ASSEMBLAGE ORGANIZATION OF SURFACE-ACTIVE ARTHROPODS ALONG HORIZONTAL MOISTURE GRADIENTS IN A COASTAL SONORAN DESERT ECOSYSTEM

Examinamos las diferencias a corto plazo en la organización de las comunidades de artrópodos activos en la superficie del suelo en una porción restringida del ecosistema de dunas cerca de Puerto Peñasco, Sonora, México. Para probar la hipótesis de que el gradiente de humedad del suelo influye en tal organización, se estabecieron tres transectos de 32 m en dirección oeste hacia la costa f) área de estero, 2) estanque de agua salada, y 3) área intermedia de desierto seco (control). El gradiente de humedad varió en el estero y estanque de 15% y 11% a <1% respectivamente, mientras que la humedad del suelo en la área control fue de <1% (valores promedio a 15 cm de profundidad). Cuatro lotes, proporcionalmente espaciados de 3 x 7 m a lo largo del transecto con trampas "pitfair capturaron artrópodos continuamente por períodos de 12 horas, el número de trampas fue ocho en el estero, ocho en el estanque y seis en el control. Se capturaron 558 artrópodos pertenecientes a 50 especies, se excluyeron las numerosas hormigas del género Solenopsis. El análisis de "rarefaction" con 80 como tamaño de muestra, mostró valores de 27 en el estero, 21.5 en el estanque y 18 para el sitio de control, cuando se eliminó el efecto de pantano de Uca ¡atimanus (cangrejo que fue dominante en el estero y ausente en los otros dos sitios). los artrópodos, excluyendo cangrejos, fueron doblemente abundantes en el estero durante el día y cuatro veces más abundantes en la noche que en los otros dos sitios durante el día. la proporción carnívoros-detritívoros en los tres sitios fue aproximadamente 2:1 (estero), 1:1 (estanque) y 1:2 (control). El valor de similitud (modificado de Hill E5) sin Uca fue similar en todos los sitios; sin embargo, grandes valores en diversidad (Hill N2) confirman la presencia de numerosas especies en el estero (escarabajos Carabidae y arañas lycosídae). No se encontró relación significativa entre el porcentaje de cobertura vegetal y la densidad de artrópodos capturados. la medida del valor beta-diversidad (coeficiente de comunidad de S^rensen) reafirma la particularidad de la organización en el estero. Nuestra hipótesis inicial fue parcial­ mente apoyada porque la diferencia de especies, abundancia de individuos y proporción carnívoros-detritívoros tendió a incrementarse con el gradiente de humedad

Diversity of animal communities on southwestern rangelands: Species patterns, habitat relationships, and land management

The rangelands of the southwestern United States comprise a mosaic of biome types, including deserts, grasslands, chaparral, woodlands, forests, subalpine meadows, and alpine tundra. Taken together, these ecosystems support exceptionally high numbers of vertebrate and invertebrate animal species. Biogeographic patterns of mammal, bird, and reptile species across North America show trends of increasing species numbers for these vertebrate groups, and some invertebrate groups, occur in Texas, New Mexico, Arizona, and California, especially in the border region with Mexico. Underlying causes of the region\u27s high biodiversity are related to (1) the elevational variability inherent in the basin-and-range topography, with its concomitant range of climate conditions, (2) the diverse biogeographic history of the region, particularly with respect to the merging of major faunal groups during glacier retreats, and (3) the architectural variations in vegetation structure across the region\u27s component ecosystems. Climate dynamics and disturbance also play major roles in maintaining a habitat mosaic, promoting greater regional faunal diversity. Disturbances affect animal diversity at many scales, from individuals\u27 home ranges to continental species\u27 distributions. Human activities have generated new suites of disturbances (livestock grazing, timber harvesting, mining, agriculture, prescribed fires, construction of roads and buildings), many of which contribute to the habitat patchiness of the landscape. Studies have shown that these disturbances prove beneficial to some species and detrimental to others. Hence, local increases in biodiversity can be orchestrated by creating or maintaining habitat diversity and disturbance regimes. Such management strategies can be scaled up to regional landscapes, in which areas of intensive human land use and disturbance are interspersed with regions of little or no human interference. Historically, this has been accomplished at local or state levels on an ad hoc bases (i.e., crisis management), with little evidence of long-term, large-scale, regional planning or coordination. If faunal biodiversity is to be preserved and enhanced on southwestern rangelands, human activities must be managed in a fashion that integrates faunal biology, resource requirements, and movement patterns with landscape scale attributes. Therefore, the task of the modern land manager will be to balance carefully the various scales and intensities of human activities, for the purpose of promoting sustainable use of natural resources and assuring the maintenance or enhancement of biodiversity. Future regional planning for biodiversity attributes will clearly require extensive communication and close cooperation among concerned citizens, private landowners, scientists, and government land managers

Genetic modifiers in rare disorders: the case of fragile X syndrome.

Methods employed in genome-wide association studies are not feasible ways to explore genotype-phenotype associations in rare disorders due to limited statistical power. An alternative approach is to examine relationships among specific single nucleotide polymorphisms (SNPs), selected a priori, and behavioural characteristics. Here, we adopt this strategy to examine relationships between three SNPs (5-HTTLPR, MAOA, COMT) and specific clinically-relevant behaviours that are phenotypic of fragile X syndrome (FXS) but vary in severity and frequency across individuals. Sixty-four males with FXS participated in the current study. Data from standardised informant measures of challenging behaviour (defined as physical aggression, property destruction, stereotyped behaviour, and self-injury), autism symptomatology, attention-deficit-hyperactivity-disorder characteristics, repetitive behaviour and mood/interest and pleasure were compared between each SNP genotype. No association was observed between behavioural characteristics and either 5-HTTLPR (serotonin) or MAOA (monoamine oxidase) genotypes. However, compared to the COMT (dopamine) AG and GG genotypes, the AA genotype was associated with greater interest and pleasure in the environment, and with reduced risk for property destruction, stereotyped behaviour and compulsive behaviour. The results suggest that common genetic variation in the COMT genotype affecting dopamine levels in the brain may contribute to the variability of challenging and repetitive behaviours and interest and pleasure in this population. This study identifies a role for additional genetic risk in understanding the neural and genetic mechanisms contributing to phenotypic variability in neurodevelopmental disorders, and highlights the merit of investigating SNPs that are selected a priori on a theoretical basis in rare populations

Spatial and temporal patterns of surface-atmosphere energy exchange in a dense urban environment using scintillometry

Spatially-integrated measurements of the surface energy balance (SEB) are needed in urban areas to evaluate urban climate models and satellite observations. Scintillometers allow observations of sensible heat flux (QH) over much larger areas than techniques such as eddy covariance (EC), however methods are needed to partition between remaining unmeasured SEB terms. This is the first study to use observed spatial and temporal patterns of QH from a scintillometer network to constrain estimates of remaining SEB terms in a dense, heterogeneous urban environment. Results show that QH dominates the surface energy balance in central London throughout the year, with expected diurnal courses and seasonal trends in QH magnitude related to solar radiation input. Measurements also reveal a clear anthropogenic component of QH with winter (summer) weekday QH values 11.7% (5.1%) higher than weekends. Spatially, QH magnitude is correlated with vegetation and building land cover fraction in the measurement source areas. Spatial analysis provides additional evidence of anthropogenic influence with highest weekday/weekend ratios (1.55) from the City of London. Spatial differences are used to estimate horizontal advection and a novel method to estimate monthly latent heat flux is developed based on observed land cover and wet-dry surface variations in normalized QH. Annual anthropogenic heat emissions are estimated to be 46.3 W m−2 using an energy balance residual approach. The methods presented here have potential to significantly enhance understanding of urban areas, particularly in areas with tall buildings where there is little observational data

Long-term cognitive outcomes in tuberous sclerosis complex.

AIM: To investigate the interdependence between risk factors associated with long-term intellectual development in individuals with tuberous sclerosis complex (TSC). METHOD: The Tuberous Sclerosis 2000 Study is a prospective longitudinal study of individuals with TSC. In phase 1 of the study, baseline measures of intellectual ability, epilepsy, cortical tuber load, and mutation were obtained for 125 children (63 females, 62 males; median age=39mo). In phase 2, at an average of 8 years later, intellectual abilities were estimated for 88 participants with TSC and 35 unaffected siblings. Structural equation modelling was used to determine the risk pathways from genetic mutation through to IQ at phase 2. RESULTS: Intellectual disability was present in 57% of individuals with TSC. Individuals without intellectual disability had significantly lower mean IQ compared to unaffected siblings, supporting specific genetic factors associated with intellectual impairment. Individuals with TSC who had a slower gain in IQ from infancy to middle childhood were younger at seizure onset and had increased infant seizure severity. Structural equation modelling indicated indirect pathways from genetic mutation, to tuber count, to seizure severity in infancy, through to IQ in middle childhood and adolescence. INTERPRETATION: Early-onset and severe epilepsy in the first 2 years of life are associated with increased risk of long-term intellectual disability in individuals with TSC, emphasizing the importance of early and effective treatment or prevention of epilepsy. WHAT THIS PAPER ADDS: Intellectual disability was present in 57% of individuals with tuberous sclerosis complex (TSC). Those with TSC without intellectual disability had significantly lower mean IQ compared to unaffected siblings. Earlier onset and greater severity of seizures in the first 2 years were observed in individuals with a slower gain in intellectual ability. Risk pathways through seizures in the first 2 years predict long-term cognitive outcomes in individuals with TSC

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Cinemaethnographic specta(c)torship: discursive readings of what we choose to (dis)possess

This article examines critical methodological issues emerging from the interstices of applied educational research, social science research, and arts-based research, bringing criticality into the field of childhood. The author aims to question how she might w(rest)le (un)comfortably with "what is worth looking at" when studying children. Maneuvering between observations of children in classrooms and representations of children in film, the author will not only consider ways she enacts discrete performances of specta(c)torship but also how she might resist revoking one performance for another within her "practices of looking" by conjuring the menace of ambivalent narratives. Rather than falling into familiar framing devices that serve to embrace some, but prohibit other ways of seeing, she will procure notions of colonialism and restless hybridity to incite antagonistic play on the edges of ethnographic specta(c)torship, drawing on Stronach’s notion of "lean-to" concepts

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead