The first fossil Compsocidae from Cretaceous Burmese amber (Insecta, Psocoptera, Troctomorpha)

The first fossil record of the Compsocidae, Burmacompsocus perreaui gen. et sp. nov., is described from Late Albian Burmese amber. Its strong similarity to the two extant compsocid genera suggests a remarkable morphological stability within this group of 100 Ma. This family, now known only in Central America, was certainly more widespread in the past.     

Geological evidence for subglacial deformation of Pleistocene permafrost

Recent work in modern and ancient glacial environments has demonstrated the ability of cold-based glaciers to interact with permafrost. Geological evidence for glacier–permafrost interactions is revealed in Arctic regions where permafrost has persisted since deglaciation. Whilst similar interactions probably occurred near the margins of former ice sheets in the mid-latitudes, this interpretation is rarely applied to unfrozen glacigenic sequences. This review considers the extent to which this alternative hypothesis can explain two key aspects of the glaciotectonic sequences of North Norfolk that have traditionally been attributed to the deformation of unfrozen sediment. The substantial thickness (>10 m) of the pervasively deformed sequences and the preservation of stratified sand intraclasts within them are consistent with deformation at temperatures slightly below the pressure melting point (warm permafrost). Such deformation is also consistent with the pre-glacial environment, which was characterised by continuous permafrost. The hypothesis of deformation at sub-freezing temperatures should be considered more widely when interpreting glaciotectonically deformed, ice-marginal sequences in the mid-latitudes. The application of geological evidence to reconstruct basal thermal regimes beneath former glaciers would complement existing geomorphological inverse models and provide additional information to improve the parameterisation of subglacial processes in numerical ice-sheet models.     

The Tilia decline: vegetation change in lowland Britain during the mid and late Holocene

Pollen data indicate Tilia was an important component of the primary woodland cover of many lowland areas in northern and central Europe. High values recorded in mid-Holocene pollen diagrams are generally followed by well-defined declines. In this study the palynological, spatial and temporal trends associated with declines in Tilia pollen at sites from lowland Britain are assessed to evaluate the nature and relative importance of the processes responsible. Processes primarily related to the depositional environment (paludification, marine inundation, breaks in sedimentation) and percentage representation of pollen data play the dominant role in 44% of the 164 declines included in the study. Anthropogenic activity can account for the remainder. Tilia rarely recovers from low values after anthropogenic declines, suggesting such declines have the potential to elucidate patterns in the destruction of primary woodland across lowland Britain. Other than declines associated with the mid-Holocene Ulmus decline event, few anthropogenic Tilia declines have been reliably dated prior to c. 5000 cal. BP. Tilia largely disappeared from areas with calcareous and loamy soils as a result of clearance activity in the period 5000–3000 cal. BP (Late Neolithic to Late Bronze Age). Between 3000 and 2500 cal. BP few declines are recorded suggesting a link between clearance activity and climate change. Later declines are concentrated on the sandier lithologies and often associated with heathland formation. The scarcity of declines after 2000 cal. BP is likely to be related to the exhaustion of primary woodland.     

Holocene environmental change in the West African Sahel: sedimentological and mineral‐magnetic analyses of lake sediments from Jikariya Lake,northeastern Nigeria

Previous studies have demonstrated long‐term changes in effective moisture in sub‐Saharan Africa. Here, we reconstruct Holocene environments using a ～7 m lake‐sediment sequence recovered from the northeastern Nigerian Sahel and attempt to distinguish basin‐specific changes from regional climatic variations. The sequence was analysed for sedimentological properties, mineral magnetism and pollen, and dated by ¹³⁷Cs, ²¹⁰Pb excess and ¹⁴C. Extremely arid conditions of the terminal Pleistocene ended ca. 11 500 cal. BP (calendar years) when climate ameliorated and a lake developed until the occurrence of an arid event leading to lake desiccation at ～11 200 cal. BP. Following this, climate ameliorated and a water body re‐emerged. Very wet conditions predominated 11 200–5600 cal. BP, followed by drought between 5600 and 5500 cal. BP and a return to moderate humidity from 5500 to 4000 cal. BP. After 4000 cal. BP, a marked deterioration occurred, culminating in lake desiccation at ca. 800 cal. BP. After this time the climate remained generally dry and the re‐emerging lake was shallow. Comparison of these results with other well‐dated sequences in the region demonstrates the importance of basin‐specific influences on the palaeolimnological records in addition to regional climatic controls. Disentangling these different controls, as well as the reconstruction of Holocene climate, therefore requires a multiple‐basin approach. Copyright © 2008 John Wiley & Sons, Ltd.     

The influence of the ocean on the chemistry of precipitation in Nova Scotia*

Abstract

Between the fall of 1977 and December 1980, over 800 samples of precipitation were collected at 9 rural locations across Nova Scotia.

Average pH was 4.61, and an average conductivity of 25 μS cm^?1 confirmed the low ionic strength of rain and snow. Of all ions, chloride was the most abundant at 76 μeq L^?1 (2.7 mg L^?1). Oceanic origins were perceived as the source for chloride as well as for Na, Mg, 51 % of K, 21% of Ca, and 21% of SO₄, and the sea collectively accounted for 66% of all ions inNova Scotian precipitation. In contrast, the dominating ions in New York, New Hampshire, Ontario and Norway were H⁺ and SO₄.

In Nova Scotia, chloride concentrations in rain (mg L^?1) are a function of distance D (km) from the coast and may be described by the equation Cl [mg L^?1] = 4.5D^?0.42. It indicates that Cl concentrations are reduced by about 50% within 0.5 km of the coast, and 80% within 5 km. The continental North American chloride data examined are also consistent with the relationship.

The shape of the chloride curve is similar to curves others have developed from rain and lake water chemistry observations in Holland and the United Kingdom, although those, and other European data, indicate that the marine influence is less pronounced in northeastern North America.

The marine influence of precipitation chemistry on Nova Scotia has a maximum seasonal amplitude during the winter.     

Linking places to problems: geospatial theories of neighborhoods, alcohol and crime

This paper provides a critical review of two broad categories of social ecological theories of crime, social integration and place-based theories, and their relationships to spatial assessments of crime patterns. Social integration theories emphasize the role of neighborhood disorganization on crime, while place-based theories stress the social interactions within and between places as a source of crime. We provide an analysis of the extent to which these two types of theorizing describe processes and mechanisms that are truly ecologic (identify specific interactions between individuals and their environments) and truly spatial (identify specific movement and interaction patterns of individuals and groups) as they endeavor to explain crime outcomes. We suggest that social integration theories do not provide spatial signatures of sufficient specificity to justify the application of spatial statistical techniques as quantitative arbiters of the theory. On the other hand, place based theories go some way toward addressing these issues because the emphasis is placed on understanding the exact physical and social characteristics of place and the activities that occur around locations as sources of crime. Routine activities and crime potential theories attempt to explain clustering or “hot spots” of crime in ways that give clear spatial dimension by looking at micro-spatial interactions between offenders and targets of crime. These theories have strong ecological implications as well, since they contain specific statements about how people use the space around them and how these patterns of use are related to patterns of criminal activity. We conclude by identifying a set of requirements for successful empirical tests of geospatial theories, including the development of valid measures of key theoretical constructs and the formulation of critical empirical assessments of geospatial hypotheses derived from motivating theory.     

Exploring the spread of methamphetamine problems within California, 1980 to 2006

The introduction and spread of high potency methamphetamine has led to dramatic increases in drug-related problems in California. Prior research suggests that drug abuse rates are related to local demographic and economic characteristics, law enforcement activities, and sentencing practices. Methamphetamine abuse in particular has been shown to be reduced by laws regulating the raw materials needed for its production. This research models the regional effects of such laws on the spatio-temporal patterns of growth of methamphetamine-related problems across California from 1980 to 2006. Amphetamine-related arrests and hospital discharges related to amphetamine abuse/dependence were assembled for California counties over the years 1980–2006. Varying-parameter Bayesian space–time models were used to relate the implementation of major laws controlling the distribution of methamphetamine precursors to observed patterns of arrests and discharges and to allow such associations to vary by location. The models used conditionally autoregressive (CAR) Bayesian spatial priors to allow spatial correlation in estimation of county-specific growth in these measures over three distinct time periods: before the 1989 law, between the 1989 and 1997 laws, and after the 1997 law. Growth of arrests and discharges were related to demographic and economic indicators to determine geographic areas more or less susceptible to the spread of methamphetamine problems. Although both problem measures increased during all three periods, each of the precursor laws was associated with short-term reductions in the growth of arrests and discharges. Growth was greatest in central California counties prior to 1989 and increased in coastal counties in later years. From 1980 to 1989 growth was highest for counties with low incomes and high proportions of white residents, while 1989–1997 growth was highest in counties with fewer whites and more Hispanics. Growth after 1997 was not significantly associated with county characteristics. This research demonstrates that the precursor laws did suppress the growth of methamphetamine related arrests and hospital discharges. It also demonstrates specific geographic patterns in the growth of methamphetamine arrests and abuse across California during this time. Early patterns of growth were related to economic and demographic characteristics, while later patterns were not. This suggests that some counties were uniquely susceptible to the early spread of the methamphetamine epidemic, although problems eventually grew dramatically in all California counties.     

Spatial-temporal disease mapping of illicit drug abuse or dependence in the presence of misaligned ZIP codes

Geo-referenced data often are collected in small, administrative units such as census enumeration districts or postal code areas. Such areas vary in geographic area and population size and may change over time. In research into drug-related health issues within the United States, U.S. Postal Service ZIP codes represent a commonly used unit for data collection, storage, and spatial analysis because of their widespread availability in health databases through patient contact and billing information. However, the ZIP code was developed for the specific purpose of delivering mail and may be changed at any time, and its design and development does not take into consideration problems that may arise in data collection, analysis, and presentation in health studies. In this paper, we propose a spatial hierarchical modeling approach to quantify trends within ZIP-code based counts when some fraction of ZIP codes change over the study period, that is, when the data are spatially misaligned across time. We propose a data vector approach and adjust the spatial auto-correlation structure within our Bayesian hierarchical model to provide inference for our misaligned data. We motivate and illustrate our approach to explore spatio-temporal patterns of amphetamine abuse and/or dependence in Tracy, California over the years 1995–2005. Uncertainty associated with misaligned data is modeled, quantified, and visualized. The approach offers a framework for further investigation into other risk factors in order to more fully understand the dynamics of illicit drug abuse or dependence across time and space in imperfectly measured data.     

Observing the reconnection region in a transequatorial loop system

A vertical current sheet is a crucial element in many flare/coronal mass ejection (CME) models. For the first time, Liu et al. reported a vertical current sheet directly imaged during the flare rising phase with the EUV Imaging Telescope (EIT) onboard the Solar and Heliospheric Observatory (SOHO). As a follow-up study, here we present the comprehensive analysis and detailed physical interpretation of the observation. The current sheet formed due to the gradual rise of a transequatorial loop system. As the l...     

Genetic improvement of New Zealand aquaculture species: programmes,progress and prospects

Aquaculture, like terrestrial farming, cannot achieve economic and sustainable production without high performing genetic stocks tailored to the conditions under which they are grown. It is essential, therefore, that aquaculture investment includes genetics and biotechnology to adapt marine livestock to the novel conditions of intensive aquaculture and to the demanding markets into which they are sold. The return on investment in well-structured breeding programmes can be very high, and significant performance and economic gains have been demonstrated in multiple species. Many factors must be considered in designing a genetic improvement programme, including the reproductive biology of the species and the identification of realistic and commercially relevant breeding goals based on the resources and facilities available. This paper reviews the options available to aquaculturists and provides examples of how these are being applied to six aquaculture species in New Zealand: king salmon, hāpuku, kingfish, Greenshell^TM mussels, Pacific oysters and pāua (abalone).