inbreeding was

R. Mrode; J. F. Kearney; S. Biffani; M. Coffey; F. Canavesi

2009-01-01

378

Adaptive Development  

NASA Technical Reports Server (NTRS)

The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

2005-01-01

379

Human Physiological Responses to Acute and Chronic Cold Exposure  

NASA Technical Reports Server (NTRS)

When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

2001-01-01

380

Adaptive optics  

NASA Technical Reports Server (NTRS)

An estimation of the costs and potential resolution and sensitivity benefits of adaptive optics systems is presented. The effects of atmospheric disturbances on the peak-to-peak wavefront errors are assessed. Definitions are included of the maximum permissible controlled patch of entrance pupil of the system, the permissible response time, the permissible field radius, and the required magnitude and frequency of a reference star. It is pointed out that adaptive optics system for visible of near-visible wavelengths is likely to be very expensive, whereas operation at 2-3 microns under best seeing conditions is expected to be useful and have reasonable cost.

Woolf, N. J.

1984-01-01

381

Effects of ?-hydroxybutyrate and isoproterenol on lipolysis in isolated adipocytes from periparturient dairy cows and cows with clinical ketosis.  

PubMed

An in vitro model was used to investigate effects of ?-hydroxybutyrate and isoproterenol (?-adrenergic receptor agonist) on lipolysis in isolated adipocytes from late pregnant and recently calved dairy cows (n=5) and cows with clinical ketosis (n=3). Incubation with 3.0 mmol/L ?-hydroxybutyrate reduced lipolysis in isolated adipocytes. This inhibitory effect was lower in the first lactation week (47%±16%) compared with late pregnancy (71%±6.5%). Incubation with 0.3 ?mol/L isoproterenol stimulated lipolysis in isolated adipocytes from periparturient dairy cows. Basal lipolysis resulted in non-esterified fatty acid to glycerol ratios in the incubation media of 2.0±0.23 in prepartum samples, 2.1±0.23 in the first lactation week and 2.2±0.09 in cows with clinical ketosis. ?-Hydroxybutyrate reduced lipolysis by 45%±9.6% in isolated adipocytes from cows with clinical ketosis, indicating that impaired feedback of ?-hydroxybutyrate may not play a role in the disease etiology. PMID:23256919

van der Drift, S G A; Everts, R R; Houweling, M; van Leengoed, L A M G; Stegeman, J A; Tielens, A G M; Jorritsma, R

2013-06-01

382

Molecular population genetic analysis of Staphylococcus aureus recovered from cows.  

PubMed Central

Staphylococcus aureus is one of the most common causes of bovine mastitis. To estimate genetic relationships among S. aureus strains recovered from cows, 357 isolates from milk samples from worldwide localities were examined for electrophoretic variation at 13 metabolic-enzyme loci. Thirty-nine electrophoretic types which represented distinctive multilocus enzyme genotypes were identified, and nearly 90% of all isolates were assigned to one of eight clones. Genetic heterogeneity was found among organisms recovered from dairy herds from which multiple isolates were obtained, indicating that the S. aureus population in a single herd can be multiclonal. Although humans and cows shared 7 of the 39 S. aureus clones, each clone was predominantly associated with one of these host species. These results are consistent with the concept of host specialization among S. aureus clones and imply that successful transfer of bacteria between humans and cows is limited. PMID:7714195

Kapur, V; Sischo, W M; Greer, R S; Whittam, T S; Musser, J M

1995-01-01

383

Peptidomic profile of milk of holstein cows at peak lactation.  

PubMed

Bovine milk is known to contain naturally occurring peptides, but relatively few of their sequences have been determined. Human milk contains hundreds of endogenous peptides, and the ensemble has been documented for antimicrobial actions. Naturally occurring peptides from bovine milk were sequenced and compared with human milk peptides. Bovine milk samples from six cows in second-stage peak lactation at 78-121 days postpartum revealed 159 peptides. Most peptides (73%) were found in all six cows sampled, demonstrating the similarity of the intramammary peptide degradation across these cows. One peptide sequence, ALPIIQKLEPQIA from bovine perilipin 2, was identical to another found in human milk. Most peptides derived from ?-casein, ?s1-casein, and ?s2-casein. No peptides derived from abundant bovine milk proteins such as lactoferrin, ?-lactoglobulin, and secretory immunoglobulin A. The enzymatic cleavage analysis revealed that milk proteins were degraded by plasmin, cathepsins B and D, and elastase in all samples. PMID:24344900

Dallas, David C; Guerrero, Andres; Parker, Evan A; Garay, Luis A; Bhandari, Aashish; Lebrilla, Carlito B; Barile, Daniela; German, J Bruce

2014-01-01

384

The Physiology of Bed Rest. Chapter 39  

NASA Technical Reports Server (NTRS)

Prolonged rest in bed has been utilized by physicians and other health-care workers to immobilize and confine patients for rehabilitation and restoration of health since time immemorial. The sitting or horizontal position is sought by the body to relieve the strain of the upright or vertical postures, for example during syncopal situations, bone fractures, muscle injuries, fatigue, and probably also to reduce energy expenditure. Most health-care personnel are aware that adaptive responses occurring during bed rest proceed concomitantly with the healing process; signs and symptoms associated with the former should be differentiated from those of the latter. Not all illnesses and infirmities benefit from prolonged bed rest. Considerations in prescribing bed rest for patients-including duration, body position, mode and duration of exercise, light-dark cycles, temperature, and humidity-have not been investigated adequately. More recently, adaptive physiological responses have been measured in normal, healthy subjects in the horizontal or slightly head-down postures during prolonged bed rest as analogs for the adaptive responses of astronauts exposed to the microgravity environment of outer and bed-rest research.

Fortney, Suzanne M.; Schneider, Victor S.; Greenleaf, John E.

1996-01-01

385

Mechanism of Salinity Tolerance in Plants: Physiological, Biochemical, and Molecular Characterization  

PubMed Central

Salinity is a major abiotic stress limiting growth and productivity of plants in many areas of the world due to increasing use of poor quality of water for irrigation and soil salinization. Plant adaptation or tolerance to salinity stress involves complex physiological traits, metabolic pathways, and molecular or gene networks. A comprehensive understanding on how plants respond to salinity stress at different levels and an integrated approach of combining molecular tools with physiological and biochemical techniques are imperative for the development of salt-tolerant varieties of plants in salt-affected areas. Recent research has identified various adaptive responses to salinity stress at molecular, cellular, metabolic, and physiological levels, although mechanisms underlying salinity tolerance are far from being completely understood. This paper provides a comprehensive review of major research advances on biochemical, physiological, and molecular mechanisms regulating plant adaptation and tolerance to salinity stress. PMID:24804192

Huang, Bingru

2014-01-01

386

[Carbohydrate metabolic indices of ketotic and healthy cows].  

PubMed

Some of the indices of carbohydrate metabolism were studied in 30 freshly calved, high-producing cows affected with the disease and after they had recovered from ketosis as well as in 25 control cows. Investigated were the volatile fatty acids (VFA), ketone bodies, pH, and the count and composition of infusoria in the rumen content; the sugar, ketone bodies, and VFA in the blood--all being considered the most characteristic indices of carbohydrate metabolism in ruminants. With diseased cows pH in the rumen was 22 per cent lower than in the controls; the total count of infusoria per cu.cm was more than twice lower than the values found after recovery and those in the controls. Diplodinium and Isotricha infusoria were twice as low as the values found in the controls and after recovery. Entodinium infusoria were totally lacking in the rumen content of the affected animals, while the ketone bodies were 13.5 to 15.5 times as high, and VFA were 37 to 49 per cent lower. The level of the individual VFA fractions was altered; it was 2.4 to 2.8 times lower for acetic acid and 1.8 to 1.9 lower for propionic acid, while it was 1.8 to 2.1 times higher for butyric acid. The blood level of sugar in the diseased cows was more than twice lower, while the blood level of ketone bodies was 12 to 13 times higher; it was also higher (8 to 13 times) for VFA as compared with the values shown by normal cows and cows that had recovered from ketosis. PMID:3101278

Simeonov, S I

1986-01-01

387

Cleanliness scores as indicator of Klebsiella exposure in dairy cows.  

PubMed

This study was designed to explore the relationship between cow and udder cleanliness scores and the risk of isolation of Klebsiella spp. from lower hind legs and teat ends, respectively. The distribution of Klebsiella species was compared among isolates from teat ends, legs, and cases of clinical mastitis obtained from 2 dairy farms in New York State, with 850 and 1,000 cows, respectively. Farms were visited twice approximately 4 wk apart in August and September 2007 to obtain cleanliness scores and swabs from legs and teats. Isolates of Klebsiella clinical mastitis from each farm were collected from July through October 2007. Two studies were conducted. In the first study, whole-cow cleanliness of a purposive sample of 200 lactating cows was scored using a 4-point scale, and swabs were taken from their lower hind legs. In the second study, udder cleanliness of a separate convenience sample of 199 lactating cows was scored in the milking parlor, and swabs were taken from their teat ends before and after premilking udder preparation. Prevalence of Klebsiella spp. on legs and teat ends before udder preparation was 59 and 60%, respectively. Logistic regression was used to explore the association between isolation of Klebsiella spp. and cleanliness scores. Cow cleanliness scores and udder cleanliness scores were not associated with detection of Klebsiella on legs and on teats before udder preparation, respectively. After udder preparation, 43% of previously Klebsiella positive teat end samples remained positive, with significant differences between farms and months. Teats from dirty udders were significantly more likely to test positive for Klebsiella after udder preparation than teats from clean udders. The proportion of Klebsiella pneumoniae and Klebsiella oxytoca isolates was similar for isolates from teat end swabs and clinical mastitis cases, supporting the notion that the presence of Klebsiella on teat ends may lead to opportunistic intramammary infections. Udder cleanliness scores could be used as a management tool to monitor the risk of exposure to Klebsiella spp. on teat ends. PMID:18832213

Munoz, M A; Bennett, G J; Ahlström, C; Griffiths, H M; Schukken, Y H; Zadoks, R N

2008-10-01

388

Health and productivity of dairy cows fed polychlorinated biphenyls  

SciTech Connect

Holstein cows were studied through a complete lactation, a nonlactating period, and 42 days of a subsequent lactation for overt and subtle responses to a commercial mixture of polychlorinated biphenyls. Dosed cows (n = 4) received consecutive 60-day periods of daily dosing with 10, 100, and 1000 mg of Aroclor 1254. Control cows (n = 6) received daily sham doses. The following were recorded: daily milk production, feed intake, and health observations; weekly body weight, temperature, heart and respiratory rates and rectal palpation; semi-monthly clinical chemistry determinations; and monthly milk fat, microbiological culture of quarter foremilk samples, and composite milk somatic cell counts. Mean daily milk production (22.4 +/- 1.1 vs 24.8 +/- 1.0 kg) and net energy of a complete lactation (1.46 +/- 0.05 vs 1.45 +/- 0.03 Mcal/kg dry matter intake) were not different (p = 0.85) for control and PCB-dosed cows. Milk production during the first 42 days of the subsequent lactation was also similar for control and dosed cows. Occurrences of injuries, dysfunctions, and general infections were not related to polychlorinated biphenyl exposure. Intramammary infections were detected for both lactations with 51 and 32 infections detected in microbiological cultures, respectively, for the control and dosed groups. Environmental pathogens were most frequently isolated from cases of clinically apparent mastitis. The majority of quarter infections detected were due to Corynebacterium bovis. Only one animal (dosed, necropsy revealed left oviduct obstructed) failed to conceive with three to six services required before conception for the other control and dosed cows. Exposure to polychlorinated biphenyls resulting in maximal residues in milk fat, near 100 micrograms/g, had no apparent effect on health and productivity.

Willett, L.B.; Liu, T.T.; Durst, H.I.; Smith, K.L.; Redman, D.R.

1987-07-01

389

Using rumen probes to examine effects of conjugated linoleic acids and dietary concentrate proportion on rumen pH and rumen temperature of periparturient dairy cows.  

PubMed

The study aimed to examine the influence of supplemented conjugated linoleic acids (CLA) to periparturient cows receiving different concentrate proportions antepartum on rumen pH (RpH) and rumen temperature (RT). Twenty pregnant German Holstein cows were equipped with rumen probes for continuous RpH and RT measurement in a frequency of 15 min to investigate effects of dietary concentrate and CLA around parturition and the impact of parturition itself on RpH and RT. Cows had ad libitum access to partial mixed rations, 3 weeks prior to calving until day 7 post-partum. Antepartum, cows received 100 g/day control fat (CON) or CLA supplement, either in low (20%; CON-20, CLA-20) or high concentrate diet (60%; CON-60, CLA-60). Post-partum, concentrate proportion was adjusted to 50% while fat supplementation continued. Compared with adapted feeding, high concentrate proportions antepartum tended to increase DMI and reduced RpH. Groups CON-60 and CLA-60 spent more than 4 h per day below RpH 5.6 during late pregnancy, indicating the presence of subacute rumen acidosis (SARA). The RT remained unaffected antepartum. Before calving, cows spent less time below RpH 5.6 and SARA could be detected in each group post-partum. Mean RpH increased slightly antepartum, whereas few hours before parturition a sharp decrease in RpH could be observed, accompanied with increased RT. Overall, it seems that CLA supplementation influences RpH and RT. Bearing in mind that rumen parameters fluctuate during day and herd level must be known, rumen probes for continuous RpH and RT measurement could be a useful management tool for animal health surveillance and may also help to predict parturition. PMID:25180374

Petzold, M; Meyer, U; Spilke, J; Dänicke, S

2014-08-01

390

Relationship of psychological and physiological parameters during an arctic ski expedition  

NASA Astrophysics Data System (ADS)

Considerable data (primarily physiological) have been collected during expeditions in extreme environments over the last century. Physiological measurements have only recently been examined in association with the emotional or behavioral state of the subject. Establishing this psychophysiological relationship is essential to understanding fully the adaptation of humans to the stresses of extreme environments. This pilot study investigated the simultaneous collection of physiological, psychological and behavioral data from a two-man Greenland expedition in order to model how specific relationships between physiological and psychological adaptation to a polar environment may be identified. The data collected describes changes in adrenal and other hormonal activity and psychological functioning. Levels of cortisol and testosterone were calculated. Factors influencing the plasma profiles of the aforementioned included 24-hour sunlight, high calorific intake of more than 28 000 kJ/day and extreme physical exercise. There was a difference between individual psychological profiles as well as self-report stress and physiological stress.

Bishop, Sheryl L.; Grobler, Lukas C.; SchjØll, Olaf

2001-08-01

391

Evolutionary history underlies plant physiological responses to global change since the last glacial maximum  

PubMed Central

Assessing family- and species-level variation in physiological responses to global change across geologic time is critical for understanding factors that underlie changes in species distributions and community composition. Here, we used stable carbon isotopes, leaf nitrogen content and stomatal measurements to assess changes in leaf-level physiology in a mixed conifer community that underwent significant changes in composition since the last glacial maximum (LGM) (21 kyr BP). Our results indicate that most plant taxa decreased stomatal conductance and/or maximum photosynthetic capacity in response to changing conditions since the LGM. However, plant families and species differed in the timing and magnitude of these physiological responses, and responses were more similar within families than within co-occurring species assemblages. This suggests that adaptation at the level of leaf physiology may not be the main determinant of shifts in community composition, and that plant evolutionary history may drive physiological adaptation to global change over recent geologic time. PMID:24636555

Becklin, Katie M.; Medeiros, Juliana S.; Sale, Kayla R.; Ward, Joy K.

2014-01-01

392

The Electroretinogram of the Horseshoe Crab, Limulus polyphemus: A Laboratory Exercise in Sensory Physiology  

NSDL National Science Digital Library

The eye of the horseshoe crab, Limulus polyphemus represents an easily-excised and durable preparation for investigating various parameters of a typical sensory system. One can study the time course of dark adaptation as well as the dependence of response amplitude and latency on stimulus intensity in both the dark-adapted and light-adapted eye. Requirements for specialized, technical equipment are minimal. Suitable for undergraduates in advanced general biology, physiology, and special projects.

Robert A. Linsenmeier (Northwestern University;); Charles M. Yancey (Northwestern University;); Wesley W. Ebert (Northwestern University;)

2008-04-11

393

Body Condition, Nutrition and Reproduction of Beef Cows.  

E-print Network

IOC rA245.7 73 1.1526 ". 1\\ ? '-h~'i'll U lilERSITY LIBRARY '" 8-1526 Texas Agricultural Extension Service -----~- PfU),o& H~bt? PfU),o& ------------' Body Condition, Nutrition and Reproduction of Beef Cows MAR311986 iT exas A...IOC rA245.7 73 1.1526 ". 1\\ ? '-h~'i'll U lilERSITY LIBRARY '" 8-1526 Texas Agricultural Extension Service -----~- PfU),o& H~bt? PfU),o& ------------' Body Condition, Nutrition and Reproduction of Beef Cows MAR311986 iT exas A...

Herd, Dennis B.; Sprott, L.R.

1986-01-01

394

Dilatation of the Lower Cervical Esophagus in a Cow  

PubMed Central

Acquired megaesophagus of suspected neuromuscular origin was diagnosed in a six year old Holstein cow. The dilatation was restricted to the lower cervical esophagus. Signs included projectile regurgitation of chewed ingesta at variable periods of time after swallowing, nasal discharge of mucus and feed particles, and a cough. A secondary aspiration pneumonia was associated with this condition. The dilated portion of the esophagus was detected utilizing positive contrast radiography and fiberoptic endoscopy. Treatment consisted of feed management and antibiotics. Deglutition in the cow returned to normal over a three month period despite radiographic and fiberoptic endoscopic evidence of a persistent dilatation of the esophagus. ImagesFigure 1. PMID:17422388

Kasari, T. R.

1984-01-01

395

Risk factors and effects of postpartum anovulation in dairy cows.  

PubMed

The objectives were to identify risk factors for and to quantify the effect of postpartum anovulation on reproductive performance in dairy cows. Data from 2,178 Holstein cows in 6 commercial herds enrolled in a randomized clinical trial were used. Data on periparturient disease incidence, calving history, and body condition score were collected. Cows were examined at wk 5 postpartum for reproductive tract disease; cytological endometritis was defined as ?6% polymorphonuclear cells in endometrial cytology, and purulent vaginal discharge was defined as the presence of mucopurulent or purulent vaginal discharge. Cows were followed until 300 d in milk (DIM) for reproductive performance. Serum nonesterified fatty acids (NEFA) concentration was measured once during the week before expected calving. Serum ?-hydroxybutyrate, NEFA, and haptoglobin were measured at wk 1, 2, and 3 postpartum. Serum progesterone (P4) was measured at wk 3, 5, 7, and 9 postpartum. The end of the postpartum anovulation period was defined as the first sampling time at which P4 was >1 ng/mL. Statistical analyses were performed using logistic regression models and Cox proportional hazard models. The prevalence of anovulation was 72, 44, 26, and 17% at wk 3, 5, 7, and 9, respectively. Cows were classified according to their ovulatory status as having luteal function at 21 DIM (Cyc21), as having low P4 at 21 DIM but having luteal function at least once at 35 or 49 or 63 DIM (Cyc63), or being anovulatory at 63 DIM (Anov63; no samples with P4 >1 ng/mL). Factors associated with early ovulation (Cyc21) included season, parity, decreased haptoglobinemia, and decreased serum NEFA concentration before and after parturition. Risk factors for prolonged anovulation (Anov63) included cytological endometritis, increased haptoglobinemia, and greater serum NEFA concentrations before and after parturition. Cows classified as Anov63 had an increased median time to first breeding compared with Cyc63 (74.1 vs. 73.2 d). The effect of prolonged postpartum anovulation on median time to pregnancy was conditional on parity group; a detrimental effect was present in cows of parity ?3 (129 d for Cyc21, 151 d for Cyc63, and 180 d for Anov63), but no effect was observed in cows of parity ?2. Overall, these findings suggest that postpartum anovulation was associated with indicators of energy balance and uterine inflammation, and with detrimental effects on reproductive performance. PMID:22459832

Dubuc, J; Duffield, T F; Leslie, K E; Walton, J S; LeBlanc, S J

2012-04-01

396

Adaptive defrost  

Microsoft Academic Search

The adaptive defrost concept operates on demand, initiating a defrost cycle only when needed, thereby saving energy and yet maintaining refrigeration system efficiency. This is accomplished by automatically adjusting the frost accumulation period to achieve an optimal predetermined defrost time. The optimal defrost time is previously determined for the particular refrigeration system and programmed into the control. The next frost

J. Allard; R. Heinzen

1988-01-01

397

Study of Physiological Profile of Indian Boxers  

PubMed Central

The present study was conducted to study the morphological, physiological and biochemical characteristics of Indian National boxers as well as to assess the cardiovascular adaptation to graded exercise and actual boxing round. Two different studies were conducted. In the first study [N = 60, (junior boxers below-19 yrs, n = 30), (senior boxers-20-25 yrs, n = 30)] different morphological, physiological and biochemical parameters were measured. In the second study (N = 21, Light Weight category- <54 kg, n = 7; Medium weight category <64 kg, n = 7 and Medium heavy weight category <75 kg, n = 7) cardiovascular responses were studied during graded exercise protocol and actual boxing bouts. Results showed a significantly higher (p < 0.05) stature, body mass, LBM, body fat and strength of back and grip in senior boxers compared to juniors. Moreover, the senior boxers possessed mesomorphic body conformation where as the juniors' possessed ectomorphic body conformation. Significantly lower (p < 0.05) aerobic capacity and anaerobic power were noted in junior boxers compared to seniors. Further, significantly higher (p < 0.05) maximal heart rates and recovery heart rates were observed in the seniors as compared to the juniors. Significantly higher maximum heart rates were noted during actual boxing compared to graded exercise. Blood lactate concentration was found to increase with the increase of workload during both graded exercise and actual boxing round. The senior boxers showed a significantly elevated (p < 0.05) levels of hemoblobin, blood urea, uric acid and peak lactate as compared to junior boxers. In the senior boxers significantly lower levels of total cholesterol, triglyceride and LDLC were observed as compared to junior boxers. No significant change has been noted in HDLC between the groups. The age and level of training in boxing has significant effect on Aerobic, anaerobic component. The study of physiological responses during graded exercise testing may be helpful to observe the cardiovascular adaptation in boxers. Key Points Study on Indian boxers Laboratory testing. Physical, physiological and biochemical monitoring. Performance analysis during actual boxing and laboratory testing. PMID:24357980

Khanna, Gulshan Lal; Manna, Indranil

2006-01-01

398

Evaluation of udder and teat characteristics, calf growth, and reproduction in young Bos indicus-Bos taurus cows  

E-print Network

the same 4 F1 Nellore-Angus sires, and were analyzed separately. Sire of cow was significant for calf birth weight (P = 0.014) among ET cows, but not NS cows. Among NS families, calves from cows out of Brahman-Hereford dams were 2.0 kg heavier (P = 0...

Gladney, Cody Jack

2008-10-10

399

Prostaglandin F2? for Lactating Dairy Cows with a Palpable Corpus Luteum but Unobserved Estrus[1], [2] and [3  

Microsoft Academic Search

Two experiments in 17 dairy herds were for the effectiveness of prostaglandin F2c~ (treatment) in inducing luteolysis and reducing intervals to conception of 308 cycling lactating dairy cows. Cows with unobserved estrus before first insemination (Experiment 1) and non- pregnant cows with unobserved estrus after insemination (Experiment 2) were eligible for treatment. Cows in Experiment 1 were assigned alternately either

S. S. Plunkett; J. S. Stevenson; E. P. Call

1984-01-01

400

Extremophiles and their adaptation to hot environments  

Microsoft Academic Search

Water-containing terrestrial, subterranean and submarine high temperature areas harbor a variety of hyperthermophilic bacteria and archaea which are able to grow optimally above 80°C. Hyperthermophiles are adapted to hot environments by their physiological and nutritional requirements. As a consequence, cell components like proteins, nucleic acids and membranes have to be stable and even function best at temperatures around 100°C. The

Karl O Stetter

1999-01-01

401

The physiology of adiposity.  

PubMed

Normal energy homeostasis requires a balance between fat storage and energy utilization that is guaranteed by regulation of one billion fat cells which arguably constitute the body's largest endocrine unit. Such physiology is required to maintain normal adiposity which if depleted from under- or malnutrition results in lipodystrophy that causes hormonal, reproductive, and developmental abnormalities. Conversely, excess adiposity provides inflammatory secretagogues, particularly from central visceral fat depots that enhance insulin resistance, excessive fatty acids with lipotoxicity and hypertension that escalate atherosclerosis including coronary artery disease. This review describes normal adiposity for maintenance of normal body mass and the roles of adipocyte hormones and adipokines for normal regulation of energy storage and its utilization. Therefore, in this context, the roles of leptin, insulin, adiponectin, and lesser known acylation-stimulating protein, visfatin, and apelin are outlined. Further, adipocyte inflammatory secretagogues are outlined that affect diabetes mellitus 2 with insulin resistance,fatty acid lipotoxicity, dyslipidemia, and hypertension that contribute to the metabolic syndrome. These effects are opposed by adipocyte hormones adiponectin, acylation-stimulating protein, visfatin, and apelin that help maintain normal energy utilization. PMID:18390031

Redinger, Richard N

2008-02-01

402

Physiology of Volition  

NASA Astrophysics Data System (ADS)

The idea of free will is a conscious awareness of the brain concerning the nature of the movement that it produces. There is no evidence for it to be a driving force in movement generation. This review considers the physiology of movement generation and how the concepts of willing and agency might arise. Both the anatomical substrates and the timing of events are considered. Movement initiation and volition are not necessarily linked, and one line of evidence comes from consideration of patients with disorders of volition. Movement is generated subconsciously, and the conscious sense of willing the movement comes later, but the exact time of this event is difficult to assess because of the potentially illusory nature of introspection. The evidence suggests that movement is initiated in frontal lobe, particularly the mesial areas, and the sense of volition arises as the result of a corollary discharge from premotor and motor areas likely involving the parietal lobe. Agency probably involves a similar region in the parietal lobe and requires both the sense of volition and movement feedback.

Hallett, Mark

403

Choosing the Time of Year to Breed and Calve Beef Cows in Texas  

E-print Network

. Principle 2?It is important to properly feed cows so that they can show estrus early in the breeding period. Table 2 shows that cows that display estrus within the first 21 days of breeding have higher pregnancy rates compared to cows displaying estrus after... the first 21 days of breeding. Consequently, pregnancy rates are high in herds that have a high proportion of cows showing estrus early in the breeding period. Principle 3?Most of the pregnancies within a herd occur in the cows with highest fertility. Table...

Sprott, L. R.

2001-01-04

404

Adaptive Velocity Tuning for Visual Motion Estimation  

E-print Network

In the brain, both neural processing dynamics as well as the perceptual interpretation of a stimulus can depend on sensory history. The underlying principle is a sensory adaptation to the statistics of the input collected over a certain amount of time, allowing the system to tune its detectors, e.g. by improving the sampling of the input space. Here we show how a generative formulation for the problem of visual motion estimation leads to an online adaptation of velocity tuning that is compatible with physiological sensory adaptation and observed perceptual effects. 1

Volker Willert; Julian Eggert

405

Physiologic Effects of Bowel Preparation  

Microsoft Academic Search

PURPOSE: Despite the universal use of bowel preparation before colonoscopy and colorectal surgery, the physiologic effects have not been described in a standardized setting. This study was designed to investigate the physiologic effects of bowel preparation. METHODS: In a prospective study, 12 healthy volunteers (median age, 63 years) underwent bowel preparation with bisacodyl and sodium phosphate. Fluid and food intake

Kathrine Holte; Kristine Grubbe Nielsen; Jan Lysgård Madsen; Henrik Kehlet

2004-01-01

406

Physiological computation of binocular disparity  

Microsoft Academic Search

We previously proposed a physiologically realistic model for stereo vision based on the quantitative binocular receptive field profiles mapped by Freeman and coworkers. Here we present several new results about the model that shed light on the physiological processes involved in disparity computation. First, we show that our model can be extended to a much more general class of receptive

Ning Qian; Yudong Zhu

1997-01-01

407

Non-invasive physiological measurements  

SciTech Connect

This book discusses the diagnostic techniques of nondestructive type for monitoring the physiology of various organ systems. The topics covered are: non-invasive assessment of gastric activity; uterine activity, intestinal activity; monitoring of fetal cardiovascular system and bilirubin physiology of infants. Respiratory system of infants is monitored and ultrasonography of heart is discussed.

Rolfe, P.

1983-01-01

408

Effects of Feeding Diets Containing Endophyte-Infected Fescue Seed on Luteinizing Hormone Secretion in Postpartum Beef Cows and in Cyclic Heifer; and Cows  

Microsoft Academic Search

Two experiments were conducted to investigate the effect of feeding endophyte (Acrernonium coenophialuml-infected fescue Westuca arundinacea Shreb.) seed on LH secretion in postpartum beef cows and in cycling heifers and cows. In Exp. 1, spring-calving primiparous Angus cows (n = 16) were pair-fed for 75 d diets that contained endophyte-free or endophyte-infected (95%) fescue seed that contained 1.3 pg\\/g of

K. M. Mizinga; F. N. Thompson; J. A. Stuedemann; T. E. Kisert

2010-01-01

409

Survival adaptations of three Euphorbia spp. in arid ecosystem  

Microsoft Academic Search

Three species ofEuphorbia (E. granulata, E. prostrata andE. hirta) exhibited both morphological and physiological adaptations in dry environmental conditions. High bound water, thick cuticle,\\u000a dense hair covering and low stomatal index are some of the survival adaptations they developed under water stress conditions\\u000a of the Indian arid zone.

Sudeep Kumar; D. N. Sen

1985-01-01

410

Adaptive and Self-adaptive Evolutionary Computations  

Microsoft Academic Search

This paper reviews the various studies that have introduced adaptive and self- adaptive parameters into Evolutionary Computations. A formal definition of an adaptive evolutionary computation is provided with an analysis of the types of adaptive and self-adaptive parameter update rules currently in use. Previous stud- ies are reviewed and placed into a categorization that helps to illustrate their simi- larities

Peter J. Angeline

1995-01-01

411

Physiological correlates of mental workload  

NASA Technical Reports Server (NTRS)

A literature review was conducted to assess the basis of and techniques for physiological assessment of mental workload. The study findings reviewed had shortcomings involving one or more of the following basic problems: (1) physiologic arousal can be easily driven by nonworkload factors, confounding any proposed metric; (2) the profound absence of underlying physiologic models has promulgated a multiplicity of seemingly arbitrary signal processing techniques; (3) the unspecified multidimensional nature of physiological "state" has given rise to a broad spectrum of competing noncommensurate metrics; and (4) the lack of an adequate definition of workload compels physiologic correlations to suffer either from the vagueness of implicit workload measures or from the variance of explicit subjective assessments. Using specific studies as examples, two basic signal processing/data reduction techniques in current use, time and ensemble averaging are discussed.

Zacharias, G. L.

1980-01-01

412

Connector adapter  

NASA Technical Reports Server (NTRS)

An adapter for installing a connector to a terminal post, wherein the connector is attached to a cable, is presented. In an embodiment, the adapter is comprised of an elongated collet member having a longitudinal axis comprised of a first collet member end, a second collet member end, an outer collet member surface, and an inner collet member surface. The inner collet member surface at the first collet member end is used to engage the connector. The outer collet member surface at the first collet member end is tapered for a predetermined first length at a predetermined taper angle. The collet includes a longitudinal slot that extends along the longitudinal axis initiating at the first collet member end for a predetermined second length. The first collet member end is formed of a predetermined number of sections segregated by a predetermined number of channels and the longitudinal slot.

Hacker, Scott C. (Inventor); Dean, Richard J. (Inventor); Burge, Scott W. (Inventor); Dartez, Toby W. (Inventor)

2007-01-01

413

Educational puzzles for understanding gastrointestinal physiology.  

PubMed

We developed four innovative, creative, and fun educational tools to promote active learning, enhance problem-solving skills, and encourage small group discussion. Furthermore, the tools encourage deductive reasoning and critical thinking rather than passive memorization of material. The tools include crossword puzzles, hidden messages, word scrambles, and word searches. These tools were developed using two computer programs: the Crossword Construction Kit and The New Puzzle Factory. Instructors are encouraged to optimize the value of the tools by using the additional options presented at the end of each of the puzzles. The additional options encourage students to become active learners by creating their own tools. Although the principles of these four tools can be adapted to many disciplines, these specific games focused on gastrointestinal physiology. Our goal was to create tools that can be used either inside or outside the classroom to complement and enhance the lecture. PMID:16211663

Bailey, C M; Hsu, C T; DiCarlo, S E

1999-06-01

414

McArdle Disease and Exercise Physiology  

PubMed Central

McArdle disease (glycogen storage disease Type V; MD) is a metabolic myopathy caused by a deficiency in muscle glycogen phosphorylase. Since muscle glycogen is an important fuel for muscle during exercise, this inborn error of metabolism provides a model for understanding the role of glycogen in muscle function and the compensatory adaptations that occur in response to impaired glycogenolysis. Patients with MD have exercise intolerance with symptoms including premature fatigue, myalgia, and/or muscle cramps. Despite this, MD patients are able to perform prolonged exercise as a result of the “second wind” phenomenon, owing to the improved delivery of extra-muscular fuels during exercise. The present review will cover what this disease can teach us about exercise physiology, and particularly focuses on the compensatory pathways for energy delivery to muscle in the absence of glycogenolysis. PMID:24833339

Kitaoka, Yu

2014-01-01

415

Effect of maize processing on diet selection in cows  

Microsoft Academic Search

The effect of maize, processed by three different methods, on the diet selection process was studied in 12 fistulated dry cows in a randomized block design. The experimental period lasted 20 days and was repeated twice (eight animals\\/treatment). Treatments allowed selection of different processed maize grains by the animals: sugar cane and coarsely ground maize (CG), sugar cane and finely ground

Fernanda Altieri Ferreira; Roberta Passini; Laura Maria Oliveira Borgatti; Rondon T. Y. B. de Souza; Paula Marques Meyer; Paulo Henrique Mazza Rodrigues

2007-01-01

416

A Body Condition Scoring Chart for Holstein Dairy Cows  

Microsoft Academic Search

A chart for body condition scoring of freely moving Holstein dairy cows was developed using an iterative process consisting of literature review, interviews with experts, field testing, statistical analysis, and comments from chart users. The chart consists of text and diagrams that detail changes in con- formation with body condition change for eight body locations identified as important in body

A. J. Edmonson; I. J. Lean; L. D. Weaver; T. Farver; G. Webster

1989-01-01

417

Estimates of Ammonia Emission from Dairy Cow Collecting Yards  

Microsoft Academic Search

Two approaches were used to estimate ammonia (NH3) emission from dairy cow collecting yards. In the first, a system of small wind tunnels was used to estimate emission from urine spread on small concreted areas dirtied with faeces and to identify some of the factors controlling the extent of the loss. In the second, a hood was used to measure

T. H. Misselbrook; B. F. Pain; D. M. Headon

1998-01-01

418

Bone mineral status in children with cow milk allergy.  

PubMed

To investigate bone mineral status in children with verified cow milk allergy for more than 4 yr compared with a large reference population of 343 local healthy controls. Whole body bone mineral content (BMC), projected bone area and bone mineral density (BMD) were determined by dual energy x-ray absorptiometry in nine children (8-17 yr old, one girl and eight boys). All children had cow milk allergy for more than 4 yr. All children had asthma and was treated with corticosteroids. BMC and BMD were reduced for age (p < 0.01). Height for age was significantly reduced (p < 0.01), indicating 'short' bones. BMC for bone area was borderline reduced (p = 0.05), indicating reduced bone mineralization. The growth of the children was reduced compared with there parents and siblings (p < 0.01), and the bone age was retarded (mean 1.4 yr, p < 0.01). Calcium consumption calculated from food intake was about 25% of the recommended. All laboratory tests were normal. Short bones were the main reason for reduced BMC and BMD for age in children with cow milk allergy, but a borderline low BMC for bone area indicated reduced bone mineralization of the bones. A supplementation of calcium to children with cow milk allergy is recommended. PMID:15610372

Jensen, Vagn Braendholt; Jørgensen, Inger Merete; Rasmussen, Kirsten Braendholt; Mølgaard, Christian; Prahl, Palle

2004-12-01

419

From the Baltimore Sun Cows get along fine with robot  

E-print Network

data -- even keeps the cows calm. "This is a huge, labor-saving device that gives us a lot more's ballgames without rushing home. David Dallam can spend more time in the fields, and Kate can tend their ice rate, with 50 farms going out of production in the past two years, officials said. Anything that can

Hamza, Iqbal

420

Toxic bovine mastitis caused by Staphylococcus aureus in twin cows.  

PubMed

In this report, we describe two cases of bovine toxic mastitis associated with S. aureus and we provide DNA microarray based characterization data of the strain causing the disease. Both cows had recently calved and suffered from anorexia, pyrexia, and an elevated heart rate. In both animals, at least one mammary gland was swollen, hardened, sensitive to touch, and produced brownish or bloody secretions. The clinical state of the animals deteriorated quickly and both cows had to be euthanized within 48 hours after presentation. The S. aureus strain, which was isolated from the mastitis milk of both cows, was assigned to spa type t267, agr type I, capsule type 5 and CC97, a clonal complex recently identified as the evolutionary origin of two emerging clones of human epidemic community-associated methicillin-resistant S. aureus. The strain did not harbour any genes conferring resistance to antimicrobial agents and we did not detect any genes coding for enterotoxins, toxic shock syndrome toxin, or exfoliative toxins. Taking into consideration that twin cows were affected by this rare disease, we suggest that host factors may play a crucial role in toxic mastitis associated with S. aureus. PMID:25359115

Rüegsegger; Corti; Sihto; Johler

2014-11-01

421

Maximizing a Cow's Immune Response Max Irsik DVM, MAB  

E-print Network

Maximizing a Cow's Immune Response Max Irsik DVM, MAB Beef Cattle Extension Veterinarian University vaccination results from the stimulation of the acquired immune response. The acquired immune response of specific antibodies and immune cells to dispose of the antigen, (3) the development of a memory for each

Watson, Craig A.

422

The cow as a geomorphic agent — A critical review  

Microsoft Academic Search

Cows are important agents of geomorphological change. On the uplands, heavy grazing compacts the soil, reduces infiltration, increases runoff, and increases erosion and sediment yield. However, light and moderate grazing have effects that are much less significant. In riparian zones, grazing decreases erosional resistance by reducing vegetation and exposing more vulnerable substrate. Trampling directly erodes banks, thus increasing turbulence and

Stanley W. Trimble; Alexandra C. Mendel

1995-01-01

423

Original article Relative bioavailability of vitamin E in dairy cows  

E-print Network

Original article Relative bioavailability of vitamin E in dairy cows following intraruminal; accepted 31 July 1997) SummaryDL-a-tocopheryl acetate, a synthetic form of vitamin E, is routinely given no vitamin E supplementation with an interval of 8 days between each administration. Blood samples were

Boyer, Edmond

424

Mixed grazing trial with suckling cows and dry pregnant ewes  

E-print Network

Mixed grazing trial with suckling cows and dry pregnant ewes N Grenet1 J Billant2 'Institut de l'Elevage, Theix, 63122 St-Genès-Champanelle ; 2LEGTA, 52903 Chaumont Cedex 9, France Mixed grazing of sheep be profitable if suckled calves' growth is maintained or improved. During three successive grazing seasons (from

Paris-Sud XI, Université de

425

Potential for Altering Energy Partition in the Lactating Cow  

Microsoft Academic Search

Partitioning of nutrients in lactating cows is discussed in terms of processes requiring energy associated with main- tenance and production with emphasis upon kinetic properties that determine patterns and rates of nutrient use and nutrient interactions. Rates of nutrient oxidation by tissues are determined largely by energy expenditures, con- centrations of nutrients in blood, and relative affinities of tissues for

B. R. Baldwin; N. E. Forsberg; C. Y. Hu

1985-01-01

426

COLOSTRUM IMMUNOGLOBULIN CONCENTRATION IN COWS: RELATIONSHIP WITH THEIR CALF MORTALITY  

E-print Network

COLOSTRUM IMMUNOGLOBULIN CONCENTRATION IN COWS: RELATIONSHIP WITH THEIR CALF MORTALITY AND WITH THE COLOSTRUM QUALITY OF THEIR FEMALE OFFSPRING Jacqueline DARDILLAT* G. TRILLAT* P. LARVOR* I, 63110 Beaumont, France. Résumé. CONCENTRATION EN IMMUNOGLOBULINES DU COLOSTRUM DES VACHES : RELATION

Paris-Sud XI, Université de

427