Complete nucleotide sequences of bovine alpha S2- and beta-casein cDNAs: comparisons with related sequences in other species

The nucleotide sequences corresponding to bovine alpha S2- and beta- casein mRNAs have been determined by cDNA analysis. Both sequences appear to be complete at their 5' ends. The nucleotide sequence of alpha S2-casein, when compared with the corresponding cavine A sequence, helps to define the boundaries of a large amino acid repeat (approximately 80 residues) whereas comparisons with the nucleotide sequences of rat gamma- and mouse epsilon-casein mRNAs also reveal extensive sequence similarities. An alignment of these four sequences shows that the divergence of their translated regions has been characterized by the duplication and deletion of discrete segments of sequence that probably correspond to exons. A high degree of nucleotide substitution is also found when the four sequences are compared, except for well-conserved leader-peptide and phosphorylation-site sequences and, to a lesser extent, the 5'-untranslated regions. Similar comparison of the bovine and rat beta-caseins shows that their divergence has involved a high rate of nucleotide substitution but that no major insertions or deletions of sequence have occurred. The several splice sites that have veen defined in the rat beta-casein gene are likely to have been conserved in the bovine. The contrasting evolutionary histories of the alpha- and beta-casein coding sequences correlate with the distinctive functions of these proteins in the casein micelle system in milk.      

Studies of the metabolism of carbon disulfide by rat liver microsomes

Carbon disulfide has been examined as a substrate for the hepatic mixed function oxidase enzyme system. These studies have revealed that carbonyl sulfide is formed when carbon disulfide is incubated with rat liver microsomes in the presence of NADPH. No carbonyl sulfide is formed in the absence of NADPH. The formation of carbonyl sulfide is inhibited when the reaction is carried out in an atmosphere containing carbon monoxide. The other product of the reaction leading to carbonyl sulfide formation appears to be a highly reactive form of sulfur which covalently binds to the microsomal membrane. A chemical mechanism for the mixed function oxidase catalyzed metabolism of carbon disulfide to carbonyl sulfide is proposed.     

A cytochemical study of GERL in cultured human fibroblasts

Cultured human skin fibroblasts contain an extensive GERL network. The GERL consists of acid phosphatase-positive polygonal tubules and tuberous thickenings which are adjacent to the Golgi cisternae. It often surrounds lucent vacuoles and rarely lipid bodies. Cultures examined at various intervals after subculturing, passages in culture and at different ages of the source of the primary fibroblasts demonstrate no significant morphologic variation in GERL. However, the network appears to fragment in mitotic fibroblasts. Cultured fibroblasts from patients with lysosomal storage diseases exhibit a normal GERL. Exposure of fibroblasts to non-toxic levels of chloroquine and ammonium chloride result in increasing dilatation of the GERL and the resultant formation of large cytoplasmic vacuoles. These observations support the previously proposed theory that this network is a special form of lysosome packaged to contain a large membrane pool.     

Thirty two years of continuous assessment reveal first year university biology students in Australia are rapidly abandoning beliefs in theistic involvement in human origins

Background

For the past 32 years, we have polled first-year biology students annually at the University of New South Wales concerning their views about evolution and creationism. The purposes of the research were to identify the level of commitment among incoming students to creationist beliefs that could interfere with their receptivity to evolutionary science and to assess in retrospect whether these creationist beliefs were changing over time.

Results

The results have demonstrated a downward shift over time from 60% of the class in 1986 believing a god had something to do with the origin of humans, to 29% in 2017. Conversely, the percentage of students convinced that a god had nothing to do with the origin of humans rose from 25% in 1986 to 62% in 2017. The creationist belief that a god created the world de novo within the last 10,000 years declined from 10% in 1986 to 3.6% in 2017. The decline in the Australian students’ commitment to religious views about divine creation, especially creationism, considerably exceeded the corresponding beliefs among American students and their general public, where belief in creationism while slowly declining appears to have remained in the 40% range, four times that seen in our Australian survey.

Conclusions

The very low and declining levels of commitment to the creationist view that god created humans de novo suggests this view is unlikely to be a significant obstruction to accepting the scientific evidence for evolution. The results of the survey of UNSW students correlate with changes documented in the census of the general Australian public suggesting that our survey results of first-year biology students reflect overall changes in the Australian community as a whole.

     

Assessing the effect of genetic diversity on the early establishment of the threatened seagrass Posidonia australis using a reciprocal‐transplant experiment

Two common goals for restoration are rapid plant establishment and long‐term plant persistence. The success of transplanted populations may be jeopardized if the donor transplants are not genetically diverse, and/or poorly matched to their new environment. Here, we test the effects of local adaptation and plot‐level genetic diversity on the early establishment phase of a threatened seagrass species, Posidonia australis, by performing a reciprocal transplant experiment across two genetically and geographically distinct populations in southeastern Australia. Posidonia australis is a long‐lived, slow‐growing species that has no seed bank, and the successful transplantation of live shoots and seedlings is the only available restoration method. Our results show a strong effect of local adaptation and genetic diversity on P. australis survivorship and performance over the first 6 months following transplantation. High‐genetic diversity plots displayed higher survival rates and exhibited reduced productivity and increased carbohydrate reserves within the rhizome. This suggests that high‐diversity plots included shoots that were conserving energy stores by actively reducing growth rates during the early stages of transplantation. The lowest diversity plots exhibited high leaf and root productivity and corresponding low carbohydrate reserves. This may be a sign of stress in the low‐diversity transplants, potentially explaining the very low survival rate. We suggest that future restoration efforts source donor transplants from multiple local sources to ensure both local adaptation and sufficient genetic diversity to increase the likelihood of early establishment success.     

The Role of Polygalacturonase (PG) in the Ripening of Apple Fruits

Polygalacturonase (PG) activity and changes in respiratory intensity of apple fruits were investigated. The respiratory rate was decreased to a preclimacteric minimum from 30 Aug. to 20 Sept., Then increased to a climacteric peak (20–30 Sept.) and again drop down gradually with approaching the senescence stage. The PG activity was undetectable in a developing fruit until the onset climacteric phase. It rose rapidly after harvest, and reaching its highest level on 27 Oct. Just a month after the climacteric peak. The PG activity fell gradually. The amount of the fractions of pectic acid in fruits changed with the modifications of PG activity. With the ripening of fruits, the content of alcohol-soluble small molecules of pectic acids was increased from 12 to 13 5 mg/100 g of tissue, while the amount of alcohol- insoluble large molecules of pectic acids reduced from 530 to 280/100 g of tissue. PG activity would indicate the destruction of cell walls and the separation of cells. The onset of softening of fruits occurred 20 days after the rise of PG activity. It is supposed that the process of softening is directly controlled by PG activity.     

Disturbances,Their Interactions,and Cumulative Effects on Carbon and Charcoal Stocks in a Forested Ecosystem

Disturbances have a strong role in the carbon balance of many ecosystems, and the cycle of vegetation growth, disturbance, and recovery is very important in determining the net carbon balance of terrestrial biomes. Compound disturbances are phenomena of growing concern which can impact ecosystems in novel ways, altering disturbance intensity, severity, and recovery trajectories. This research focuses on carbon stocks in a compound disturbance environment, with special attention on black carbon (charcoal), a potential source of long-term carbon sequestration. We report on a well-studied compound disturbance event (wind, logging, and severe fire) in a Colorado, USA subalpine forest that was extensively surveyed for impacts on carbon, black carbon, and regeneration. All major pools were considered, including organic and mineral soil (10 cm depth), and contrasted with neighboring undisturbed forests as a reference. The disturbances had an additive effect on carbon loss, with increasing numbers of disturbances resulting in progressively decreasing carbon/black carbon stocks. This resulted from lower substrate availability and higher fire intensity. Surprisingly, there was no significant difference between reference and burned plots in terms of total black carbon. It appears that high-intensity fires do not significantly increase net black carbon in these forests (over the entire fire-return interval), with additional disturbances potentially resulting in a net loss. Disturbances, and their interactions, will have long-lasting legacies for carbon and black carbon.     

Doppler ultrasound method for detecting human fetal breathing in utero.

An audible Doppler ultrasound method for detecting human fetal breathing movements in utero has been developed. The frequencies synchronous with fetal breathing movements probably originate from the lung rather than the chest wall. This method is much cheaper and simpler than the ultrasound A-scan method and is suitable for screening large numbers of people.     

Patterns of distribution for southern Australian marine echinoderms and decapods

Aim To relate patterns of distribution of marine echinoderms and decapods around southern Australia to major ecological and historical factors. Location Shallow‐water (0–100 m) marine waters off southern Australia, south of 30° S. Methods (1) Record the presence/absence of known echinoderm and decapod species in cells of c. 1° latitude and longitude, along the coast of southern mainland Australia and Tasmania. (2) Describe patterns in species composition, species richness and endemism through gradient analysis, ordination and cluster analysis. (3) Relate these patterns to distance and temperature gradients, the area of continental shelf, the average size of species range, and known historical factors. Results Species composition varied with both latitude and longitude. Species richness was relatively constant from east to west but graded with latitude from high in the warm‐temperate regions around Perth and Sydney to low in cool‐temperate southern Tasmania. Species richness was not related to the area of continental shelf or average species range size. Species turnover was not correlated with rates of temperature change. It was problematic to separate distance from temperature gradients, but there was evidence that the southern distribution limits of some species are related to minimum sea surface temperature. Within the taxonomic groups surveyed, evolutionary radiation has been largely limited to a few cosmopolitan species‐rich genera. Main conclusions There are historical as well as ecological hypotheses explaining the latitudinal gradient of marine species richness in southern Australia: (1) the continual invasion and speciation of species of tropical origin as Australia has split from Gondwana and drifted northward; (2) progressive extinction of some Gondwanan cool‐temperate species at the limits of their range; (3) low level of immigration of additional cool‐temperate species; and (4) some in situ endemic speciation.     

ST-segment elevation associated with allergic reaction to echocardiographic contrast agent administration

We report a case of an allergic reaction after the administration of an echocardiographic contrast agent which resulted in ST-segment elevation. Hypersensitivity and allergic reactions are known causes of acute cardiovascular events. However, only limited reports are available which suggest the exact mechanism of the occurrence of angina or myocardial infarction during severe allergic reactions. In our case, through invasive imaging (coronary angiography and IVUS) we have shown for the first time a transient coronary spasm in the absence of intra-coronary thrombus and only minimal neointimal hyperplasia.