RESUMEN
INTRODUCTION: Mastitis is one of the most important factor diseases in dairy cattle worldwide. Milking technique represents one of the factors involved in the development of mastitis. The purpose of this study was to investigate the influence of vibrations during milking on the rate of clinical and subclinical mastitis. For this purpose, milking measurements, tank milk analyses and survey forms (general farm data, assessment of milking work and milking hygiene, teat condition, feeding, farm problems, animal behavior) were assessed in 8 Swiss dairy farms. The results show a correlation between present vibrations at the output of the milk meter and increasing bulk milk somatic cell count. Further, a tendency was shown for vibrations at the input of the milk meter to influence bulk milk somatic cell count. Also, a tendency regarding vibrations at the outlet of the milk meter and acute phase protein milk amyloid A was evident. In conclusion, the results suggest that vibration during milking might have a negative effect on udder health. However, further research with a larger number of dairies is needed to make a more generally valid statement.
INTRODUCTION: La mammite est l'une des maladies les plus importantes chez les vaches laitières dans le monde entier. La technique de traite représente l'un des facteurs impliqués dans le développement de la mammite. L'objectif de cette étude était d'étudier l'influence des vibrations pendant la traite sur le taux de mammites cliniques et subcliniques. Pour ce faire, des mesures de traite, des analyses de lait de tank et des formulaires d'enquête (données générales de l'exploitation, évaluation du travail de traite et de l'hygiène de la traite, état des trayons, alimentation, problèmes de l'exploitation, comportement des animaux) ont été évalués dans 8 exploitations laitières suisses. Les résultats montrent une corrélation entre les vibrations présentes à la sortie du compteur à lait et l'augmentation du nombre de cellules somatiques du lait en vrac. En outre, les vibrations à l'entrée du compteur à lait ont tendance à influencer le nombre de cellules somatiques du lait en vrac. De même, une tendance concernant les vibrations à la sortie du compteur à lait et la protéine amyloïde A du lait de phase aiguë a été mise en évidence. En conclusion, les résultats suggèrent que les vibrations pendant la traite pourraient avoir un effet négatif sur la santé de la mamelle. Cependant, des recherches supplémentaires avec un plus grand nombre de laiteries sont nécessaires pour faire une déclaration plus généralement valable.
Asunto(s)
Enfermedades de los Bovinos , Mastitis Bovina , Animales , Bovinos , Femenino , Vibración/efectos adversos , Industria Lechera/métodos , Mastitis Bovina/epidemiología , Leche , Glándulas Mamarias Animales , Recuento de Células/veterinariaRESUMEN
"Rafts" in the plasma membrane are nanoscopic domains rich in sphingolipids and cholesterol. Groups of them are thought to provide stable platforms for various proteins. How several rafts can form a larger stable platform has yet to be made clear. Here, we show that in the microemulsion theory of rafts, in which they, and the sea in which they float, are characterized by a naturally occurring length, rafts separated by a sea larger than this length will attract one another, thus making the sea smaller. Similarly, if rafts are separated by a sea that is smaller than the characteristic size, they will repel one another thus allowing the sea to increase in size. Such an elastic force can clearly stabilize a platform of many rafts.
Asunto(s)
Membrana Celular , Microdominios de MembranaRESUMEN
We investigate the effects on the distribution of lipids in the plasma membrane that are caused by the insertion of a protein, Piezo1, that significantly distorts the membrane toward the cytosol. From coarse-grained molecular dynamics simulations, we find that the major effects occur in the outer, extracellular, leaflet. The mol fraction of cholesterol increases significantly in the curved region of the membrane close to Piezo1, while those of phosphatidylcholine and of sphingomyelin decrease. In the inner leaflet, mol fractions of cholesterol and of phosphatidylethanolamine decrease slightly as the protein is approached, while that of phosphatidylserine increases slightly. The mol fraction of phosphatidylcholine decreases markedly as the protein is approached. Most of these results are understood in the context of a theoretical model that utilizes two elements: 1) a coupling between the leaflets' actual curvatures and their compositionally dependent spontaneous curvatures and 2) the dependence of the spontaneous curvatures not only on the mol fractions of the phospholipids, but also on the effect that cholesterol has on the spontaneous curvatures of the phospholipids.
Asunto(s)
Fosfatidilcolinas , Fosfolípidos , Fosfolípidos/metabolismo , Membrana Celular/metabolismo , Membranas/metabolismo , Colesterol/metabolismo , Membrana Dobles de LípidosRESUMEN
STUDY QUESTION: When couples have to face recurrent pregnancy loss (RPL), what are the partners' wishes and needs and what is their perception of helpful and unhelpful factors with regard to their own, their partners' and their families' and friends' ways of dealing with the problem? SUMMARY ANSWER: Women and men with repeated miscarriages want open communication about their losses, but expect a sensitive and empathetic attitude from others, not pity or trivialization. WHAT IS KNOWN ALREADY: RPL not only causes the women affected and their partners considerable emotional distress; it also has an impact on the couples' relationships and the way they relate to their families and friends. Studies suggest that women have a greater need than their male partners to talk about their losses and that these differences may lead to dissatisfaction and cause relational tension. In addition, men often assume a 'mainstay' role, supporting their partners and displaying fortitude in the face of distress. As yet, however, little research has been conducted so far on the question of what the members of couples with RPL expect from one another and from their families and friends. STUDY DESIGN SIZE DURATION: The study sample consisted of 147 couples and 17 women with at least 2 miscarriages attending the special unit for RPL at the University Women's Hospital in Heidelberg (Germany) for the first time between September 2018 and October 2020 (response rate: 82.7%). The patients were asked to participate in this combined qualitative and questionnaire study. PARTICIPANTS/MATERIALS SETTING METHODS: In order to explore the wishes and needs of those affected in more detail, the free text responses obtained were examined in this study by using qualitative content analysis. Categories and subcategories were created inductively to summarize and systematize content. MAIN RESULTS AND THE ROLE OF CHANCE: Patients affected by RPL want their partners and their families and friends to deal with the topic openly and empathically. In the partnership itself, acceptance of individual grieving modes and sharing a common goal are important factors. Men, in particular, want their partners to be optimistic in facing up to the situation. Regarding communication with family and friends, it transpired that 'good advice', playing the matter down, inquiries about family planning, pity and special treatment are explicitly not appreciated. LIMITATIONS REASONS FOR CAUTION: The sample was a convenience sample, so self-selection effects cannot be excluded. In addition, the level of education in the sample was above average. Accordingly, the sample cannot be regarded as representative. The results of the content analysis are based on the respondents' written answers to open-ended questions in the questionnaire. Unlike qualitative interview studies, further questioning was not possible in the case of ambiguities or to request more details. WIDER IMPLICATIONS OF THE FINDINGS: Frank and sincere communication about miscarriages and about one's own emotions and needs should be promoted both in the partnership and among family members and friends in order to strengthen the potential of social support as a resource. Open communication about the different needs of both partners is necessary to create mutual understanding. The results show the importance not only of empathy and consideration for the couples concerned but also their desire not to be pitied. Striking a fine balance between fellow-feeling and pity may also lead to tension, and this potential dilemma should be addressed in psychosocial counselling. Overall, the study contributes to a better understanding of what couples want from their families and friends when they are attempting to come to terms with RPL and highlights potential challenges in the interaction between affected couples and their families and friends. STUDY FUNDING/COMPETING INTERESTS: No funding was received for this study. None of the authors declared any conflicts of interest. TRIAL REGISTRATION NUMBER: DRKS00014965.
RESUMEN
We review the current theories of nanodomain, or "raft," formation. We emphasize that the idea that they are co-exisiting Lo and Ld phases is fraught with difficulties, as is the closely related idea that they are due to critical fluctuations. We then review an alternate theory that the plasma membrane is a two-dimensional microemulsion, and that the mechanism that drives to zero the line tension between Lo and Ld phases is the coupling of height and composition fluctuations. The theory yields rafts of SM and cholesterol in the outer leaf and POPS and POPC in the inner leaf. The "sea" between rafts consists of POPC in the outer leaf and POPE and cholesterol in the inner leaf. The characteristic size of the domain structures is tens of nanometers.
Asunto(s)
Colesterol , Microdominios de Membrana , Microdominios de Membrana/química , Colesterol/química , Membrana CelularRESUMEN
It is widely, but not universally, believed that the lipids of the plasma membrane are not uniformly distributed, but that "rafts" of sphingolipids and cholesterol float in a "sea" of unsaturated lipids. The physical origin of such heterogeneities is often attributed to a phase coexistence between the two different domains. We argue that this explanation is untenable for several reasons. Further, we note that the results of recent experiments are inconsistent with this picture. However, they are quite consistent with an alternate explanation, namely, that the plasma membrane is a microemulsion of the two kinds of regions. To show this, we briefly review a simplified version of this theory and its phase diagram. We also explicate the dependence of the predicted domain size on four physical parameters. They are the energy cost of gradients in the composition, the spontaneous curvature of the membrane, its bending modulus and its surface tension. Taking values of the latter two from experiment, we obtain domain sizes for several different cell types that vary from 58 to 88 nm.
RESUMEN
We consider a model lipid plasma membrane, one that describes the outer leaf as consisting of sphingomyelin, phosphatidylcholine, and cholesterol and the inner leaf of phosphatidylethanolamine, phosphatidylserine, phosphatidylcholine, and cholesterol. Their relative compositions are taken from experiment; the cholesterol freely interchanges between leaves. Fluctuations in local composition are coupled to fluctuations in the local membrane curvature, as in the Leibler-Andelman mechanism. Structure factors of components in both leaves display a peak at nonzero wavevector. This indicates that the disordered fluid membrane is characterized by structure of the corresponding wavelength. The scale is given by membrane properties: its bending modulus and its surface tension, which arises from the membrane's connections to the cytoskeleton. From measurements on the plasma membrane, this scale is on the order of 100 nm. We find that the membrane can be divided into two different kinds of domains that differ not only in their composition but also in their curvature. The first domain in the outer, exoplasmic leaf is rich in cholesterol and sphingomyelin, whereas the inner, cytoplasmic leaf is rich in phosphatidylserine and phosphatidylcholine. The second kind of domain is rich in phosphatidylcholine in the outer leaf and in cholesterol and phosphatidylethanolamine in the inner leaf. The theory provides a tenable basis for the origin of structure in the plasma membrane and an illuminating picture of the organization of lipids therein.
Asunto(s)
Colesterol , Esfingomielinas , Membrana Celular , Microdominios de Membrana , Fosfatidilcolinas , Hojas de la PlantaRESUMEN
We consider the plasma membrane that contains a cholesterol molar fraction of 0.4 and ask how that cholesterol is distributed between the two leaves. Because of the rapid flip-flop of cholesterol between leaves, we assume that its distribution is determined by the equality of its chemical potentials in the two leaves. When we consider only the contributions of entropy and interactions to the cholesterol chemical potential in our model system, we find, not surprisingly, that the cholesterol is mostly in the outer leaf because of the strong attraction between cholesterol and sphingomyelin (SM), which is predominantly in that leaf. We find 72% there. We then include the contribution from the bending energy in each leaf that must be overcome to join the leaves in a flat bilayer. The product of bending modulus and spontaneous curvature is obtained from simulation. We find that the addition of cholesterol to the outer leaf reduces the spontaneous curvature, which is initially positive, until it passes through zero when the molar fraction of cholesterol in the outer leaf is 0.28. Additional cholesterol is driven toward the inner leaf by the sphingomyelin phosphatidylcholine mixture. This is resisted by the bending energy contribution to the inner leaf. We find, again by simulation, that the addition of cholesterol monotonically increases the magnitude of the spontaneous curvature of the inner leaf, which is negative. This increases its bending energy. We conclude that, as a result of these competing effects, the percentage of cholesterol in the outer leaf is reduced to â¼63 ± 6%.
Asunto(s)
Membrana Celular/metabolismo , Colesterol/metabolismo , Fenómenos Mecánicos , Fenómenos Biomecánicos , Colesterol/química , Modelos Moleculares , Conformación Molecular , TermodinámicaRESUMEN
The commercially available collar device MooMonitor+ was evaluated with regards to accuracy and application potential for measuring grazing behavior. These automated measurements are crucial as cows feed intake behavior at pasture is an important parameter of animal performance, health and welfare as well as being an indicator of feed availability. Compared to laborious and time-consuming visual observation, the continuous and automated measurement of grazing behavior may support and improve the grazing management of dairy cows on pasture. Therefore, there were two experiments as well as a literature analysis conducted to evaluate the MooMonitor+ under grazing conditions. The first experiment compared the automated measurement of the sensor against visual observation. In a second experiment, the MooMonitor+ was compared to a noseband sensor (RumiWatch), which also allows continuous measurement of grazing behavior. The first experiment on n = 12 cows revealed that the automated sensor MooMonitor+ and visual observation were highly correlated as indicated by the Spearman's rank correlation coefficient (rs) = 0.94 and concordance correlation coefficient (CCC) = 0.97 for grazing time. An rs-value of 0.97 and CCC = 0.98 was observed for rumination time. In a second experiment with n = 12 cows over 24-h periods, a high correlation between the MooMonitor+ and the RumiWatch was observed for grazing time as indicated by an rs-value of 0.91 and a CCC-value of 0.97. Similarly, a high correlation was observed for rumination time with an rs-value of 0.96 and a CCC-value of 0.99. While a higher level of agreement between the MooMonitor+ and both visual observation and RumiWatch was observed for rumination time compared to grazing time, the overall results showed a high level of accuracy of the collar device in measuring grazing and rumination times. Therefore, the collar device can be applied to monitor cow behavior at pasture on farms. With regards to the application potential of the collar device, it may not only be used on commercial farms but can also be applied to research questions when a data resolution of 15 min is sufficient. Thus, at farm level, the farmer can get an accurate and continuous measurement of grazing behavior of each individual cow and may then use those data for decision-making to optimize the animal management.
Asunto(s)
Acelerometría/veterinaria , Bovinos/fisiología , Conducta Alimentaria , Monitoreo Fisiológico/veterinaria , Acelerometría/instrumentación , Animales , Granjas , FemeninoRESUMEN
Feeding behaviour is an important parameter of animal performance, health and welfare, as well as reflecting levels and quality of feed available. Previously, sensors were only used for measuring animal feeding behaviour in indoor housing systems. However, sensors such as the RumiWatchSystem can also monitor such behaviour continuously in pasture-based environments. Therefore, the aim of this study was to validate the RumiWatchSystem to record cow activity and feeding behaviour in a pasture-based system. The RumiWatchSystem was evaluated against visual observation across two different experiments. The time duration per hour at grazing, rumination, walking, standing and lying recorded by the RumiWatchSystem was compared to the visual observation data in Experiment 1. Concordance Correlation Coefficient (CCC) values of CCC=0.96 for grazing, CCC=0.99 for rumination, CCC=1.00 for standing and lying and CCC=0.92 for walking were obtained. The number of grazing and rumination bouts within one hour were also analysed resulting in Cohen's Kappa (κ)=0.62 and κ=0.86 for grazing and rumination bouts, respectively. Experiment 2 focused on the validation of grazing bites and rumination chews. The accordance between visual observation and automated measurement by the RumiWatchSystem was high with CCC=0.78 and CCC=0.94 for grazing bites and rumination chews, respectively. These results indicate that the RumiWatchSystem is a reliable sensor technology for observing cow activity and feeding behaviour in a pasture based milk production system, and may be used for research purposes in a grazing environment.
Asunto(s)
Herbivoria/fisiología , Monitoreo Ambulatorio/instrumentación , Monitoreo Ambulatorio/normas , Rumiación Digestiva/fisiología , Dispositivos Electrónicos Vestibles/normas , Animales , Bovinos , Femenino , Reproducibilidad de los ResultadosRESUMEN
I consider a model of a bilayer characterized by two order parameters, one in each leaf. That of the inner leaf represents the difference in mole fractions of lipids with large spontaneous curvature, phosphatidylethanolamine (PE), and those with small spontaneous curvatures, phosphatidylcholine (PC) and phosphatidylserine (PS). Similarly, the order parameter in the outer leaf represents the difference in mole fractions of lipids with small spontaneous curvature, PC, and large curvature, sphingomyelin (SM). Each order parameter is coupled to the variations in the height of the membrane that is assumed to be of constant thickness. The couplings are of different strength. I show that, with reasonable parameters, a microemulsion is formed in each leaf, and that the two microemulsions are strongly coupled. Their characteristic size of domains is found to be on the order of 75 nm. In this picture, rafts consist of regions of SM in the outer leaf and PC and PS in the inner leaf, floating in a sea of PC in the outer leaf and PE in the inner leaf. I argue that microemulsions have been observed, but not identified as such, in model systems.
Asunto(s)
Membrana Dobles de Lípidos/química , Hojas de la Planta/química , Esfingomielinas/química , Fosfatidilcolinas/química , Fosfatidiletanolaminas/química , Fosfatidilserinas/químicaRESUMEN
We address questions posed by experiments that show small-chain alcohols reduce the miscibility transition temperature when added to giant plasma membrane vesicles (GPMVs), but increase that temperature when added to giant unilamellar vesicles. In giant unilamellar vesicles the change in temperature displays a definite minimum, between decanol and tetradecanol, as a function of alcohol chain length; in GPMVs there is no such minimum. To emphasize the competition between internal entropies of the components and the interactions between them, we model the system as consisting of three different linear polymers. Two of them are the constituents of a liquid, one that can undergo a miscibility transition. To this liquid is added the third polymer component, which represents the short-chain alcohol. We show that, within Flory-Huggins theory, the addition of alcohol causes an increase or decrease of the miscibility transition temperature depending upon the competition of two effects. The first is the dilution of the interactions between the two components of the liquid caused by the introduction of the alcohol. This tends to lower the transition temperature. The second effect is the preferential partitioning of the alcohol into one phase of the liquid or the other. This tends to raise the transition temperature irrespective of which phase the alcohol prefers. This second effect is the smallest, and the decrease in transition temperature the largest, when the alcohol partitions equally between the two phases. Such equal partitioning occurs when the effect of the entropic excluded volume interactions (which cause the alcohol to prefer one phase) just balances the effect of the direct interactions, which cause it to prefer the other. These results allow us to make several predictions, and to propose an explanation for the different behavior of the transition temperature in GPMVs and giant unilamellar vesicles that results from the addition of alcohols.
Asunto(s)
Soluciones/química , Temperatura de Transición , Liposomas Unilamelares/química , Alcoholes/química , Entropía , Modelos Teóricos , Polímeros/químicaRESUMEN
Sepsis is commonly associated with loss of microvascular endothelial barrier function (capillary leak) and dysfunctional microcirculation, which both promote organ failure. The development of a distinct therapy of impaired endothelial barrier function and disturbed microcirculation is highly relevant because both of these phenomena constitute crucial processes which critically influence the prognosis of patients. Numerous in vivo and in vitro trials over the past years have fostered a better understanding of the pathophysiology of capillary leak. Furthermore, promising data in animal models show that therapeutic modulation of endothelial barrier function and microcirculation can be achieved by stabilizing endothelial cAMP (cyclic adenosine monophosphate) levels followed by activation of Rho-GTPase Rac1, e. g. by phosphodiesterase 4 inhibitors. This review summarizes and discusses recent findings of cellular mechanisms and in vivo trials.
Asunto(s)
Síndrome de Fuga Capilar/tratamiento farmacológico , Endotelio Vascular/efectos de los fármacos , Microcirculación/efectos de los fármacos , Inhibidores de Fosfodiesterasa 4/uso terapéutico , Sepsis/tratamiento farmacológico , Sepsis/fisiopatología , Animales , Humanos , Pronóstico , Enfermedades Vasculares/tratamiento farmacológico , Enfermedades Vasculares/fisiopatologíaRESUMEN
Goal of this study was to investigate differences in quality of life in men contingent upon various fertility treatment stages, infertility causes and adoption of roles. A quantitative study with n = 115 men in three German fertility centres was devised. Participants completed a standardised, fertility-specific questionnaire devised for men (TLMK), sociodemographic and role items. Men having experienced severe medical conditions, for example cancer, reported significant higher quality of life compared to men with other infertility reasons [F(1,56) = 12.77, P = 0.001]. Furthermore, allocating participants into distinctive groups by means of kind and duration of treatment revealed significant group differences [F(2,111) = 4.94, P = 0.009], with quality of life decreasing with the use of more invasive fertility methods. A higher satisfaction with life was also stated by men adopting many tasks in the treatment process. The high quality of life displayed by men having experienced severe medical conditions contains valuable and far-reaching information about possible resilience factors that need to be researched more in detail. The finding of decreasing quality of life in men with the use of more invasive methods in treatment applies for increased psychosocial services in fertility clinics.
Asunto(s)
Infertilidad Masculina/psicología , Infertilidad Masculina/terapia , Adulto , Femenino , Identidad de Género , Humanos , Infertilidad Masculina/etiología , Masculino , Calidad de Vida/psicología , Conducta Reproductiva/psicología , Clase Social , Estrés Psicológico , Encuestas y CuestionariosRESUMEN
The distribution of cholesterol between the two leaves of the plasma membrane in mammalian cells presents a conundrum; given cholesterol's known affinity for sphingomyelin, which resides predominantly in the exoplasmic leaf, why is it that experiment finds a majority of the cholesterol in the cytoplasmic leaf? This article reviews a recently proposed solution to this puzzle.
Asunto(s)
Membrana Celular/metabolismo , Colesterol/metabolismo , Animales , Transporte BiológicoRESUMEN
I consider the effect of a small concentration of a molecule, such as a short-chain alcohol, on the miscibility transition temperature of a giant plasma membrane vesicle. For concentrations sufficiently small such that the system can be treated as a dilute solution, the change in transition temperature is known to depend upon the extent of the molecule's partition into the coexisting liquid-disordered and liquid-ordered phases. Preferential partitioning into the former decreases the miscibility temperature, while preferential partitioning into the latter causes an increase. The analysis, combined with calculated values of the partition coefficient of saturated chains, illuminates the results of recent experiments on the change in miscibility transition temperatures with changing alcohol chain length, and makes several testable predictions.
RESUMEN
We examine the behavior of lamellar phases of charged/neutral diblock copolymer thin films containing mobile ions in the presence of an external electric field. We employ self-consistent field theory and focus on the aligning effect of the electric field on the lamellae. Of particular interest are the effects of the mobile ions on the critical field, the value required to reorient the lamellae from the parallel configuration favored by the surface interaction to the perpendicular orientation favored by the field. We find that the critical field depends strongly on whether the neutral or charged species is favored by the substrates. In the case in which the neutral species is favored, the addition of charges decreases the critical electric field significantly. The effect is greater when the mobile ions are confined to the charged lamellae. In contrast, when the charged species is favored by the substrate, the addition of mobile ions stabilizes the parallel configuration and thus results in an increase in the critical electric field. The presence of ions in the system introduces a new mixed phase in addition to those reported previously.
Asunto(s)
Hemangioma/diagnóstico , Hemangioma/cirugía , Procedimientos Neuroquirúrgicos/métodos , Neoplasias del Sistema Nervioso Periférico/diagnóstico , Neoplasias del Sistema Nervioso Periférico/cirugía , Nervio Cubital/patología , Adulto , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Resultado del Tratamiento , Nervio Cubital/cirugía , Ultrasonografía/métodosRESUMEN
Milking postures have shifted from seated milking in tethered stalls to milking in a standing position in parlors. However, the musculoskeletal workload of dairy farmers remains high. Previous studies have shown that different working heights affect ergonomics, but they could not objectively evaluate and quantify the workload. The aim of the present study was to assess the effect of working height in different milking parlor types on the milker's workload during the task of attaching milking clusters. Computer-assisted recording and long-term analysis of movements were used to record positions of joints and body regions while performing certain tasks in terms of angular degrees of joints (ADJ) according to the neutral zero method. The 5th, 50th, and 95th percentiles described the distribution of angular degree values measured for each joint. The ADJ were evaluated according to international standards and other scientific literature on the issue to assess the muscular load. The workload was compared between 5 parlor types (auto tandem, herringbone 30°, herringbone 50°, parallel, and rotary) on 15 farms with 2 subjects per parlor and 1 milking period per subject. The working height was defined as a coefficient based on the milker's body height, the floor level, and the cow's udder height. The data recorded during the attachment task were analyzed using generalized linear mixed-effects models taking into account the hierarchical experimental design. The results indicated that the interaction of the cow's udder height, the milker's body height, and the parlor type had a larger effect on ergonomics than each parameter had independently. The interaction was significant in at least 1 of the 3 percentiles in 28 out of 31 ADJ. The postural differences between parlor types, however, were minor. A milking health formula was created to calculate the ideal depth of pit by considering the parlor type, the milker's height, and the mean herd udder height. This formula can be used to develop individual recommendations for future parlor construction.