Experimental study of laser detected magnetic resonance based on atomic alignment

We present an experimental study of the spectra produced by optical/radio-frequency double resonance in which resonant linearly polarized laser light is used in the optical pumping and detection processes. We show that the experimental spectra obtained for cesium are in excellent agreement with a very general theoretical model developed in our group and we investigate the limitations of this model. Finally, the results are discussed in view of their use in the study of relaxation processes in aligned alkali vapors.Comment: 8 pages, 9 figures. Submitted to Phys. Rev. A. Related to physics/060523

The surface-associated exopolysaccharide of Bifidobacterium longum 35624 plays an essential role in dampening host proinflammatory responses and repressing local TH17 responses

The immune-modulating properties of certain bifidobacterial strains, such as Bifidobacterium longum subsp. longum 35624 (B. longum 35624), have been well described, although the strain-specific molecular characteristics associated with such immune-regulatory activity are not well defined. It has previously been demonstrated that B. longum 35624 produces a cell surface exopolysaccharide (sEPS), and in this study, we investigated the role played by this exopolysaccharide in influencing the host immune response. B. longum 35624 induced relatively low levels of cytokine secretion from human dendritic cells, whereas an isogenic exopolysaccharide-negative mutant derivative (termed sEPSneg) induced vastly more cytokines, including interleukin-17 (IL-17), and this response was reversed when exopolysaccharide production was restored in sEPSneg by genetic complementation. Administration of B. longum 35624 to mice of the T cell transfer colitis model prevented disease symptoms, whereas sEPSneg did not protect against the development of colitis, with associated enhanced recruitment of IL-17+ lymphocytes to the gut. Moreover, intranasal administration of sEPSneg also resulted in enhanced recruitment of IL-17+ lymphocytes to the murine lung. These data demonstrate that the particular exopolysaccharide produced by B. longum 35624 plays an essential role in dampening proinflammatory host responses to the strain and that loss of exopolysaccharide production results in the induction of local TH17 responses. IMPORTANCE: Particular gut commensals, such as B. longum 35624, are known to contribute positively to the development of mucosal immune cells, resulting in protection from inflammatory diseases. However, the molecular basis and mechanisms for these commensal-host interactions are poorly described. In this report, an exopolysaccharide was shown to be decisive in influencing the immune response to the bacterium. We generated an isogenic mutant unable to produce exopolysaccharide and observed that this mutation caused a dramatic change in the response of human immune cells in vitro. In addition, the use of mouse models confirmed that lack of exopolysaccharide production induces inflammatory responses to the bacterium. These results implicate the surface-associated exopolysaccharide of the B. longum 35624 cell envelope in the prevention of aberrant inflammatory responses

Design and performance of laser-pumpedCs-magnetometers for the planned UCN EDMExperiment at PSI

We designed laser-pumped cesium vapor magnetometers in the Mx configuration for the control and stabilization of magnetic field fluctuations and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. The intrinsic sensitivity of the device was determined to be 30 fT in a measurement bandwidth of 1 Hz, limited by laser noise. In the shot noise limit the magnetometer can reach a sensitivity of 7 fT for 1 s integration time. Test measurements of the stability of a 2 μT magnetic field in a threefold magnetic shield have revealed fluctuations on the order of 200 fT to 300 fT with integration times in the range of 2 s to 100 s. Those fluctuations were traced back to the stability of the power supply used to generate the magnetic field. The laser-pumped magnetometer fulfills the requirements set by the planned neutron electric dipole moment experiment

Untersuchungen zur Beeinflussung des Ovulationszeitpunktes beim laktierenden Rind durch intravenöse Glukoseinfusionen im Proöstrus

Die Fruchtbarkeitsleistung hochleistender laktierender Kühe ist in den letzten Jahren deutlich schlechter geworden. Unter anderem wird die gesteigerte Milchleistung für einen sinkenden Erstbesamungserfolg verantwortlich gemacht. Eine mangelhafte Brunsterkennung und Störungen im Ovulationsprozess spielen dabei eine bedeutende Rolle. Feldstudien detektierten in bis zu 46,1 % der dokumentierten Zyklen laktierender Kühe eine verzögerte Ovulation. Es konnte ein signifikanter Zusammenhang zwischen der Energieversorgung am Tag der Besamung und der Inzidenz der verzögerten Ovulation nachgewiesen werden. Aus diesem Ergebnis leiten wir die Hypothese ab, dass eine aktuelle hypoenergetische Stoffwechselsituation den Ovulationsprozess verzögert. Ziel der vorliegenden Studie war es, zu überprüfen, inwiefern intravenöse Glukoseinfusionen zu verschiedenen Zeitpunkten im Proöstrus die endokrine Sekretion, den Ovulationszeitpunkt und verschiedene Zyklusparameter beeinflussen. Dazu wurden zehn multipare, laktierende Deutsche-Holstein-Schwarzbunte Kühe in der mittleren Laktation in vier Gruppen mit unterschiedlichen Behandlungen gelost. Jede Kuh durchlief in unterschiedlicher Reihenfolge alle vier Gruppen. Die Zyklen wurden alle zwei Tage mittels transrektaler Sonographie der Ovarien dokumentiert. Ab einem Durchmesser des dominanten Follikels von über 10 mm erfolgte die Sonographie der Ovarien täglich. Gruppe 1 stellte die unbeeinflusste Kontrolle dar, in der jeweils drei Zyklen von jeder Kuh erhoben wurden (n = 30). In den Gruppen 2 bis 4 erfolgte eine Infusion von 1 Liter einer 5 %igen Glukoselösung an den Tagen 20, 19 und 18 des Zyklus (jeweils n = 10). Die Auswirkungen auf die Zykluslänge, die Östrussymptome, die Anzahl der Follikelwellen, den Follikeldurchmesser und das Alter des dominanten Follikels wurden untersucht. Vom 17. Zyklustag bis zum 5. Tag und am 7. Tag post ovulationem erfolgte die Entnahme von Serumproben zur Bestimmung der Konzentrationen des Östradiol-17 beta, Progesterons und der Glukose.Nachdem die Glukoseinfusion am 19. Zyklustag eine signifikante Verkürzung der Zykluslänge im Vergleich zur Gruppe 1 ergab, wurde in zwei weiteren Gruppen der Effekt der Behandlung am 19. Zyklustag auf die präovulatorische Sekretion des Luteinisierenden Hormons getestet. Die zehn Kühe wurden zwei Gruppen zugelost, in der Gruppe 5 erfolgte eine Glukoseinfusion und in der Gruppe 6 eine Infusion mit dergleichen Menge 0,9 %iger Natriumchloridlösung am 19. Zyklustag (jeweils n = 5). Serumproben wurden alle drei Stunden nach der Behandlung bis zur Ovulation entnommen. Die statistische Auswertung der gewonnen Daten erfolgte mittels den Programmen SPSS 15.0 für Windows und SAS 12.0 für MS-DOS. Folgende relevante Ergebnisse konnten erhoben werden: - Die Zykluslänge in Gruppe 3 nach Glukoseinfusion am 19. Zyklustag betrug 21,3 ± 1,3 Tage und war somit signifikant kürzer als in der Gruppe 1 (23,3 ± 1,9 Tage; p < 0,01), während die Behandlung in den Gruppen 2 und 4 ohne signifikanten Einfluss auf die Zykluslänge blieb. - In Gruppe 1 wurden in 56,7 % der Zyklen Östrussymptome detektiert. Es bestand ein Trend zur Detektion von mehr Zyklen mit Östrussymptomen in der Gruppe 3 (90 %), der jedoch nicht als statistisch signifikant belegt werden konnte (p = 0,12). - Der Durchmesser des präovulatorischen Follikels wurde nicht signifikant durch die Behandlung beeinflusst (p > 0,05), allerdings variierte der Follikeldurchmesser signifikant zwischen den zehn einzelnen Kühen (p = 0,018). - Die Glukosekonzentration steigt in den Gruppen 1 bis 4 präovulatorisch an. - Ein Zusammenhang zwischen der Glukosekonzentration und den Konzentrationen des Östradiol-17 beta und des Progesterons in der Gruppe 1 konnte nicht detektiert werden. - Die maximalen Östradiol-17 beta-Konzentrationen zwei Tage vor der Ovulation waren in den Gruppen 2 bis 4 nach Glukoseinfusion signifikant höher als in Gruppe 1. - In Gruppe 3 steigt die Glukosekonzentration vier und sechs Stunden (p = 0,022 und p = 0,028) sowie in der Gruppe 4 vier Stunden nach der Behandlung (p = 0,050) signifikant an. - Ein Einfluss der Behandlung auf die Östradiol-17& #946;-Konzentration war nur für die Gruppe 3 nachweisbar. Der Anstieg der mittleren Östradiol-17 beta-Konzentration war zum Zeitpunkt 24 Stunden nach der Infusion signifikant (p = 0,033). - Die mittlere LH-Peak-Konzentration war in Gruppe 5 nach Glukoseinfusion signifikant niedriger als in Gruppe 6 nach Infusion von 0,9 % iger Kochsalzlösung (p = 0,043). - Das Intervall zwischen der Behandlung am 19. Zyklustag und dem LH-Peak war mit 25,8 ± 9,6 Stunden in Gruppe 5 kürzer als in Gruppe 6 (52,8 ± 35,7 Stunden; p = 0,21). - An den Tagen fünf und sieben nach der Ovulation war die mittlere Progesteronkonzentration der Zyklen über 23 Tagen Dauer signifikant höher als in der Gruppe der Zykluslängen bis zu 23 Tagen (p = 0,032 und p = 0,001). - In der Gruppe der Zyklen bis 23 Tagen ist die mittlere Glukosekonzentration an den beiden Tagen vor der Ovulation signifikant höher als in der Gruppe der Zyklen über 23 Tagen Dauer (p = 0,040 und p = 0,033). Die Ergebnisse dieser experimentellen Untersuchungen konnten zum ersten Mal die Möglichkeit einer Beeinflussung des Ovulationszeitpunktes durch einen kurzfristigen Energiebolus beim laktierenden Rind belegen. Die Glukoseinfusion in einer zeitlich eng limitierten Phase des Proöstrus am 19. Zyklustag bedingt eine Steigerung der Östradiol-17 beta-Synthese, wodurch es zu einer frühzeitigeren Ausschüttung des präovulatorischen LH-Peaks kommt. Dies ist im Zusammenhang mit Untersuchungen bei Labornagern und beim kleinen Wiederkäuer zu sehen. Die vorliegende Arbeit zeigt eine weitere Ebene auf, auf der ein Zusammenhang zwischen der Energieversorgung und der Fruchtbarkeit beim laktierenden Rind besteht.The reproductive performance of high producing dairy cows has clearly been decreasing for years. Among others the increasing milk yield is responsible for decreasing conception rates after first artificial insemination. A lack of oestrus detection and failures of the ovulatory process play thereby an important role. Field studies revealed in up to 46.1 % of documented cycles in dairy cows a delayed ovulation. A significant correlation between the energy supply at the day of artificial insemination and the incidence of delayed ovulations could be demonstrated. From these results we suggested, that an actual hypoenergetic metabolic situation delays the ovulatory process. The aim of the present study was therefore to check, if intravenous infusions of glucose at different terms in pre-oestrus influence the endocrine secretion, the time of ovulation and different oestrus cycle parameters. Ten lactating, multiparous German Holstein Cows in the middle of lactation were randomized in six groups with different treatments. Each cow passed through all four groups in different order. All oestrus cycles were documented via transrectal ultrasonography of the ovaries. The transrectal sonography took place daily when the dominat follicle reached a diameter of ten millimetres. Group 1 represented the untreated control in which three cycles of each cow were recorded (n = 30). In groups 2 to 4 an infusion of one litre of a 5 % glucose solution was carried out at the days 20, 19 an 18 of the oestrus cycle respectively (each group n = 10). The effects on the length of oestrus cycles, the oestrus behaviour, the number of waves of follicular growth and the diameter of the preovulatory follicle were examined. From day 17 of the cycle to the 5th day and at the 7th day after ovulation blood samples were taken to determine the concentrations of progesterone, estradiol-17 beta and glucose. Since the infusion of glucose at day 19 of the oestrus cycle resulted in a significant shortening of cycle length, the effect of the treatment at day 19 of the oestrus cycle on the preovulatory secretion of luteinizing hormone was tested. The ten cows were randomly allocated into two groups. In group 5 an infusion of a 5 % glucose solution and in group 6 an infusion of a 0.9 % sodium chloride-solution took place at day 19 of the oestrus cycle (each group n = 5). Blood samples were taken every three hours after the treatment until ovulation. Statistical analysis of the data was calculated with the programs SPSS 15.0 for Windows und SAS 12.0 for DOS. The following relevant results were documented: - The length of oestrus cycles in group 3 after glucose infusion at day 19 of the cycle was 21.3 ± 1.3 days and thus significant shorter than in group 1 (23.3 ± 1.9 days; p < 0.01), whereas the treatment in groups 2 and 4 had no significant effect on the length of oestrus cycles. - In group 1 in 56.7 % of cycles oestrus signs were detected. There was at least a trend to the detection of more cycles with characteristic oestrus symptoms in group 3 (90 %), which could not be proven significantly (p = 0.12). - The treatment did not influence the diameter of the preovulatory follicle (p > 0.05), but the diameter of the preovulatory follicle varied significantly between the ten individual cows (p = 0.018). - The concentration of glucose increases before ovulation in groups 1 to 4. - A correlation between the concentration of glucose and the concentrations of estradiol-17 beta or progesterone could not be detected.- The maximum estradiol-17 beta-concentrations two days before ovulation were significantly higher in groups 2 to 4 after infusion of glucose compared to group 1. - The concentrations of glucose increase significantly four and six hours after the treatment in group 3 (p = 0.022 and p = 0.028) and four hours after the treatment in group 4 (p = 0.050). - An influence of the treatment on the concentration of estradiol-17 beta was only given in group 3. The estradiol-17 beta concentration increases significantly 24 hours after the treatment (p = 0.033). - The mean surge-concentration of LH in group 5 after infusion of glucose was significant lower than in group 6 after infusion of 0.9% sodium chloride (p = 0.043). - The interval between the treatment at day 19 of the oestrus cycle and the surge concentration of LH was 25.8 ± 9.6 hours in group 5 and thus shorter than in group 6 (52.8 ± 35.7 hours; p = 0.21). . - The mean progesterone concentrations at days five and seven after the ovulation were significant higher in oestrus cycles over 23 days than in cycles up to 23 days (p = 0.032 and p = 0.001). - In the group of oestrus cycles up to 23 days the mean concentration of glucose at the two days before ovulation is significant higher than in cycles lasting over 23 days (p = 0.040 and p = 0.033). The results of this experimental study could for the first time prove the possibility of a manipulation of the ovulation time by a short-term energy supply in lactating dairy cows. The infusion of glucose in a temporally strictly limited period of pre-oestrus at day 19 causes an increase of estradiol-17 beta synthesis and in consequence an earlier induction of the preovulatory surge of LH. This effect has already been proven in rodents and sheep. This study points out a further level of relationship between energy balance and fertility in lactating dairy cows

Laser-pumped cesium magnetometers for high-resolution medical and fundamental research

Laser-pumped cesium magnetometers allow highly sensitive magnetometry at room temperature. We report on applications of that technique in biomagnetic diagnostics and in a neutron electric dipole moment (nEDM) experiment. In the biomagnetic application the magnetic field from the beating human heart is detected using a gradiometer, which reaches an intrinsic sensitivity of 80 fT/Hz1/2. The device can record time-resolved magnetic field maps above the human body surface with a spatial resolution of 4 cm and its performance is comparable to commercial devices based on the SQUID technique. In the nEDM experiment laser-pumped cesium magnetometers are used to measure and stabilize a dc magnetic field at a level of 10⁻⁷. Those devices reach an intrinsic sensitivity of about 14 fT/Hz1/2 with a measurement bandwidth of 1 kHz. The general principle of operation and specific results are presented

A high-sensitivity laser-pumped M_x magnetometer

We discuss the design and performance of a laser-pumped cesium vapor magnetometer in the Mx configuration. The device will be employed in the control and stabilization of fluctuating magnetic fields and gradients in a new experiment searching for a permanent electric dipole moment of the neutron. We have determined the intrinsic sensitivity of the device to be 15 fT in a 1 Hz bandwidth, limited by technical laser noise. In the shot noise limit the magnetometer can reach a sensitivity of 10 fT in a 1 Hz bandwidth. We have used the device to study the fluctuations of a stable magnetic field in a multi-layer magnetic shield for integration times in the range of 2–100 seconds. The residual fluctuations for times up to a few minutes are traced back to the instability of the power supply used to generate the field

Experimental study of laser-detected magnetic resonance based on atomic alignment

We present an experimental study of the spectra produced by optical–radio-frequency double resonance in which resonant linearly polarized laser light is used in the optical pumping and detection processes. We show that the experimental spectra obtained for cesium are in excellent agreement with a very general theoretical model developed in our group [Weis, Bison, and Pazgalev, Phys. Rev. A 74, 033401 (2006)] and we investigate the limitations of this model. Finally, the results are discussed in view of their use in the study of relaxation processes in aligned alkali-metal vapors

Prevalence of subclinical ketosis and production diseases in dairy cows in Central and South America, Africa, Asia, Australia, New Zealand, and Eastern Europe1

Subclinical ketosis (SCK) and periparturient diseases considerably account for economic and welfare losses in dairy cows. The majority of scientific reports investigating the prevalence of SCK and production diseases are based on empirical studies conducted in Western Europe and North America. The present study surveyed the prevalence of SCK and production-related clinical diseases in early lactating cows in various countries across the world other than those in North America and Western Europe. Twelve countries of South and Central America (Argentina, Brazil, Chile, Colombia, Mexico), Africa (South Africa), Asia (Thailand, China), Eastern Europe (Russia, Ukraine), Australia, and New Zealand were assessed, and data from a total of 8,902 cows kept at 541 commercial dairy farms were obtained. A minimum of five cows per farm were blood sampled and examined once after parturition up to day 21 of lactation. Blood concentration of β-hydroxybutyrate was measured (threshold for SCK: 1.2 mmol/L), and the presence of production-related diseases such as milk fever, retained placenta, mastitis, metritis, displaced abomasum, lameness, and clinical ketosis was recorded. More than 95% of all cows were examined in their second week of lactation. Across all investigated countries, the SCK prevalence was 24.1%, ranging from 8.3% up to 40.1%. The prevalence of production-related diseases detected during the first 21 d of lactation was relatively low (<5%). Calculated odds ratios did not indicate an elevated risk for production diseases in cows with SCK. Despite differences in production systems across countries and variation between individual farms within a region, the present study data on SCK prevalence align with observations in Western European and North American dairy herds. At the very early stage of sampling and clinical examination for detection of SCK, it cannot be excluded that certain production diseases such as displaced abomasum, lameness, and mastitis have developed later

The surface-associated exopolysaccharide of bifidobacterium longum 35624 plays an essential role in dampening host proinflammatory responses and repressing local TH17 responses

The immune-modulating properties of certain bifidobacterial strains, such as Bifidobacterium longum subsp. longum 35624 (B. longum 35624), have been well described, although the strain-specific molecular characteristics associated with such immune-regulatory activity are not well defined. It has previously been demonstrated that B. longum 35624 produces a cell surface exopolysaccharide (sEPS), and in this study, we investigated the role played by this exopolysaccharide in influencing the host immune response. B. longum 35624 induced relatively low levels of cytokine secretion from human dendritic cells, whereas an isogenic exopolysaccharide-negative mutant derivative (termed sEPSneg) induced vastly more cytokines, including interleukin-17 (IL-17), and this response was reversed when exopolysaccharide production was restored in sEPSneg by genetic complementation. Administration of B. longum 35624 to mice of the T cell transfer colitis model prevented disease symptoms, whereas sEPSneg did not protect against the development of colitis, with associated enhanced recruitment of IL-17+ lymphocytes to the gut. Moreover, intranasal administration of sEPSneg also resulted in enhanced recruitment of IL-17+ lymphocytes to the murine lung. These data demonstrate that the particular exopolysaccharide produced by B. longum 35624 plays an essential role in dampening proinflammatory host responses to the strain and that loss of exopolysaccharide production results in the induction of local TH17 responses. IMPORTANCE: Particular gut commensals, such as B. longum 35624, are known to contribute positively to the development of mucosal immune cells, resulting in protection from inflammatory diseases. However, the molecular basis and mechanisms for these commensal-host interactions are poorly described. In this report, an exopolysaccharide was shown to be decisive in influencing the immune response to the bacterium. We generated an isogenic mutant unable to produce exopolysaccharide and observed that this mutation caused a dramatic change in the response of human immune cells in vitro In addition, the use of mouse models confirmed that lack of exopolysaccharide production induces inflammatory responses to the bacterium. These results implicate the surface-associated exopolysaccharide of the B. longum 35624 cell envelope in the prevention of aberrant inflammatory responses