Temporal variation of cephalopods in the diet of Cape fur seals in Namibia

Cape fur seal (Arctocephalus pusillus pusillus) scats were sampled over a period of eight years (1994-2001) at Atlas and Wolf Bay seal colonies in order to assess the cephalopod component of the diet of these seals and cephalopod diversity off the coast of Namibia. The temporal variation within the cephalopod component was investigated. A low diversity of cephalopods, only six species, are preyed upon, with Todarodes angolensis being the most important component both in numbers and wet weight in all years. Its lowered weight contribution during winter coincided with a greater diversity of other cephalopod species in the diet, which showed higher proportional weight contribution relative to Todarodes angolensis. Scat sampling was found to be an unreliable method of providing estimates of total prey weight consumption by seals, but was considered an acceptable method for proportional comparisons, especially given the ease of scat collection over extended periods

Roles of spatial scale and rarity on the relationship between butterfly species richness and human density in South Africa

Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2' to 60' across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation.SM was supported by a postdoctoral fellowship from the University of Pretoria (www.up.ac. za), followed by one from the South African National Biodiversity Institute (www.sanbi.org.za). RA was supported by the National Research Foundation of South Africa (Grant 85802; www.nrf.ac.za). JFC was supported by a National Research Foundation of South Africa's Research Career Award Fellowship.http://www.plosone.orgam201

Fossil microbialites of the Ja?ba Formation, Bambu? Group, Minas Gerais, Brazil.

Microbialites are carbonatic deposits, whose genesis is organosedimentary, deposited by benthic microbial mats. Microbialites are the most common fossils in rocks of the Proterozoic, worldwide and in Brazil. They exhibit morphological diversity since the oldest Archean forms, and are fundamental in studies concerning the biota and environmental aspects of past times, allowing better comprehension of biological and carbonate biosedimentary evolution through time. Microbial laminites and thrombolites of the Ja?ba Formation, upper Bambu? Group, are described. Thrombolites show columnar and irregular shape, centimetric size, and are locally coalescent. Laminites, overlying the thrombolitic strata, display smooth, wavy, and crenulate synoptic relief. Five microfabrics and microfossils of two distinct morphologies, coccoidal and filamentous, were identified. Microfabrics may be of biogenic or abiogenic origin, representing different processes involved in the formation of microbialites. Thus, microbialites and microfossils of the Ja?ba Formation show potential to better understand the producer biota in the context of the Ediacaran-Cambrian transition, probable age of this unit, and an important moment of profound changes in biosphere, due to the diversification of metazoans.Os microbialitos s?o dep?sitos carbon?ticos cuja origem ? organossedimentar, depositados por esteiras microbianas bent?nicas. Microbialitos s?o os f?sseis mais comuns encontrados no Brasil e no mundo em rochas do Proterozoico. Apresentam diversidade morfol?gica desde as formas mais antigas, datadas do Arqueano, e s?o fundamentais nos estudos da paleobiota e aspectos ambientais pret?ritos, permitindo o melhor entendimento da evolu??o biol?gica e biossedimentar carbon?tica ao longo do tempo geol?gico. Neste trabalho s?o descritos laminitos e tromb?litos da Forma??o Ja?ba, na por??o superior do Grupo Bambu?. Os tromb?litos encontrados apresentam formas colunares e irregulares, centim?tricas e pontualmente coalescentes. J? os laminitos microbiais, sobrejacentes aos tromb?litos, apresentam lamina??es com relevo sin?ptico entre plano, ondulado e crenulado. Cinco microtexturas e microf?sseis de duas morfologias distintas, cocoides e filamentosos, foram identificados. As microtexturas s?o de origem biog?nica e abiog?nica, e representam os diferentes processos de forma??o dos microbialitos. Dessa forma, os microbialitos e microf?sseis encontrados na Forma??o Ja?ba apresentam potencial para melhor compreender a paleobiota produtora no contexto da transi??o Ediacarano?Cambriano, prov?vel idade desta unidade, um momento importante de mudan?as profundas na biosfera, devido ? diversifica??o dos metazo?rios

Temporal variation of cephalods in the diet of Cape fur seals in Namibia

Cape fur seal (Arctocephalus pusillus pusillus) scats were sampled over a period of eight years (1994–2001) at Atlas and Wolf Bay seal colonies in order to assess the cephalopod component of the diet of these seals and cephalopod diversity off the coast of Namibia. The temporal variation within the cephalopod component was investigated. A low diversity of cephalopods, only six species, are preyed upon, with Todarodes angolensis being the most important component both in numbers and wet weight in all years. Its lowered weight contribution during winter coincided with a greater diversity of other cephalopod species in the diet, which showed higher proportional weight contribution relative to Todarodes angolensis. Scat sampling was found to be an unreliable method of providing estimates of total prey weight consumption by seals, but was considered an acceptable method for proportional comparisons, especially given the ease of scat collection over extended periods

Association of kidney disease measures with risk of renal function worsening in patients with type 1 diabetes

Background: Albuminuria has been classically considered a marker of kidney damage progression in diabetic patients and it is routinely assessed to monitor kidney function. However, the role of a mild GFR reduction on the development of stage 653 CKD has been less explored in type 1 diabetes mellitus (T1DM) patients. Aim of the present study was to evaluate the prognostic role of kidney disease measures, namely albuminuria and reduced GFR, on the development of stage 653 CKD in a large cohort of patients affected by T1DM. Methods: A total of 4284 patients affected by T1DM followed-up at 76 diabetes centers participating to the Italian Association of Clinical Diabetologists (Associazione Medici Diabetologi, AMD) initiative constitutes the study population. Urinary albumin excretion (ACR) and estimated GFR (eGFR) were retrieved and analyzed. The incidence of stage 653 CKD (eGFR < 60 mL/min/1.73 m2) or eGFR reduction > 30% from baseline was evaluated. Results: The mean estimated GFR was 98 \ub1 17 mL/min/1.73m2 and the proportion of patients with albuminuria was 15.3% (n = 654) at baseline. About 8% (n = 337) of patients developed one of the two renal endpoints during the 4-year follow-up period. Age, albuminuria (micro or macro) and baseline eGFR < 90 ml/min/m2 were independent risk factors for stage 653 CKD and renal function worsening. When compared to patients with eGFR > 90 ml/min/1.73m2 and normoalbuminuria, those with albuminuria at baseline had a 1.69 greater risk of reaching stage 3 CKD, while patients with mild eGFR reduction (i.e. eGFR between 90 and 60 mL/min/1.73 m2) show a 3.81 greater risk that rose to 8.24 for those patients with albuminuria and mild eGFR reduction at baseline. Conclusions: Albuminuria and eGFR reduction represent independent risk factors for incident stage 653 CKD in T1DM patients. The simultaneous occurrence of reduced eGFR and albuminuria have a synergistic effect on renal function worsening

Roles of spatial scale and rarity on the relationship between butterfly species richness and human density in South Africa

Wildlife and humans tend to prefer the same productive environments, yet high human densities often lead to reduced biodiversity. Species richness is often positively correlated with human population density at broad scales, but this correlation could also be caused by unequal sampling effort leading to higher species tallies in areas of dense human activity. We examined the relationships between butterfly species richness and human population density at five spatial resolutions ranging from 2′ to 60′ across South Africa. We used atlas-type data and spatial interpolation techniques aimed at reducing the effect of unequal spatial sampling. Our results confirm the general positive correlation between total species richness and human population density. Contrary to our expectations, the strength of this positive correlation did not weaken at finer spatial resolutions. The patterns observed using total species richness were driven mostly by common species. The richness of threatened and restricted range species was not correlated to human population density. None of the correlations we examined were particularly strong, with much unexplained variance remaining, suggesting that the overlap between butterflies and humans is not strong compared to other factors not accounted for in our analyses. Special consideration needs to be made regarding conservation goals and variables used when investigating the overlap between species and humans for biodiversity conservation

Diet of Cape fur seals Arctocephalus pusillus pusillus at three mainland breeding colonies in Namibia. 2. Temporal variation

Scat analysis was used to assess temporal variability in the diet composition of Cape fur seals Arctocephalus pusillus pusillus from three breeding colonies in Namibia (January 1994 to April 2002). The diet displayed significant inter- and intra-annual variation in composition at each of the study colonies. The diet was not predictable on an annual pattern, and little consistent seasonality was apparent at each of the study sites. However, some prey species tended to display some seasonality, possibly as a result of their life-history patterns. At the Cape Cross colony, small Cape hake Merluccius spp. in the diet coincided with their spawning season. At the Atlas-Wolf Bay and Van Reenen Bay colonies, lanternfish Lampanyctodes hectoris were most prevalent in the diet during the upwelling season (August–January). Outside that period, pelagic goby Sufflogobius bibarbatus were most abundant in the diet at those colonies. This pattern may be a result of the gobies' southwards migration from northern Namibian waters where smaller goby are dominant in the diet at the Cape Cross colony in the upwelling season. The prevalence of Cape horse mackerel Trachurus trachurus capensis in the diet at Cape Cross was coincident with the pelagic phase of juvenile horse mackerel. Keywords: Arctocephalus pusillus pusillus, breeding colony, Cape fur seal, diet, Namibia, scat analysis, temporal variationAfrican Journal of Marine Science 2006, 28(1): 73–8

Seabirds in the diet of Cape fur seals Arctocephalus pusillus pusillus at three mainland breeding colonies in Namibia

Predation by Cape fur seals Arctocephalus pusillus pusillus on seabirds has previously been attributed to a few individuals, mainly males. Scat samples were collected at three mainland breeding colonies of seals in Namibia to determine the extent of seabird predation. Mainly females were sampled. No scats from the van Reenen Bay and Atlas-Wolf Bay colonies, and only two from Cape Cross, contained feather remains, giving an overall frequency of occurrence of feathers in scats of 0.1%. The feathers found were of African penguin Spheniscus demersus and a species of cormorant (Phalacrocorax sp.). Keywords: Arctocephalus pusillus pusillus; Cape fur seal; diet; predation; scat analysis; seabirdsAfrican Journal of Marine Science 2005, 27(2): 509–51

Diet of Cape fur seals Arctocephalus pusillus pusillus at three mainland breeding colonies in Namibia. 1. Spatial variation

The diet composition of Cape fur seals Arctocephalus pusillus pusillus was investigated from three breeding colonies in Namibia between January 1994 and April 2002 using scat analysis. Otolith numbers were corrected for those lost during digestion before determining the percentage numerical abundance of prey in each sample. Otolith diameters were corrected for erosion during digestion and then converted to fish length and mass to determine the percentage mass of prey in samples. In all, six main groups of teleost prey were identified, consisting of at least 48 species and 19 families. Cape Cross seals mainly consumed Cape horse mackerel Trachurus trachurus capensis, whereas lanternfish Lampanyctodes hectoris were negligible in their diet. At Van Reenen Bay and Atlas-Wolf Bay, the two southerly colonies, lanternfish were numerically prevalent in scats but not important in terms of mass. Cape hake Merluccius spp. and goby Sufflogobius bibarbatus featured in scats from all three colonies. The species in the pelagics prey group were of lesser dietary importance, with round herring Etrumeus whiteheadi being most prevalent in the south at Van Reenen Bay and anchovy Engraulis encrasicolus and sardine Sardinops sagax most prevalent in scats from Cape Cross. The difference in the prevalence of prey in seal diets seems to be related to fish distributions.Keywords: Arctocephalus pusillus pusillus, breeding colony, Cape fur seal, diet, Namibia, scat analysis, spatial variationAfrican Journal of Marine Science 2006, 28(1): 57–7