Status of the Jamaican Iguana (Cyclura collei): Assessing 15 Years of Conservation Effort

Following its rediscovery in 1990 in the remote Hellshire Hills, the Jamaican Iguana (Cyclura collei) has been the focus of a sustained conservation effort aimed at securing the species’ short- and long-term survival. Major threats to the iguana’s persistence include habitat destruction by humans and predation by introduced mammals such as dogs, cats, and the Indian Mongoose.Beginning in 1990 with field surveys of the remnant C. collei population and the formation of the Jamaican Iguana Research and Conservation Group (JIRCG), a variety of conservation measures have been implemented. Protection and monitoring of known nesting areas have facilitated the collection of founder stock for captive breeding and “headstart” programs, and have resulted in the collection, mark, and release of hundreds of C. collei hatchlings. As hedges against extinction in the wild, breeding nuclei of C. collei have been established at the Hope Zoo in Kingston and also at six U. S. zoos (Central Florida, Fort Worth, Gladys Porter in Brownsville, Texas, Indianapolis, San Diego, and Sedgwick County in Wichita, Kansas). The first captive-bred hatchlings were produced in September 2004 at the Hope Zoo. Adult-sized, headstarted C. collei reared at the Hope Zoo have been successfully repatriated into the Hellshire Hills, and we have now verified post-release survival of up to eight years. Egg-laying has been observed in repatriated females, suggesting that this zoo-based augmentation effort is having a positive effect on the remaining wild population.Ongoing exotic predator removal efforts seek to maintain a conservation zone that is largely devoid of nonnative mammalian predators such as cats and mongooses. To date, hundreds of these invasive predators have been trapped and removed from the core C. collei area, and preliminary data suggest that the iguana may be benefiting from this predator control program. More recently (2003–2004), efforts to control feral dog and pig populations have been intensified.Overall, the biological interventions directed at C. collei appear to have been highly successful. Unfortunately, C. collei’s dry forest habitat is at risk of ecological destruction. The remaining primary forest in Hellshire is under constant assault from the activities of illegal tree cutters, primarily charcoal burners. The JIRCG has protected a small portion of the forest in the vicinity of the known nesting areas and major iguana concentration, and attempts to discourage charcoal burners from penetrating farther into the undisturbed forest. If implemented, tabled government plans from the 1960s for large-scale commercial and residential development would likely cause the extinction of C. collei. Encouragingly, increased national and international appreciation of Hellshire’s stature as one of the finest remaining examples of Caribbean dry forest, together with considerable interest in the iguana’s plight, give hope that this unique ecosystem and its endangered occupants will receive adequate protection. Indeed, the Jamaican government’s declaration of the Portland Bight Protected Area (PBPA) in 1999 (including the Hellshire Hills and the Goat Islands) and the recent (2004) delegation of management authority to the Urban Development Corporation (UDC) is a positive step in that direction

Status of the Jamaican Iguana (Cyclura collei): Assessing 15 Years of Conservation Effort

Following its rediscovery in 1990 in the remote Hellshire Hills, the Jamaican Iguana (Cyclura collei) has been the focus of a sustained conservation effort aimed at securing the species’ short- and long-term survival. Major threats to the iguana’s persistence include habitat destruction by humans and predation by introduced mammals such as dogs, cats, and the Indian Mongoose.Beginning in 1990 with field surveys of the remnant C. collei population and the formation of the Jamaican Iguana Research and Conservation Group (JIRCG), a variety of conservation measures have been implemented. Protection and monitoring of known nesting areas have facilitated the collection of founder stock for captive breeding and “headstart” programs, and have resulted in the collection, mark, and release of hundreds of C. collei hatchlings. As hedges against extinction in the wild, breeding nuclei of C. collei have been established at the Hope Zoo in Kingston and also at six U. S. zoos (Central Florida, Fort Worth, Gladys Porter in Brownsville, Texas, Indianapolis, San Diego, and Sedgwick County in Wichita, Kansas). The first captive-bred hatchlings were produced in September 2004 at the Hope Zoo. Adult-sized, headstarted C. collei reared at the Hope Zoo have been successfully repatriated into the Hellshire Hills, and we have now verified post-release survival of up to eight years. Egg-laying has been observed in repatriated females, suggesting that this zoo-based augmentation effort is having a positive effect on the remaining wild population.Ongoing exotic predator removal efforts seek to maintain a conservation zone that is largely devoid of nonnative mammalian predators such as cats and mongooses. To date, hundreds of these invasive predators have been trapped and removed from the core C. collei area, and preliminary data suggest that the iguana may be benefiting from this predator control program. More recently (2003–2004), efforts to control feral dog and pig populations have been intensified.Overall, the biological interventions directed at C. collei appear to have been highly successful. Unfortunately, C. collei’s dry forest habitat is at risk of ecological destruction. The remaining primary forest in Hellshire is under constant assault from the activities of illegal tree cutters, primarily charcoal burners. The JIRCG has protected a small portion of the forest in the vicinity of the known nesting areas and major iguana concentration, and attempts to discourage charcoal burners from penetrating farther into the undisturbed forest. If implemented, tabled government plans from the 1960s for large-scale commercial and residential development would likely cause the extinction of C. collei. Encouragingly, increased national and international appreciation of Hellshire’s stature as one of the finest remaining examples of Caribbean dry forest, together with considerable interest in the iguana’s plight, give hope that this unique ecosystem and its endangered occupants will receive adequate protection. Indeed, the Jamaican government’s declaration of the Portland Bight Protected Area (PBPA) in 1999 (including the Hellshire Hills and the Goat Islands) and the recent (2004) delegation of management authority to the Urban Development Corporation (UDC) is a positive step in that direction

Method of Bonding Optical Elements with Near-Zero Displacement

The International X-ray Project seeks to build an x-ray telescope using thousands of pieces of thin and flexible glass mirror segments. Each mirror segment must be bonded into a housing in nearly perfect optical alignment without distortion. Forces greater than 0.001 Newton, or displacements greater than 0.5 m of the glass, cause unacceptable optical distortion. All known epoxies shrink as they cure. Even the epoxies with the least amount of shrinkage (<0.01%) cause unacceptable optical distortion and misalignment by pulling the mirror segments towards the housing as it cures. A related problem is that the shrinkage is not consistent or predictable so that it cannot be accounted for in the setup (i.e., if all of the bonds shrunk an equal amount, there would be no problem). A method has been developed that allows two components to be joined with epoxy in such a way that reduces the displacement caused by epoxy shrinking as it cures to less than 200 nm. The method involves using ultraviolet-cured epoxy with a displacement sensor and a nanoactuator in a control loop. The epoxy is cured by short-duration exposures to UV light. In between each exposure, the nano-actuator zeroes out the displacement caused by epoxy shrinkage and thermal expansion. After a few exposures, the epoxy has cured sufficiently to prevent further displacement of the two components. Bonding of optical elements has been done for many years, but most optics are thick and rigid elements that resist micro-Newton-level forces without causing distortion. When bonding thin glass optics such as the 0.40-mm thick IXO X-ray mirrors, forces in the micro- and milli-Newton levels cause unacceptable optical figure error. This innovation can now repeatedly and reliably bond a thin glass mirror to a metal housing with less than 0.2 m of displacement (<200 nm). This is an enabling technology that allows the installation of virtually stress-free, undistorted thin optics onto structures. This innovation is applicable to the bonding of thin optical elements, or any thin/flexible structures, that must be attached in an undistorted, consistent, and aligned way

Mirror Metrology Using Nano-Probe Supports

Thin, lightweight mirrors are needed for future x-ray space telescopes in order to increase x-ray collecting area while maintaining a reduced mass and volume capable of being launched on existing rockets. However, it is very difficult to determine the undistorted shape of such thin mirrors because the mounting of the mirror during measurement causes distortion. Traditional kinematic mounts have insufficient supports to control the distortion to measurable levels and prevent the mirror from vibrating during measurement. Over-constrained mounts (non-kinematic) result in an unknown force state causing mirror distortion that cannot be determined or analytically removed. In order to measure flexible mirrors, it is necessary to over-constrain the mirror. Over-constraint causes unknown distortions to be applied to the mirror. Even if a kinematic constraint system can be used, necessary imperfections in the kinematic assumption can lead to an unknown force state capable of distorting the mirror. Previously, thicker, stiffer, and heavier mirrors were used to achieve low optical figure distortion. These mirrors could be measured to an acceptable level of precision using traditional kinematic mounts. As lighter weight precision optics have developed, systems such as the whiffle tree or hydraulic supports have been used to provide additional mounting supports while maintaining the kinematic assumption. The purpose of this invention is to over-constrain a mirror for optical measurement without causing unacceptable or unknown distortions. The invention uses force gauges capable of measuring 1/10,000 of a Newton attached to nano-actuators to support a thin x-ray optic with known and controlled forces to allow for figure measurement and knowledge of the undeformed mirror figure. The mirror is hung from strings such that it is minimally distorted and in a known force state. However, the hanging mirror cannot be measured because it is both swinging and vibrating. In order to stabilize the mirror for measurement, nano-probes support the mirror, causing the mirror to be over-constrained

Screenomics : a new approach for observing and studying individuals' digital lives

This study describes when and how adolescents engage with their fast-moving and dynamic digital environment as they go about their daily lives. We illustrate a new approach—screenomics—for capturing, visualizing, and analyzing screenomes, the record of individuals’ day-to-day digital experiences. Sample includes over 500,000 smartphone screenshots provided by four Latino/Hispanic youth, age 14 to 15 years, from low-income, racial/ethnic minority neighborhoods. Screenomes collected from smartphones for 1 to 3 months, as sequences of smartphone screenshots obtained every 5 seconds that the device is activated, are analyzed using computational machinery for processing images and text, machine learning algorithms, human labeling, and qualitative inquiry. Adolescents’ digital lives differ substantially across persons, days, hours, and minutes. Screenomes highlight the extent of switching among multiple applications, and how each adolescent is exposed to different content at different times for different durations—with apps, food-related content, and sentiment as illustrative examples. We propose that the screenome provides the fine granularity of data needed to study individuals’ digital lives, for testing existing theories about media use, and for generation of new theory about the interplay between digital media and development

Influencia de las altas temperaturas superficiales en las propiedades del acero al carbono ASTM A36

El presente proyecto investigativo tuvo como objetivo analizar la influencia de las altas temperaturas superficiales en las propiedades del acero al carbono ASTM A36. Para lo cual se comenzó con el análisis del estado del arte, luego se prosiguió con la experimentación de placas de acero de 12 mm de espesor, sometido a las altas temperaturas superficiales alcanzando rangos de temperaturas entre 700 °C a 1110 °C en diferentes tiempos de exposición, una vez que se culminó con la experimentación a cada una de las probetas se realizó ensayos de ultrasonido mediante la norma ASTM E797/E797M-21, análisis metalográfico de las probetas basado a la norma ASTM E3-11, determinación del tamaño de grano de acuerdo a la norma ASTM E112-13 y finalmente se determina la dureza mediante la norma ASTM E10-18, estos ensayos se realizaron con la finalidad de constatar los cambios en las propiedades del acero. Los resultados de los ensayos de espesor y dureza después de la experimentación, han proporcionado valores promedios obteniendo el espesor de 11,81 mm y durezas de 145 HB y 79, 4 HRB en la zona A, 138 HB y 76,8 HRB en la zona B, finalmente se evidenció la presencia de las fases de ferrita y perlita y una reducción en el tamaño de grano del acero que paso de 8,41 a 7,61. Se concluyó que el espesor, la dureza y el tamaño de grano del acero ASTM A36 se redujeron debido a la exposición de las altas temperaturas en un intervalo de tiempo de 90 minutos y una distancia de 100 mm. Se recomienda continuar con investigaciones de este campo aplicado a otros tipos de acero al carbono y realizar cortes en frio de las muestras metalográficas para evitar cambios de fases.The objective of this research project was to analyze the influence of high surface temperatures on the carbon steel properties ASTM A36. It began with the analysis of the state of the art, then continued with the experimentation of 12 mm thick steel plates. They were subjected to high surface temperatures, reaching temperature ranges between 700 °C to 1110 °C at different times of exposure. Once the experimentation was completed on each of the specimens, ultrasound tests were carried out using the ASTM E797/E797M-21 standard, metallographic analysis of the specimens based on the ASTM E3-11 standard, determination of the size of grain according to the ASTM E112-13 standard and finally the hardness is determined by the ASTM E10-18 standard. These tests were carried out in order to verify the changes in the steel properties. The results of the thickness and hardness tests after experimentation have provided average values, obtaining a thickness of 11,81 mm and hardnesses of 145 HB and 79,4 HRB in zone A, 138 HB and 76,8 HRB in zone B. Finally the presence of the ferrite and pearlite phases and a reduction in the steel grain size that went from 8,41 to 7,61 was evidenced. It was concluded that the thickness, hardness and steel grain size of ASTM A36 were reduced due to exposure to high temperatures in a time interval of 90 minutes and a distance of 100 mm. It is recommended to continue with research in this field applied to other types of carbon steel and cold cut metallographic samples to avoid phase changes

Variation in the organization and subunit composition of the mammalian pyruvate dehydrogenase complex E2/E3BP core assembly

The final version of this article is available at the link below.Crucial to glucose homoeostasis in humans, the hPDC (human pyruvate dehydrogenase complex) is a massive molecular machine comprising multiple copies of three distinct enzymes (E1–E3) and an accessory subunit, E3BP (E3-binding protein). Its icosahedral E2/E3BP 60-meric ‘core’ provides the central structural and mechanistic framework ensuring favourable E1 and E3 positioning and enzyme co-operativity. Current core models indicate either a 48E2+12E3BP or a 40E2+20E3BP subunit composition. In the present study, we demonstrate clear differences in subunit content and organization between the recombinant hPDC core (rhPDC; 40E2+20E3BP), generated under defined conditions where E3BP is produced in excess, and its native bovine (48E2+12E3BP) counterpart. The results of the present study provide a rational basis for resolving apparent differences between previous models, both obtained using rhE2/E3BP core assemblies where no account was taken of relative E2 and E3BP expression levels. Mathematical modelling predicts that an ‘average’ 48E2+12E3BP core arrangement allows maximum flexibility in assembly, while providing the appropriate balance of bound E1 and E3 enzymes for optimal catalytic efficiency and regulatory fine-tuning. We also show that the rhE2/E3BP and bovine E2/E3BP cores bind E3s with a 2:1 stoichiometry, and propose that mammalian PDC comprises a heterogeneous population of assemblies incorporating a network of E3 (and possibly E1) cross-bridges above the core surface.This work was partly supported by EPSRC (under grants GR/R99393/01 and EP/C015452/1)

The place of strategic environmental assessment in the privatised electricity industry

The private sector has given relatively little attention to the emergence of strategic environmental assessment (SEA); even recently privatised utilities, where SEA might be deemed particularly appropriate, and whose activities are likely to fall within the scope of the European Union SEA Directive, have shown less interest than might be expected. However, the global trend towards the privatisation of state-owned enterprises makes the adaptation of SEA towards these industries all the more pressing. This paper addresses the place that SEA might take within the electricity sector, taking the privatised UK electricity industry as an example. Particular challenges are posed by the radical restructuring of the industry, designed to introduce competitive behaviour, making the development of comprehensive SEA processes problematic, and requiring SEA to be placed in the context of corporate environmental policy and objectives.</p

LIM-kinase1 Hemizygosity Implicated in Impaired Visuospatial Constructive Cognition

AbstractTo identify genes important for human cognitive development, we studied Williams syndrome (WS), a developmental disorder that includes poor visuospatial constructive cognition. Here we describe two families with a partial WS phenotype; affected members have the specific WS cognitive profile and vascular disease, but lack other WS features. Submicroscopic chromosome 7q11.23 deletions cosegregate with this phenotype in both families. DNA sequence analyses of the region affected by the smallest deletion (83.6 kb) revealed two genes, elastin (ELN ) and LIM-kinase1 (LIMK1). The latter encodes a novel protein kinase with LIM domains and is strongly expressed in the brain. Because ELN mutations cause vascular disease but not cognitive abnormalities, these data implicate LIMK1 hemizygosity in impaired visuospatial constructive cognition