An Analysis of Spatial and Temporal Dimension of Drought Vulnerability in Turkey Using the Standardized Precipitation Index

Drought has become a recurrent phenomenon in Turkey in the last few decades. Significant drought conditions were observed during years of late 1980s and the trend continued in the late 1990s. The countrys agricultural sector and water resources have been under severe constraints from the recurrent droughts. In this study, spatial and temporal dimensions of meteorological droughts in Turkey have been investigated from vulnerability concept. The Standardized Precipitation Index (SPI) method was used to detail geographical variations in the drought vulnerability based on frequency and severity of drought events at multiple time steps. Critical (threshold) rainfall values were derived for each station at multiple-time steps in varying drought categories to determine least amount of rainfall required to avoid from drought initiation. The study found that drought vulnerability portrays a very diverse but consistent picture with varying time steps. At regional scale, south-eastern and eastern Anatolia are characterized with moderate droughts at shorter time steps, while the occurrence of severe droughts at shorter time steps is observed at non-coastal parts of the country. A similar picture was observed with very severe droughts. The critical (threshold) values exhibited rising numbers during the growing season at 3-month step in the South-eastern Anatolia, which might have significant consequences considering presence of large irrigation projects under-development in the region. In general, rainfall amounts required for non-drought conditions decrease from the coastal parts toward the interiors with increasing time steps.     

Nature and timing of magma interactions before,during, and after the caldera-forming eruption of Volcán Ceboruco,Mexico

Volcán Ceboruco, Mexico, erupted ~1,000 years ago, producing the Jala pumice and forming a ~4-km-wide caldera. During that eruption, 2.8 to 3.5 km³ of rhyodacite (~70 wt% SiO₂) magma and 0.2 to 0.5 km³ of mixed dacite (~67 wt% SiO₂) magma were tapped and deposited as the Jala pumice. Subsequently, the caldera was partially filled by extrusion of the Dos Equis dome, a low-silica (~64 wt% SiO₂) dacite dome with a volume of ~1.3 km³. Petrographic evidence indicates that the Jala dacite and Dos Equis dacite originated largely through the mixing of three end-member magmas: (1) rhyodacite magma, (2) dacite magma, and (3) mafic magma. Linear least-squares modeling and detailed modal analysis indicate that the Jala dacite is predominantly a bimodal mixture of rhyodacite and dacite with a small additional mafic component, whereas the Dos Equis dacite is composed of mostly dacite mixed with subordinate amounts of rhyodacite and mafic magma. According to Fe–Ti oxide geothermometry, before the caldera-forming eruption the rhyodacite last equilibrated at ~865 °C, whereas the dacite was originally at ~890 °C but was heated to ~960 °C by intrusion of mafic magma as hot as ~1,030 °C. Zoning profiles in plagioclase and/or magnetite phenocrysts indicate that mixing between mafic and dacite magma occurred ~34–47 days prior to eruption, whereas subsequent mixing between rhyodacite and dacite magmas occurred only 1–4 days prior to eruption. Following the caldera-forming eruption, continued inputs of mafic magma led to effusion of the Dos Equis dome dacite. In this case, timing between mixing and eruption is estimated at ~93–185 days based on the thickness of plagioclase overgrowth rims.Editorial responsibility: T.L. Grove     

Ex-seafarers shore-based employment: the current UK situation

The decline of the British shipping industry has had a significant impact on those sectors of the UK economy which have traditionally relied on ex-seafarers as a source of skilled labour. An in-depth study of the impacts of this problem was undertaken in 2003 to consider the implications of developments which have taken place in the industry since 1996. The UK economy's requirement for people with seafaring experience to fill land-based jobs was assessed, together with the implications of any shortfall. This paper considers the demand aspects of changes which have occurred since 1996.     

The policy implications of market failure for the land-based jobs market for British seafarers

People with seafaring experience and skills are employed in the maritime sector of the UK economy in land-based jobs as well as in seagoing ones. This paper examines the balance of supply and demand in the land-based jobs market. It then considers the likely effects of a shortfall in the supply of British ships’ officers to fill net vacancies in jobs ashore, including the policy implications of this and the consequences for the economy's maritime skills base if the Government fails to act decisively now to correct market failure.     

Simplified procedure for the manual analysis of nitrate in seawater

The use of small volumes of sample and reagents permits the adaption of a copper-coated cadmium column to the manual analysis of nitrate in seawater. The apparatus used for this modification is described.     

Conjugation of 4-hydroxynonenal by largemouth bass (Micropterus salmoides) glutathione S-transferases

The glutathione S-transferases (GST) are a major group of conjugative enzymes involved in the detoxification of electrophilic compounds and products of oxidative stress. We have previously described the kinetics of hepatic GST conjugation in largemouth bass using a variety of synthetic GST reference substrates. In the present study, we investigated the ability of largemouth bass hepatic GSTs to conjugate 4-hydroxynon-2-enal (4HNE), a mutagenic and cytotoxic alpha-beta-unsaturated aldehyde produced during oxidative injury. Hepatic cytosolic fractions from largemouth bass rapidly catalyzed GSH-dependent 4HNE conjugation, with the rate of GST-4HNE conjugation in bass liver exceeding those of several other mammalian and aquatic species. No apparent sex-related differences in GST-4HNE activity were observed among adult bass. SDS-PAGE and Western blotting analysis of GSH affinity-purified bass liver cytosolic GST revealed the presence of two major GST subunits of approximately 30 and 27 KDa that exhibited slight cross-reactivity when probed with a rat alpha class GST antibody, but not to rat mu, pi or theta class GST. The rapid conjugation of 4HNE by hepatic GST suggests an important role for GSTs in protecting against peroxidation of polyunsaturated fatty acids in bass liver.     

Improved chromatographic analysis of N:N ratios in ammonium or nitrate for isotope addition experiments

Estimating nitrogen transformation rates in aquatic ecosystems by isotope dilution techniques is simplified by directly measuring nitrogen isotopic ratios for NH₄⁺ in the water using high performance cation exchange liquid chromatography (HPLC). Modifications of HPLC conditions and implementation of a median-area method for retention time determination improved and linearized a previously reported sigmoid relationship between the retention time shift (RT_shift) of the NH₄⁺ peak and the ratio of [¹⁵NH₄⁺]: [Total NH₄⁺] in seawater fortified with ¹⁵NH₄⁺. Increasing the temperature of the HPLC column from 47 to 85 °C increased mobile phase buffer flow rate relative to column back pressure, decreased the retention time for NH₄⁺, and allowed the buffer pH to be optimized relative to the pK of NH₄⁺. The use of median-area rather than maximum-height to define the retention time of NH₄⁺ further improved the linearity (r > 0.995) of the relationship between the ratio [¹⁵NH₄⁺]: [Total NH₄⁺] and RT_shift over the range of isotope ratios. Reduction of NO₃⁻ to NH₄⁺ by adding zinc dust to acidified (pH 2) seawater or lakewater samples, followed by pH neutralization, and subsequent analysis of NH₄⁺ isotope ratios by HPLC, extended application of the method to isotope dilution experiments with NO₃⁻. Advantages of this direct-injection method over mass-measurement approaches traditionally used for isotope dilution experiments include small sample size and minimal sample preparation.     

A comparative study of the differential blood cell counts of winter flounder (Pseudopleuronectes americanus) collected in New England

Major alterations in the distribution of peripheral blood cells were observed among winter flounder (Pseudopleuronectes americanus) from Martha's Vineyard (MV), East Cape Cod Bay (ECCB), Fox Island (FI) (Narragansett Bay), Central Long Island Sound (CLIS), Gaspee Point (GP) (Narragansett Bay), Black Rock Harbor (BRH) (Bridgeport, CT), New Bedford Harbor (NBH) and Quincy Bay (QB) (Boston Harbor). Collection locations ranged from relatively uncontaminated offshore (MV) and nearshore (ECCB) sites to the more contaminated estuarine (FI, CLIS) and urban embayments (GP, BRH, NBH, QB). Differential diagnosis demonstrated a shift in lymphocyte counts from 28% (MV) to 54% (QB) that increased with the incidence of liver lesions in relation to known and suspected levels of sediment chemical contamination. A significant change in the ratio of circulating immature to mature erythrocytes was observed in flounder collected from Boston Harbor. Immature erythrocytes comprised 18% of the total erythrocyte population of fish from QB in comparison to 6% observed in flounder from ECCB.     

Collaborative geomatics and the Mushkegowuk Cree First Nations: Fostering adaptive capacity for community-based sub-arctic natural resource management

The remote First Nation (FN) communities of the Mushkegowuk Territory on the west coast of James Bay, Ontario, Canada are currently facing increased development pressures and the imposition of a government land use planning process. The land use planning process is mandated in the Far North Act (received Royal Assent on September 23, 2010). There is a need for capacity enhancement for community-based natural resource planning and management in the Territory. A number of frameworks are emerging for addressing change brought on by resource development and building resilience to such change at the community level. Among these include the concept of adaptive capacity. In collaboration with FN community leaders, we explored the use of “collaborative geomatics” tools to foster adaptive capacity. Our action research suggests that collaborative geomatics technologies should enhance the Mushkegowuk First Nations’ adaptive capacity to address environmental and policy change by allowing them to collect and manage data collaboratively (e.g., traditional environmental knowledge, western science) to create opportunities for innovative community development, including natural resource development and management.