Late Part Research Articles

Growth and Physiological Responses of Maize and Sorghum Genotypes to Salt Stress

The growth and physiological responses of four maize inbred lines (CUBA1, B73, B5C2, and BR1) and four sorghum hybrids (SS304, NK7829, Sordan 79, and KS585) to salinity were determined. Fifteen days after sowing, seedlings were irrigated with nutrient solution (control) at electrical conductivity (EC) of 1.5 dS m−1or saline solution at EC of 8.0 dS m−1(salt treatment) for 40 days. Dry weight of shoots in maize was reduced by 58%, 65%, 62%, and 69% in CUBA1, B73, B5C2, and BR1, respectively, while that of sorghum was reduced by 51%, 56%, 56%, and 76% in SS304, NK7829, Sordan79, and KS585, respectively, in the salt treatment compared to their respective control. Salinity stress reduced all or some of the gas exchange parameters, leaf transpiration (E), stomatal conductance (gs), and net photosynthetic rate (Pn) in the late part of the experiment for both crops. Salinity treatment greatly increased Na+uptake in all maize genotypes but did not affect the Na+uptake in sorghum, regardless of genotype. In maize, CUBA1 was slightly more resistant to salt stress, while BR1 was more sensitive to salt stress. In sorghum, Sordan79 was the most tolerant genotype, and KS585 was the least tolerant genotype.

Una teoría darwinista de la coevolución gen-cultura

Darwin believed that his theory of evolution would stand or fall on its ability to account for human behavior. The ideas in the Descent of Man were widely discussed by his contemporaries although they were far from the only evolutionary theories current in the late 19th Century. Darwin’s specific evolutionary ideas and those of his main followers had very little impact on the social sciences as they emerged as separate disciplines in the early 20th Century. The social and biological sciences continued to diverge until the late part of the twentieth century. In the 1960s, Donald T. Campbell, an American social psychologist, published some of the first theoretical work that adapted principles of evolutionary theory to the problem of the evolution of cultures. Since the pioneering work of Campbell several research programmes on evolutionary approaches to human culture have been developed. Here we sketch our own theory of gene-culture coevolution. Despite his prestige, Darwin convinced only a few of his contemporaries that he had the correct theory of the origin of the human mind. His strongest influence was on the pioneering psychologists, Romanes, Morgan, James, and Baldwin, but their importance in psychology waned drastically after the turn of the 20th Century (Richards, 1987). No 20th Century social science derives any significant influence from the Descent of Man, and to this day, eminent social scientists are quite hostile to Darwinism. How can it be that a theory can generate so much controversy, and yet not attract enough critical work to test its worth for over a century? Can we flesh out a satisfactory theory of the evolution of human behavior along Darwinian lines, or is the enterprise really fatally flawed?

Controls On Focused-Flow and Dispersed-Flow Deepwater Carbonates: Miocene Agua Amarga Basin, Spain

Abstract Common models for carbonate slope or basin-margin sedimentation emphasize the contrasts between linear sediment sources and point sediment sources. Geologic mapping and high-resolution stratigraphic study of a set of Miocene outcrops, exceptional for their three-dimensional exposure and preservation of paleotopography, demonstrates that paleotopographic focus (or lack thereof) may be a dominant control on geometries and sediment character of sediment-gravity-flow deposits in line-sourced systems. In the Agua Amarga basin, SE Spain, basin topography is initially modified by subaerial exposure and erosion of volcanic basement to form paleovalley systems. After late Miocene marine inundation, topography is partially modified by infilling of high-energy, shallow-water heterozoan deposits (Units 1 and 2) that subdued topography in one area to produce a ramp-like surface, but did not significantly infill a large paleovalley located in another area. Further relative rise in sea level resulted in an extensive reefal platform that formed along a paleo-high adjacent to both features (La Rellana platform). Subsequent sediment-gravity-flow deposits shed from this reefal platform followed two pathways: down the ramp-like surface (dispersed flow), or into the large flooded paleovalley (focused flow). Deposits within each system display contrasting lithofacies architectures. These deepwater deposits (Units 3–7 in this study) consist of carbonate breccia facies (coarse facies), graded skeletal packstone facies (coarse facies), and planktonic foraminifera-rich facies (fine facies) that are interpreted as sediment-gravity-flow deposits and pelagic sediments. Relative sea-level fluctuations resulted in deepwater facies variations in the large paleovalley as a result of significant backstepping and progradation of the Rellana reefal platform on a gently sloping surface. Fining of basinal deposits and shelfward migration of the locus of deposition for sediment gravity flows is associated with sea-level rise. Coarsening of basinal deposits and basinward migration of the locus of deposition for sediment gravity flows is associated with stillstand and relative fall in sea level. Both relationships demonstrate a direct link between the locus of reefal platform growth and style of basin sedimentation. Early parts of relative rises in sea level, late parts of highstands, and falling stages led to transport of abundant coarse sediment into the basin. Focused-flow deposits were line-sourced and funneled into the axis of a large, margin-parallel paleovalley, and confined to a channel. Volume ratio of coarse facies to fine facies is estimated at 0.7. Deposits in proximal paleovalley locations display compensation geometries around positive relief on debrites, channelization, erosional truncation, lapout against paleovalley walls, and some drape as a result of lateral confinement and proximity to the sediment source. Deposits in distal paleovalley locations display increasingly tabular geometries as a result of decreasing lateral confinement and concentration of coarse-grained sediment gravity flows down depositional dip. Dispersed-flow deposits were line-sourced into the basin along a gently inclined ramp-like surface that lacked paleotopographic focus. Volume ratio of coarse facies to fine facies is estimated at 0.1. The less complex sheet-like depositional geometries and locations of these deposits result from the absence of lateral confinement and subtle changes in substrate slope. Focused-flow sediment-gravity-flow deposits that are confined by topographic elements such as channels are most likely to form sizeable accumulations of coarse facies with characteristics most appropriate for conventional oil and gas exploration. There are many paleotopographic configurations that can lead to focusing of flows, so this deepwater carbonate system may be more common than previously recognized.

Impact of Part D on previously uninsured Medicare beneficiaries with hypertension

Abstract Objectives US Medicare Part D began in January 2006, but beneficiaries could wait until May to sign up without being assessed a premium penalty. The availability of this penalty-free period offers a unique opportunity to study selection patterns and demand response to Part D coverage. The objective is to examine factors associated with early and late Part D enrolment and assess impact of enrolment timing on changes in drug use. Methods Nationally representative sample of community-dwelling Medicare beneficiaries with hypertension and no drug coverage in 2005 (n = 641).We used 2005 and 2006 Medicare Current Beneficiary Survey data with a multinomial logistic model to predict Part D enrolment and a difference-in-difference (DID) model to compare changes in monthly antihypertensive drug fills pre- and post-enrolment. Key findings Of the sample enrolled in Part D in 2006, 63.3% (23.5% by January and 39.8% late). Early enrolees had higher antihypertensive use prior to Part D (1.6 monthly fills) compared to late enrolees (1.2) and non-enrolees (0.9). Post-Part D monthly antihypertensive use averaged 2.2 fills for early enrolees, 1.4 for late enrolees and 1.0 for non-enrolees. The estimated DID programme effect was 0.54 additional monthly antihypertensive prescription fills for early enrolees (P < 0.01) and 0.26 fills for late enrolees (P < 0.01). Conclusions The estimated Part D demand response from early enrolees was unrealistically high suggesting selection bias. The price elasticity for late enrolees (−0.29 to −0.43) was consistent with best evidence in the literature. Failure to consider selection can lead to overestimating the impact of Part D on drug use.

Coupled U-series and OSL dating of a Late Pleistocene cave sediment sequence, Morocco, North Africa: Significance for constructing Palaeolithic chronologies

Cave sequences provide some of the most important archives of Palaeolithic archaeology that are currently available. The potential value of such sequences is, however, frequently limited by the problems associated with constructing robust chronologies for archaeologically significant levels. In this study, we apply 230Th/U and OSL SAR techniques to the dating of deposits from the Calcareous Group at Grotte des Pigeons, Taforalt, eastern Morocco. The advantage of combining these techniques is: 1) they allow the cross-checking of chronologies derived from independent sets of measurements and assumptions, and 2) they date different facies of cave sediments (i.e. clastic cave sediments as opposed to cave precipitates such as speleothems) allowing the timing of deposition by different cave processes to be constrained more robustly. The age estimates derived by these techniques from different sampling locations are in good agreement with one another, suggesting the potential of these techniques when used in tandem for producing more robust chronologies of Palaeolithic sequences. The deposition of the Calcareous Group is placed within the middle to late part of MIS 5 (MIS 5c to 5a). Furthermore, the Bayesian analysis of the dates derived in this study along with those that have been previously published, allows the duration of deposition of this unit to be estimated at 25.4 ± 3.7 ka (mean ± 1σ). The paper concludes by discussing the significance of these ages for the archaeology of the Taforalt sequence. We suggest that the collection of samples for multiple independent dating methods in direct association combined with the use of careful, stratigraphic constraints in Bayesian models results in the most robust dates available for such cave sequences.

Mechanisms defining the electrotonic potential abnormalities in simulated amyotrophic lateral sclerosis

Electrotonic potentials allow the accommodative processes to polarizing stimuli to be assessed. Electrotonic potential transients in response to applied polarizing stimuli are caused by the kinetics of underlying axonal conductances. Here, we study these transients using our multi-layered model of the human motor nerve, in three simulated cases of the motor neuron disease amyotrophic lateral sclerosis (ALS): ALS1, ALS2 and ALS3 are three consecutively greater degrees of uniform axonal dysfunctions along the human motor nerve fibre. The results show that the responses in the ALS1 case are quite similar to the normal case. In contrast, in the ALS2 and ALS3 cases, long-lasting (100 ms) subthreshold depolarizing stimuli activate the classical "transient" Na(+) channels in the nodal and in the internodal axolemma beneath the myelin sheath; this leads to action potential generation during the early parts of the electrotonic responses in all compartments along the fibre length. The results also show that the electrotonic potentials in response to long-lasting (100 ms) subthreshold hyperpolarizing stimuli in the ALS1 and ALS2 cases are quiet similar to those of the normal case. However, the current kinetics in the ALS3 case differs from the normal case after the termination of the long-lasting hyperpolarizing stimuli. In the most abnormal ALS3 case, the activation of the Na(+) channels in the nodal and in the internodal axolemma leads to repetitive action potential generation in the late parts (100-200 ms) of the hyperpolarizing electrotonic responses. The results show that the repetitive firing, due to the progressively increased nodal and internodal ion channel dysfunction, are consistent with the loss of functional potassium channels involving both the fast and the slow potassium channel types. The results confirm that the electrotonic potentials in the three simulated ALS cases are specific indicators for the motor neuron disease ALS. The mechanisms underlying the simulated ALS are also discussed.

Research and Improvement on Content-Based Web Search Engine

There is a lot of information contained in the World Wide Web. It has become a research focus to obtain the required related resources quickly and accurately from the web through the content-based search engines. Most current tools of full text web search engine, such as Lucene which is a widely used open source retrieval library in information retrieval field, are purely keyword based. This may not sufficient for users to retrieve in the web. In this paper, we employ a method to overcome the limitations of current full text search engines in represent of Lucene. We propose a Query Expansion and Information Retrieval approach which can help users to acquire more accurate contents from the web. The Query Expansion component finds expanded candidate words of the query word through WordNet which contains synonyms in several different senses; In the Information Retrieval component, the query word and its candidate words are used together as the input of the search module to get the result items. Furthermore, we can put the result items into different classes based on the expansion. Some experiments and the results are described in the late part of this paper.

Tough Lovelies: Crotons in Queensland from the 1870s to Now

When surveying the histories of plants under cultivation, one becomes immediately aware of the vagaries of shifting tastes. So it is with one of my favourite plants: the hardy croton, Codaieum variegatum. It was a popular hot-house plant in Europe during the nineteenth century, when colourful and variegated plants from the far corners of the world were all the rage. In the late part of the nineteenth century, these plants made their way to Australia, and were especially cultivated in Queensland. Even in sub-tropical Brisbane, plants can lose all their leaves in cold snaps during the mild winters, but further north, Queensland has a plant that can offer gardens a wide variety of colour and leaf shape. For a plant from the tropics, they are remarkably drought tolerant and have proved their resilience in both summer's heat and humidity, and our occasional extended droughts.

Elevated responding to safe conditions as a specific risk factor for anxiety versus depressive disorders: Evidence from a longitudinal investigation.

The current study evaluated the degree to which startle reflexes (SRs) in safe conditions versus danger conditions were predictive of the onset of anxiety disorders. Specificity of these effects to anxiety disorders was evaluated in comparison to unipolar depressive disorders and with consideration of level of neuroticism. A startle paradigm was administered at baseline to 132 nondisordered adolescents as part of a longitudinal study examining risk factors for emotional disorders. Participants underwent a repetition of eight safe-danger sequences and were told that delivery of an aversive stimulus leading to a muscle contraction of the arm would occur only in the late part of danger conditions. One aversive stimulus occurred midway in the safe-danger sequences. Participants were assessed for the onset of anxiety and unipolar depressive disorders annually over the next 3 to 4 years. Larger SR magnitude during safe conditions following delivery of the aversive stimulus predicted the subsequent first onset of anxiety disorders. Moreover, prediction of the onset of anxiety disorders remained significant above and beyond the effects of comorbid unipolar depression, neuroticism, and subjective ratings of intensity of the aversive stimulus. In sum, elevated responding to safe conditions following an aversive stimulus appears to be a specific, prospective risk factor for the first onset of anxiety disorders.

Multi-proxy analyses of a peat bog on Isla de los Estados, easternmost Tierra del Fuego: a unique record of the variable Southern Hemisphere Westerlies since the last deglaciation

We have analyzed an almost 14,000 year old peat sequence on the island of Isla de los Estados (55° S, 64° W), east of Tierra del Fuego, in the core of the Southern Hemisphere Westerlies. A multitude of methods have been used: high resolution 14C dating; detailed lithologic descriptions including humification degree; loss on ignition; magnetic susceptibility; bulk density; pollen and spore analysis and determination of Aeolian sand influx. By combining proxies for wind and precipitation we have been able to reconstruct how the westerlies have varied over time in the Atlantic sector of the Southern Ocean. It shows that this westerly wind belt was most intense at the onset of the record, 13,600–13,200 cal BP, coinciding with the mid to late part of the Antarctic Cold Reversal, followed by a gradual decline. At 12,200 cal BP the westerlies seem to have shifted to a position south of Tierra del Fuego and this phase, the calmest and driest period on the island throughout the sequence, ended at 10,000 cal BP when the westerlies moved equatorward again. Since then the westerlies have been present but with a variable impact on the 55° S latitude of the Atlantic. Mostly conditions have been fairly similar to today, but occasionally with a wider or narrower and/or weaker or stronger wind belt. At 7200 cal BP wind intensity began to increase and between 4500 and 3500 cal BP these southern latitudes experienced a distinct wind and precipitation maximum, both in terms of perseverance and intensity. Our results show a both wide and strong wind belt, with possible niveo-aeolian activity in Tierra del Fuego in winter, and possibly creating milder summers around the Antarctic Peninsula. In the later part of the Holocene, expansion–contraction phases of the wind belt, especially in winter, seem to have been a common phenomenon.

English, ‘so to say’

Among common speculations about the ultimate demise of English as the world's lingua franca (see Jeffrey Gil in ET 105, March 2011, reconsidering Chinese as a possible replacement) Nicholas Ostler (2010) is one more to project ‘the breakdown of English-speaking hegemony’, but his case is more curious than most. After an exhaustive, not to say exhausting, survey of ancient empires and modes of communication, in which Latin as the last lingua franca has but a late bit part, he arrives at an unrelated conclusion: ready machine translation sooner or later rendering a global ‘lingua-franca’ irrelevant (his hyphenation to legitimise an English plural – ‘lingua-francas’). Our springtime island-hopping pilgrimage rather gave the lie to this.

Geochemistry of C, O, and Sr isotopes and chemostratigraphy of neoproterozoic rocks in the northern Yenisei Ridge

Isotopic compositions of C, O, and Sr in carbonates, as well as Rb-Sr systems in the silicate material from Upper Precambrian and Lower Cambrian rocks exposed by the Chapa River in the northern Yenisei Ridge, are studied. The Late Precambrian part of the section includes the following formations (from the bottom to top): Lopatinskaya (hereafter, Lopatino), Vandadykskaya (hereafter, Vandadyk) or Kar’ernaya, Chivida, Suvorovskaya (hereafter, Suvorovo), Pod”emskaya (hereafter, Podyom), and Nemchanka. They are characterized by alternation of horizons with anomalously high and low δ13C values (such alternation is typical of the ∼700–550 Ma interval). The lower, relatively thin (20 m), positive excursion (δ13C up to 4.3‰) was established in dolomites from the lower subformation of the Vandadyk (Kar’ernaya) Formation (hereafter, lower Vandadyk subformation). The upper positive excursion (δ13C = 2.2 ± 0.6‰) was recorded in the 3-km-thick Nemchanka Formation enriched in terrigenous rocks. The lower negative excursion stands out as uniform, moderately low δ13C values (−2 ± 1‰) and significant thickness. It comprises the upper part of the Vandadyk Formation, as well as Chivida and Podyom formations. The upper negative excursion is related to a thin (∼20 m) marker carbonate horizon of the upper Nemchanka subformation, in which δ13C values fall down to −8.3‰. The lower part of the Lebyazhinskaya (hereafter, Lebyazhino) Formation, which overlies the Nemchanka Formation, shows a step-by-step increase in δ13C from −2.2 to 2.5‰ typical of the Vendianto-Cambrian (Nemakit-Daldyn Horizon/Stage) transitional sequences. The absence of relationships between the carbon and oxygen isotope compositions and other parameters of postsedimentary alterations suggests that the excursions characterized above could form at the sedimentation stage and coincide in general with δ13C fluctuations in seawater. The value of 87Sr/86Sr = 0.7076−0.7078 in limestones of the Podyom Formation points to their early Ediacaran age. Values of 87Sr/86Sr = 0.70841 and 0.70845 in dolomites of the lower Lebyazhino subformation correspond to the Early Cambrian. The Rb-Sr systems of the clay material from the Vandadyk and Chivida formations are approximated by a straight line, parameters of which correspond to the age of 695 ± 20 Ma (87Sr/86Sr0 = 0.7200 ± 0.0013) and probably characterize the epigenetic stage of older sedimentary rocks, which were subjected to very rapid exhumation and “polar” sulfuric acid weathering in the course of glacioeustatic regression.

Emergence of antigenic variants with in serotype A foot and mouth disease virus in India and evaluation of a new vaccine candidate panel

Emergence of genetically and antigenically divergent lineages/genotypes and poor intergenotypic antigenic coverage is a major concern in serotype A foot-and-mouth-disease virus (FMDV) in India. In 2009, to cover antigenic diversity emerged in serotype A virus field isolates, IND40/2000 was selected as the new vaccine strain for incorporation in the trivalent FMD vaccine formulation used in India. Although current vaccine strain (IND40/2000) covers most isolates antigenically, a few VP359-deletion group isolates showed low r-value in routine vaccine matching exercise. The VP359-deletion group within genotype 18 emerged first in late part of 2002 and in 2007 causing outbreaks along with non-deletion isolates of the same genotype. In case of emergence or re-emergence of more antigenically divergent isolates in future, a need for a new vaccine candidate to cover maximum isolates of both deletion and non-deletion group may arise. Four alternate candidate vaccine strains (IND281/2003, IND195/2007, IND360/2007 and IND123/2008) were selected based on set criteria and antigenic relationships with field isolates sampled between 2002 and 2009 were analyzed using a micro-neutralization test. Phylogenetic analysis based on capsid region of serotype A isolates revealed existence of two broad distinct clusters (VP359-deletion and non-deletion group) within genotype 18. The VP359-deletion group has diversified genetically with time giving rise to three different sub-lineages (clade18a, 18b and 18c). The present study indicates that the virus candidates IND281/2003 (VP359-deletion group) and IND195/2007 (non-deletion group) can be used as an adjunct or alternative strain to currently used vaccine strain IND40/2000 in case of emergence of more antigenically divergent isolates in future.

Origin and fate of A/H1N1 influenza in Scotland during 2009

The spread of influenza has usually been described by a ‘density’ model, where the largest centres of population drive the epidemic within a country. An alternative model emphasizing the role of air travel has recently been developed. We have examined the relative importance of the two in the context of the 2009 H1N1 influenza epidemic in Scotland. We obtained genome sequences of 70 strains representative of the geographical and temporal distribution of H1N1 influenza during the summer and winter phases of the pandemic in 2009. We analysed these strains, together with another 128 from the rest of the UK and 292 globally distributed strains, using maximum-likelihood phylogenetic and Bayesian phylogeographical methods. This revealed strikingly different epidemic patterns within Scotland in the early and late parts of 2009. The summer epidemic in Scotland was characterized by multiple independent introductions from both international and other UK sources, followed by major local expansion of a single clade that probably originated in Birmingham. The winter phase, in contrast, was more diverse genetically, with several clades of similar size in different locations, some of which had no particularly close phylogenetic affinity to strains sampled from either Scotland or England. Overall there was evidence to support both models, with significant links demonstrated between North American sequences and those from England, and between England and East Asia, indicating that major air-travel routes played an important role in the pattern of spread of the pandemic, both within the UK and globally.

Geomorphological patterns in a linear dune field and ages of the linear dunes in the northern Kumtagh Desert, northwest China

The unique linear dunes in the northern Kumtagh Desert of northwest China have inspired enthusiastic debate among aeolian geomorphologists over their origins and classification. Their uniqueness lies not only in their morphology, but also in their geomorphological patterns. In this paper, the geomorphological patterns and ages of the linear dunes in the northern Kumtagh Desert are analyzed using the pattern analysis method that was recently adopted by geomorphologists. The analysis suggests that these linear dunes have developed since 13 ka BP, during the late part of the most recent deglaciation stage, when the region’s dry climate was favorable for dune formation. The differences in dune construction time within this region result from the complex factors that control their formation and spatial variations in the local environment, but these factors were not strong enough to prevent us from estimating the dune age recorded by the geomorphological patterns with acceptable precision. It is also suggested that the pattern analysis method can be used to estimate dune ages in the absence of more reliable dating methods.

Concurrent hypermethylation of DNMT1, MGMT and EGFR genes in progression of gliomas

BackgroundGliomas are the most common neoplasm of the brain. High-grade gliomas often resist treatment even with aggressive surgical resection and adjuvant radiation and chemotherapy. Despite the combined treatment, they frequently recur with the same or higher-grade histology. Genetic instability is commonly associated with inactivation of the normal DNA repair function and tumour suppressor genes as well as activation of oncogenes resulting from alterations of promoter hypermethylation, but the molecular mechanisms of the histological and clinical progression of gliomas are still poorly understood.MethodsThis study involved longitudinal analysis samples of primary and recurrent gliomas to determine whether the progression of low- and high-grade gliomas is associated with the promoter methylation of the DNMT1, MGMT and EGFR genes by PCR-based restriction enzyme assay. Epigenetic inactivation of these three important glioma-associated genes was analyzed in paired biopsy samples from 18 patients with tumour recurrence.ResultsThe methylation analysis of the CpG sites in the DNA methyltransferase (DNMT1) promoter revealed a total of 6 hypermethylations (6/18), the methylguanine-DNA methyltransferase (MGMT) promoter revealed a total of 10 hypermethylations (10/18) and the epithelial grow factor receptor (EGFR) promoter revealed a total of 12 (12/18) hypermethylations respectively in recurrent gliomas. The results demonstrated that DNMT1 promoter hypermethylation does not occur in low-grade gliomas, it was mainly observed in secondary glioblastomas. Additionally, the MGMT and EGFR promoter was hypermethylated in both low-and high-grade GLs and their corresponding histological transformed GLs.ConclusionThis study has provided further evidence that the histological transformation and progression of gliomas may be associated with the inactivation of the EGFR and MGMT genes. It seems that EGFR and MGMT promoter hypermethylations are early events in the clonal evolution of gliomas and this gene inactivation has proved to be stable even in tumour recurrence. However, the DNMT hypermethylation is a late part of glioma progression.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1935054011612460

Nud locus and the effects on seedling vigour related traits for genetic improvement of hulless barley

Introduction Spring barley (Hordeum vulgare L.) is widely grown throughout the Canadian prairies. Soil moisture in these areas is usually high at the time of seeding but becomes limited over the mid and late part of the growing season. Physiological studies of spring barley in water-limited environments have identified several traits

A 1000-year reconstruction of summer precipitation from Ireland: Calibration of a peat-based palaeoclimate record

Calibration of proxy climate records is well-established for annually resolved proxies such as tree rings, but it has not been attempted for non-annually resolved proxies such as those from peatland surface wetness records. Several previous studies have suggested that peatland surface wetness is primarily driven by warm season moisture balance and implied a potential for producing calibrated records of deficit or precipitation. This paper presents a high-resolution testate amoebae analysis of a peat record from central Ireland covering the last c.1000 years, and provides the first attempt to produce a calibrated record of past precipitation from a peat record. Past water table depth was reconstructed using a transfer function applied to contiguous samples for the top 1m of the profile. The chronology was constrained by a series of radiocarbon ages (including ‘bomb-spike’ ages) and spheroidal carbonaceous particles. Correlations between reconstructed water tables and meteorological records (1958–1995) of precipitation and deficit were strongly positive and were used to reconstruct precipitation and deficit from the last 1000 years. Validation using earlier meteorological records was hampered by very low peat accumulation rates, but suggested the summer precipitation and deficit reconstructions were more robust than a reconstruction of annual precipitation. The summer precipitation reconstruction suggests that the period AD1400–1850 experienced higher summer rainfall than for much of both the preceding 400 years and the last 150 years. The change in regime from low to high summer rainfall may be attributed to changes in the summer North Atlantic Oscillation. Combined with tree ring and speleothem records of winter NAO, this suggests a major change in seasonality of precipitation in far western Europe between the Medieval Climate Anomaly and the Little Ice Age. The MCA was characterised by dry summers and wet winters, whilst the LIA had wet summers and dry winters. Calibration of peat surface wetness records using meteorological records holds much potential for the future and may lead to improved insights into seasonal precipitation and water balance changes. This study was limited by slow accumulation rates leading to low temporal resolution for the late 19th and early 20th century part of the record. Further development of the technique will require more highly temporally resolved records of change over the whole of the instrumental time period to allow a full calibration and validation approach to be applied.

Nutrient enrichment reduces complementarity and increases priority effects in prairies managed for bioenergy

Abstract Prairies are a potential bioenergy feedstock that could benefit the environment while providing biomass for bioenergy. Increased diversity and nitrogen fertilization are two methods of increasing prairie productivity. Diversity may enhance complementarity of resource use within prairies, whereas the application of nitrogen fertilizer may cause priority effects whereby species with early phenologies or high responsiveness to fertilization are stimulated. We tested the effects of functional-group identity and nitrogen fertilization on resource capture and growth of prairie plants. To determine whether functionally-diverse mixtures of prairie plants exhibited complementarity and/or priority effects, we measured light interception, canopy duration, and aboveground biomass production of C3 grasses, C4 grasses, legumes, and multi-functional group mixtures grown without fertilization and with 150 kg ha−1 spring-applied nitrogen fertilizer. Under the conditions of our experiment, nitrogen consistently stimulated C3 grasses, whereas it stimulated C4 grasses only in the middle and late parts of the growing season and had no effect on legumes. In functionally-diverse mixtures, priority effects of C3 grasses in fertilized mixtures reduced overall resource capture and growth by suppressing growth of the more productive C4 grasses in the middle and late parts of the growing season. Complementarity occurred in unfertilized mixtures in which C3 and C4 grasses were dominant at different parts of the growing season. Prairies receiving more modest nutrient inputs than those used in this study or nutrient inputs later in the growing season may maximize the production of multiple ecosystem services by producing large amount of biomass while still capturing resources throughout the whole growing season.

The New Cambridge history of Islam

Volume 1. The Formation of the Islamic World, Sixth to Eleventh Centuries: Part I. The Late Antique Context Part II. Universalism and Imperialism Part III. Regionalism Part IV. The Historiography of Early Islamic History Volume 2. The Western Islamic World, Eleventh to Eighteenth Centuries: Part I. Al-Andalus, North and West Africa Part II. Egypt and Syria Part III. Muslim Anatolia and the Ottoman Empire Part IV. North and West Africa Part V. Rulers, Soldiers, Peasants, Scholars and Traders Volume 3. The Eastern Islamic World, Eleventh to Eighteenth Centuries: Part I. The Impact of the Steppe Peoples Part II. The Gunpowder Empires Part III. The Maritime Oecumene Part IV. Themes Volume 4. Islamic Cultures and Societies to the End of the Eighteenth Century: Part I. Religion and Law Part II. Societies, Politics and Economics Part III. Arts, Literature and Learning Volume 5. The Islamic World in the Age of Western Dominance: Part I. The Onset of Western Domination Part II. Independence and Revival Volume 6. Muslims and Modernity: Culture and Society since 1800: Part I. Social Transformations Part II. Religion and Law Part III. Political and Economic Thought Part IV. Cultures, Arts and Learning.