14,320 research outputs found
The climate of eastern Tasmania indicated by its lichen flora
During a visit of five weeks to Tasmania, in February and
March, 1891, while exploring for lichens in the 'neighbourhoods
of Launceston, Mount Arthur, Ulverstone, Hobart,
Mount Wellington, the Huon River, and St. Mary's Pass, I
was struck with the general and unexpected poverty of the
lichen flora, and, on looking about for the cause of this, I
noted the evident frequency of bush fires, which are the most
destructive enemies of lichen growth. This, however, did
not wholly explain the matter, for, even where the plants
might be expected to recover from the action of the fire, their
vitality seemed to be checked by the dryness of the climate.
This was a discovery surprising to a Victorian, who had been
accustomed to consider the climate of Tasmania a humid one.
An examination of meteorological authorities, however,
showed that in the eastern portion of the island the rainfall
is rot only less than it is in the western, but less than it is in
Victoria. In the west and the highlands of Tasmania 75in. of
rain have been registered in one year, and the average of the
whole island is said to be 35in.; but the annual rainfall at
Hobart is only 21-52in
General practitioner provision of preventive child health care: analysis of routine consultation data
<b>Background</b> GPs contribute to preventive child health care in various ways, including provision of child health
surveillance (CHS) reviews, opportunistic preventive care, and more intensive support to vulnerable children. The
number of CHS reviews offered in Scotland was reduced from 2005. This study aimed to quantify GPs’ provision of
different types of preventive care to pre-school children before and after the changes to the CHS system.<p></p>
<b>Methods</b> GP consultation rates with children aged 0–4 years were examined for the 2½ years before and after the
changes to the CHS system using routinely available data from 30 practices in Scotland. Consultations for CHS
reviews; other aspects of preventive care; and all reasons were considered.<p></p>
<b>Results:</b> Prior to the changes to the CHS system, GPs often contributed to CHS reviews at 6–8 weeks and 8–9 and
39–42 months. Following the changes, GP provision of the 6–8 week review continued but other reviews
essentially ceased. Few additional consultations with pre-school children are recorded as involving other aspects of
preventive care, and the changes to CHS have had no impact on this. In the 2½ years before and after the changes,
consultations recorded as involving any form of preventive care accounted for 11% and 7.5% respectively of all
consultations with children aged 0–4 years, with the decline due to reductions in CHS reviews.<p></p>
<b>Conclusions:</b> Effective preventive care through the early years can help children secure good health and
developmental outcomes. GPs are well placed to contribute to the provision of such care. Consultations focused on
preventive care form a small minority of GPs’ contacts with pre-school children, however, particularly since the
reduction in the number of CHS reviews
Electron-Spin Excitation Coupling in an Electron Doped Copper Oxide Superconductor
High-temperature (high-Tc) superconductivity in the copper oxides arises from
electron or hole doping of their antiferromagnetic (AF) insulating parent
compounds. The evolution of the AF phase with doping and its spatial
coexistence with superconductivity are governed by the nature of charge and
spin correlations and provide clues to the mechanism of high-Tc
superconductivity. Here we use a combined neutron scattering and scanning
tunneling spectroscopy (STS) to study the Tc evolution of electron-doped
superconducting Pr0.88LaCe0.12CuO4-delta obtained through the oxygen annealing
process. We find that spin excitations detected by neutron scattering have two
distinct modes that evolve with Tc in a remarkably similar fashion to the
electron tunneling modes in STS. These results demonstrate that
antiferromagnetism and superconductivity compete locally and coexist spatially
on nanometer length scales, and the dominant electron-boson coupling at low
energies originates from the electron-spin excitations.Comment: 30 pages, 12 figures, supplementary information include
Association between congenital toxoplasmosis and preterm birth, low birthweight and small for gestational age birth.
OBJECTIVE: To determine the association between congenital toxoplasmosis and preterm birth, low birthweight and small for gestational age birth. DESIGN: Multicentre prospective cohort study. SETTING: Ten European centres offering prenatal screening for toxoplasmosis. POPULATION: Deliveries after 23 weeks of gestation in 386 women with singleton pregnancies who seroconverted to toxoplasma infection before 20 weeks of gestation. Deliveries after 36 weeks in 234 women who seroconverted at 20 weeks or later, and tested positive before 37 weeks. METHODS: Comparison of infected and uninfected births, adjusted for parity and country of birth. MAIN OUTCOME MEASURES: Differences in gestational age at birth, birthweight and birthweight centile. RESULTS: Infected babies were born or delivered earlier than uninfected babies: the mean difference for seroconverters before 20 weeks was -5.4 days (95% CI: -1.4, -9.4), and at 20 weeks or more, -2.6 days (95% CI: -0.5, -4.7). Congenital infection was associated with an increased risk of preterm delivery when seroconversion occurred before 20 weeks (OR 4.71; 95% CI: 2.03, 10.9). No significant differences were detected for birthweight or birthweight centile. CONCLUSION: Babies with congenital toxoplasmosis were born earlier than uninfected babies but the mechanism leading to shorter length of gestation is unknown. Congenital infection could precipitate early delivery or prompt caesarean section or induction of delivery. We found no evidence for a significant association between congenital toxoplasmosis and reduced birthweight or small for gestational age birth
Monorail/Foxa2 regulates floorplate differentiation and specification of oligodendrocytes, serotonergic raphe neurones and cranial motoneurones
In this study, we elucidate the roles of the winged-helix transcription factor Foxa2 in ventral CNS development in zebrafish. Through cloning of monorail (mol), which we find encodes the transcription factor Foxa2, and phenotypic analysis of mol(-/-) embryos, we show that floorplate is induced in the absence of Foxa2 function but fails to further differentiate. In mol(-/-) mutants, expression of Foxa and Hh family genes is not maintained in floorplate cells and lateral expansion of the floorplate fails to occur. Our results suggest that this is due to defects both in the regulation of Hh activity in medial floorplate cells as well as cell-autonomous requirements for Foxa2 in the prospective laterally positioned floorplate cells themselves. Foxa2 is also required for induction and/or patterning of several distinct cell types in the ventral CNS. Serotonergic neurones of the raphe nucleus and the trochlear motor nucleus are absent in mol(-/-) embryos, and oculomotor and facial motoneurones ectopically occupy ventral CNS midline positions in the midbrain and hindbrain. There is also a severe reduction of prospective oligodendrocytes in the midbrain and hindbrain. Finally, in the absence of Foxa2, at least two likely Hh pathway target genes are ectopically expressed in more dorsal regions of the midbrain and hindbrain ventricular neuroepithelium, raising the possibility that Foxa2 activity may normally be required to limit the range of action of secreted Hh proteins
Management and efficacy of intensified insulin therapy starting in outpatients
Diabetic patients under multiple injection insulin therapy (i.e., intensified insulin therapy, IIT) usually start this treatment during hospitalization. We report here on the logistics, efficacy, and safety of IIT, started in outpatients. Over 8 months, 52 type I and type II diabetics were followed up whose insulin regimens consecutively had been changed from conventional therapy to IIT. Two different IIT strategies were compared: free mixtures of regular and intermediate (12 hrs)-acting insulin versus the basal and prandial insulin treatment with preprandial injections of regular insulin, and ultralente (24 hrs-acting) or intermediate insulin for the basal demand. After 8 months HbA1 levels had decreased from 10.6%±2.4% to 8.0%±1.3% (means±SD). There was no difference between the two regimens with respect to metabolic control; but type II patients maintained the lowered HbA1 levels better than type I patients. Only two patients were hospitalized during the follow-up time because of severe hypoglycemia. An increase of body weight due to the diet liberalization during IIT became a problem in one-third of the patients. Our results suggest that outpatient initiation of IIT is safe and efficacious with respect to near-normoglycemic control. Weight control may become a problem in IIT patients
A Decomposed Fourier-Motzkin Elimination Framework to Derive Vessel Capacity Models
Accurate Vessel Capacity Models (VCMs) expressing thetrade-off between different container types that can be stowed on containervessels are required in core liner shipping functions such as uptake-,capacity-, and network management. Today, simple models based on volume,weight, and refrigerated container capacity are used for these tasks,which causes overestimations that hamper decision making. Though previouswork on stowage planning optimization in principle provide finegrainedlinear Vessel Stowage Models (VSMs), these are too complexto be used in the mentioned functions. As an alternative, this papercontributes a novel framework based on Fourier-Motzkin Eliminationthat automatically derives VCMs from VSMs by projecting unneededvariables. Our results show that the projected VCMs are reduced byan order of magnitude and can be solved 20–34 times faster than theircorresponding VSMs with only a negligible loss in accuracy. Our frameworkis applicable to LP models in general, but are particularly effectiveon block-angular structured problems such as VSMs. We show similarresults for a multi-commodity flow problem
PB.23: Effect of detector type on cancer detection in digital mammography
This work measured the effect that image quality associated with different detectors has on cancer detection in mammography using a novel method for changing the appearance of images.\ud
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A set of 270 mammography cases (one view, both breasts) was acquired using five Hologic Selenias and two Hologic Dimensions X-ray units: 80 normal, 80 with simulated inserted subtle calcification clusters, 80 with subtle real noncalcification malignant lesions and 30 with benign lesions (biopsy proven). These 270 cases (Arm 1) were converted to appear as if they had been acquired on two other imaging systems: needle image plate computed radiography (CR) (Arm 2) and powder phosphor CR (Arm 3). Three experienced mammography readers marked the location of suspected cancers in the images and classified whether each lesion would require further investigation and the confidence in that decision. Performance was calculated as the area under curve (AUC) of the alternative free-response receiver operating characteristic curv
Sustained antimicrobial activity and reduced toxicity of oxidative biocides through biodegradable microparticles
The spread of antibiotic-resistant pathogens requires new treatments. Small molecule precursor compounds that produce oxidative biocides with well-established antimicrobial properties could provide a range of new therapeutic products to combat resistant infections. The aim of this study was to investigate a novel biomaterials-based approach for the manufacture, targeted delivery and controlled release of a peroxygen donor (sodium percarbonate) combined with an acetyl donor (tetraacetylethylenediamine) to deliver local antimicrobial activity via a dynamic equilibrium mixture of hydrogen peroxide and peracetic acid. Entrapment of the pre-cursor compounds into hierarchically structured degradable microparticles was achieved using an innovative dry manufacturing process involving thermally induced phase separation (TIPS) that circumvented compound decomposition associated with conventional microparticle manufacture. The microparticles provided controlled release of hydrogen peroxide and peracetic acid that led to rapid and sustained killing of multiple drug-resistant organisms (methicillin-resistant Staphylococcus aureus and carbapenem-resistant Escherichia coli) without associated cytotoxicity in vitro nor intracutaneous reactivity in vivo. The results from this study demonstrate for the first time that microparticles loaded with acetyl and peroxygen donors retain their antimicrobial activity whilst eliciting no host toxicity. In doing so, it overcomes the detrimental effects that have prevented oxidative biocides from being used as alternatives to conventional antibiotics
Human Female Genital Tract Infection by the Obligate Intracellular Bacterium Chlamydia trachomatis Elicits Robust Type 2 Immunity
While Chlamydia trachomatis infections are frequently asymptomatic, mechanisms that regulate host response to this intracellular Gram-negative bacterium remain undefined. This investigation thus used peripheral blood mononuclear cells and endometrial tissue from women with or without Chlamydia genital tract infection to better define this response. Initial genome-wide microarray analysis revealed highly elevated expression of matrix metalloproteinase 10 and other molecules characteristic of Type 2 immunity (e.g., fibrosis and wound repair) in Chlamydia-infected tissue. This result was corroborated in flow cytometry and immunohistochemistry studies that showed extant upper genital tract Chlamydia infection was associated with increased co-expression of CD200 receptor and CD206 (markers of alternative macrophage activation) by endometrial macrophages as well as increased expression of GATA-3 (the transcription factor regulating TH2 differentiation) by endometrial CD4+ T cells. Also among women with genital tract Chlamydia infection, peripheral CD3+ CD4+ and CD3+ CD4- cells that proliferated in response to ex vivo stimulation with inactivated chlamydial antigen secreted significantly more interleukin (IL)-4 than tumor necrosis factor, interferon-γ, or IL-17; findings that repeated in T cells isolated from these same women 1 and 4 months after infection had been eradicated. Our results thus newly reveal that genital infection by an obligate intracellular bacterium induces polarization towards Type 2 immunity, including Chlamydia-specific TH2 development. Based on these findings, we now speculate that Type 2 immunity was selected by evolution as the host response to C. trachomatis in the human female genital tract to control infection and minimize immunopathological damage to vital reproductive structures. © 2013 Vicetti Miguel et al
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