Exact Point Of Origin Research Articles

Mitogenomes illuminate the origin and migration patterns of the indigenous people of the Canary Islands.

The Canary Islands’ indigenous people have been the subject of substantial archaeological, anthropological, linguistic and genetic research pointing to a most probable North African Berber source. However, neither agreement about the exact point of origin nor a model for the indigenous colonization of the islands has been established. To shed light on these questions, we analyzed 48 ancient mitogenomes from 25 archaeological sites from the seven main islands. Most lineages observed in the ancient samples have a Mediterranean distribution, and belong to lineages associated with the Neolithic expansion in the Near East and Europe (T2c, J2a, X3a…). This phylogeographic analysis of Canarian ancient mitogenomes, the first of its kind, shows that some lineages are restricted to Central North Africa (H1cf, J2a2d and T2c1d3), while others have a wider distribution, including both West and Central North Africa, and, in some cases, Europe and the Near East (U6a1a1, U6a7a1, U6b, X3a, U6c1). In addition, we identify four new Canarian-specific lineages (H1e1a9, H4a1e, J2a2d1a and L3b1a12) whose coalescence dates correlate with the estimated time for the colonization of the islands (1st millennia CE). Additionally, we observe an asymmetrical distribution of mtDNA haplogroups in the ancient population, with certain haplogroups appearing more frequently in the islands closer to the continent. This reinforces results based on modern mtDNA and Y-chromosome data, and archaeological evidence suggesting the existence of two distinct migrations. Comparisons between insular populations show that some populations had high genetic diversity, while others were probably affected by genetic drift and/or bottlenecks. In spite of observing interinsular differences in the survival of indigenous lineages, modern populations, with the sole exception of La Gomera, are homogenous across the islands, supporting the theory of extensive human mobility after the European conquest.

Questionable evidence of increasing incidence of invasive penile cancer in Denmark

In agreement with the findings in two prior Danish studies, which together covered the period 1943–2003 [1, 2], Baldur-Felskov et al. [3] provided compelling evidence of a stable incidence of invasive penile cancer in Denmark during 1978–2008, as judged from data in the Danish Cancer Registry (DCR) [4]. However, after adding pathology data that are notoriously incomplete before 1998, the authors reported a statistically significant rising trend in penile cancer incidence over the 31-year period. In other incidence studies of human papillomavirus-associated invasive cancers from the same group [5–7], the authors relied exclusively on DCR data. However, for unstated reasons, Baldur-Felskov et al. chose to search for additional invasive penile cancers in the Danish Pathology Data Bank (DPDB) [8], to ‘increase completeness of data’. Adding penile cancers recorded only in the DPDB is problematic, because this data source is unable to make comparable corrections of potentially missing DCR data for all 31 years under study. The authors may well have identified some missing cases of penile cancer in recent years that could not be identified under penile cancer codes in the DCR (e.g., penile skin cancers inaccurately recorded as skin cancers), but the DPDB data did not permit similar corrections before 1998. Consequently, the apparent longterm trend of increasing penile cancer incidence based on the combined dataset most likely represents an artifact resulting from selective addition in recent years of penile cancer cases identified only in the DPDB. Moreover, Fig. 1 in Baldur-Felskov et al.’s paper provides no evidence to support the claim of increasing penile cancer incidence in the most recent decade, whether based on DCR data alone, DPDB data alone, or the two combined. With respect to precancerous lesions, the authors rightly point out that the observed increase in incidence of highgrade penile intraepithelial neoplasia (PIN 2/3) during 1998–2008 might, at least in part, be ‘explained by increasing knowledge about and greater awareness of HPV-associated diseases’. Also, the reported increase in PIN 2/3 incidence should be viewed in the light of the way the authors treated recurrent episodes in the analysis. Counting recurrences more than 24 months after a prior episode as new incident cases of PIN 2/3 most likely contributed importantly to the observed doubling in incidence. Such analyses may be relevant in attempts to estimate the PIN 2/3-associated burden to the healthcare system. However, to learn if, and to what extent, the annual number of newly affected men with PIN 2/3 is truly increasing, it would be informative if the authors presented a graph of the PIN 2/3 incidence during 1998–2008 in which they counted only the first recorded episode of PIN 2/3 in each patient. As a minor point, it is unclear why the authors deliberately excluded the relatively few cases of penile cancer recorded under ICD-O3 topography code C60.8. Such cancers include lesions that overlap the boundaries of two or more anatomical sublocalizations on the penis (e.g., cancers involving both the glans and the prepuce) and penile cancers whose exact point of origin on the penis cannot be determined. Despite difficulties in determining their exact point of origin on the penis, such cancers are nevertheless penile cancers and should be included in the definition of penile cancer. The authors refer to similar findings in a recent Dutch study [9] to add credence to their claim of increasing invasive penile cancer rates in Denmark. Indeed, findings M. Frisch (&) C. J. Ulff-Moller J. Simonsen Department of Epidemiology Research, Statens Serum Institut, 2300 Copenhagen S, Denmark e-mail: mfr@ssi.dk

The point of origin of the radio radiation from the unresolved cores of radio-loud quasars

Locating the exact point of origin of the core radiation in active galactic nuclei (AGN) would represent important progress in our understanding of physical processes in the central engine of these objects. However, due to our inability to resolve the region containing both the central compact object and the jet base, this has so far been difficult. Here, using an analysis in which the lack of resolution does not play a significant role, we demonstrate that it may be impossible even in most radio loud sources for more than a small percentage of the core radiation at radio wavelengths to come from the jet base. We find for 3C279 that ∼85 percent of the core flux at 15 GHz must come from a separate, reasonably stable, region that is not part of the jet base, and that then likely radiates at least quasi-isotropically and is centered on the black hole. The long-term stability of this component also suggests that it may originate in a region that extends over many Schwarzschild radii.

ADENOCARCINOMA OF THE ETHMOID SINUS

CANCER in the ethmoid labyrinth is usually bad news to the practicing otolaryngologist. Almost invariably the malignant cells involve vital adjacent structures before a diagnosis can be made. The early symptoms of nasal obstruction and postnasal discharge can be easily attributed to benign involvements of the nose. Although pain is present in many cases, it is rarely sharp or distinctive until the later stages, and is localized usually in the area of the nasal processes of the frontal bones. It should be remembered that carcinoma of the ethmoid sinuses often spreads rapidly, extending directly to contiguous sinuses, and that the exact point of origin cannot, therefore, always be determined. Ringertz 1 pointed out that in 30 per cent of all cases of ethmoid carcinoma (55 per cent of the cylindric cell type) the disease is associated with polyposis of the nose. One can readily see, therefore, that neglect can easily