Egg mortality: predation and hydrography in the central Baltic

Cod and sprat are the dominant fish species in the Baltic pelagic ecosystem, both of great economic importance and ecologically strongly interlinked. Management of both species is challenged by highly variable recruitment success. Recent studies have identified predation and hydrographic conditions during the egg phase to be of critical importance. Two years of extensive field investigations in the Bornholm Basin, central Baltic Sea, were undertaken. In 2002, a typical stagnation situation characterized by low salinity and poor oxygen conditions was investigated, and in early 2003, a major inflow of North Sea water completely changed the hydrographic conditions by increasing salinity and oxygen content, thereby altering ecological conditions. The goal was to quantify egg mortality caused by predation and hydrography, and to compare these estimates with independent estimates based on cohort analysis. Results indicated high intra-annual variability in egg mortality. Cod and sprat egg mortality responded differently to the major Baltic inflow: mortality related to hydrographic conditions increased for sprat and decreased for cod. On the other hand, predation mortality during peak spawning decreased for sprat and increased for cod

Ecological commonalities among pelagic fishes: comparison of freshwater ciscoes and marine herring and sprat

Systematic comparisons of the ecology between functionally similar fish species from freshwater and marine aquatic systems are surprisingly rare. Here, we discuss commonalities and differences in evolutionary history, population genetics, reproduction and life history, ecological interactions, behavioural ecology and physiological ecology of temperate and Arctic freshwater coregonids (vendace and ciscoes, Coregonus spp.) and marine clupeids (herring, Clupea harengus, and sprat, Sprattus sprattus). We further elucidate potential effects of climate warming on these groups of fish based on the ecological features of coregonids and clupeids documented in the previous parts of the review. These freshwater and marine fishes share a surprisingly high number of similarities. Both groups are relatively short-lived, pelagic planktivorous fishes. The genetic differentiation of local populations is weak and seems to be in part correlated to an astonishing variability of spawning times. The discrete thermal window of each species influences habitat use, diel vertical migrations and supposedly also life history variations. Complex life cycles and preference for cool or cold water make all species vulnerable to the effects of global warming. It is suggested that future research on the functional interdependence between spawning time, life history characteristics, thermal windows and genetic differentiation may profit from a systematic comparison of the patterns found in either coregonids or clupeids

Long-term results after percutaneous transluminal angioplasty of the subclavian artery

Wstęp. Zespół podkradania tętnicy podobojczykowej jest istotnym problemem klinicznym, w którym przewlekłe niedokrwienie kończyny górnej może powodować zaburzenia ukrwienia mózgu. Obecnie postępowaniem z wyboru w przypadku całkowitej niedrożności tętnicy podobojczykowej jest leczenie chirurgiczne, natomiast w przypadkach zwężeń stosuje się techniki śródnaczyniowe. Materiał i metody. W klinice, w której pracują autorzy, w latach 1989–1998 u 74 chorych (44 kobiet i 30 mężczyzn w wieku 20–71 lat; średnio 49 lat) wykonano przezskórną dylatację (PTA, percutaneous transluminal angioplasty) z powodu zwężenia tętnicy podobojczykowej. Dobre wyniki angioplastyki uzyskano u 69 chorych (93,2%). Zgody na ponowne wykonanie zabiegów nie wyraziło 5 pacjentów (8,1%), u których doszło do szybkiego nawrotu zwężenia. Celem pracy była analiza odległych wyników PTA u 52 chorych w okresie 16–128 miesięcy (średnio 51 miesięcy) od wykonanego zabiegu. Wyniki. U 39 (75%) chorych odnotowano poprawę stanu klinicznego potwierdzoną badaniem duplex-doppler,a także zrównanie wartości ciśnienia tętniczego na tętnicach ramiennych. U żadnego z pacjentów nie stwierdzono objawów przewlekłego niedokrwienia mózgu lub kończyny górnej. W tym okresie u 8 chorych obserwowano nawrót zwężenia tętnicy podobojczykowej. Ocena morfologiczna wykazała poniżej 50-procentowe zwężenia światła naczynia, powodujące różnice ciśnienia krwi na tętnicy ramiennej poniżej 20 mm Hg.Introduction. Subclavian steal syndrome is a clinical problem of great importance, in which chronic upper limb ischaemia can cause a deficit of blood supply to the brain. Nowadays surgery is the routine approach to the management of complete subclavian artery (SA) occlusion; in the case of stenosis endovascular procedure is preferable. Material and methods. We treated 74 patients with percutaneous transluminal angioplasty (PTA) for SA stenosis in our Department in the years 1989–1998 (44 females, 30 male; age 20–71 years, mean 49 years). Good results after angioplasty were obtained in 69 patients (93.2%). Five patients (8.1%) had only a temporary improvement but they refused further procedures. Analysis of the long-term results after SA PTA was the aim of the study. Fifty-two patients were followed-up for 16 to 128 months (mean 51 months). Results. Thirty-nine patients (75%) had clinical improvement and normal vertebral artery blood flow direction confirmed by duplex-doppler, as well as equal brachial pressures. None of the patients complained of any signs of chronic brain or hand ischaemia. During follow-up 8 patients (15.4%) were diagnosed with subclavian artery stenosis, however lesser than 50%, causing a difference of brachial pressure up to 20 mm Hg

Standards of the Polish Ultrasound Society – update. Examination of extracranial carotid and vertebral arteries

The role of a standard is to describe examination techniques, recommended norms as well as principles necessary to obtain results and draw appropriate conclusions, rather than a description of pathologies. The paper presents a technique for carotid artery examination as well as currently recommended standards. According to San Francisco Consensus from 2003, a significant stenosis of 70% may be detected when systolic velocity in the internal carotid artery stenosis is >230 cm/s, and the diastolic velocity is >100 cm/s. The common carotid artery velocity is also taken into account. Hemodynamic evaluation is therefore the primary method for the assessment of the degree of internal carotid artery stenosis. It is important that the examination is performed at an insonation angle of 60° as measurements at higher angles result in an exponential increase in measurement error. Also, an extended version of standards involving measurements performed behind stenosis, which are used in some clinics, is included in the paper. The paper further presents guidelines for the description of the identified pathologies, which ensure that the findings prove unambiguous for clinicians, especially when stenosis eligible for surgical intervention is detected. Morphological measurement of stenosis (according to NASCET criteria) is only of supplementary character (confirming morphological grounds for the increase of velocity) and has no critical importance, especially due to high measurement divergence. Description of atherosclerotic plaques, especially hypoechoic ones, which are considered potentially unstable and may lead to a raised risk of stroke, is a very important element of examination. The paper is based on Standards of the Polish Ultrasound Society and updated based on the latest literature reports