Conflicting rights to the city in New York's community gardens

In the mid-1990s, New York City initiated what would prove to be a long, highly visible struggle involving rights claims related to property, housing, and public space in the form of community gardens. The competing discourses of rights were part of a struggle over the kind of city that New York was to become, and more specifically, whether it would be one in which difference is accepted and in which access to the city and the public realm would be guaranteed. Using interviews with participants in the conflict over community gardens, we evaluate how the resolution to the gardens crisis, which in part occurred through the privatization of what are often taken to be public or community rights to land, transform not only the legal status of the gardens but also, potentially, their role as places where different `publics' can both exercise their right to the city and solidify that right in the landscape.     

Visualising public transport accessibility to inform urban planning policy in Hubli-Dharwad,India

Rapid urbanisation in India is a key contributor to the overstressed public infrastructure. The urban public transport system is one of the important infrastructure systems. An effective public transportation network helps the city improve its accessibility, lower carbon footprint, and enhances economic growth and societal equity. India is a relatively poor country with limited public resources. Therefore, investing in an effective urban public transport system needs a tailored approach. Such an approach would entail using public transport to guide urban development. In this context, the first step would be to measure the accessibility levels of the existing public transport network and then use the accessibility mapping outputs to better inform the urban planning process. This study explores the Public Transport Accessibility Level (PTAL) tool that measures the accessibility of the public transport system and provides a spatial visualisation using Geographic Information System. PTAL is implemented taking Hubli-Dharwad as a case study for the base year (2020) superimposed with population and employment density, and future year (2031). The outcome of the research facilitates the city planning process by guiding transportation and land-use zoning integrations, direct public transport investments, demarcation of transit-oriented development zones, parking policies, and identifying locations of affordable and low-cost housing.

     

Application of calcite Mg partitioning functions to the reconstruction of paleocean Mg/Ca

Calcite Mg/Ca is usually assumed to vary linearly with solution Mg/Ca, that a constant partition coefficient describes the relationship between these two ratios. Numerous published empirical datasets suggests that this relationship is better described by a power function. We provide a compilation of these literature data for biotic and abiotic calcite in the form of Calcite Mg/Ca = F(Solution Mg/Ca)^H, where F and H are empirically determined fitting parameters describing the slope and deviation from linearity, respectively, of the function. This is equivalent to Freundlich sorption behavior controlling Mg incorporation in calcite. Using a power function, instead of a partition coefficient, lowers Phanerozoic seawater Mg/Ca estimates based on echinoderm skeletal material by, on average, 0.5 mol/mol from previous estimates.These functions can also be used to model the primary skeletal calcite Mg/Ca of numerous calcite phases through geologic time. Such modeling suggests that the Mg/Ca of all calcite precipitated from seawater has varied through the Phanerozoic in response to changing seawater Mg/Ca and that the overall range in Mg/Ca measured among various calcite phases would be greatest when seawater Mg/Ca was also high (e.g., “aragonite seas”) and lowest when seawater Mg/Ca was low (e.g., “calcite seas”). It follows that, during times of “calcite seas” when the seawater Mg/Ca is presumed to have been lower, deposition of calcite with low Mg contents would have resulted in a depressed drive for diagenetic stabilization of shelfal carbonate and, in turn, lead to greater preservation of crystal and skeletal microfabrics and primary chemistries in biotic and abiotic calcites.     

A Unified Assessment of Hydrologic and Biogeochemical Responses in Research Watersheds in Eastern Puerto Rico Using Runoff–Concentration Relations

An examination of the relation between runoff rate, R, and concentration, C, of twelve major constituents in four small watersheds in eastern Puerto Rico demonstrates a consistent pattern of responses. For solutes that are not substantially bioactive (alkalinity, silica, calcium, magnesium, sodium, and chloride), the log(R)–log(C) relation is almost linear and can be described as a weighted average of two sources, bedrock weathering and atmospheric deposition. The slope of the relation for each solute depends on the respective source contributions to the total river load. If a solute were strictly derived from bedrock weathering, the slope would be ?0.3 to ?0.4, whereas if strictly derived from atmospheric deposition, the slope would be approximately ?0.1. The bioactive constituents (dissolved organic carbon, nitrate, sulfate, and potassium), which are recycled by plants and concentrated in shallow soil, demonstrate nearly flat or downward-arched log(R)–log(C) relations. The peak of the arch represents a transition from dominantly soil-matrix flow to near-surface macropore flow, and finally to overland flow. At highest observed R (80 to >90 mm/h), essentially all reactive surfaces have become wetted, and the input rate of C becomes independent of R (log(R)–log(C) slope of –1). The highest R are tenfold greater than any previous study. Slight clockwise hysteresis for many solutes in the rivers with riparian zones or substantial hyporheic flows indicates that these settings may act as mixing end-members. Particulate constituents (suspended sediment and particulate organic carbon) show slight clockwise hysteresis, indicating mobilization of stored sediment during rising stage.     

Disruption, yet community reconstitution: subverting the privatization of Latin American plazas

Latin American scholars have recently discussed the privatization of urban public space. A fundamental aspect of this process is the disintegration of communities because it often targets and affects a peculiarly Latin American kind of public space: the plaza. Plazas have traditionally functioned as cultural centres in Latin American cites. They are central meeting points for political groups, sites of civic expression and public resistance, as well as places to purchase relatively cheap goods and services. Plazas are, therefore, sites in which families, neighbours, and political organizations mingle, interact, and also challenge authority. This paper uses these sorts of insights on public space in Latin America to develop a conceptualization of the plaza as a community centre. However, the multiple practices and interactions that occur in these forms of public space have been disrupted by state-led strategies which seek to privatize and sanitize public space, thereby disrupting??or even destroying??the community centre. I use primary materials on Mexico City??s Historic centre and its plaza to explore the ways in which this specific type of urban public space has been affected physically and symbolically by a regeneration scheme known as the Programa de Rescate.     

Association of subsurface radon changes in Alaska and the northeastern United States with earthquakes

Changes of radon concentration in the ground have been reported to correlate with seismic activity in many places over widely varying distances from the earthquake epicenters, sometimes over 100's and occasionally over 1000's of km depending on the magnitude M of the earthquakes. For proper use of such correlations in forecasting the location and size of impending earthquakes, it would be useful to establish a relation between M and the maximum distance x_M at which radon can be significantly altered by preseismic effects.We have monitored radon in the ground continuously at Blue Mountain Lake, NY starting Dec. 3. 1975 and at three locations in Alaska—Icy Bay, Yakataga, and Sand Point (starting Nov. 12, 1979; March 5, 1980; and June 29, 1980 respectively). Sample correlations from visual examination of the recent radon record and tentative use of a proposed scaling relation show a number of possible earthquake-related signals at these locations. The data are compatible with scaling relations that were derived from two separate models of premonitory elastic strains. In this work x_M = 10^0.48M, where x_M is in units of km and M ≥ 3. Since tilt and strain signals correlate similarly with magnitude and distance, it is likely that most earthquake-related radon signals are mechanically induced.     

Quartz c-axes orientation determination using the rotating polarizer microscope

A fast and accurate optical method to calculate quartz c-axis orientations using the rotating polarizer stage and standard thin sections is presented. c-Axis orientations are calculated for each pixel and Achsenverteilungsanalyse (AVA) can easily be constructed to study problems that would normally require a prohibitive amount of tedious work. The computer controlled rotating polarizer stage replaces the polarizer and analyzer of the standard petrographic microscope and allows a thin section to remain fixed while the polarizing filters are rotated by stepper motors. Data are collected by stepping the polarizers through a 180° rotation, capturing a frame at each step and extracting information on the intensity of the pixel and position of the polarizers. The position data are used to calculate the trend or trend+180° of the quartz c-axes, while a simple mathematical relationship between intensity and plunge is derived which allows the plunges of c-axes to be calculated.     

Assimilation of carbonate country rock by the parent magma of the Panzhihua Fe-Ti-V deposit（SW China）：Evidence from stable isotopes

The Panzhihua intrusion in southwest China is part of the Emeishan Large Igneous Province and host of a large Fe-Ti-V ore deposit.During emplacement of the main intrusion,multiple generations of mafic dykes invaded carbonate wall rocks,producing a large contact aureole.We measured the oxygen-isotope composition of the intrusions,their constituent minerals,and samples of the country rock.Magnetite and plagioclase from Panzhihua intrusion haveδ¹⁸O values that are consistent with magmatic equilibrium, and formed from magmas withδ¹⁸O values that were 1-2‰higher than expected in a mantle-derived magma.The unmetamorphosed country rock has highδ¹⁸O values,ranging from 13.2‰（sandstone） to 24.6-28.6‰（dolomite）.The skarns and marbles from the aureole have lowerδ¹⁸O andδ¹³C values than their protolith suggesting interaction with fluids that were in exchange equilibrium with the adjacent mafic magmas and especially the numerous mafic dykes that intruded the aureole.This would explain the alteration ofδ¹⁸O of the dykes which have significantly higher values than expected for a mantle-derived magma.Depending on the exactδ¹⁸O values assumed for the magma and contaminant, the amount of assimilation required to produce the elevatedδ¹⁸O value of the Panzhihua intrusion was between 8 and 13.7 wt.%,assuming simple mixing.The exact mechanism of contamination is unclear but may involve a combination of assimilation of bulk country rock,mixing with a melt of the country rock and exchange with CO₂-rich fluid derived from decarbonation of the marls and dolomites.These mechanisms,particularly the latter,were probably involved in the formation of the Fe-Ti-V ores.     

Applications of geospatial analysis to surveillance data: a spatial examination of HIV/AIDS prevalence in Zambia

Techniques of spatial statistics and GIS are applied to socio-economic, demographic and HIV sentinel data to characterize the geographical distribution of HIV prevalence in Zambia and to estimate current prevalence rates. Maps of the 4?years under study (i.e. 1994, 1998, 2002 and 2004) reveal a spatial variation in HIV prevalence with urban and provincial districts having higher prevalence than rural areas. However, there was an overall trend of decrease in HIV prevalence across the country. The year 2004 exhibited the most reduction, coinciding with protective sexual behavior campaigns operating in the country. Risk factors for HIV prevalence included literacy rates, unemployment, poverty and urban residency. Analysis of regression residual maps indicated high spatial autocorrelation: Moran’s I value was 0.28 (z?=?4.12 and p?<?0.000) and a highly significant Robust LM (lag; p?<?0.00000) suggestive of contagious and hierarchic spatial diffusion processes. High HIV prevalence rates among interdependent districts and locational similarity patterns suggest that HIV control programs in the country would require an integrated approach combining HIV prevention messages as well as an understanding of social and cultural interactions between interdependent districts that produce behavioral diffusion of HIV prevalence rates.     

Developing markets for water reallocation: Revisiting the experience of Spanish water mercantilización

Economic instruments are being promoted as a desirable alternative to public sector action in the allocation and management of natural resources. A wide body of literature has developed that critically analyzes this phenomenon as part of a wider project of ‘neoliberalization of nature’, trying to uncover the underlying rationale and commonalities of geographically specific phenomena. The case of water is at the vanguard of these processes and is proving to be particularly contentious. In the European Union water policies are increasingly emphasizing the application of economic instruments to improve the allocative equity and economic efficiency in the use of scarce resources. However, there are few analyses of how these instruments are really working on the ground and whether they are meeting their objectives. This paper aims to contribute to this debate by critically analyzing the experience with water markets in Spain, the only country in the European Union where they are operative. It looks at water permit sales during the 2005–2008 drought period using the Tajo–Segura transfer infrastructure. The paper describes how the institutional process of mercantilización of water works in practice in Spain. It shows that the use of markets requires an intense process of institutional development to facilitate and encourage their operation. These institutions tend to favor the interests of clearly identifiable elites, instead of the public interest they supposedly promote.     

Records of ancient cosmic radiation in extraterrestrial rocks

Recent results on cosmic ray interactions in lunar samples and meteorites resulting in production of stable and radionuclides, particle tracks and thermoluminescence are reviewed. A critical examination of²⁶A1 depth profiles in lunar rocks and soil cores, together with particle track data, enables us to determine the long term average fluxes of energetic solar protons (>10 MeV) which can be represented by (J _s,R _o)=(125, 125). The lunar rock data indicate that this flux has remained constant for 5×10⁵ to 2×10⁶ years. Production rates of stable and radionuclides produced by galactic cosmic rays is given as a function of size and depth of the meteoroid. Radionuclide (⁵³Mn,²⁸Al) depth profiles in meteorite cores, whose preatmospheric depths are deduced from track density profiles are used to develop a general procedure for calculating isotope production rates as a function of meteoroid size. Based on the track density and²²Ne/²¹Ne production rates, a criterion is developed to identify meteorites with multiple exposure history.²²Ne/²¹Ne ratio <1·06 is usually indicative of deep shielded exposure. An examination of the available data suggests that the frequency of meteorites with multiple exposure history is high, at least 15% for LL, 27% for L and 31% for H chondrites. The epi-thermal and the thermal neutron density profiles in different meteorites are deduced from⁶⁰Co and track density data in Dhajala, Kirin and Allende chondrites. The data show that the production profile depends sensitively on the size and the chemical composition of the meteoroid. Cosmic ray-induced thermoluminescence in meteorites of known preatmospheric sizes has been measured which indicates that its production profile is nearly flat and insensitive to the size of the meteoroid. Some new possibilities in studying cosmic ray implanted radionuclides in meteorites and lunar samples using resonance ionisation spectroscopy are discussed.     

Office dispersal in metropolitan areas II: Case study results and conclusions

A case study of office dispersal options in Sydney, Australia is presented within a Planning Balance Sheet Framework. Two dispersal options, one involving a limited number of large subcentres, the other a large number of smaller subcentres are examined. It is shown that both options are likely to result in considerable work-journey time savings for employees in relocated offices (particularly clerical and female workers) and considerable improvements in job access for many suburban residents. Overall, however, the large subcentre option appears to offer greater net benefits to both office employees and relocated organizations. Yet both options are likely to generate high external costs in terms of suburban road congestion, increased energy consumption, financial losses to public transport operators, and inequities of access to captive public transport users. These problems could be avoided if the government were to embark on a programme of upgrading public transport services and restricting car usage to the point where the majority of suburban commuters used public transport. This would involve considerable public expenditure, which is unlikely to be forthcoming in the present economic climate. But without such a programme, a policy of office dispersal would create more problems than it would solve.     

Landslide management in the UK—the problem of managing hazards in a ‘low-risk’ environment

The UK is a country with limited direct experience of natural disasters. Whilst landslide losses are not negligible and fatalities are rare, accounts are under-reported. Financial losses from landslides are poorly understood but likely to be considerably in excess of £10 million per year. As a result, a strategic management framework has evolved based upon small, low-impact events punctuated by occasional larger events or larger landslides affecting urban areas. We present an overview of the different landslide management mechanisms in the UK and discuss them in context of cases studies to explore their effectiveness. We conclude with three issues that may have implications for landslide management in the UK and other ‘low-risk’ countries. Firstly, the evidence base by which landslide hazards and risks are measured is insufficient and limitations in existing information need to be better understood. Secondly, existing guidance on strategic and responsive management needs to be assessed for its fitness for purpose. Thirdly, we encourage debate about the importance of near misses.     

Garnet-bearing ultramafic rocks from the Erzgebirge, and their relation to other settings in the Bohemian Massif

Garnet-bearing ultramafic rocks (GBU) enclosed in high-grade gneisses are known from several parts of the Bohemian Massif. One of these is the high-pressure(HP)-unit 1 in the Erzgebirge Crystalline Complex, which is the subject of the present study. Hitherto, two different models have been put forward to explain the stabilisation of garnet in mantle-derived ultramafic rocks from the Bohemian Massif and their emplacement into the crust. (1) Garnetiferous assemblages were formed in the ultramafics before they came in contact with their crustal host rocks. (2) Garnet was formed in the ultramafics at the expense of spinel due to cooling caused by their tectonic emplacement in the crust. The PT-evolution revealed by the investigated GBU from the Erzgebirge Crystalline Complex, however, requires a third model. The reconstruction of the PT-paths for the Erzgebirge GBU is based on both conventional thermobarometry and phase relations. Thermodynamic calculations allowed the construction of a PT-phase diagram for the system Na₂O-CaO-MgO-Al₂O₃-SiO₂-H₂O, which is the first quantitative petrogenetic grid in this model system relevant to ultramafic HP-rocks. The grid shows the uni-, di-, and tri-variant assemblages stable in peridotitic rocks at different PT-conditions, providing a tool to constrain PT-paths from the succession of mineral assemblages observed in a rock. The PT-path obtained for the Erzgebirge GBU suggests that the garnet-bearing assemblages formed by HP-metamorphism of spinel peridotite which was emplaced into the crust prior to or during the HP-compressional stage. This model is supported by peak PT-conditions around 900?°C and 30–35 kbar recorded by the ultramafic rocks, which are very similar to those attained in the eclogites sensu stricto which occur in the same tectonic unit (HP-unit 1) and for which an in situ metamorphism has been inferred (Schmädicke et al. 1992). On the other hand, the other two high-pressure units in the Erzgebirge, HP-units 2 and 3, which also contain eclogites sensu stricto but lack peridotites, record lower peak PT-conditions of 650–750?°C/24–26 kbar and 600–650?°C/20–24 kbar, respectively. Postulating an in situ HP-metamorphism for the garnet peridotites as result of continental collision during the Variscan orogeny, a crustal thickness of 90–110 km would be required. A comparison of the distribution of eclogites sensu stricto and mantle-derived rocks from the Bohemian Massif together with their reported PT-conditions reveals a correlation between peak PT-conditions in eclogites sensu stricto and the prevailing assemblages in the ultramafic rocks in the same unit. Furthermore, the Erzgebirge Crystalline Complex and the Snieznik Complex on one hand as well?as the Granulitgebirge and the Sowie Góry on the other hand are thought to be genetically linked. The garnet peridotites from the Granulitgebirge, the Sowie Góry and the Gföhl unit seem to have experienced peak PT-conditions not recorded by their country rocks with non-eclogitic basic interlayers, inferring a formation of?HP-assemblages in the ultramafics prior to their emplacement into the crust.     

Geobotanical and biogeochemical reconnaissance of the ultramafics of Central Iran

In Iran, ultramafic rocks cover substantial areas at many locations in the country. These rocks consist predominantly of peridotite which has been serpentinized to some degree. Anarak and Nain are two ultramafic areas in Central Iran comprising about 180 and 270 km², respectively, located in a coloured melange zone. There is little information available regarding the geobotany and biogeochemistry of these areas. They have a dry climate, with low rainfall and high temperatures in summer which encourages mostly annual and perennial herbaceous types of plants. In this paper, we report a reconnaissance study of these two ultramafic areas of Iran. Soil analysis of total elements indicates that typical concentrations of Ni, Cr, Co, Mn, Fe, Mg and Ca are about 1500, 300, 75, 800, 45.000 150.000 and 2000 μg g^− 1, respectively. During this study 176 plant species were collected, belonging to 29 families. The species diversity at Anarak is more than at Nain, possibly due to microclimatic differences and a greater precipitation. The number of plants endemic to ultramafic soils of these two areas is very low. The herb Cleome heratensis (Capparaceae) appears to be an indicator of ultramafics in Central Iran. Populations of this plant cover quite extensive areas during summer and autumn when there is no rainfall. Analysis of the dry matter of the leaves of all plants collected did not reveal any hyperaccumulator of nickel or any other ‘serpentine’ metals. The ultramafic endemic plant C. heratensis contained low concentrations of all metals and thus it possesses exclusion mechanisms to restrict excessive metal uptake. The Mg/Ca ratio for some plants collected is high—up to 4.9. This initial survey suggests that a more complete investigation of the ultramafic areas of Iran would be valuable.     

A bothremydid from the middle Cenomanian of Portugal identified as one of the oldest pleurodiran turtles in Laurasia

The relatively complete and well preserved shell of a turtle, from the middle Cenomanian of Nazaré (Portugal), is studied here. It is recognized as a member of the crown group Pleurodira and, more specifically, of Bothremydidae. Pleurodira are one of the two lineages of modern turtles, their origin being in Gondwana. Pleurodira are very abundant in the uppermost Cretaceous record of Europe. However, this new finding is one of the few occurrences in the lower Upper Cretaceous of Laurasia. A single member of Bothremydidae had so far been identified in Portugal: the late Campanian-early Maastrichtian Rosasia soutoi. It was the only Cretaceous turtle identified in that country both at specific and at generic levels, being exclusive of Portugal. The taxon from Nazaré is identified as Algorachelus peregrinus, this form is also present in the contemporaneous beds in Spain, and is the oldest member of Bothremydidae in Laurasia. Algorachelus peregrinus is confirmed here to be a coastal form, which facilitated its spread. The two oldest known bothremydids from Laurasia, the European A. peregrinus and the North American Paiutemys tibert, are compared for the first time. They are recognized as closely related taxa. This study provides new data allowing a more precisely characterization of the oldest so far known dispersal event of Pleurodira in Laurasia, which was performed by an African lineage of Bothremydidae that reached the east coast of the Atlantic Ocean at least in the middle Cenomanian, and the west region of that Ocean at least in the late Cenomanian.     

Oysters and the Chesapeake Bay ecosystem: A case for exotic species introduction to improve environmental quality?

Restoration of the Chesapeake Bay ecosystem has been a priority for residents and governments of the bay watershed for the past decade. One obstacle in the efforts to “save the bay” has been continuing nutrient enrichment from agricultural and sewer runoff. The attainability of a mandated 40% nutrient reduction goal has yet to be seen. Furthermore, disappearance of certain organisms may have had an adverse effect on the resilience of the ecosystem. The Eastern oyster (Crassostrea virginica), once abundant in Chesapeake Bay, was a vital part of the food web, processing excess phytoplankton and depositing materials on the bottom. Over harvesting and disease have decimated the native oyster population. The introduction of an exotic species, the Japanese oyster (Crassostrea gigas), may be a way to reestablish a robust oyster community in the bay. The literature on the role of bivalve molluscs in estuarine ecosystems shows that they are an essential part of healthy estuaries around the world. A comparison ofC. virginica andC. gigas in terms of temperature and salinity tolerance and resistance to disease shows thatC. virginica is ideally adapted to conditions in Chesapeake Bay, but it is unable to stave off the endemic diseases, whereasC. gigas is adapted to conditions in the lower bay only but is much less susceptible to the same diseases. We conclude that the potential introduction ofC. gigas to Chesapeake Bay would be limited by the Japanese species’ physiological requirements but that the revitalization of a bivalve population is imperative to the restoration of ecosystem function.     

Stay or leave? Potential climate change adaptation strategies among Aboriginal people in coastal communities in northern Australia

Coastal northern Australia is largely owned and occupied by Aboriginal people who are strongly connected to their traditional country. We assess the views of Aboriginal people in Arnhem Land on the impacts of climate change and their possible precautionary responses to both sea level rise and a potential increase in the intensity of tropical cyclones in coastal communities. All respondents had heard about climate change, and 48 % had already seen environmental changes, particularly sea level rise, which they attributed to climate change. Fifty-eight percent of respondents would consider relocating in the future for safety reasons, although most respondents perceived living close to the sea as highly important for their future well-being, emphasising their strong connection to their traditional sea country. Many of those willing to relocate would consider moving inland, either temporarily or permanently, provided that community facilities could also be moved. Other respondents who said they would be unlikely to relocate in the future because of climate change impacts, and would prefer to adapt in situ with government support (e.g. building more shelters for severe cyclones, building sea walls and better roads for quick evacuation if necessary). We recommend that the diversity of adaptation preferences among Aboriginal people should be accommodated in policy to minimise social impacts of climate change and to take advantage of potential opportunities that could arise from moving.     

The amplitude spectra of P- and S-waves and the body-wave magnitude of earthquakes

Synthetic calibration functions for body-wave magnitudes are presented. They have been obtained from computations made under the assumption that the variation of amplitude spectra along the earth's surface is due to radial velocity heterogeneity and radial changes of the dissipation factor Q inside the earth only. The new calibration functions depend on the epicentral distance and the focal depth of the earthquake, as well as on the period of the body-wave under consideration.No single calibration function exists which would produce magnitude figures identical for all Fourier components of a body-wave. Observations on several hundreds of strong earthquakes in recent years show that the P-wave magnitudes vary systematically with the period of the wave. With the application of the synthetic calibration function a general increase of the teleseismically determined P-wave magnitudes with frequency is observed. This fact reconciles acceleration response spectra from narrowband strong-motion analyzers in the near-field of an earthquake and spectral magnitudes determined from far-field observations by sensitive narrow-band seismographs. The strength of high-frequent spectral components generally exceeds the strength of low-frequent components determined in both cases.