First study on the ecology of Sepia australis in the Southern Benguela Ecosystem

Sepia australis is most abundant in the eastern South Atlantic between Luderitz and St. Helena Bay (about 27-35°S in 100-200m). There seems to be no link between the variation in abundance of S. australis and that of its most important predator, the shallow-water Cape hake, Merluccius capensis. The variations in abundance of S. australis and one of its most important prey species, the stomatopod crustacean Pterygosquilla armata capensis, show simultaneous changes, suggesting that both species respond to the same environmental factors. Mantle length, total weight, gonad weight, and sex ratio of Sepia australis vary from year to year and by region off the west coast of southern Africa. Animals from the south coast (eastward of Cape Point) were very different: length-weight relationhips were found to be similar in slope and intercept for both sexes and within each sex between years and regions off the west coast, but different for the south coast

Drift routes of Cape hake eggs and larvae in the southern Benguela Current system

The aim of this study was to combine observed circulation pattern with data on distribution of hake eggs and larvae in the southern Benguela from a survey in September/October 2005 to investigate drift routes of hake eggs and larvae. Genetic information enabled species-specific information about drift routes of the two hake species (Merluccius capensis and M. paradoxus) to be established. The results showed that both species were transported from spawning areas to nursery areas in the jet current, but differential cross-shelf distribution would most likely lead to species-specific drift routes which could explain why the two species seem to have different nursery areas

Biological and ecological aspects of the distribution of Sepia australis,/i> (Cephalopoda: Sepiidae) off the south coast of southern Africa

During the South Coast Biomass Survey in 1988, 49,4 kg (6336 individuals) of Sepia australis were caught between Cape Agulhas and Algoa Bay. A biomass index of 8031 of S. australis wascalculated for the area at that time. Largest catches were taken between about 20°E and 22°E, in waters of 10-11°C and 50-150 m depth. The overall sex ratio was 2M : 3F and mean individual mass was 6,47 g for males and 8,67 g for females. The largest animals were a mature male of 58 mm mantle length and a maturing female of 65 mm mantle length. Most of the animals trawled off the South Coast were maturing or fully mature in early winter and very few immature animals were found. Differences in mean mantle length and maturity stage of the animals in different areas were found to be correlated most strongly with water temperature but also with depth and longitude. Largest numbers and mean sizes of mature animals caught suggest that the main spawning grounds off the South Coast may be in deeper water on the western side of the Agulhas Bank. To the east the deeper water is warmer and the animals there may be at a disadvantage, as optimum temperatures and depths for spawning do not coincide

Characteristics of survivors: growth and nutritional condition of early stages of the hake species <i>Merluccius paradoxus</i> and <i>M. capensis</i> in the southern Benguela ecosystem

Larval mortality in marine fish is strongly linked to characteristic traits such as growth and condition, but the variability in these traits is poorly understood. We tried to identify the variability in growth in relation to conditions leading to greater survival chances for early stages of Cape hake, Merluccius paradoxus and M. capensis, in the Benguela upwelling ecosystem. During two cruises in 2007 and one cruise in 2008, hake larvae and juveniles were caught. Otolith microstructures revealed a larval age ranging from 2 to 29 days post-hatching (dph), whereas juvenile age was 67–152 dph. RNA:DNA ratios, used to evaluate nutritional condition, were above the relevant threshold level for growth. No strong coupling between growth and condition was detected, indicating a complex relationship between these factors in the southern Benguela ecosystem. Merluccius paradoxus juveniles caught in 2007 (the surviving larvae of 2006) had significantly higher larval growth rates than larvae hatched in 2007 and 2008, possibly indicating selection for fast growth in 2006. High selection pressure on growth could be linked to predation avoidance, including cannibalism

Cohesin complex-associated holoprosencephaly

Marked by incomplete division of the embryonic forebrain, holoprosencephaly is one of the most common human developmental disorders. Despite decades of phenotype-driven research, 80–90% of aneuploidy-negative holoprosencephaly individuals with a probable genetic aetiology do not have a genetic diagnosis. Here we report holoprosencephaly associated with variants in the two X-linked cohesin complex genes, STAG2 and SMC1A, with loss-of-function variants in 10 individuals and a missense variant in one. Additionally, we report four individuals with variants in the cohesin complex genes that are not X-linked, SMC3 and RAD21. Using whole mount in situ hybridization, we show that STAG2 and SMC1A are expressed in the prosencephalic neural folds during primary neurulation in the mouse, consistent with forebrain morphogenesis and holoprosencephaly pathogenesis. Finally, we found that shRNA knockdown of STAG2 and SMC1A causes aberrant expression of HPE-associated genes ZIC2, GLI2, SMAD3 and FGFR1 in human neural stem cells. These findings show the cohesin complex as an important regulator of median forebrain development and X-linked inheritance patterns in holoprosencephaly

Search for leptophobic Z ' bosons decaying into four-lepton final states in proton-proton collisions at root s=8 TeV

Peer reviewe

Search for black holes and other new phenomena in high-multiplicity final states in proton-proton collisions at root s=13 TeV

Peer reviewe

Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

Peer reviewe

Search for high-mass diphoton resonances in proton-proton collisions at 13 TeV and combination with 8 TeV search

Peer reviewe