The contribution of <Emphasis Type="Italic">Potamogeton crispus</Emphasis> to the phosphorus budget of an urban shallow lake: Lake Monger,Western Australia

Lake Monger (Perth, Western Australia) is a highly eutrophic lake, characterised by very low species richness of macrophytes with the dominance of Potamogeton crispus. Mesocosm experiments were performed using water and plants collected from the lake to determine the effects of vegetation decay on the phosphorus (P) concentrations in the overlying waters. After 2 weeks of experimental incubation of mesocosms with and without re-oxygenation, P concentrations in the water column were significantly higher, showing a quite similar effect of P. crispus on the phosphorus release in different mesocosms. The results of our study provide clear evidence that the P concentrations in overlying waters mainly depend upon the plant P content and developmental stage. Although many sources contribute to the nutrient load of Lake Monger, macrophyte harvesting, prior to its senescence, might constitute a significant in-lake measure for reducing the internal P load.     

Population‐based analysis of health care contacts among suicide decedents: identifying opportunities for more targeted suicide prevention strategies

The objective of this study was to detail the nature and correlates of mental health and non‐mental health care contacts prior to suicide death. We conducted a systematic extraction of data from records at the Office of the Chief Coroner of Ontario of each person who died by suicide in the city of Toronto from 1998 to 2011. Data on 2,835 suicide deaths were linked with provincial health administrative data to identify health care contacts during the 12 months prior to suicide. Sub‐populations of suicide decedents based on the presence and type of mental health care contact were described and compared across socio‐demographic, clinical and suicide‐specific variables. Time periods from last mental health contact to date of death were calculated and a Cox proportional hazards model examined covariates. Among suicide decedents, 91.7% had some type of past‐year health care contact prior to death, 66.4% had a mental health care contact, and 25.3% had only non‐mental health contacts. The most common type of mental health contact was an outpatient primary care visit (54.0%), followed by an outpatient psychiatric visit (39.8%), an emergency department visit (31.1%), and a psychiatric hospitalization (21.0%). The median time from last mental health contact to death was 18 days (interquartile range 5‐63). Mental health contact was significantly associated with female gender, age 25‐64, absence of a psychosocial stressor, diagnosis of schizophrenia or bipolar disorder, past suicide attempt, self‐poisoning method and absence of a suicide note. Significant differences between sub‐populations of suicide decedents based on the presence and nature of their health care contacts suggest the need for targeting of community and clinical‐based suicide prevention strategies. The predominance of ambulatory mental health care contacts, often close to the time of death, reinforce the importance of concentrating efforts on embedding risk assessment and care pathways into all routine primary and specialty clinical care, and not only acute care settings.     

Differences in oscillatory whistles produced by spinner (Stenella longirostris) and pantropical spotted (Stenella attenuata) dolphins

Acoustic recordings of two closely related species, spinner dolphin (Stenella longirostris) and pantropical spotted dolphin (Stenella attenuata), were investigated from four different geographic locations: two in the Central Tropical Pacific, one in the Eastern Tropical Pacific and one in the Indian Ocean. The two delphinid species occur in tropical and warm temperate waters, with overlapping ranges. They produce very similar vocalizations, but at the same time their calls exhibit a certain degree of intraspecific variation among different geographic locations as has been observed in other delphinid species. Oscillatory whistles (whistles with at least two oscillations in their frequency contours) were identified and manually extracted from the recordings. Whistles with four or more maxima (oscillations) occurred only in spinner dolphins and they were present in all geographic regions investigated. In addition, the oscillatory whistles with two and three maxima were significantly more frequent in spinner than in spotted dolphins. The differences in oscillatory whistles for these two species seem to be consistent across study areas and therefore, could be used in addition to other whistle features to help distinguish between them.     

Odontocete occurrence in relation to changes in oceanography at a remote equatorial Pacific seamount

Seamounts are considered hot spots of biodiversity and can aggregate pelagic predators and their prey. Passive acoustic monitoring was conducted over 3 mo in 2012 to document the occurrence of odontocetes near a seamount chain in the central equatorial Pacific in relation to oceanographic changes over time. Beaked whale echolocation signals were most frequently encountered. The main beaked whale signal was an unknown type, BW38, which resembled signals produced by Blainville's beaked whales. It had high occurrence during high sea surface temperature and low sea surface salinity. Cuvier's beaked whales were the second most detected. They had an opposite pattern and were encountered more often when sea surface temperature was low and net primary productivity was high. Risso's dolphins and short‐finned pilot whales had high acoustic densities, and echolocated predominantly at night. Risso's dolphins occurred more often during low sea surface height deviation. False killer whales were less frequently detected and mostly occurred during the day. Sperm whale detections were fewer than expected and associated with high chlorophyll a. Short duration Kogiidae encounters occurred on average every third day. These types of long‐term site studies are an informative tool to comparatively assess species composition, relative abundance, and relationship to oceanographic changes.     

Structural and biochemical insights into 7β‐hydroxysteroid dehydrogenase stereoselectivity

Hydroxysteroid dehydrogenases are of great interest as biocatalysts for transformations involving steroid substrates. They feature a high degree of stereo‐ and regio‐selectivity, acting on a defined atom with a specific configuration of the steroid nucleus. The crystal structure of 7β‐hydroxysteroid dehydrogenase from Collinsella aerofaciens reveals a loop gating active‐site accessibility, the bases of the specificity for NADP⁺, and the general architecture of the steroid binding site. Comparison with 7α‐hydroxysteroid dehydrogenase provides a rationale for the opposite stereoselectivity. The presence of a C‐terminal extension reshapes the substrate site of the β‐selective enzyme, possibly leading to an inverted orientation of the bound substrate. Proteins 2016; 84:859–865. © 2016 Wiley Periodicals, Inc.     

Response of soil microbial biomass and activity in early restored lands in the northeastern Brazilian Atlantic Forest

Intensive land use of the Brazilian Atlantic Forest accelerated with the rise of sugar cane plantations in the northeastern part of Brazil. Consequently, many ecosystems were destroyed, including riparian forests. The number of studies of riparian restoration has increased but comparative studies on the belowground effects of common reforestation strategies are rare. Here, we compared soil microbial properties among four different land use types: native rainforest, sugar cane plantation, single species reforestation, and mixed species reforestation, each replicated at two spatially independent sites. Soil samples were taken in 2013 and 2014, that is 2 and 3 years after reforestation, respectively. In both years, land use types had a significant effect on basal respiration, microbial biomass, and specific respiration (whereas specific respiration was marginally affected in 2014). In 2013, basal respiration in sugar cane plantations was significantly lower (?65%) when compared to native forests. In 2014, basal respiration (+60%) and soil microbial biomass (+90%) were significantly higher in mixed species reforestation compared to sugar cane, whereas single species reforestation had comparable values as in sugar cane plantations. Our results indicate that soil microbial biomass and activity respond rapidly to land use change when mixed species reforestation is used. Thus, using mixed species reforestation may enhance the provisioning of ecosystem services already in the short term.     

Protein Paucimannosylation Is an Enriched N‐Glycosylation Signature of Human Cancers

While aberrant protein glycosylation is a recognized characteristic of human cancers, advances in glycoanalytics continue to discover new associations between glycoproteins and tumorigenesis. This glycomics‐centric study investigates a possible link between protein paucimannosylation, an under‐studied class of human N‐glycosylation [Man_1‐3GlcNAc₂Fuc_0‐1], and cancer. The paucimannosidic glycans (PMGs) of 34 cancer cell lines and 133 tissue samples spanning 11 cancer types and matching non‐cancerous specimens are profiled from 467 published and unpublished PGC‐LC‐MS/MS N‐glycome datasets collected over a decade. PMGs, particularly Man_2‐3GlcNAc₂Fuc₁, are prominent features of 29 cancer cell lines, but the PMG level varies dramatically across and within the cancer types (1.0–50.2%). Analyses of paired (tumor/non‐tumor) and stage‐stratified tissues demonstrate that PMGs are significantly enriched in tumor tissues from several cancer types including liver cancer (p = 0.0033) and colorectal cancer (p = 0.0017) and is elevated as a result of prostate cancer and chronic lymphocytic leukaemia progression (p < 0.05). Surface expression of paucimannosidic epitopes is demonstrated on human glioblastoma cells using immunofluorescence while biosynthetic involvement of N‐acetyl‐β‐hexosaminidase is indicated by quantitative proteomics. This intriguing association between protein paucimannosylation and human cancers warrants further exploration to detail the biosynthesis, cellular location(s), protein carriers, and functions of paucimannosylation in tumorigenesis and metastasis.