Popliteal aneurysms: a 10-year experience

Background:Popliteal aneurysms account for 70% of peripheral arterial aneurysms and, if untreated, pose a serious threat to the affected limb. Debate continues about the best form of treatment especially for asymptomatic lesions.Methods:We reviewed the computer records and charts of patients seen at this department with a diagnosis of popliteal aneurysm over the last 10 years. Patients who had not been seen within the last year were followed-up through their G.P.Results:Twenty-four patients (M 23/F 1) presented with 40 popliteal aneurysms. The mean age was 63.5±9 years. Symptoms were present in 23 of the affected limbs while 17 were asymptomatic. Thirty were treated surgically and 10 followed with regular ultrasound. The mean diameter of the repaired aneurysms was 3.3±1 cm. Aneurysms <2 cm were more likely to be asymptomatic. No limbs were lost in patients undergoing elective repair of popliteal aneurysms. The secondary patency and limb salvage rates at 3 years were 84% and 96% respectively. Conservative management of asymptomatic lesions <2 cm was not complicated by the development of symptoms.Conclusions:Elective repair of popliteal aneurysms by exclusion and bypass is a safe, effective and durable technique. Small asymptomatic lesions can be safely managed with close follow-up

‘O sibling, where art thou?’ – a review of avian sibling recognition with respect to the mammalian literature

Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where ‘mixing potential’ of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through ‘direct familiarisation’ (commonly known as associative learning or familiarity); future experiments should also incorporate tests for ‘indirect familiarisation’ (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic

Search for gravitational waves from Scorpius X-1 in the second Advanced LIGO observing run with an improved hidden Markov model

We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J-statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h095%=3.47×10-25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering. © 2019 American Physical Society

Evolutionary Lineages in Emballonura and Mosia Bats (Mammalia: Microchiroptera) from the Southwestern Pacific.

v. ill. 23 cm.QuarterlyThe microchiropteran bat family Emballonuridae is widely distributed in archipelagos of the southwestern Pacific, with especially strong representation of genera Emballonura and Mosia. DNA sequences from three segments of the mitochondrial genome were collected from four species of Emballonura and from M. nigrescens to investigate the relationship of genetic differentiation to archipelago biogeography. Specimens of each species formed monophyletic clades in maximum parsimony and Bayesian analyses. Mosia nigrescens was genetically distant to the other four species. The other four studied species formed a monophyletic clade composed of the pairs E. beccarii, E. serii and E. raffrayana, E. semicaudata. Clades within species were strongly concordant with geography, with only two counterexamples (E. semicaudata in Fiji and E. raffrayana in the Solomon Islands) to the general finding that each island’s population of a species constitutes a monophyletic clade. Genetic results do not agree with current subspecific designations within M. nigrescens. Samples from Woodlark, Alcester, and Manus Islands are phylogenetically closer to Papuan mainland samples than to Solomon Islands and New Ireland samples supposedly belonging to the same subspecies. Results suggest that Emballonura can establish populations across wide water barriers but does so infrequently. The isolating effect of water barriers is exemplified by the substantial genetic distinctiveness of Solomon Islands and New Ireland populations of both E. raffrayana and M. nigrescens. Absence from New Britain of E. beccarii, E. raffrayana, and E. serii (all known from New Ireland) may also reflect effects of water barriers if not due to collecting artifacts

Phylogenetics of the brachyuran crabs (Crustacea: Decapoda): The status of Podotremata based on small subunit nuclear ribosomal RNA

10.1016/j.ympev.2007.03.022Molecular Phylogenetics and Evolution452576-586MPEV