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Aim Drivers of extant population genetic structure include past climate-driven range shifts and vicariant events, as well as gene flow mediated by dispersal and habitat continuity. Their integration as alternative or complementary drivers is often missing or incomplete, potentially overlooking relevant processes and time scales. Here we ask whether it is the imprint of past range shifts or habitat connectivity driven by oceanographic transport that best explain genetic structure in a poorly understood model, a forest-forming African kelp. Location Southwestern coast of Africa (Benguela current region). Taxon Laminaria pallida. Methods We estimated genetic variability along the species distributional range using 14 microsatellite markers. This genetic variability was compared to estimates of past range shifts derived from species distribution modelling for the Last Glacial Maximum (LGM), the mid-Holocene (MH) and the present, and estimates of habitat connectivity derived from oceanographic biophysical modelling. Results The species is structured in two clusters, a southern cluster with much richer (allelic richness A: 10.40 +/- 0.33) and unique (private alleles PA: 56.69 +/- 4.05) genetic diversity, and a northern cluster (A: 4.75 +/- 0.17; PA: 6.70 +/- 1.45). These clusters matched well-known biogeographical regions and their transition coincided with a dispersal barrier formed by upwelled offshore transport. No major range shifts or vicariant events were hindcasted along the present range, suggesting population stability from the LGM to the present. Main conclusions Habitat connectivity, rather than past range shifts, explains the extant population structure. Future environmental requirements of the species along the Benguela upwelling system are projected to persist or even intensify, likely preserving the observed genetic patterns for the years to come. Yet, the differentiation and endemicity between clusters, and the isolation structured by the regional oceanography, implies high conservation value for genetic biodiversity, and even more if considering the ecological, social and economic services provided by kelp forests. info:eu-repo/semantics/acceptedVersion

Methods have been developed to allow quantitative connectivity of the whole fixed mouse brain by means of magnetic resonance imaging (MRI). We have translated what we have learned in clinical imaging to the very special domain of the mouse brain. Diffusion tensor imaging (DTI) of perfusion fixed specimens can now be performed with spatial resolution of 45 um(3), i.e. voxels that are 21,000 times smaller than the human connectome protocol. Specimen preparation has been optimized through an active staining protocol using a Gd chelate. Compressed sensing has been integrated into high performance reconstruction and post processing pipelines allowing acquisition of a whole mouse brain connectome in < 12 hrs. The methods have been validated against retroviral tracer studies. False positive tracts, which are especially problematic in clinical studies, have been reduced substantially to ~ 28 %. The methods have been streamlined to provide high-fidelity, whole mouse brain connectomes as a routine study. The data package provides holistic insight into the mouse brain with anatomic definition at the meso scale, quantitative volumes of subfields, scalar DTI metrics, and quantitative tractography.

The existence of massive cryptic diversity in algae makes linking DNA-based lineages to existing taxa exceedingly difficult. A better integration of historical collections into modern taxonomic research is therefore highly desirable. Using the brown, algal genus Lobophora as a test case, we explore the feasibility of linking taxonomic names to clades in modern phylogenies. Despite Lobophora being a pantropical genus with probably more than 100 species, traditionally only a handful of species have been recognized. In this study we reevaluated the identity of 17 historical taxa thought to belong to Lobophora by attempting DNA amplification of herbarium material as well as specimens recently collected from the type localities (epitypes). In an attempt to assign them to Molecular Operational Taxonomic Units, the obtained sequences were integrated in a global Lobophora phylogeny based upon data derived from more than 650 specimens. Our results indicate that although five sequences were obtained from type specimens, exclusive reliance on information preserved in type specimens is problematic. Epitype material proved a more successful way forward, but this route often comes with a considerable degree of uncertainty, especially in tropical regions where the extent of sympatry among Lobophora lineages is often considerable. More problematic from a broader perspective is the fact that for 35% of historical taxa, either the type could not be traced or permission was not granted to extract DNA from the types. Such a low accessibility rate may reduce our reliance on type material and jeopardize future efforts to integrate historical taxa into a framework of a modern DNA-based taxonomy.

Zeacarpa leiomorpha is a crustose brown alga endemic to South Africa. The species has been tentatively placed in Ralfsiaceae, but its ordinal assignment has been uncertain. The molecular phylogeny of brown algae based on concatenated DNA sequences of seven chloroplast and mitochondrial gene sequences (atpB, psaA, psaB, psbA, psbC, rbcL, and cox1) of taxa covering most of the orders revealed the most related phylogenetic relationship of Z. leiomorpha to Nemoderma tingitanum (Nemodermatales) rather than Ralfsiaceae (Ralfsiales). Morphologically, Zeacarpa and Nemoderma share crustose thallus structure and multiple discoidal chloroplasts without pyrenoids in each cell, however, the formation of lateral unilocular zoidangia in tufts in loose upright filaments in Zeacarpa is distinctive in brown algae. Considering the relatively distant genetic divergence between the two taxa, comparable to that among families or orders in representative brown algae, in addition to the above-mentioned unique morphological features, we propose the classification of Zeacarpa in a new family Zeacarpaceae in the order Nemodermatales.

Paleoanthropologists (scientists studying human origins) universally recognize the evolutionary significance of ancient climates and environments for understanding human origins.[1-6] Even those scientists working in recent phases of human evolution, when modern humans evolved, agree that hunter-gatherer adaptations are tied to the way that climate and environment shape the food and technological resource base.[7-10] The result is a long tradition of paleoanthropologists engaging with climate and environmental scientists in an effort to understand if and how hominin bio-behavioral evolution responded to climate and environmental change. Despite this unusual consonance, the anticipated rewards of this synergy are unrealized and, in our opinion, will not reach potential until there are some fundamental changes in the way the research model is constructed. Discovering the relation between climate and environmental change to human origins must be grounded in a theoretical framework and a causal understanding of the connection between climate, environment, resource patterning, behavior, and morphology, then move beyond the strict correlative research that continues to dominate the field.

The correlation between brain connectivity and psychiatric or neurological diseases has intensified efforts to develop brain connectivity mapping techniques on mouse models of human disease. The neural architecture of mouse brain specimens can be shown non-destructively and three-dimensionally by diffusion tensor imaging, which enables tractography, the establishment of a connectivity matrix and connectomics. However, experiments on cohorts of animals can be prohibitively long. To improve throughput in a 7-T preclinical scanner, we present a novel two-coil system in which each coil is shielded, placed off-isocenter along the axis of the magnet and connected to a receiver circuit of the scanner. Preservation of the quality factor of each coil is essential to signal-to-noise ratio (SNR) performance and throughput, because mouse brain specimen imaging at 7 T takes place in the coil-dominated noise regime. In that regime, we show a shielding configuration causing no SNR degradation in the two-coil system. To acquire data from several coils simultaneously, the coils are placed in the magnet bore, around the isocenter, in which gradient field distortions can bias diffusion tensor imaging metrics, affect tractography and contaminate measurements of the connectivity matrix. We quantified the experimental alterations in fractional anisotropy and eigenvector direction occurring in each coil. We showed that, when the coils were placed 12 mm away from the isocenter, measurements of the brain connectivity matrix appeared to be minimally altered by gradient field distortions. Simultaneous measurements on two mouse brain specimens demonstrated a full doubling of the diffusion tensor imaging throughput in practice. Each coil produced images devoid of shading or artifact. To further improve the throughput of mouse brain connectomics, we suggested a future expansion of the system to four coils. To better understand acceptable trade-offs between imaging throughput and connectivity matrix integrity, studies may seek to clarify how measurement variability, post-processing techniques and biological variability impact mouse brain connectomics.

Aim To study the siting of marine protected areas (MPAs) with respect to the biogeographical distribution of seaweeds within the Agulhas Marine Province and to assess the effectiveness of current MPAs in including (conserving) seaweeds of the South African south coast. Location South Africa – the south coast between Cape Agulhas and the Eastern Cape/Kwazulu-Natal border, and eight MPAs within that area. Methods We used interpolated seaweed distribution records from all available sources, in 50-km coastal sections. Cluster analysis (Jaccard Average Linkage) of species presence/absence data provided measures of similarity between coastal sections and between MPAs. Complementarity analyses identified the sequence of ‘importance’ of sections/MPAs for conserving seaweed species. Results Species presence/absence data indicated two main groups, representing western (cooler water) and eastern (warmer water) biogeographical divisions, as well as several biogeographical subdivisions within each of these groups. Complementarity analysis yielded a sequence of ‘importance’ of coastal sections (in terms of the highest number of species included) that began with a section just east of central in the Agulhas Marine Province, around Port Alfred, where there is no MPA. This was followed by the easternmost section (warmest water), which contains the Pondoland MPA, and then by the westernmost (coolest water) section, containing the De Hoop MPA. Similar analysis of the actual species collected in MPAs showed a generally similar pattern. Main conclusions Seven current MPAs and one proposed coastal MPA in the Agulhas Marine Province appear to be well distributed and well sited to include (conserve) the full biogeographical range of seaweeds. However, if further MPAs are to be considered, the Port Alfred area is recommended for improved conservation. This study did not examine estuaries, which may require improved conservation efforts. Seaweed distribution data, which are often relatively complete, offer a good tool for planning the siting of coastal MPAs.

Personality and demographic attributes for a set of 1221 focal managers were examined as correlates of leadership effectiveness evaluations that were obtained via a 360° feedback program. Polynomial regression was used to study the congruence of self-ratings provided by focal managers relative to the different evaluative perspectives (i.e., immediate superior, peer, and subordinate). Analyses supported the prediction that focal manager's sex and age would be associated with the ratings provided by themselves and others. Plus, the tendency to overestimate one's own leader effectiveness relative to evaluations provided by others was found to be greater for males and older managers. Focal managers who expressed greater social sensitivity were evaluated more favorably by subordinates and peers, although not by superiors. Ratings of leader effectiveness from immediate superiors were, instead, more readily predicted by judgments of the performance of the focal manager's organizational unit relative to comparable units. Results of polynomial regression analysis, however, indicated that self–other agreement was related to the focal's sex, social sensitivity, and social dominance. Implications for understanding obstacles to openness to change are discussed.

SUMMARY Sponge–seaweed associations in the seaweed genus Ptilophora are poorly understood; therefore, 94 specimens, representing all 17 species of Ptilophora, were examined to detail this phenomenon. All but 2 Ptilophora species were shown to produce surface proliferations, with 13 species found to have sponge associations. Evidence for facultative sponge epiphytism was found with species–specific interactions being unlikely. Results show that surface proliferations are not induced by sponge epiphytes, as they often occur in the absence of sponge epiphytes, and vice versa. The significant number of proliferate thalli found with sponge epiphytes suggests that there is a likely relationship between the presence of surface proliferations and sponge infestation. Sponge epiphytes and Ptilophora species appeared structurally related in that the sponge probably exploits a niche habitat provided by the alga, for which surface proliferations might aid the sponge in bonding to the alga.

OBJECTIVES: Little is known about the impact of mandatory (involuntary) disenrollment of patients from Medicare managed care organization (MCO) plans. We hypothesized that involuntary disenrollment raises significant concerns for patients, that younger enrollees (aged less than 65, Medicare disabled) have different concerns than older patients, and that younger patients respond to termination of their plan within the MCO differently from older patients. We also examined other factors associated independently with enrollee decisions to stay in the MCO or return to Medicare fee-for-service. DESIGN: A cross-sectional telephone questionnaire. SETTING: A Medicare managed care plan at two outpatient clinics at an academic medical center in Denver, Colorado. PARTICIPANTS: Four hundred fifty enrollees recently notified of termination of their clinic's contract with a Medicare managed care plan were surveyed. MEASUREMENTS: Survey questions on demographics, patient concerns about disenrollment, and factors associated with staying at the academic medical center or switching to another clinic or plan associated with the MCO. RESULTS: Of 371 respondents, 57% switched to another plan within the MCO, including 65% of the Medicare disabled enrollees and 57% of the Medicare nondisabled enrollees. More than 60% of both Medicare disabled and older patients who switched felt that it was a significant problem for them. By multivariate analysis, age was not associated with switching, but a distant relationship with one's physician was associated with switching (odds ratio (OR) = 10.2; confidence interval (CI), 1.13-91.09) and having received care at the academic medical center for 1 year or longer (OR = 0.35, 95% CI, 0.17-0.69), postcollege education (OR = 0.34; CI, 0.16-0.69), and black race (OR = 0.29; CI, 0.13-0.68) were independently associated with not switching. Older and younger patients cited similar concerns raised by switching, but financial issues were identified as a major concern by more younger patients than older patients (P = .001). CONCLUSIONS: Involuntary disenrollment raised significant concerns for patients in a Medicare managed care plan.

The results of incidence ratings to assess the host response of maize (Zea mays L.) to natural infection, or to controlled inoculation in either the field or the greenhouse, with maize chlorotic dwarf virus (MCDV) appear inconsistent for identification of resistant or tolerant responses. Our objective was to determine whether assessment of the severity of three symptoms on the leaves (veinbanding, chlorosis, and twisting of the leaf and tearing of the leaf margin) would consistently allow differentiation of the host response of maize inbreds and hybrids to inoculation with two isolates of MCDV. Symptom severity was assessed using a 1 to 5 visual rating for each of the three symptoms at three to four time intervals after controlled inoculation with a severe isolate of MCDV in both greenhouse and field experiments [...]

Rabbit nephron segments of proximal convoluted tubules (PCT); proximal straight tubules (PST); cortical and medullary thick ascending limbs of Henle's loop (CAL, MAL); and cortical, outer medullary, and inner medullary collecting tubules (CCT, OMCT, IMCT) were individually microdissected and grown in monolayer culture in hormone supplemented, defined media. Factors favoring a rapid onset of proliferation included young donor age, distal tubule origin, and the addition of 3% fetal calf serum to the medium. All primary cultures had polarized morphology with apical microvilli facing the medium and basement membrane-like material adjacent to the dish. Differentiated properties characteristic of the tubular epithelium of origin retained in cultures included ultrastructural characteristics and cytochemically demonstrable marker enzyme proportions. PCT and PST were rich in alkaline phosphatase; CAL stained strongly for NaK-ATPase; CCT contained two cell populations with regard to cytochrome oxidase reaction. A CCT-specific anti-keratin antibody (aLEA) was immunolocalized in CCT cultures, and a PST cytokeratin antibody stained PST cultures. The biochemical response of adenylate cyclase to putative stimulating agents was the same in primary cultures as in freshly isolated tubules. In PCT and PST adenylate cyclase activity was stimulated by parathyroid hormone (PTH) but not by arginine vasopressin (AVP); CAL and MAL adenylate cyclase was stimulated by neither PTH nor AVP; CCT, OMCT, and IMCT adenylate cyclase was stimulated by AVP but not by PTH. NaF stimulated adenylate cyclase activity in every cultured segment. It is concluded that primary cultures of individually microdissected rabbit PCT, PST, CAL, MAL, CCT, OMCT, and IMCT retain differentiated characteristics with regard to ultrastructure, marker enzymes, cytoskeletal proteins, and hormone response of adenylate cyclase and provide a new system for studying normal and abnormal functions of the heterogeneous tubular epithelia in the kidney.

The relative palatability of 13 algae common in the kelp beds of the west coast of the Cape Peninsula, South Africa, is experimentally investigated with respect to feeding by the sea urchin Parechinus angulosus. We investigated 2 hypotheses: 1) that this important herbivore would feed selectively on these algae and 2) that Desmarestia firma, one of these algae, would be unattractive to Parechinus on account of the H2S04 in the thallus. Algal preferences are determined from 3 types of feeding experiment, results of which support our first hypothesis, and allow us to group the algae into 3 arbitrary categories: “preferred”, “intermediate”, and “non-preferred”. To explain these patterns, we measured “relative astringen-cy” of each species (essentially a phenol measurement), and phenol content of 4 species (FOUN-DENIS method). Rates of feeding on single species are negatively correlated with relative astringen-cies (r = 0.76, P = 0.99). The high relative astringency of D. firma is caused by its high (18 % per dry mass) H2S04 content, and it is non-preferred. Our results therefore support our second hypothesis. Other implications of these results are discussed.

An inverse relationship between the cerebrospinal fluid (CSF) opening pressure and the corresponding protein value was found for patients with idiopathic pseudotumor cerebri who underwent their first lumbar puncture (LP) prior to the initiation of therapy. This relationship provides evidence for a pressure-dependent bulk flow absorption for CSF and also suggests that patients with high CSF pressures will have low CSF protein concentration.

In my recent paper [1], the corollary on p. 241 is not correct. It should be Corollary. There is a sequence S, tending to infinity, such that for each t in S we have where γ is any zero of