Objective: To compare the birth characteristics of the Growing Up in New Zealand cohort with those of all New Zealand (NZ) births over a similar time period, and to describe cohort alignment to current NZ births. Method:The Growing Up in New Zealand longitudinal study recruited 6,846 children from before birth via their pregnant mothers who were residing in the greater Auckland and Waikato regions during 2009 and 2010. Data were collected from mothers antenatally and six weeks after their expected delivery date, and from routine perinatal health records. These data were compared to Ministry of Health data for all births in NZ between 2007 and 2010. Results:The proportion of males and singleton births were not statistically different to national births. Compared to national births fewer of the cohort children were born low birth weight (4.9% vs. 6.1%, p<0.0001) or preterm (6.4% vs. 7.4%, p=0.001) and the cohort was expected to be more ethnically diverse than national births. Conclusion:Birth parameters for the cohort were generally closely aligned to all NZ births in 2007-2010. Some statistically significant differences reflected small absolute differences, attributable in some part to cohort recruitment requiring survival to six weeks post expected delivery. Implications:The explicit documentation of the alignment of the cohort to national data provides assurance that the study is well placed to deliver findings that can inform policy development relevant to the diversity of the contemporary NZ child population.
The microfossil record suggests that cyanobacteria or cyanobacteria-like prokaryotes were present on the primitive Earth in the Archaean era more than 3.5 billion years ago (28). The exquisite preservation of these microfossils is thought to reflect the intrinsic stability of the extracellular polysaccharide (EPS) and its ability to bind heavy metals as well as resist degradation (13). Extant cyanobacteria dominate the microbial populations of many extreme environments including soda lakes (Spirulina, Cyanospira), the nutrient-poor open ocean (Trichodesmium), thermal springs (Synechococcus and Mastigocladis), and the cold dry polar deserts (Chroococcidiopsis) (35). In these environments the cyanobacteria produce copious amounts of EPSs in the form of sheaths, slimes, and capsules. Very little is known about the diversity, mode of synthesis, structure, or properties of these biopolymers (19). A recent review emphasized the potential role of EPSs in the desiccation tolerance of prokaryotes (23). However, much further research is needed to resolve the specific mechanisms which biopolymers contribute to such a complex process.The terrestrial cyanobacterium Nostoc commune has a marked capacity for desiccation tolerance and can survive storage at Ϫ400 MPa (0% relative humidity) for centuries (23). The cells produce large amounts of an unusual excreted polysaccharide that contributes in at least four ways to the marked stabilization of cells during prolonged storage in the air-dried state, at low or high temperatures. First, the glycan inhibits fusion of membrane vesicles during desiccation and freezedrying (10) and acts as an immobilization matrix for a range of secreted enzymes which remain fully active after long-term air-dried storage (11,27,32). Second, the glycan provides a structural and/or molecular scaffold with rheological properties which can accommodate the rapid biophysical and physiological changes in the community upon rehydration and during recovery from desiccation. The glycan swells from brittle dried crusts to cartilaginous structures within minutes of rehydration. Third, the glycan matrix contains both lipid-and watersoluble UV radiation-absorbing pigments which protect the cell from photodegradation (12). Fourth, although epiphytes colonize the surfaces of Nostoc colonies, there is no penetration of the glycan due in part to a silicon-and calcium-rich pellicle and inherent resistance of the glycan to enzymatic breakdown. Preliminary structural work on one water-soluble UV-absorbing pigment (released from the glycan by acid hydrolysis) indicated the presence of an oligosaccharide (4), raising the possibility that the pigment may be covalently linked to the glycan in the desiccated state.An understanding of the biochemical and biophysical properties of such biopolymers and the isolation of genes and enzymes required for their synthesis and modification can lead to an understanding of the underlying principles of extremophile stability. Furthermore, one can envision the utilization of such materials f...
From January to July 1938, experiments with Anopheles maculipennis race atroparvus, Van Thiel, were undertaken to discover whether humidity and the age at which the females fed influenced their longevity. It was found that they lived longer at higher than at lower humidities; that most of the females which fed did so in the first three days; that those which fed on the second day after emergence lived longer than those which fed at other ages; and that the feeding period was slightly extended in the later experiments, though only a small proportion lived long enough to take their first blood meals on the fourth and fifth days.Rather more than 50 per cent. of each batch of newly emerged adults were females.A large proportion of the deaths of unfed males and females occurred during the first three days, most of them on the second day; this mortality decreased in successive experiments.Culex fatigans, Wied., behaved similarly.
The hatching of the eggs of Pediculus humanus corporis De Geer is influenced by temperature.High temperatures accelerate and low temperatures delay development.The lowest constant temperature at which eggs will hatch is 24° and the highest 37°.At 24° eggs begin to hatch on the seventeenth day and continue hatching until the twenty-first. At 37° eggs hatch on the sixth and seventh days. The temperature at which eggs hatch in the shortest time is 35° and the time 5 days. At these extremes many eggs are killed so that the percentages of successful hatches are very low. Eggs are killed by 2 days' exposure to 39°.Temperatures at which the maximum number of eggs hatch he between 29 and 32°. In this range of “favourable” temperatures, up to 97% of successful hatches may be recorded. The incubation period is from 7 to 11 days. This is a convenient range of temperatures for laboratory purposes and gives largest numbers in a reasonably short time.Newly deposited eggs will not hatch if kept for 14 days at 23° or for shorter periods at lower temperatures, until at 8° exposure for 7 days is sufficient to ensure that all eggs are dead.If partially developed eggs are exposed to temperatures of 15° or lower, development ceases. If they are restored to a favourable temperature within 7 days, development is resumed and some of the eggs will hatch.Older eggs which have almost reached hatching point at a “favourable” temperature hatch if transferred to temperatures as low as 18°. They do not hatch at 15° or lower if kept at such temperatures for at least 9 days.
The tick, Ornithodoros moubata, was named by Murray in 1877 as Argas moubata; his specimens came from Angola (Portuguese West Africa), where twenty years earlier, Livingstone had noticed that such ticks were common in native huts; but Murray's description was “quite useless” (Nuttall & others, 1908) and it was Pocock (1900) who first published a recognizable description of the species and distinguished between 0. moubata and 0. savignyi (Audouin).
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