Credit cycles and macro fundamentals

We study the relation between the credit cycle and macro economic fundamentals in an intensity based framework. Using rating transition and default data of U.S. corporates from Standard and Poor’s over the period 1980–2005 we directly estimate the credit cycle from the micro rating data. We relate this cycle to the business cycle, bank lending conditions, and financial market variables. In line with earlier studies, these variables appear to explain part of the credit cycle. As our main contribution, we test for the correct dynamic specification of these models. In all cases, the hypothesis of correct dynamic specification is strongly rejected. Moreover, accounting for dynamic mis-specification, many of the variables thought to explain the credit cycle, turn out to be insignificant. The main exceptions are GDP growth, and to some extent stock returns and stock return volatilities. Their economic significance appears low, however. This raises the puzzle of what macro-economic fundamentals explain default and rating dynamics. JEL Classification: G11, G2

Current generation time-of-flight 18F-FDG PET/CT provides higher SUVs for normal adrenal glands, while maintaining an accurate characterization of benign and malignant glands

OBJECTIVE: Modern PET/CT scanners have significantly improved detectors and fast time-of-flight (TOF) performance and this may improve clinical performance. The aim of this study was to analyze the impact of a current generation TOF PET/CT scanner on standardized uptake values (SUV), lesion-background contrast and characterization of the adrenal glands in patients with suspected lung cancer, in comparison with literature data and commonly used SUV cut-off levels. METHODS: We included 149 adrenal glands from 88 patients with suspected lung cancer, who underwent (18)F-FDG PET/CT. We measured the SUV(max) in the adrenal gland and compared this with liver SUV(mean) to calculate the adrenal-to-liver ratio (AL ratio). Results were compared with literature derived with older scanners, with SUV(max) values of 1.0 and 1.8 for normal glands [1, 2]. Final diagnosis was based on histological proof or follow-up imaging. We proposed cut-off values for optimal separation of benign from malignant glands. RESULTS: In 127 benign and 22 malignant adrenal glands, SUV(max) values were 2.3 ± 0.7 (mean ± SD) and 7.8 ± 3.2 respectively (p < 0.01). Corresponding AL ratios were 1.0 ± 0.3 and 3.5 ± 1.4 respectively (p < 0.01). With a SUV(max) cut-off value of 3.7, 96 % sensitivity and 96 % specificity was reached. An AL ratio cut-off value of 1.8 resulted in 91 % sensitivity and 97 % specificity. The ability of both SUV(max) and AL ratio to separate benign from malignant glands was similar (AUC 0.989 vs. 0.993, p = 0.22). CONCLUSIONS: Compared with literature based on the previous generation of PET scanners, current generation TOF (18)F-FDG PET/CT imaging provides higher SUVs for benign adrenal glands, while it maintains a highly accurate distinction between benign and malignant glands. Clinical implementation of current generation TOF PET/CT requires not only the use of higher cut-off levels but also visual adaptation by PET readers

Fetal Exposure to PCBs and Their Hydroxylated Metabolites in a Dutch Cohort

Polychlorinated biphenyls (PCBs) are still the most abundant pollutants in wildlife and humans. Hydroxylated PCB metabolites (OH-PCBs) are known to be formed in humans and wildlife. Studies in animals show that these metabolites cause endocrine-related toxicity. The health effects in humans have not yet been evaluated, especially the effect on the fetus and newborn. The aim of this study is to measure the levels of PCBs and OH-PCBs in maternal and cord blood samples in a population with background levels of PCBs. We analyzed 51 maternal and corresponding cord blood samples in the northern part of the Netherlands. The PCB concentrations in maternal plasma ranged from 2 to 293 ng/g lipid, and OH-PCB concentrations from nondetectable (ND) to 0.62 ng/g fresh weight. In cord plasma, PCB concentrations were 1–277 ng/g lipid, and OH-PCB concentrations, ND to 0.47 ng/g fresh weight. The cord versus maternal blood calculated ratio was 1.28 ± 0.56 for PCBs and 2.11 ± 1.33 for OH-PCBs, expressed per gram of lipid. When expressed per gram fresh weight, the ratios are 0.32 ± 0.15 and 0.53 ± 0.23 for PCBs and OH-PCBs, respectively. A significant correlation between the respective maternal and cord levels for both PCBs and OH-PCBs was found. Our results indicate that OH-PCBs and PCBs are transferred across the placenta to the fetus in concentrations resulting in levels of approximately 50 and 30%, respectively, of those in maternal plasma. More research in humans is needed to evaluate potential negative effects of these endocrine disruptors on the fetus

Could tierless languages reduce IoT development grief?

Internet of Things (IoT) software is notoriously complex, conventionally comprising multiple tiers. Traditionally an IoT developer must use multiple programming languages and ensure that the components interoperate correctly. A novel alternative is to use a single tierless language with a compiler that generates the code for each component and ensures their correct interoperation. We report a systematic comparative evaluation of two tierless language technologies for IoT stacks: one for resource-rich sensor nodes (Clean with iTask), and one for resource-constrained sensor nodes (Clean with iTask and mTask). The evaluation is based on four implementations of a typical smart campus application: two tierless and two Python-based tiered. (1) We show that tierless languages have the potential to significantly reduce the development effort for IoT systems, requiring 70% less code than the tiered implementations. Careful analysis attributes this code reduction to reduced interoperation (e.g. two embedded domain-specific languages (DSLs) and one paradigm versus seven languages and two paradigms), automatically generated distributed communication, and powerful IoT programming abstractions. (2) We show that tierless languages have the potential to significantly improve the reliability of IoT systems, describing how Clean iTask/mTask maintains type safety, provides higher order failure management, and simplifies maintainability. (3) We report the first comparison of a tierless IoT codebase for resource-rich sensor nodes with one for resource-constrained sensor nodes. The comparison shows that they have similar code size (within 7%), and functional structure. (4) We present the first comparison of two tierless IoT languages, one for resource-rich sensor nodes, and the other for resource-constrained sensor nodes

Severe Daily Headache as an Uncommon Manifestation of Widespread Skull Base Osteomyelitis

Temporal bone osteomyelitis has been recognized for decades as a complication of otitis externa, specifically in elderly patients with diabetes. A much less prevalent form is skull base osteomyelitis. We report a 70-year-old man with diabetes who presented to our outpatient clinic with severe chronic daily complaints of headache. The headache was located frontoparietally and kept him awake at night. Imaging (nonenhanced computed tomography [CT], magnetic resonance imaging, and positron emission tomography/CT) showed a hypermetabolic mass on the right side of the skull base, in the middle ear, and in the mastoid process, with invasion and partial destruction of the surrounding elements of the petrous bone, the occipital bone, and the sphenoid bone on the right, with extension by way of the clivus into the apex of the left petrous bone. Diagnostic puncture revealed Streptococcus pneumoniae.The final diagnosis was severe daily headache due to central skull base osteomyelitis. Our case emphasizes the need for proper clinical and radiological investigation keeping the diagnosis of skull base osteomyelitis in mind with patients with diabetes or otherwise immunocompromised status who present with chronic daily headache and otalgia

Plasma polychlorinated biphenyl levels in Dutch preschool children either breast-fed or formula-fed during infancy

OBJECTIVES: This study examined the influence of lactational and in utero exposure to polychlorinated biphenyls (PCBs) on plasma PCB levels in children. METHODS: Plasma PCB levels were measured in 173 children at 3.5 years, of whom 91 were breast-fed and 82 were formula-fed in infancy. RESULTS: Median plasma PCB levels were 3.6 times higher in breast-fed children (0.75 microgram/L) than in their formula-fed peers (0.21 microgram/L). Breast-feeding period and breast-milk PCB levels were important predictors for PCB levels in the breast-fed group. For children in the formula-fed group, PCB levels were significantly related to their material plasma PCB levels. CONCLUSIONS: PCB levels in Dutch preschool children are related to transfer of maternal PCBs; therefore, strategies should be aimed at reducing maternal PCB body burden

Dioxin and PCB levels in blood and human milk in relation to living areas in the Netherlands

Dioxins and polychlorinated biphenyls (PCBs) are ubiquitous toxic compounds in the environment. Negative influences of these compounds on the health status of human beings have been described. Especially susceptible might be the fetus, which is exposed in utero, and the newborn breast-fed infant, since both are exposed to relatively high levels of dioxins and PCBs during a critical period of organ growth and development. We investigated PCB levels in 406 maternal plasma samples as well as PCB and dioxin levels in 172 human milk samples with relation to living area of women living for at least five years in the western industrialized part of the Netherlands or the northern more rural part. The western part was further subdivided into one urban and two highly industrialized areas. After correction for covariates, we found significantly higher levels of PCB 118 in maternal plasma as well as significantly higher levels of the dioxin-TEQ and of ten individual dioxin and PCB congener levels in human milk in the western more industrialized areas of the Netherlands compared to the northern more rural part. We did not find significant differences in planar, mono-ortho or di-ortho PCB-TEQ levels in human milk between all different areas. We conclude that significantly higher levels of a number of dioxin and PCB congeners are found in women living in industrialized areas compared to women living in rural areas in the Netherlands