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The complex topography of mountainous landscapes can create biogeographical barriers and promote allopatric speciation—even among morphologically cryptic species. However, these biogeographical barriers may not be permanent, and secondary contact between previously independently evolving populations can result in hybridization and introgression. In this study, we used genome-wide single nucleotide polymorphism data to re-examine a classic example of cryptic species in the Appalachian Mountains: the slimy salamander (Plethodon glutinosus) species complex. This group of morphologically similar terrestrial salamanders includes 14 species with parapatric distributions across the eastern USA. We focused on the Chattahoochee slimy salamander (P. chattahoochee) in northern Georgia and used a series of complementary phylogenomic and population genomic analyses to evaluate spatial genetic structure within this species and admixture with at least four other species of parapatric woodland salamanders. Our results highlight the utility of genomic data in clarifying species boundaries and underline the difficulty of species delimitation in organisms with complex evolutionary histories. [ABSTRACT FROM AUTHOR]

Statistical tools found in the service quality assessment literature--the "T"[superscript 2] statistic combined with factor analysis--can enhance the feedback instructors receive from student ratings. "T"[superscript 2] examines variability across multiple sets of ratings to isolate individual respondents with aberrant response patterns (i.e., outliers). Analyzing student responses that are outside the "normal" range of responses can identify aspects of the course that cause pockets of students to be dissatisfied. This fresh insight into sources of student dissatisfaction is particularly valuable for instructors willing to make tactical classroom changes that accommodate individual students rather than the traditional approach of using student ratings to develop systemwide changes in course delivery. A case study is presented to demonstrate how the recommended procedure minimizes data overload, allows for valid schoolwide and longitudinal comparisons of correlated survey responses, and helps instructors identify priority areas for instructional improvement.

Lungless salamanders of the family Plethodontidae have historically been considered to be passive conformers to their surrounding thermal environment because there is no evidence that they thermoregulate behaviourally in the field. In contrast, plethodontids readily choose optimal temperatures when placed on experimental thermal gradients. It has been hypothesized that restriction to moist habitats prevents these salamanders from exploiting thermally diverse microhabitats in nature. We tested this hypothesis, as well as the hypothesis that response to temperature differs among plethodontid species, by investigating the thermal ecology of two species (Cave Salamander, Eurycea lucifuga Rafinesque, 1822, and Northern Slimy Salamander, Plethodon glutinosus (Green, 1818)) occupying twilight zones of six caves in northwestern Georgia. We recorded inside and outside temperatures, as well as the number of each species, for each of three seasons (summer, fall, spring) over 13 years. We also tested for differences in thermal preference along experimental gradients in the laboratory. We further generated environmental niche models (ENMs) to investigate the potential role of abiotic variables, including environmental temperature, in determining the geographic range of each species. We found that both species responded to cave temperature in such a way as to suggest that these salamanders thermoregulate behaviourally when given a diversity of thermal options within a relatively constant moisture regime. We also determined that E. lucifuga prefers lower temperatures than P. glutinosus. ENM analysis indicated that, while abiotic variables both strongly influence the ecological niche of both species, the range of E. lucifuga is strongly predicted by them. The geographic distribution of P. glutinosus is apparently heavily influenced by the presence of closely related, contiguous neighbors with similar niche requirements. Key words: salamander, thermal behaviour, caves, occupancy, Amphibia, Eurycea lucifuga, Plethodon glutinosus, cave salamander. Les salamandres sans poumon de la famille des plethodontides sont traditionnellement considerees comme se conformant passivement au milieu thermique qui les entoure parce que rien n'indique des comportements de thermoregulation sur le terrain. En revanche, les plethodontides optent d'emblee pour des temperatures optimales quand ils sont places le long de gradients de temperature experimentaux. Il a ete postule que le fait qu'elles soient limitees a des habitats humides empeche ces salamandres d'exploiter des microhabitats varies sur le plan thermique en milieu naturel. Nous avons verifie cette hypothese ainsi que celle voulant que la reaction a la temperature varie selon les especes de plethodontides en etudiant l'ecologie thermique de deux especes (eurycee des grottes, Eurycea lucifuga Rafinesque, 1822, et salamandre visqueuse, Plethodon glutinosus (Green, 1818)) qui occupent des zones de penombre de six cavernes du nord--ouest de la Georgie (Etats--Unis). Nous avons mesure les temperatures interieures et exterieures ainsi que le nombre d'individus de chaque espece pour trois saisons (ete, automne, printemps) sur une periode de 13 ans. Nous avons egalement verifie la presence de preferences thermiques le long de gradients experimentaux en laboratoire. Nous avons aussi produit des modeles de niche ecologique (MNE) pour etudier le role eventuel de variables abiotiques, dont la temperature ambiante, dans la determination de la repartition geographique de chaque espece. Nous avons constate que la reaction des deux especes a la temperature de la caverne semble indiquer que ces salamandres adoptent des comportements de thermoregulation quand differentes options de temperature s'offrent a elles dans des conditions d'humidite relativement constantes. Nous avons egalement determine que E. lucifuga prefere des temperatures plus faibles que P. glutinosus. L'analyse des MNE indique que, si des variables abiotiques influencent fortement la niche ecologique des deux especes, elles predisent fortement l'aire de repartition d'E. lucifuga. La repartition geographique de P. glutinosus serait fortement influencee par la presence de voisins etroitement relies presentant des exigences semblables en matiere de niche. [Traduit par la Redaction] Mots--cles : salamandre, comportement thermique, cavernes, occupation, amphibien, Eurycea lucifuga, Plethodon glutinosus, salamandre des cavernes., Introduction The thermal ecology of ectothermic vertebrates, particularly fishes and reptiles, has been studied for many decades. Amphibians, on the other hand, have received less attention, in part because they [...]

The employment of cellular manufacturing (CM) in group production is examined by a comparison of the functioning of different shops, which adopt separate levels of CM. Experiments with simulated examples suggest that on the basis of shop settings and management goals, higher performance levels may be attained by the exclusive job shop, the totally cellular shop, or shops existing between these two extremes.

The Alabama Map Turtle, found only in Mobile Bay drainages, is state-listed in Georgia as rare and has been petitioned for federal listing as threatened. Because this species has been poorly studied in Georgia, and in the Coosa River especially, a survey was undertaken to determine its status in the Coosa to help inform the federal listing decision. The 2014-2015 survey involved counting basking turtles from a motorboat with the aid of binoculars. The Alabama Map Turtle was the third most abundantly observed turtle species during the survey, preceded by only the Slider and River Cooter. All size/age classes were observed. The species' abundance and age distribution suggest a healthy, reproductive population in the Georgia portion of this river. It is unlikely that federal listing of the Alabama Map Turtle is warranted based on the results of this study and a 2003 survey of inhabited Alabama streams. Keywords: Alabama Map Turtle, Graptemys pulchra, Coosa River, status, survey, conservation., INTRODUCTION The Alabama Map Turtle (Graptemys pulchra) is a decidedly riverine species that has a specialized invertebrate-based diet. Males and females are strongly sexually dimorphic in head and overall size. [...]

The scheduling of the orders of normal and vital priority customers in a job shop is studied. Results show that when due dates are tight, servicing the orders of vital customers causes deterioration of service to normal priority customers. In cases of limited resources and capacity, managers must decide which orders to give up. The Forced Pace and Preempt were also found to be the most efficient dispatching rules.

Path based bottleneck (PBB) and modified infinite loading (MIL) procedures are used to investigate the performance of capacity-sensitive order review and release (ORR) procedures in job shop environments that have never been previously explored. A comparison is made with that of an immediate release rule under different conditions of capacity utilization and customer specified exogenous due-dates. Results indicate that MIL performs well in relatively loose to medium due-dates, while PBB is a better procedure in lowering total costs when due-dates are tight.

We provide an annotated checklist of species recorded from caves and other subterranean habitats in the state of Georgia, USA. We report 281 species (228 invertebrates and 53 vertebrates), including 51 troglobionts (cave-obligate species), from more than 150 sites (caves, springs, and wells). Endemism is high; of the troglobionts, 17 (33% of those known from the state) are endemic to Georgia and seven (14%) are known from a single cave. We identified three biogeographic clusters of troglobionts. Two clusters are located in the northwestern part of the state, west of Lookout Mountain in Lookout Valley and east of Lookout Mountain in the Valley and Ridge. In addition, there is a group of troglobionts found only in the southwestern corner of the state and associated with the Upper Floridan Aquifer. At least two dozen potentially undescribed species have been collected from caves; clarifying the taxonomic status of these organisms would improve our understanding of cave biodiversity in the state. Conservation concerns related to species found in Georgia caves are significant, with fourteen species (including 13 vertebrates) considered "High Priority Species" under the Georgia State Wildlife Action Plan, many of these species have additional state or federal protections. In addition, 17 invertebrate troglobionts (33% of those known in the state) are considered "Critically Imperiled" by Nature- Serve. Several biologically important caves are not protected, these are an important conservation concern. However, remarkably, around one third of all caves in the state are on protected lands, including seven of the eight caves known to host ten or more troglobionts. [ABSTRACT FROM AUTHOR]

Recent studies have shown that in a cellular shop that benefits from learning due to repetitive processing, limitations attributable to routing flexibility can be more than offset. Moreover, the shop can respond more quickly to changes in demand than a job shop. This study examines the impact of labour assignments in a dual constrained cellular shop in which processing times decrease with operator task repetition. Results indicate that in the presence of operator learning, shop performance is significantly affected by the flexibility permitted in labour assignments. Moreover, the sensitivity of performance to labour assignments is significantly impacted by staffing levels and the magnitude of learning effects. [ABSTRACT FROM AUTHOR]