Conserving Endangered Black-Footed Ferrets: Biological Threats, Political Challenges, and Lessons Learned

There may be few stories in the annals of wildlife management that are as dramatic as the near demise and comeback of the black-footed ferret (Mustela nigripes). Endemic only to North America, this charming little carnivore found only in the continent’s central grasslands was hardly known to science until the mid-20th century. By then, vast colonies of the prey it depended on for food and shelter, the prairie dog (Cynomys spp.), had been wiped out through disease (sylvatic plague) and an agricultural industry with little tolerance for burrowing and grazing rodents. At its low point, the species’ fate would come down to 18 remaining ferrets and a scientific gamble that humans could intervene to save a species on the very brink of extinction. With heroic efforts by federal, state, and private scientists, immediate extinction was forestalled, and a comeback effort mounted. Like so many endangered species stories, the ferret’s tale is a story of tragedy, luck, science, and the acts of people that will determine its ultimate fate. Understanding the challenges going forward for the ferret requires an understanding of the natural history and ecology of black-footed ferrets and prairie dogs, diseases and disease management, and the political landscape, which we present here. The future for black-footed ferrets remains unclear. Ultimately we will need to summon the efforts of conservation biologists, policy makers, and the agricultural industry to determine if ferrets will continue to exist as a valued and unique part of North America’s natural heritage

Microstructural length scale parameters to model the high-cycle fatigue behaviour of notched plain concrete

The present paper investigates the importance and relevance of using microstructural length scale parameters in estimating the high-cycle fatigue strength of notched plain concrete. In particular, the accuracy and reliability of the Theory of Critical Distances and Gradient Elasticity are checked against a number of experimental results generated by testing, under cyclic bending, square section beams of plain concrete containing stress concentrators of different sharpness. The common feature of these two modelling approaches is that the required effective stress is calculated by using a length scale which depends on the microstructural material morphology. The performed validation exercise demonstrates that microstructural length scale parameters are successful in modelling the behaviour of notched plain concrete in the high-cycle fatigue regime

Testicular masses in association with Adrenogenital syndrome: US findings

Adrenogenital syndrome (AGS) is the result of inborn enzymatic defects in the synthesis of steroid hormones. The production of cortisol is deficient and that of adrenocorticotropic hormone is increased. Sometimes male patients have clinically detectable testicular lesions, known as testicular tumors of AGS (TTAGS). From 1985 to 1991, scrotal ultrasonography (US) was performed in 30 consecutive pubertal and postpubertal patients with AGS to investigate the prevalence and US characteristics of TTAGS. Eight of 30 patients had a testicular lesion (27%); six of the eight lesions were clinically undetected. The mean diameter of the lesions was 16.44 mm (range, 2-28 mm). The lesions were hypoechoic in all cases, with well-defined margins in six cases. The nodules were multifocal in all patients and bilateral in six (75%). If testicular lesions are present in a patient with AGS, TTAGS are likely, and frequent US monitoring is adequate for diagnostic evaluation

Definition of obesity in childhood: criteria and limits

A rigorous scientific definition of obesity in childhood is not yet available: in fact, there is not agreement among researchers on the adiposity index to use and on the best cut-off to define overweight and obesity. In this review, the reference methods for the diagnosis of childhood obesity in the clinical practice in Italy are reported. All the statements are based on evidences of the literature and obtained the consensus of the pediatricians of the Study Group on Obesity of the Italian Society of Pediatric Diabetology and Endocrinology. Obesity is caused by an excess of body fat. The methods more frequently used to measure body fat are the measure of subcutaneous skinfold thickness, bioimpedence assessment and DXA. The measure of skinfolds is preferable in the clinical setting because it is easy to use and cheap, although reproducibility is modest. Triceps skinfold is commonly used to define obesity: children with triceps higher than the 85 th centile for age and gender, using Tanner's tables, are obese. An estimation of fat mass obtained, for instance, with skinfolds is always suggested in addition to the measure of weight and height. It is possible to define a child as obese calculating the ratio between weight (kg) and height squared (m). This ratio is an index, called body mass index (BMI), which is strictly associated to the level of adiposity in children, reproducible and valid. The BMI was recently proposed as the reference index for the diagnosis of childhood obesity at the international level. The use of the centiles of BMI may offer useful information on the changes of weight excess, simplifying the follow-up of the patient and the sensitivity to treatment. The cut-off limits of BMI to define overweight or obesity are still debated. However, in agreement with Cole et al, the choice to use the BMI cut-offs centiles passing through the adult BMI cut-off of 30, is reasonable. However, it is always preferable to use population specific BMI reference tables

Engineering chiral induction in centrally functionalized ortho-phenylenes

Work on foldamers, non-biological oligomers that mimic the hierarchical structure of biomacromolecules, continues to yield new architectures of ever increasing complexity. o-Phenylenes, a class of helical aromatic foldamers, are well-suited to this area because of their structural simplicity and the straightforward characterization of their folding in solution. However, control of structure requires, by definition, control over folding handedness. Control over o-phenylene twist sense is currently lacking. While chiral induction from groups at o-phenylene termini has been demonstrated, it would be useful to instead direct twisting from internal positions in order to leave the ends free. Here, we explore chiral induction in a series of o-phenylenes with chiral imides at their centers. Conformational behavior has been studied by NMR and CD spectroscopies and DFT calculations. Chiral induction in otherwise unfunctionalized o-phenylenes is generally poor. However, strategic functionalization of the helix surface with trifluoromethyl and methyl groups allows it to better interact with the imide groups, greatly increasing diastereomeric excesses. The sense of chiral induction is consistent with computational models that suggest that it primarily arises from a steric effect