Tackling unemployment, supporting business and developing careers

The issue of unemployment remains high on the political agenda. However, there is evidence that employers can be wary of employing people who are out of work. Employer practice is key, both in terms of providing employment opportunities to job seekers, and in providing space for low-skilled people to develop their skills and cement their attachment to the labour market. This report discusses the role of career guidance in mediating between job seekers and employers to allow both to achieve their objectives.The issue of unemployment remains high on the political agenda. However, there is evidence that employers can be wary of employing people who are out of work. Employer practice is key, both in terms of providing employment opportunities to job seekers, and in providing space for low-skilled people to develop their skills and cement their attachment to the labour market. This report discusses the role of career guidance in mediating between job seekers and employers to allow both to achieve their objectives

The identification of markers of macrophage differentiation in PMA-stimulated THP-1 Cells and monocyte-derived macrophages

Differentiated macrophages are the resident tissue phagocytes and sentinel cells of the innate immune response. The phenotype of mature tissue macrophages represents the composite of environmental and differentiation-dependent imprinting. Phorbol-12-myristate-13-acetate (PMA) and 1,25-dihydroxyvitamin D3 (VD3) are stimuli commonly used to induce macrophage differentiation in monocytic cell lines but the extent of differentiation in comparison to primary tissue macrophages is unclear. We have compared the phenotype of the promonocytic THP-1 cell line after various protocols of differentiation utilising VD3 and PMA in comparison to primary human monocytes or monocyte-derived macrophages (MDM). Both stimuli induced changes in cell morphology indicative of differentiation but neither showed differentiation comparable to MDM. In contrast, PMA treatment followed by 5 days resting in culture without PMA (PMAr) increased cytoplasmic to nuclear ratio, increased mitochondrial and lysosomal numbers and altered differentiation-dependent cell surface markers in a pattern similar to MDM. Moreover, PMAr cells showed relative resistance to apoptotic stimuli and maintained levels of the differentiation-dependent anti-apoptotic protein Mcl-1 similar to MDM. PMAr cells retained a high phagocytic capacity for latex beads, and expressed a cytokine profile that resembled MDM in response to TLR ligands, in particular with marked TLR2 responses. Moreover, both MDM and PMAr retained marked plasticity to stimulus-directed polarization. These findings suggest a modified PMA differentiation protocol can enhance macrophage differentiation of THP-1 cells and identify increased numbers of mitochondria and lysosomes, resistance to apoptosis and the potency of TLR2 responses as important discriminators of the level of macrophage differentiation for transformed cells

Vegetation change over fifty years in humid grasslands of KwaZulu-Natal (Acocks's sites)

Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1997.Eighty three of Acocks's sites, originally surveyed about 50 years ago, were resurveyed in 1996 to determine the extent of grassland change in the humid grasslands of KwaZulu-Natal. Sites were relocated using 1:10 000 scale ortho-photos and present land cover was determined for each site. Forty six of the sites that were still under original grassland were further examined to determine present species composition. A survey method was designed that would emulate Acocks's data and comparisons were drawn between original and present species composition. These differences were then analysed together with some environmental variables to try to determine the factors which had the most influence on the change and which environment and management factors are related to the present variation in composition among sites. Of the 83 sites, 26 had changed from natural vegetation to some other form of agriculture such as forestry or cultivation. Most of this change had occurred in the Natal Mistbelt Ngongoni Veld where large areas are forested. Cultivation is found predominantly in the communal areas where subsistence, cultivation practices are employed. The remainder of the sites had changed significantly in terms of their species composition. The most pronounced change had occurred in areas under communal tenure although significant changes had occurred in the commercially farmed areas. The direction of change was also more consistent towards species that commonly predominate in heavily grazed areas in the communal areas compared to the commercial areas. The exact reasons for this were unclear but this could possibly be attributed to heavier stocking rates in the communal areas. Change in floristic composition was also more pronounced at lower altitudes where the mean annual rainfall is lower and the mean annual temperature higher. This could possibly be a result of the vegetation at lower altitudes being less stable and thus less resistant to change. Basal cover differed significantly between commercial and communally grazed sites. Lower basal cover was found in the communal sites where intensive grazing limits the growth of individual tufts. Number of species found at each site did not differ significantly between communal and commercially grazed sites. This study was also a practical implementation of the resurveying of Acocks's sites and the original data set was found to be a useful baseline data set to determine coarse long-term changes in the vegetation

Development stage distribution as a proxy for feeding success and growth for first feeding Norwegian spring spawning herring larvae

The estimation of growth rates in young herring larvae (Clupea harengus) in the field can be difficult because the primary increments in the otoliths may not be discernible or formed at a daily level. Likewise, the estimation of mortality rates of fish larvae in the field is very difficult to achieve, especially in a rigorous quantitative manner. In this study, the authors suggest the use of a stage‐based proxy of feeding success, growth and potential survival or mortality risk of field‐caught larvae. The stage‐based proxy is derived based on observations from previous laboratory studies where larvae successfully completing start‐feeding on external food sources will advance through the early development stages, whereas those that do not (unsuccessful larvae) remain and accumulate in the development stage preceding first feeding. The relative occurrence of larvae in the early development stages is therefore expected to reflect feeding conditions of the larvae, with higher ratios of unsuccessful larvae indicative of poor feeding success and higher mortality risk. Using field data on Norwegian spring spawning herring, the authors document that the relative occurrence of larvae in the late non‐feeding stage is significantly higher at lower average zooplankton concentrations, in line with the predictions of the authors that this novel approach of using a stage‐based proxy could be a useful indication of feeding success, growth and mortality in the field. Further, there was a significant interaction effect with ambient temperature, with the ratio being higher at low zooplankton concentrations at higher temperatures. This study also suggests that these findings are not population specific as the same accumulation of non‐feeding larvae in the late non‐feeding stage was observed in laboratory‐reared larvae of both autumn and spring spawning herring populations.publishedVersio

Demographic characteristics of exploited tropical lutjanids: a comparative analysis

Demographic parameters from seven exploited coral reef lutjanid species were compared as a case study of the implications of intrafamily variation in life histories for multispecies harvest management. Modal lengths varied by 4 cm among four species (Lutjanus fulviflamma, L. vitta, L. carponotatus, L. adetii), which were at least 6 cm smaller than the modal lengths of the largest species (L. gibbus, Symphorus nematophorus, Aprion virescens). Modal ages, indicating ages of full selection to fishing gear, were 10 years or less for all species, but maximum ages ranged from 12 (L. gibbus) to 36 years (S. nematophorus). Each species had a unique growth pattern, with differences in length-at-age and mean asymptotic fork length (L∞), but smaller species generally grew fast during the first 1–2 years of life and larger species grew more slowly over a longer period. Total mortality rates varied among species; L. gibbus had the highest mortality and L. fulviflamma, the lowest mortality. The variability in life history strategies of these tropical lutjanids makes generalizations about lutjanid life histories difficult, but the fact that all seven had characteristics that would make them particularly vulnerable to fishing indicates that harvest of tropical lutjanids should be managed with caution

Lemon sole Microstomus kitt in the northern North Sea: a multidisciplinary approach to the early life-history dynamics

Lemon sole Microstomus kitt is a commercially valuable flatfish species that occurs in shelf waters around the northeast Atlantic. Only the most basic life-history information is available for the North Sea. Spawning is generally assumed to occur between early May and October, with a peak between May and August. Lemon sole larvae have been found in the water column in the northern North Sea in winter during standard surveys. Larvae captured in November/December 2016 and January/February 2017 using the International Council for the Exploration of the Seas standard 2 m Midwater Ring trawls (MIK) were analysed to gain a better understanding of the pelagic early life-history stages of lemon sole, especially in relation to the timing of spawning and the dispersal of overwintering larvae. Larval age was estimated from sagittal otolith primary increment counts. The larvae caught in November/December ranged in nominal age from 4 to 45 days post-hatching which suggests that spawning continues into late October and November. Most, but not all, of the larvae caught in January/February were post metamorphosis, and the difference in age between the two sampling dates was consistent with the elapsed time between samplings. The estimated hatching dates confirm that lemon sole spawning extends into late autumn in the northern North Sea, with overwintering larvae in all developmental stages. Drift modelling of eggs and larvae released at historically documented spawning grounds in the northern North Sea suggests that these grounds are also the source for all of the larvae sampled during the 2016–2017 surveys.publishedVersio

Management Scenarios Under Climate Change – A Study of the Nordic and Barents Seas

The effects of increasing fishing pressure in combination with temperature increases in the Nordic and Barents Seas have been evaluated using an end-to-end model for the area forced by a downscaled RCP 4.5 climate scenario. The scenarios that have been applied have used four different fractions of fisheries mortality at maximum sustainable yield (Fmsy); 0.6, 0.8, 1.0 and 1.1 × Fmsy. As it is highly likely that more ecosystem components will be harvested in the future, the four scenarios have been repeated with fishing on a larger number of ecosystem components, including harvesting of lower trophic levels (mesozooplankton and mesopelagic fish). The zooplankton biomass had an increasing trend, regardless of the increase in fishing pressure on their predators. However, when introducing harvest on the lower trophic levels, this increase was no longer evident. When harvesting more components, the negative response in biomass of pelagic and demersal fish to increasing harvest became more prominent, indicating an increasing vulnerability in the ecosystem structure to stressors. Although harvest on lower trophic level led to an immense increase in the total catch, it also resulted in a decrease in the total catches of pelagic and demersal fish, despite more species being harvested in these guilds.publishedVersio

Drift indices confirm that rapid larval displacement is essential for recruitment success in high-latitude oceans

Larval drift is a key process for successful fish recruitment. We used Norwegian spring-spawning herring (Clupea harengus) as model species to investigate the relationship between larval drift and recruitment. Larval drift indices were derived from simulations based on survey observations between 1993 and 2016. We show that forward simulated larval drift indices have an important positive relation to recruitment success. The relationship demonstrates elevated recruitment when larvae relocate rapidly northwards toward the Barents Sea. Negative or low larval drift indices coincide with only weak recruitment emphasizing limited survival in years with enhanced larval retention. Hence, with this work we combine drift model outcomes refined with survey data indicating that more extensive larval drift is an important component in population dynamics for high-latitude small pelagic fishes. However, larval displacement alone represents only one among many controlling factors but may offer possible predictions of the probability of higher or lower recruitment in the short term. The applicability of the drift indices is adaptable in all world oceans and all marine organisms that occupy planktonic life stages exposed to dynamic ocean currents. The study demonstrates how larval drift indices help to identify larval transport or retention to be crucial for population replenishment.publishedVersio

A cardinal role for cathepsin D in co-ordinating the host-mediated apoptosis of macrophages and killing of pneumococci

The bactericidal function of macrophages against pneumococci is enhanced by their apoptotic demise, which is controlled by the anti-apoptotic protein Mcl-1. Here, we show that lysosomal membrane permeabilization (LMP) and cytosolic translocation of activated cathepsin D occur prior to activation of a mitochondrial pathway of macrophage apoptosis. Pharmacological inhibition or knockout of cathepsin D during pneumococcal infection blocked macrophage apoptosis. As a result of cathepsin D activation, Mcl-1 interacted with its ubiquitin ligase Mule and expression declined. Inhibition of cathepsin D had no effect on early bacterial killing but inhibited the late phase of apoptosis-associated killing of pneumococci in vitro. Mice bearing a cathepsin D-/- hematopoietic system demonstrated reduced macrophage apoptosis in vivo, with decreased clearance of pneumococci and enhanced recruitment of neutrophils to control pulmonary infection. These findings establish an unexpected role for a cathepsin D-mediated lysosomal pathway of apoptosis in pulmonary host defense and underscore the importance of apoptosis-associated microbial killing to macrophage function