402 research outputs found
Cryptosporidium parvum and Giardia intestinalis in Calf Diarrhoea in Sweden
The objective of this study conducted in 75 herds was to investigate the presence and significance of Cryptosporidium parvum and Giardia intestinalis in Swedish dairy calves in comparison with rotavirus, coronavirus and Escherichia coli K99+. The farmers were asked to collect faecal samples from each heifer calf that had diarrhoea between birth and 90 days of age, and also from a healthy calf of the same age. In total, 270 samples were collected and analysed. C. parvum, either alone or together with G. intestinalis and/or rotavirus, was detected in 16 (11%) and 6 (5%) of the samples from diarrhoeic and healthy calves, respectively. Even though a higher proportion of diarrhoeic calves shed C. parvum, the difference between the groups was not statistically significant (p = 0.067), possibly due to the low number of positive samples. G. intestinalis was found in 42 (29%) of the diarrhoea samples and in 29 (23%) of the samples from healthy calves. Rotavirus and coronavirus were demonstrated in 24% and 3% of the diarrhoea samples, respectively, whereas E. coli K99+ was only found in samples from 2 healthy calves. C. parvum and G. intestinalis were found in samples from calves 7 to 84 days of age and during all seasons. The results confirm that C. parvum is present in Swedish dairy herds and might have clinical significance. G. intestinalis was the most common agent found but the importance of this parasite remains unclear. Both parasites have suggested zoonotic potential and thus warrant further attention. In addition, rotavirus is a major pathogen in neonatal enteritis in Sweden, whereas coronavirus and E. coli K99+ seem to be of less importance
Prolonged sexual abstinence after childbirth: gendered norms and perceived family health risks. Focus group discussions in a Tanzanian suburb
Background: Prolonged sexual abstinence after childbirth is a socio-cultural practice with health implications, and is described in several African countries, including Tanzania. This study explored discourses on prolonged postpartum sexual abstinence in relation to family health after childbirth in low-income suburbs of Dar es Salaam, Tanzania.
Methods: Data for the discourse analysis were collected through focus group discussions with first-time mothers and fathers and their support people in Ilala, Dar es Salaam, Tanzania.
Results: In this setting, prolonged sexual abstinence intended at promoting child health was the dominant discourse in the period after childbirth. Sexual relations after childbirth involved the control of sexuality for ensuring family health and avoiding the social implications of non-adherence to sexual abstinence norms. Both abstinence and control were emphasised more with regard to women than to men. Although the traditional discourse on prolonged sexual abstinence for protecting child health was reproduced in Ilala, some modern aspects such as the use of condoms and other contraceptives prevailed in the discussion.
Conclusion: Discourses on sexuality after childbirth are instrumental in reproducing gender-power inequalities, with women being subjected to more restrictions and control than men are. Thus, interventions that create openness in discussing sexual relations and health-related matters after childbirth and mitigate gendered norms suppressing women and perpetuating harmful behaviours are needed. The involvement of males in the interventions would benefit men, women, and children through improving the gender relations that promote family health
The Cosmic Microwave Background and Helical Magnetic Fields: the tensor mode
We study the effect of a possible helicity component of a primordial magnetic
field on the tensor part of the cosmic microwave background temperature
anisotropies and polarization. We give analytical approximations for the tensor
contributions induced by helicity, discussing their amplitude and spectral
index in dependence of the power spectrum of the primordial magnetic field. We
find that an helical magnetic field creates a parity odd component of gravity
waves inducing parity odd polarization signals. However, only if the magnetic
field is close to scale invariant and if its helical part is close to maximal,
the effect is sufficiently large to be observable. We also discuss the
implications of causality on the magnetic field spectrum.Comment: We have corrected a normalisation error which was pointed out to us
by Antony Lewis. It enhances our limits on the magnetic fields by
(2\pi)^{3/4} ~
Magnetic fields in the early universe in the string approach to MHD
There is a reformulation of magnetohydrodynamics in which the fundamental
dynamical quantities are the positions and velocities of the lines of magnetic
flux in the plasma, which turn out to obey equations of motion very much like
ideal strings. We use this approach to study the evolution of a primordial
magnetic field generated during the radiation-dominated era in the early
Universe. Causality dictates that the field lines form a tangled random
network, and the string-like equations of motion, plus the assumption of
perfect reconnection, inevitably lead to a self-similar solution for the
magnetic field power spectrum. We present the predicted form of the power
spectrum, and discuss insights gained from the string approximation, in
particular the implications for the existence or not of an inverse cascade.Comment: 12 pages, 2 figure
Full characterization of vibrational coherence in a porphyrin chromophore by two-dimensional electronic spectroscopy
In this work we present experimental and calculated two-dimensional electronic spectra for a 5,15-bisalkynyl porphyrin chromophore. The lowest energy electronic Qy transition couples mainly to a single 380 cm–1 vibrational mode. The two-dimensional electronic spectra reveal diagonal and cross peaks which oscillate as a function of population time. We analyze both the amplitude and phase distribution of this main vibronic transition as a function of excitation and detection frequencies. Even though Feynman diagrams provide a good indication of where the amplitude of the oscillating components are located in the excitation-detection plane, other factors also affect this distribution. Specifically, the oscillation corresponding to each Feynman diagram is expected to have a phase that is a function of excitation and detection frequencies. Therefore, the overall phase of the experimentally observed oscillation will reflect this phase dependence. Another consequence is that the overall oscillation amplitude can show interference patterns resulting from overlapping contributions from neighboring Feynman diagrams. These observations are consistently reproduced through simulations based on third order perturbation theory coupled to a spectral density described by a Brownian oscillator model
Periodic magnetoconductance fluctuations in triangular quantum dots in the absence of selective probing
We have studied the magnetoconductance of quantum dots with triangular
symmetry and areas down to 0.2 square microns, made in a high mobility
two-dimensional electron gas embedded in a GaAs-AlGaAs heterostructure.
Semiclassical simulations show that the gross features in the measured
magnetoconductance are caused by ballistic effects. Below 1 K we observe a
strong periodic oscillation, which may be explained in terms of the
Aharanov-Bohm flux quantization through the area of a single classical periodic
orbit. From a numerical and analytical analysis of possible trajectories in
hard- and soft-walled potentials, we identify this periodic orbit as the
enscribed triangle. Contrary to other recent experiments, this orbit is not
accessible by classical processes for the incoming collimated beam.Comment: RevTex 8 pages, including 5 postscript figure
Point-of-admission hypothermia among high-risk Nigerian newborns
<p>Abstract</p> <p>Background</p> <p>Facilities which manage high-risk babies should frequently assess the burden of hypothermia and strive to reduce the incidence.</p> <p>Objective</p> <p>To determine the incidence and outcome of point-of-admission hypothermia among hospitalized babies.</p> <p>Methods</p> <p>The axillary temperatures of consecutive admissions into a Nigerian Newborn Unit were recorded. Temperature <36.5°C defined hypothermia. The biodata and outcome of these babies were studied.</p> <p>Results</p> <p>Of 150 babies aged 0 to 648 hours, 93 had hypothermia with an incidence of 62%. Mild and moderate hypothermia accounted for 47.3% and 52.7% respectively. The incidence of hypothermia was highest (72.4%) among babies aged less than 24 hours. It was also higher among out-born babies compared to in-born babies (64.4% <it>vs </it>58.3%). Preterm babies had significantly higher incidence of hypothermia (82.5%) compared with 54.5% of term babies (RR = 1.51; CI = 1.21 – 1.89). The incidence of hypothermia was also highest (93.3%) among very-low-birth-weight babies.</p> <p>The Case-Fatality-Rate was significantly higher among hypothermic babies (37.6% vs 16.7%; RR = 2.26, CI = 1.14 – 4.48) and among out-born hypothermic babies (50% vs 17.1%; RR = 0.34, CI = 0.16 – 0.74). CFR was highest among hypothermic babies with severe respiratory distress, sepsis, preterm birth and asphyxia.</p> <p>Conclusion</p> <p>The high incidence and poor outcome of hypothermia among high-risk babies is important. The use of the 'warm chain' and skin-to-skin contact between mother and her infant into routine delivery services in health facilities and at home may be useful.</p
Effective suckling in relation to naked maternal-infant body contact in the first hour of life: an observation study
Background
Best practice guidelines to promote breastfeeding suggest that (i) mothers hold their babies in naked body contact immediately after birth, (ii) babies remain undisturbed for at least one hour and (iii) breastfeeding assistance be offered during this period. Few studies have closely observed the implementation of these guidelines in practice. We sought to evaluate these practices on suckling achievement within the first hour after birth.
Methods
Observations of seventy-eight mother-baby dyads recorded newborn feeding behaviours, the help received by mothers and birthing room practices each minute, for sixty minutes.
Results
Duration of naked body contact between mothers and their newborn babies varied widely from 1 to 60 minutes, as did commencement of suckling (range = 10 to 60 minutes). Naked maternal-infant body contact immediately after birth, uninterrupted for at least thirty minutes did not predict effective suckling within the first hour of birth. Newborns were four times more likely to sustain deep rhythmical suckling when their chin made contact with their mother’s breast as they approached the nipple (OR 3.8; CI 1.03 - 14) and if their mothers had given birth previously (OR 6.7; CI 1.35 - 33). Infants who had any naso-oropharyngeal suctioning administered at birth were six times less likely to suckle effectively (OR .176; CI .04 - .9).
Conclusion
Effective suckling within the first hour of life was associated with a collection of practices including infants positioned so their chin can instinctively nudge the underside of their mother’s breast as they approach to grasp the nipple and attach to suckle. The best type of assistance provided in the birthing room that enables newborns to sustain an effective latch was paying attention to newborn feeding behaviours and not administering naso-oropharyngeal suction routinely
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