The mentality of crows: convergent evolution of intelligence in corvids and apes

Discussions of the evolution of intelligence have focused on monkeys and apes because of their close evolutionary relationship to humans. Other large-brained social animals, such as corvids, also understand their physical and social worlds. Here we review recent studies of tool manufacture, mental time travel, and social cognition in corvids, and suggest that complex cognition depends on a "tool kit" consisting of causal reasoning, flexibility, imagination, and prospection. Because corvids and apes share these cognitive tools, we argue that complex cognitive abilities evolved multiple times in distantly related species with vastly different brain structures in order to solve similar socioecological problems.     

Assay of aroma active components of virgin olive oils from southern Italian regions by SPME-GC/ion trap mass spectrometry

An SPME-GC/ion trap method was exploited to determine the chromatogram of volatile compounds of organic olive oils of southern Italian regions. The method is based on the assay of the terminal species of the "lipoxygenase pathway", which are present in the volatile fraction of the sampled compounds. Ethyl isobutanoate was used as internal standard in either the EI or CI ionization mode. The absolute concentration values of each analyte were evaluated through good-to-excellent calibration curves. Case studies on oils obtained from different cultivars or harvesting times are presented. The quantitative data for each compound were subjected to principal component analysis to characterize the different cultivars of this work.     

Analyses of genes encoding Theileria parva p104 and polymorphic immunodominant molecule (PIM) reveal evidence of the presence of cattle-type alleles in the South African T. parva population

Restriction fragment length polymorphism analysis of PCR products (PCR-RFLP) and sequencing of the variable region of the p104 and PIM genes was performed on samples obtained from South African T. parva parasites originating from cattle on farms with suspected theileriosis and from buffalo. p104 and PIM PCR-RFLP profiles similar to those of the T. parva Muguga stock, an isolate that causes ECF in Kenya, were obtained from three of seven cattle samples collected on a farm near Ladysmith in KwaZulu-Natal Province. Amino acid sequences of the p104 and PIM genes from two of these samples were almost identical to the T. parva Muguga p104 and PIM sequences. This result supports findings from a recent p67 study in which p67 alleles similar to those of the T. parva Muguga stock were identified from the same samples. While these results suggest the presence of a cattle-derived T. parva parasite, reports of cattle-to-cattle transmission could not be substantiated and ECF was not diagnosed on this farm. Although extensive diversity of p104 and PIM gene sequences from South African T. parva isolates was demonstrated, no sequences identical to known cattle-type p104 and PIM alleles were identified from any of the buffalo T. parva samples analyzed. 'Mixed' PIM alleles containing both cattle- and buffalo-type amino acid motifs were identified for the first time, and there appeared to be selection of cattle-type and 'mixed'-type PIM sequences in the cattle samples examined.     

Confronting collinearity: comparing methods for disentangling the effects of habitat loss and fragmentation

Estimating the relative importance of habitat loss and fragmentation is necessary to estimate the potential benefits of specific management actions and to ensure that limited conservation resources are used efficiently. However, estimating relative effects is complicated because the two processes are highly correlated. Previous studies have used a wide variety of statistical methods to separate their effects and we speculated that the published results may have been influenced by the methods used. We used simulations to determine whether, under identical conditions, the following 7 methods generate different estimates of relative importance for realistically correlated landscape predictors: residual regression, model or variable selection, averaged coefficients from all supported models, summed Akaike weights, classical variance partitioning, hierarchical variance partitioning, and a multiple regression model with no adjustments for collinearity. We found that different methods generated different rankings of the predictors and that some metrics were strongly biased. Residual regression and variance partitioning were highly biased by correlations among predictors and the bias depended on the direction of a predictor’s effect (positive vs. negative). Our results suggest that many efforts to deal with the correlation between amount and fragmentation may have done more harm than good. If confounding effects are controlled and adequate thought is given to the ecological mechanisms behind modeled predictors, then standardized partial regression coefficients are unbiased estimates of the relative importance of amount and fragmentation, even when predictors are highly correlated.     

Control of black thread (Phytophthora palmivora) in hevea brasiliensis with Difolatan

Further investigations have shown that Difolatan applications initially slow down bark renewal; however, the thickness of the living bark becomes about normal after 2 years. The previous finding that Difolatan has no direct effect on latex yield was confirmed. Evidence was obtained that the renewing bark is of normal yield capacity.A suitable colouring agent to check the application of Difolatan is yellow iron oxide; Sterox NJ — a synthetic detergent — should be added to obtain stable suspensions.Promising yield increase was obtained when 0.25–1% 2,4-D was added to the Difolatan suspension in water. The percentage yield increase depends not only on the 2,4-D concentration but also on the use of admixtures, which give more bulk to the 2,4-D coating on the bark. The mixtures which gave the highest yield increase caused the greatest proliferation of the renewing bark and were less effective in controlling the disease. When relatively low concentrations of 2,4-D (up to 0.25%) are mixed with the Difolatan suspension, important yield increases can be obtained without much bark proliferation or loss of fungitoxicity; such applications open up possibilities for mild stimulation of younger tress.Samenvatting Gebleken is dat het fungicide Difolatan, toegepast bij de bestrijding vanPhytophthora palmivora — veroorzaker van een tapvlakziekte, bekend als black thread (Ned. naam: streepjeskanker) — aanvankelijk een remmende invloed heeft op het herstel van deHevea-bast. Echter, na enkele jaren bereikt de levende bast toch een normale dikte. Waarschijnlijk vermindert Difolatan in het begin de activiteit van het kurkcambium, waardoor minder harde bast en kurk worden gevormd. In verscheidene veldproeven werd aangetoond dat Difolatan geen effect heeft op de latexproduktie; de produktiecapaciteit van de herstellende bast zelf is waarschijnlijk ook normaal. Difolatantoepassingen op de bast worden beter zichtbaar door 1% geel ijzeroxide toe te voegen aan de waterige suspensie, welke 1% Difolatan (1.25% van het 80% spuitpoeder) en 0.1% Ortho spray sticker bevat; in dit geval dient nog 0.01% Sterox NJ (een uitvloeier) te worden toegevoegd om een stabiele suspensie te verkrijgen.Hogere rubberopbrengsten werden verkregen door 0.25–1% 2,4-D aan de suspensie toe te voegen. De produktie kan nog verder worden opgevoerd met behulp van hechters, die een dikkere laag residu op de bast achterlaten. De grootste produkties gingen gepaard met sterke woekering van de herstellende bast en een minder bevredigende ziektebestrijding. Evenwel, in betrekkelijk lage 2,4-D concentraties (niet hoger dan 0.25%) werden toch nog belangrijke meeropbrengsten verkregen zonder noemenswaardige bastwoekering of een sterke teruggang in fungitoxische eigenschappen van het mengsel. Deze formuleringen bieden mogelijkheden voor een milde stimulatie van jongere bomen, terwijl tegelijkertijd de streepjeskanker wordt bestreden.     

Effects of CD28 blockade on subsets of naïve T cells in cats

OBJECTIVE: To determine whether human CTLA4-Ig ([hu]CTLA4-Ig) inhibits costimulation-dependent lymphocyte proliferation in vitro, compare the effects of (hu)CTLA4-Ig with cyclosporine and steroids on CD4+ and CD8+ T-cell lymphocyte proliferation, and determine whether memory T-cell function remains intact in the presence of (hu)CTLA4-Ig. ANIMALS: 29 cats. PROCEDURE: Peripheral blood mononuclear cells (PBMCs) were stimulated with concanavalin A (costimulation-dependent mitogen) or phorbol 12-myristate 13-acetate and ionomycin (costimulation independent mitogens) alone or in the presence of (hu)CTLA4-Ig, cyclosporine, or dexamethasone; effects of these treatments on lymphocyte proliferation were assessed by incorporation of thymidine labeled with tritium or flow cytometry. Antigen-specific proliferation was determined by stimulating PBMCs from 2 healthy cats seropositive for Toxoplasma gondii with soluble Toxoplasma antigen alone or in the presence of (hu)CTLA4-Ig or cyclosporine. RESULTS: (hu)CTLA4-Ig inhibited costimulation-dependent lymphocyte proliferation in vitro but had no effect on costimulation-independent lymphocyte proliferation. Compared with mitogen alone, (hu)CTLA4-Ig caused a significant decrease in responder frequency and proliferative capacity of CD4+ T cells; however, the effect on CD8+ T cells was not significant. Cyclosporine alone or with dexamethasone had a significantly greater suppressive effect on responder frequency and proliferative capacity of CD4+ and CD8+ T cells, compared with (hu)CTLA4-Ig. Compared with cyclosporine, (hu)CTLA4-Ig appeared to have a sparing effect on antigen-specific proliferation of memory CD4+ and CD8+ T cells. CONCLUSIONS AND CLINICAL RELEVANCE: (hu)CTLA4-Ig selectively inhibited costimulation-dependent proliferation of lymphocytes in vitro and had a sparing effect on antigen-specific proliferation of memory cells. The specificity of its mechanism of action suggests that (hu)CTLA4-Ig may prevent allograft rejection but leave memory responses to previously encountered antigens intact.     

Survey of the large-animal diplomates of the American College of Veterinary Internal Medicine regarding knowledge and clinical use of polymerase chain reaction: implications for veterinary education

A questionnaire was developed to document the knowledge base of large-animal diplomates of the American College of Veterinary Internal Medicine (ACVIM) regarding polymerase chain reaction (PCR) technology and to identify the common use of this technology in equine practice. Ninety-three of the 278 mailed questionnaires were returned, for an overall response rate of 33.4%. Ninety respondents (99%) reported being familiar with the general principles of nucleic acid probe technology; however, only 52 (57%) knew the difference between conventional (traditional) and real-time (second-generation) PCR. The majority of the respondents (88%) emphasized the need for continuing education on molecular diagnostics. Eighty-four (92%) of the respondents regularly use PCR (conventional and/or real-time) for the detection of equine pathogens, and 80 (88%) commonly submit their samples to university/state veterinary laboratories. Blood, nasal swabs, and feces are the three equine specimens most commonly submitted for PCR analysis of Streptococcus equi, Lawsonia intracellularis, Neorickettsia risticii, equine herpesvirus 1/4, Rhodococcus equi, Sarcocystis neurona, and equine influenza virus. Diplomates reported costs associated with molecular diagnostics and unreliability of PCR as the most common limitations of PCR. Didactic training in veterinary curricula and during continuing-education opportunities continues to be necessary to produce veterinarians who have an understanding of the clinical applications of molecular diagnostics.     

Impacts of biodiversity loss on ocean ecosystem services

Human-dominated marine ecosystems are experiencing accelerating loss of populations and species, with largely unknown consequences. We analyzed local experiments, long-term regional time series, and global fisheries data to test how biodiversity loss affects marine ecosystem services across temporal and spatial scales. Overall, rates of resource collapse increased and recovery potential, stability, and water quality decreased exponentially with declining diversity. Restoration of biodiversity, in contrast, increased productivity fourfold and decreased variability by 21%, on average. We conclude that marine biodiversity loss is increasingly impairing the ocean's capacity to provide food, maintain water quality, and recover from perturbations. Yet available data suggest that at this point, these trends are still reversible.