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"McFarlane, Joyce"
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The second Chinese revolution
\"If there is one image of China that is popular in the West, it is that of an economic giant that seems to just grow and grow. An economic growth made particularly striking by the country's huge scale. Its 9.6 million square kilometres make it the third-largest country in the world after Russia and Canada. Like them, it has continental dimensions, as do the United States, India and Brazil. But if we add to this territorial expanse a population of 1,347 million in 2011, only India can stand comparison. The Second Chinese Revolution explores China's growing impact on the global economy\"-- Provided by publisher.
Book
The nitrogen dynamics of Deer Cave, Sarawak, and the role of bat caves as biogeochemical sinks in Tropical Moist Forests
A better understanding of the role of bat caves as nitrogen sinks in tropical moist forest ecosystems can be expected to shed light on regional and spatial variability in nutrient recycling studies. We measured the nitrogen flux (in air and water) associated with a very large
Chaerephon plicata
bat colony in Deer Cave, Borneo, in the process generating a new, quantitative, estimate of the total bat population (774,828 ±48,320), and the first detailed modelling of an ammonia plume in a cave. Long-term storage of N does not occur in this wet cave. Our final budget numbers indicate that, of the daily input of N (i.e., ecologically-useful fixed-N in guano) to this cave, ammonia production is minor (and most of it is exported in water rather than air). The conclusion is that the export budget is dominated (perhaps as large as 94.4%) by microbial denitrification of fixed-N to diatomic N exported in air. Deer Cave thus acts as a nitrogen sink, potentially removing up to 39% of the ecologically-useful fixed-N from the total forest nitrogen budget over an area of hundreds of square kilometers.
Journal Article
Time-transgressive microbial diversity in a tropical bat guano accumulation, Deer Cave, Mulu, Borneo
Bat guano accumulations in caves can constitute large deposits of organic material, particularly chitin and its degradation products, that host a diverse microbiome. Previous microbiological studies have not addressed the stratified nature of these deposits in the context of the timeframe of the decomposition process. We present such data (temperature, pH, DNA sampling of eight carbon-dated strata) for a 75 cm-deep tropical guano accumulation that undergoes complete decomposition over a timescale of ~120 years. The aerobic, surface layer of freshly-fallen guano has the greatest diversity of taxa, with Bacteroidota co-dominant with Pseudomonadota, and includes many taxa unique to this zone (including those from guanophagic invertebrates, bat guts, and insects). The ~20-40-year-old, more anaerobic, middle layer of increasing acidity and temperature has fewer taxa, with Pseudomonadota dominant and Bacteroidota almost disappearing, and many taxa tolerant of high temperatures and anaerobic conditions. The ~60-120-year-old, deepest, zone has the lowest diversity with a single genus of Actinomycetota (Mycobacterium) taking over as dominant. We also present data on the significantly different microbiomes of guano falling into aerobic versus water-logged, anaerobic conditions at the surface, the anaerobic having almost twice the diversity of the aerobic, including many taxa that are unique to this sample. Taxa of especial interest include methanogens, sulphur reducers and oxidizers, chitin decomposers, halophiles, acidophiles, and extremophiles.
Journal Article
The impact of burning on the structure and mineral composition of bat guano
Here we addressed the question of whether burning of guano produces a characteristic suite of morphological changes and/or unique mineralogical products. The changes observed in our experimental burning of guano (both fresh and decayed) included colour change (blackening), grain size and morphological change (grain size generally reduced, morphology rendered generally less distinct), alteration of minerals by dehydration (e.g., gypsum to anhydrite, brushite to whitlockite), and production of new minerals or compounds (e.g., augelite, bayerite, giniite, graphite, oldhamite, strontium apatite, tridymite). The key morphological feature we found that may be diagnostic of burning was severe damage to crystals from rapid dehydration (cracks and striations, leading to eventual fragmentation). The key mineralogical feature we found was production of graphite. The high temperature exotic minerals that were produced (giniite, augelite, tridymite, oldhamite) were all found not to be high temperature obligate. Evidence gleaned from the literature suggests that a great number of the minerals associated with high temperatures can also be synthesized in low temperature settings such as weathering or microbial action (exemplified in the extremely complex biology and biochemistry of decaying guano). While the presence of any one of these minerals is not diagnostic of fire, it could be argued that the suite taken as a whole is moderately strong evidence for burning. In future studies, the chemistry of carbon aromaticity may prove to be the best diagnostic test for pyrolysis. A survey of the conditions under which documented spontaneous ignition occurs leads us to conclude that spontaneous ignition of guano inside a cave is an extremely unlikely event, and any suggestion/assertion to this effect should be rigorously supported.
Journal Article
New records of guano-associated minerals from caves in northwestern Borneo
Recent studies of ancient bat guano deposits in the caves of Gunung Mulu National Park and Niah National Park, Sarawak, Malaysia, have resulted in noteworthy records of phosphate minerals from these environments, including variscite, nano-particulate silica, fluorapatite, and niter.
Journal Article
Geochronological implications of 210Pb and 137Cs mobility in cave guano deposits
Some recent publications on the paleo- and historical environmental interpretation of bat guano sequences have relied on
210
Pb and
137
Cs distribution to establish age-depth models, even when these are at odds with radiocarbon models in the lower parts of the sequence. Here, we present both field and laboratory evidence for the unpredictable mobility of lead and cesium in decomposing bat guano deposits. We suggest that
210
Pb- and
137
Cs-based chronologies of bat guano deposits should only be used when independently supported, for example, by a robust radiocarbon age-depth model.
Journal Article
HCV and flaviviruses hijack cellular mechanisms for nuclear STAT2 degradation: Up-regulation of PDLIM2 suppresses the innate immune response
Host encounters with viruses lead to an innate immune response that must be rapid and broadly targeted but also tightly regulated to avoid the detrimental effects of unregulated interferon expression. Viral stimulation of host negative regulatory mechanisms is an alternate method of suppressing the host innate immune response. We examined three key mediators of the innate immune response: NF-KB, STAT1 and STAT2 during HCV infection in order to investigate the paradoxical induction of an innate immune response by HCV despite a multitude of mechanisms combating the host response. During infection, we find that all three are repressed only in HCV infected cells but not in uninfected bystander cells, both in vivo in chimeric mouse livers and in cultured Huh7.5 cells after IFNα treatment. We show here that HCV and Flaviviruses suppress the innate immune response by upregulation of PDLIM2, independent of the host interferon response. We show PDLIM2 is an E3 ubiquitin ligase that also acts to stimulate nuclear degradation of STAT2. Interferon dependent relocalization of STAT1/2 to the nucleus leads to PDLIM2 ubiquitination of STAT2 but not STAT1 and the proteasome-dependent degradation of STAT2, predominantly within the nucleus. CRISPR/Cas9 knockout of PDLIM2 results in increased levels of STAT2 following IFNα treatment, retention of STAT2 within the nucleus of HCV infected cells after IFNα stimulation, increased interferon response, and increased resistance to infection by several flaviviruses, indicating that PDLIM2 is a global regulator of the interferon response.
Journal Article
Rates of diagenesis of tropical insectivorous bat guano accumulations: implications for potential paleoenvironmental reconstruction
Cave guano deposits are increasingly being recognized as valuable repositories of paleo-climatic and paleo-environmental information. However, that value is constrained by rates of guano decomposition, and these rates have not been previously well-studied. Here we show that field and laboratory studies of deep insectivorous bat guano sequences in the caves of Borneo demonstrate the extreme dependence of decomposition rate on guano water content. Under tropical conditions, moist guanos exhibit decomposition coefficients (k) values of ~ 0.01, implying the loss of most of the organic content on decadal timescales. Under similar temperatures but drier conditions, k values drop to ~3 x 10-6, permitting significant organic (chitin) content to persist for tens of thousands of years. One of the implications of these findings for paleo-environmental records older than the limit of carbon dating is that a value for k can be calculated based on a single carbon date, which then allows an estimate of likely age at base of deposit.
Journal Article
On biospeleothems from a Venezuelan tepui cave: U-Th dating, growth rates, and morphology
Seven silica biospeleothems from Cueva Charles Brewer, Chimantá Plateau, Venezuela have been successfully U-Thdated despite very low U and high detrital Thconcentrations. Growth rates are low, between ~100 to ~800 µm/ka, and are greater closer to water level. Dates in unaltered material are in good stratigraphic order, but secondary silicification may compromise the U-Thsystem, yielding unreliable sequences of ages. Detritally-enriched layers correlate with global climate cycles of the Late Quaternary, in particular the cooler, drier phases of MIS 5d, 5a, and 4. SEM studies indicate that the peloidal material is made up of silica nano-particles assembled to form hollow tubules ~1 µm in diameter. Secondary silicification inside and outside the tubules fills most of the pores. Barite crystals are deposited close to the silicified core material. Chemical analyses suggest that the white peloidal material is deposited by stream-generated foam, while the silicified material and dark core material are closer to rock composition.
Journal Article
Predicting psychosis risk using a specific measure of cognitive control: a 12-month longitudinal study
Identifying risk factors of individuals in a clinical-high-risk state for psychosis are vital to prevention and early intervention efforts. Among prodromal abnormalities, cognitive functioning has shown intermediate levels of impairment in CHR relative to first-episode psychosis and healthy controls, highlighting a potential role as a risk factor for transition to psychosis and other negative clinical outcomes. The current study used the AX-CPT, a brief 15-min computerized task, to determine whether cognitive control impairments in CHR at baseline could predict clinical status at 12-month follow-up.
Baseline AX-CPT data were obtained from 117 CHR individuals participating in two studies, the Early Detection, Intervention, and Prevention of Psychosis Program (EDIPPP) and the Understanding Early Psychosis Programs (EP) and used to predict clinical status at 12-month follow-up. At 12 months, 19 individuals converted to a first episode of psychosis (CHR-C), 52 remitted (CHR-R), and 46 had persistent sub-threshold symptoms (CHR-P). Binary logistic regression and multinomial logistic regression were used to test prediction models.
Baseline AX-CPT performance (d-prime context) was less impaired in CHR-R compared to CHR-P and CHR-C patient groups. AX-CPT predictive validity was robust (0.723) for discriminating converters v. non-converters, and even greater (0.771) when predicting CHR three subgroups.
These longitudinal outcome data indicate that cognitive control deficits as measured by AX-CPT d-prime context are a strong predictor of clinical outcome in CHR individuals. The AX-CPT is brief, easily implemented and cost-effective measure that may be valuable for large-scale prediction efforts.
Journal Article