Worldwide Dataset Research Articles

Magnetic susceptibility as a proxy for rainfall: Worldwide data from tropical and temperate climate

The magnetic susceptibility of soils has been linked with climate, mainly through rainfall, by numerous investigators. For this study we assembled a worldwide dataset of 272 samples, both published and new, to determine the nature of the relationship between MS and rainfall. On a worldwide basis there is a crude relationship ( r 2 = 0.265) between MS and rainfall. MS increases with increasing rainfall from about 200 mm/yr to 1000–1200 mm/yr. Above 1200 mm/yr, MS decreases as rainfall increases up to about 2000 mm/yr. Under arid and semi-arid conditions, below about 200 mm/yr of rainfall, MS and rainfall exhibit no relationship, likely the result of limited pedogenic activity. When tropical and temperate localities are analyzed separately, the correlation between MS and rainfall exhibits a dramatic improvement, r 2 = 0.568 and 0.520, respectively. For similar amounts of rainfall tropical localities generally exhibit lower MS values which may be related to differences in the seasonal variation of rainfall. Because the soil environment is highly variable, it is unlikely that a global or even regional equation could accurately estimate rainfall from MS. Using data from Morocco and Mali we demonstrate that local equations using only MS to estimate rainfall produce reasonable results, r 2 = 0.700 for Morocco and 0.611 for Mali. However, a single independent variable is unlikely to capture the variability of the complex soil system. To the local equations described above we experimented with adding several independent variables in addition to MS including diffuse reflectance spectral data (DRS), x-ray diffraction (XRD), and x-ray fluorescence (XRF). For DRS data, % reflectance and red, yellow, and near-infrared wavelengths appear important; for XRD illite and kaolinite counts are important whereas for XRF Fe 2O 3 is important. The addition of these other independent variables dramatically improves prediction quality. In the case of the Mali transect, estimating rainfall from these variables produces an r 2 that exceeds 0.9. Based on these data we conclude that MS has the potential to be a reasonable proxy of rainfall for mean annual precipitation values from 200 to 2000 mm/yr, especially if local equations are used. Predictions can be improved by including other independent variables that show sensitivity to climate and are related to MS through the chemistry of the weathering process; we included DRS, XRD, and XRF data with good results.

A new future of forensic Y-chromosome analysis: Rapidly mutating Y-STRs for differentiating male relatives and paternal lineages

The panels of 9–17 Y-chromosomal short tandem repeats (Y-STRs) currently used in forensic genetics have adequate resolution of different paternal lineages in many human populations, but have lower abilities to separate paternal lineages in populations expressing low Y-chromosome diversity. Moreover, current Y-STR sets usually fail to differentiate between related males who belong to the same paternal lineage and, as a consequence, conclusions cannot be drawn on the individual level as is desirable for forensic interpretations. Recently, we identified a new panel of rapidly mutating (RM) Y-STRs, composed of 13 markers with mutation rates above 1×10−2, whereas most Y-STRs, including all currently used in forensics, have mutation rates in the order of 1×10−3 or lower. In the present study, we demonstrate in 604 unrelated males sampled from 51 worldwide populations (HGDP-CEPH) that the RM Y-STRs provide substantially higher haplotype diversity and haplotype discrimination capacity (with only 3 haplotypes shared between 8 of the 604 worldwide males), than obtained with the largest set of 17 currently used Y-STRs (Yfiler) in the same samples (33 haplotypes shared between 85 males). Hence, RM Y-STRs yield high-resolution paternal lineage differentiation and provide a considerable improvement compared to Yfiler. We also find in this worldwide dataset substantially less genetic population substructure within and between geographic regions with RM Y-STRs than with Yfiler Y-STRs. Furthermore, with the present study we provide enhanced data evidence that the RM Y-STR panel is extremely successful in differentiating between closely and distantly related males. Among 305 male relatives, paternally connected by 1–20 meiotic transfers in 127 independent pedigrees, we show that 66% were separated by mutation events with the RM Y-STR panel whereas only 15% were with Yfiler; hence, RM Y-STRs provide a statistically significant 4.4-fold increase of average male relative differentiation relative to Yfiler. The RM Y-STR panel is powerful enough to separate closely related males; nearly 50% of the father and sons, and 60% of brothers could be distinguished with RM Y-STRs, whereas only 7.7% and 8%, respectively, with Yfiler. Thus, by introducing RM Y-STRs to the forensic genetic community we provide important solutions to several of the current limitations of Y chromosome analysis in forensic genetics.

A geochemical study on mud volcanoes in the Junggar Basin, China

Abstract A comprehensive study was performed to characterize, for the first time, the mud, water, and gases released from onshore mud volcanoes located in the southern margin of the Junggar Basin, northwestern China. Chemical compositions of mud, along with the geology of the basin, suggest that a source of the mud is Mesozoic or Cenozoic shale. Oxygen and H isotope compositions of the released water suggest a local meteoric origin. Combined with the positive Eu anomalies of the water, a large 18 O shift of the water suggests extensive interaction with rocks. Gases discharged from the mud volcanoes are predominantly thermogenic hydrocarbons, and the high δ 13 C values (>+20‰ VPDB) for CO 2 gases and dissolved carbonate in muddy water suggest secondary methanogenesis with CO 2 reduction after oil biodegradation. The enrichments of Eu and 18 O in water and the low thermal gradient of the area suggest that the water–rock interactions possibly occur deeper than 3670 ± 200 m. On the other hand, considering the relationship to the petroleum reservoir around the mud volcanoes, the depth of the gases can be derived from about 3600 m, a depth that is greater than that generally estimated for reservoirs whose gas is characterized by 13 C-enriched CO 2 . Oil biodegradation with CO 2 reduction likely occurs at a shallower depth along the seepage system of the mud volcano. The results contribute to the worldwide data set of gas genesis in mud volcanoes. Moreover, they further support the concept that most terrestrial mud volcanoes release thermogenic gas produced in very deep sediments and may be early indicators of oil biodegradation, an important problem in the petroleum industry.

Stochastic and deterministic processes interact in the assembly of desert microbial communities on a global scale.

Extreme arid regions in the worlds' major deserts are typified by quartz pavement terrain. Cryptic hypolithic communities colonize the ventral surface of quartz rocks and this habitat is characterized by a relative lack of environmental and trophic complexity. Combined with readily identifiable major environmental stressors this provides a tractable model system for determining the relative role of stochastic and deterministic drivers in community assembly. Through analyzing an original, worldwide data set of 16S rRNA-gene defined bacterial communities from the most extreme deserts on the Earth, we show that functional assemblages within the communities were subject to different assembly influences. Null models applied to the photosynthetic assemblage revealed that stochastic processes exerted most effect on the assemblage, although the level of community dissimilarity varied between continents in a manner not always consistent with neutral models. The heterotrophic assemblages displayed signatures of niche processes across four continents, whereas in other cases they conformed to neutral predictions. Importantly, for continents where neutrality was either rejected or accepted, assembly drivers differed between the two functional groups. This study demonstrates that multi-trophic microbial systems may not be fully described by a single set of niche or neutral assembly rules and that stochasticity is likely a major determinant of such systems, with significant variation in the influence of these determinants on a global scale.

The Bright and the Dark Side of Cross-Border Banking Linkages

When a country's banking system becomes more linked to the global banking network, does that system get more or less prone to a banking crisis? Using model simulations and econometric estimates based on a world-wide dataset, we find an M-shaped relationship between financial stability of a country's banking sector and its interconnectedness. In particular, for banking sectors that are not very connected to the global banking network, increases in interconnectedness are associated with a reduced probability of a banking crisis. Once interconnectedness reaches a certain value, further increases in interconnectedness can increase the probability of a banking crisis. Our findings suggest that it may be beneficial for policies to support greater interlinkages for less connected banking systems, but after a certain point the advantages of increased interconnectedness become less clear.

The Bright and the Dark Side of Cross-Border Banking Linkages

When a country’s banking system becomes more linked to the global banking network, does that system get more or less prone to a banking crisis? Using model simulations and econometric estimates based on a world-wide dataset, we find an M-shaped relationship between financial stability of a country’s banking sector and its interconnectedness. In particular, for banking sectors that are not very connected to the global banking network, increases in interconnectedness are associated with a reduced probability of a banking crisis. Once interconnectedness reaches a certain value, further increases in interconnectedness can increase the probability of a banking crisis. Our findings suggest that it may be beneficial for policies to support greater interlinkages for less connected banking systems, but after a certain point the advantages of increased interconnectedness become less clear.

Empirical estimation of the Newmark displacement from the Arias intensity and critical acceleration

This study employs strong-motion data from the 1999 Chi-Chi earthquake, the 1999 Kocaeli earthquake, the 1999 Duzce earthquake, the 1995 Kobe earthquake, the 1994 Northridge earthquake and the 1989 Loma Prieta earthquake to refine the relationship among critical acceleration ( A c ), Arias intensity ( I a ), and Newmark displacement ( D n ). The results reveal that, as expected, log D n is proportional to log I a when A c is large. As A c gets smaller however, the linearity becomes less. We also found that log D n is proportional to A c , and that the linearity is very stable through all I a values. These features are common to all six sets of data. Therefore, we add a third term in addition to the Jibson's form which covers the aforementioned problem, and propose a new form for the relationship among I a , A c and D n . Two alternative forms were tested using each of the six data sets, before a final form was selected. The final analyses grouped the data into a worldwide data set and a Taiwanese data set. Coefficients for the selected form were derived from regression with the data, and two final empirical formulas, one for global, the other for local, proposed. Site conditions are also considered in this study with empirical formulas being developed for soil and rock sites, respectively. The estimation error is smaller and the goodness of fit is higher for both the local soil-site and rock-site formulas. Since landslides are more likely to occur on hillsides, the rock site formula may be more applicable for the landslide cases, whereas the soil site formula should be used for side slope of landfills.

Atmospheric nitrogen deposition: Revisiting the question of the importance of the organic component

The organic component of atmospheric reactive nitrogen plays a role in biogeochemical cycles, climate and ecosystems. Although its deposition has long been known to be quantitatively significant, it is not routinely assessed in deposition studies and monitoring programmes. Excluding this fraction, typically 25–35%, introduces significant uncertainty in the determination of nitrogen deposition, with implications for the critical loads approach. The last decade of rainwater studies substantially expands the worldwide dataset, giving enough global coverage for specific hypotheses to be considered about the distribution, composition, sources and effects of organic-nitrogen deposition. This data collation and meta-analysis highlights knowledge gaps, suggesting where data-gathering efforts and process studies should be focused. New analytical techniques allow long-standing conjectures about the nature and sources of organic N to be investigated, with tantalising indications of the interplay between natural and anthropogenic sources, and between the nitrogen and carbon cycles.

Relationship Lending versus Arm’s Length Debt – A Cultural Perspective

We examine how time preferences impact the financing decision of firms. We hypothesize that the degree of long-term orientation in a country is positively related to the use of bank relationship lending. Based on a thorough theoretical investigation and an extensive empirical analysis using a large, worldwide dataset, we find strong support for our hypothesis on the role of time preferences for financial intermediation. Our results are robust to controlling for other determinants of the choice of debt financing as well as to applying alternative variables and different estimation methods. Firms in long-term orientation countries appear to prefer relationship bank financing, since it is usually available for the long run and will not be with-drawn quickly in response to adverse developments. This allows managers to preserve a more strategic view and pursue longer planning horizons.

Surviving the Global Financial Crisis: Foreign Direct Investment and Establishment Performance

We examine in this paper the differential response of establishments to the global financial crisis, with particular emphasis on the role of foreign direct investment (FDI) in determining micro economic performance. Using a new worldwide dataset that reports the activities of more than 12 million establishments before and after 2008, we investigate how multinationals around the world responded to the crisis relative to local firms. We explore three distinct channels through which FDI affects establishment performance, (i) production linkages, (ii) financial linkages, and (iii) multinational networks. Our analysis shows that while multinational owned establishments performed, on average, better than their local competitors, there is considerable heterogeneity in the role of FDI. First, multinationals located in countries that experienced sharper declines in aggregate output, demand, and credit conditions displayed a greater advantage over local firms. Multinationals headquartered in countries with a greater incidence of the crisis, in contrast, fared less satisfactorily abroad. Second, multinationals that engaged in activities with vertical production linkages or stronger financial constraints exhibited particularly better responses compared to local firms. Finally, being part of a larger multinational network also led to superior economic performance.

Non‐native species disrupt the worldwide patterns of freshwater fish body size: implications for Bergmann’s rule

In this study, we test whether established non-native species induce functional changes in natural assemblages. We combined data on the body size of freshwater fish species and a worldwide data set of native and non-native fish species for 1058 river basins. We show that non-native fish species are significantly larger than their native counterparts and are a non-random subset of the worldwide set of fish species. We further show that the median body size of fish assemblages increases in the course of introductions. These changes are the opposite of those expected under several null models. Introductions shift body size patterns related to several abiotic factors (e.g. glacier coverage and temperature) in a way that modifies latitudinal patterns (i.e. Bergmann's rule), especially in the southern hemisphere. Together, these results show that over just the last two centuries human beings have induced changes in the global biogeography of freshwater fish body size, which could affect ecosystem properties.

Evaluating NAT2PRED for inferring the individual acetylation status from unphased genotype data

BackgroundGenetically determined differences in N-acetylation capacity have proved to be important determinants of both the effectiveness of therapeutic response and the development of adverse drug reactions and toxicity during drug treatment. NAT2PRED is a web-server that allows a fast determination of NAT2 acetylation phenotype from genotype data without taking the extra step of reconstructing haplotypes for each individual (publicly available at http://nat2pred.rit.albany.edu). However, the classification accuracy of NAT2PRED needs to be assessed before its application can be advocated at a large scale.MethodsThe ability of NAT2PRED to classify individuals according to their acetylation status (slow, intermediate and rapid acetylators) was evaluated in a worldwide dataset composed of 56 population samples (8,489 individuals) from four continental regions.ResultsNAT2PRED correctly identified slow acetylators with a sensitivity above 99% for all populations outside sub-Saharan Africa. Nevertheless, NAT2PRED showed a poor ability to distinguish between intermediate and rapid acetylators, with a classification error rate reaching up to 10% in the non-African samples.ConclusionNAT2PRED is an excellent tool to infer the individual acetylation status from NAT2 genotype data when the main interest is to distinguish slow acetylators from the others. This should facilitate the determination of the individual acetylation status in routine clinical practice and lead to better monitoring of risks associated with cancer and adverse drug reactions.

Impact of Selection and Demography on the Diffusion of Lactase Persistence

BackgroundThe lactase enzyme allows lactose digestion in fresh milk. Its activity strongly decreases after the weaning phase in most humans, but persists at a high frequency in Europe and some nomadic populations. Two hypotheses are usually proposed to explain the particular distribution of the lactase persistence phenotype. The gene-culture coevolution hypothesis supposes a nutritional advantage of lactose digestion in pastoral populations. The calcium assimilation hypothesis suggests that carriers of the lactase persistence allele(s) (LCT*P) are favoured in high-latitude regions, where sunshine is insufficient to allow accurate vitamin-D synthesis. In this work, we test the validity of these two hypotheses on a large worldwide dataset of lactase persistence frequencies by using several complementary approaches.MethodologyWe first analyse the distribution of lactase persistence in various continents in relation to geographic variation, pastoralism levels, and the genetic patterns observed for other independent polymorphisms. Then we use computer simulations and a large database of archaeological dates for the introduction of domestication to explore the evolution of these frequencies in Europe according to different demographic scenarios and selection intensities.ConclusionsOur results show that gene-culture coevolution is a likely hypothesis in Africa as high LCT*P frequencies are preferentially found in pastoral populations. In Europe, we show that population history played an important role in the diffusion of lactase persistence over the continent. Moreover, selection pressure on lactase persistence has been very high in the North-western part of the continent, by contrast to the South-eastern part where genetic drift alone can explain the observed frequencies. This selection pressure increasing with latitude is highly compatible with the calcium assimilation hypothesis while the gene-culture coevolution hypothesis cannot be ruled out if a positively selected lactase gene was carried at the front of the expansion wave during the Neolithic transition in Europe.

Relationships among geochemical indices of coal and carbonaceous materials and implication for hydrocarbon potential evaluation

A worldwide dataset of organic material from 553 samples belonging to coal and carbonaceous materials was used to analyze the evolution of hydrogen index (HI) and bitumen index (BI) with increasing thermal maturity. Basic statistical analyses were applied to detect the boundary lines of HImax and BImax in delineating the upper and lower limits of the HI and BI bands for the majority of samples. In addition, cross-plots of HI or BI versus maturity (Ro% and T max) also provide criteria for defining the HImax and BImax boundary lines. The constructed HI and BI bands are broad at low maturities and become narrower with increasing thermal maturities. The petroleum generation potential is completely exhausted at the vitrinite reflectance of 2.0–2.2% or T max of 510–520°C. An increase in HI implies extra petroleum generation which was related to changes in structure of organic materials. A declining BI means that the oil expulsion window starts to occur at the vitrinite reflectance range of 0.75–1.05%. The petroleum potential can be divided into four different areas based on the cross-plot of HI versus Ro%. The highest petroleum potential area is located in section II with Ro = 0.6–1.0% and HI > 100. The oil generation potential is rapidly exhausted at section III with Ro > 1.0%. This result is also in accordance with the result of curve regression of HI versus Ro% based on 80 samples with Ro = 1.02–3.43% (R 2 = 0.72). Overall, the total oil window can be extended up to Ro = ~1.25–1.95%. Finally, in the cross-plots of S1 versus S2, shale or C-shale exhibits a higher and slowly decreased slope, compared with a lower and then sharply increased slope of coal samples, which is attributable to their compositional difference in organic material.

Near-source ground motion attenuation relationship for PGA and PSA of the vertical and horizontal components

In this paper, empirical ground-motion models for the vertical and average horizontal components of peak ground-motion and acceleration response spectra from shallow crustal earthquakes are derived using near-source database. These attenuation relationships were derived using a worldwide dataset consisted of corrected and processed accelerograms of 678 strong-motion records recorded with 60 km of the rupture plane of earthquakes between Mw 5.2 and 7.9. Ground motion models are functions of earthquake mechanism, distance from source to site, local average shear wave velocity, nonlinear soil response, sediment depth, depth-to-top of the rupture, hanging wall effects and faulting mechanism.

A test of trade theories when expenditure is home biased

We develop a criterion to distinguish two dominant paradigms of international trade theory: homogeneous-goods perfectly competitive models, and differentiated-goods monopolistically competitive models. Our analysis makes use of the pervasive presence of home-biased expenditure. It predicts that countries’ relative output and their relative home biases are positively correlated in differentiated-goods sectors (the “home-bias effect”), while no such relationship exists in homogeneous-goods sectors. This discriminating criterion turns out to be robust to a number of generalisations of the baseline model. Our empirical results, based on a world-wide cross-country data set, suggest that the differentiated-goods model fits particularly well for the machinery, precision engineering and transport equipment industries, which account for some 40% of sample manufacturing output.

Fault displacement rates on a range of timescales

Displacements on tectonic faults primarily accrue during earthquakes at rates that vary through time. To examine the processes that underlie the temporal changes in fault displacement rates we analyse displacements and displacement rates for time periods from the present to 5, 10, 20, 300, 500, 1000 and 5000 kyr for 261 active reverse or normal faults from a worldwide dataset. Displacement rates depart from million-year average rates by up to three orders of magnitude with the size of these departures inversely related to the duration of the sample period and to fault length. Short-term (≤ 20 kyr) displacement rates generally span a greater range on small faults than large, a feature which suggests more variable growth on smaller faults. Simple earthquake-slip modeling shows that variations in displacement rates require changes in both recurrence interval and slip per event and do not support the Characteristic-slip earthquake model. As long as fault system strain rates are uniform, displacement rates generally become constant over time periods between 20 and 300 kyr, with the length of time required to reach stability being inversely related to the regional basin-wide strain rates. Stable long-term displacement rates and fluctuations in earthquake recurrence intervals and slip arise, in part, due to fault interactions.

Impact of plot length on the effectiveness of different soil-surface covers in reducing runoff and soil loss by water

Covering the soil surface by rock fragments, organic mulches or vegetation is often done to reduce runoff and soil loss by water erosion compared to a bare soil treatment. The runoff or erosion-reducing effectiveness of these soil surface covers has been investigated for a range of plot lengths under different environmental conditions. Recent research indicates that the effectiveness of soil surface covers in reducing runoff and soil loss by water erosion may be affected by the size of the laboratory or field plots (ie, spatial scale). Therefore, the main objective of this review is to explore to what extent the impact of plot length on the effectiveness of different surface covers (ie, rock fragments, organic mulch and vegetation) in reducing runoff and soil loss by water erosion emerges from a worldwide data set. Furthermore, it is investigated whether there is a significant difference in runoff or erosion-reducing effectiveness between rock fragments, organic mulches and vegetation. Data from 65 experimental studies, investigating the impact of surface cover by rock fragments, organic mulch or vegetation on runoff or soil loss, are collected and analysed in this review. The results indicate that for plot lengths <11 m there is a large variation in the runoff and erosion-reducing effectiveness of a soil cover, depending on various factors and on the larger number of studies conducted on these plots compared to longer field plots. However, with an increasing plot length (up to 50 m) this variation is reduced and surface covers by rock fragments, organic mulches and vegetation become on average more effective in reducing runoff or soil loss by water erosion. A vegetation cover is significantly more effective in reducing runoff rate compared to a rock fragment cover. No other significant differences in runoff or in erosion-reducing effectiveness between the studied soil surface covers are observed. Finally, two equations are proposed describing the possible effect of plot length and cover by rock fragments, organic mulches and vegetation on relative runoff and soil loss by water erosion. These findings have important consequences for the design of runoff and erosion plots, for modelling runoff and soil erosion rates and for scaling up plot data.

The Role of Economic Development in Tourism Demand

This paper investigates the relevance of the supply-side characteristics of countries as determinants of the growth of tourism. Particular emphasis is placed on the role of economic development as a driver of tourism over time. Much of the literature on tourism has focused on the effects of tourism as an income generator. However, to attract tourists, it may be necessary to have a minimum threshold of economic development. This paper examines whether economic development is relevant to tourists' decision making. A cross-sectional time series model which deals with autocorrelation and heteroskedasticity in the error term is proposed. First, the model considers a worldwide panel data set of destination countries for tourists from Australia, France, Germany, Japan, Spain, the UK and the USA. Then, the sample is divided into smaller areas according to geographical and GDP criteria to investigate differences within competing countries in the same area. The results show that for the worldwide case, economic development matters and makes a difference to tourists' decision making. Subsample analysis shows that in those countries with high GDP levels, differences in economic development are not significant, whereas in developing countries they are.

Worldwide distribution of NAT2 diversity: Implications for NAT2 evolutionary history

BackgroundThe N-acetyltransferase 2 (NAT2) gene plays a crucial role in the metabolism of many drugs and xenobiotics. As it represents a likely target of population-specific selection pressures, we fully sequenced the NAT2 coding region in 97 Mandenka individuals from Senegal, and compared these sequences to extant data on other African populations. The Mandenka data were further included in a worldwide dataset composed of 41 published population samples (6,727 individuals) from four continental regions that were adequately genotyped for all common NAT2 variants so as to provide further insights into the worldwide haplotype diversity and population structure at NAT2.ResultsThe sequencing analysis of the NAT2 gene in the Mandenka sample revealed twelve polymorphic sites in the coding exon (two of which are newly identified mutations, C345T and C638T), defining 16 haplotypes. High diversity and no molecular signal of departure from neutrality were observed in this West African sample. On the basis of the worldwide genotyping survey dataset, we found a strong genetic structure differentiating East Asians from both Europeans and sub-Saharan Africans. This pattern could result from region- or population-specific selective pressures acting at this locus, as further suggested in the HapMap data by extremely high values of FST for a few SNPs positions in the NAT2 coding exon (T341C, C481T and A803G) in comparison to the empirical distribution of FST values accross the whole 400-kb region of the NAT gene family.ConclusionPatterns of sequence variation at NAT2 are consistent with selective neutrality in all sub-Saharan African populations investigated, whereas the high level of population differentiation between Europeans and East Asians inferred from SNPs could suggest population-specific selective pressures acting at this locus, probably caused by differences in diet or exposure to other environmental signals.