Although many taxa show a latitudinal gradient in richness, the relationship between latitude and species richness is often asymmetrical between the northern and southern hemispheres. Here we examine the latitudinal pattern of species richness across 1003 local ant assemblages. We find latitudinal asymmetry, with southern hemisphere sites being more diverse than northern hemisphere sites. Most of this asymmetry could be explained statistically by differences in contemporary climate. Local ant species richness was positively associated with temperature, but negatively (although weakly) associated with temperature range and precipitation. After contemporary climate was accounted for, a modest difference in diversity between hemispheres persisted, suggesting that factors other than contemporary climate contributed to the hemispherical asymmetry. The most parsimonious explanation for this remaining asymmetry is that greater climate change since the Eocene in the northern than in the southern hemisphere has led to more extinctions in the northern hemisphere with consequent effects on local ant species richness.

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Wildlife extinction represents the ultimate failure of wildlife conservation. It has many causes, some of them natural, but is increasingly tied to anthropogenic factors. Wildlife loss via domestication, however, is rarely considered. We evaluated the potential for inadvertent domestication of wildlife by determining the effect of feeding and watering on Key deer (Odocoileus virginianus clavium) density, group size, and distribution. Key deer sightings were significantly higher in areas (42 ha) surrounding the households that provided food and water (0.18 deer/m; n= 8) than in randomly selected areas (0.03 deer/m; t = 3.82, 14 df , p = 0.002). Average distance to a household providing food and water decreased logistically as group size increased, and large groups (>2 individuals each) were observed more frequently in areas where food and water were provided (27.5%) than in the randomly selected areas (7.5%). The incidence of large groups outside feeding areas (7.5%), however, was similar to the incidence of large groups during early urbanization (5.1%; 1968-1973). Our results suggest illegal feeding caused changes in density, group size, and distribution indicative of domestication. Because fresh water and food were primary selective pressures for Key deer before illegal feeding and watering, genetic changes may occur in the future. For those who value "wildness" in wildlife, domestication of wildlife species is a serious problem that must be addressed. Pérdida de Vida Silvestre por Domesticación: El Caso de Odocoileus virginianus claviumResumen: La extinción de especies es el fracaso extremo de la conservación de vida silvestre. Tiene muchas causas, algunas naturales, pero cada vez más relacionadas con factores antropogénicos. Sin embargo, raramente se considera la pérdida de vida silvestre por domesticación. Evaluamos el potencial de domesticación accidental de vida silvestre mediante la determinación del efecto del suministro de agua y alimento al venado Odocoileus virginianus clavium sobre su densidad, tamaño del grupo y distribución. Los avistamientos de venados fueron significativamente mayores (0.18 venados/m; n = 8) enáreas (42 ha) circundantes a las casas en las que se les suministró agua y alimento que enáreas seleccionadas al azar (0.03 venados/m; 14 gl, p = 0.002). La distancia promedio a una casa que suministró agua y alimento decreció logísticamente a medida que aumentó el tamaño del grupo, y se observaron grupos grandes (>2 individuos) más frecuentemente eń areas en las que se suministraba agua y alimento (27.5%) que enáreas seleccionadas al azar (7.5%). Sin embargo, la incidencia de grupos grandes afuera deáreas de alimentación (7.5%) fue similar a la incidencia de grupos grandes durante los inicios de la urbanización (6.1%; 1968-1973). Nuestros resultados sugieren que la alimentación ilegal provocó cambios en la densidad, tamaño del grupo y distribución que indican domesticación. En el futuro pueden ocurrir cambios genéticos debido a que el agua fresca y el alimento fueron presiones de selección ...

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IntroductionThe traditional treatment for patients with radiculopathy and myelopathy caused by degenerative disc disease was anterior cervical discectomy and fusion (ACDF). However, a documented complication of ACDF is adjacent segment degeneration (ASD). An alternative that was developed was total disc replacement (TDR).The aim of this study was to determine and compare the short-and medium-to-long-term outcomes after a TDR or ACDF. MethodsA retrospective review of 154 patients who had single and two-level ACDFs and 90 TDRs performed by a single surgeon between 2011 and 2017 was conducted. Parameters for comparisons include both radiological evaluation and patient-reported outcome measures (PROMS) at six weeks, one year, and two years postoperatively. The Neck Disability Index (NDI) and the visual analogue scale (VAS) for neck and arm pain are used to evaluate pain, function, patient satisfaction, and overall clinical success. ResultsTDR and ACDF showed significant improvement in NDI and VAS when compared to pre-and postoperatively at both six weeks (p<0.05 & P=0.032, respectively) and two years (p<0.05 & 0=0.026, respectively). TDR vs. ACDF showed no significant difference (p<0.05). VAS scores after ACDF showed improvement from 13.41 to 3.94 at two years (p<0.001). TDR showed similar scores of 12.5 to 3.55 (p<0.001). The radiological fusion rate at 12 or 24 months showed no significant difference between the two groups. There were two cases that required re-operation after ACDF (1.2%), and two that required TDR (2.2%). ConclusionBoth TDR and ACDF lead to clinically significant improvements in pain and function scores. We did not find a statistically significant difference in NDI and VAS in the neck and arm.The results are in agreement with others' assessments of these two treatment modalities. Our conclusions supplement the literature about these operative options for degenerative disc disease of the cervical spine and are a useful addition to the armamentarium in the assessment of patients with degenerative pathology of the c-spine.