Validated age and growth estimates for the shortfin mako, Isurus oxyrinchus, in the North Atlantic Ocean

Age and growth estimates for the shortfin mako, Isurus oxyrinchus, derived from vertebral centra of 258 specimens (118 males, 140 females), ranging in size from 64 to 340 cm fork length (FL) were compared with data from 22 tag–recaptured individuals (74–193 cm FL) and length–frequency data from 1822 individuals (1035 males, 787 females; 65–215 cm FL). Annual band-pair deposition, confirmed by a concurrent bomb radiocarbon validation study, was used as the basis for band interpretation. Validation was further confirmed with a tetracycline-injected male shortfin mako recaptured after being at liberty off South Africa for 1 year and aged at 18 years. Growth rates from tag–recapture analysis (GROTAG) were higher than those derived from vertebral annuli and were only available from sharks up to 193 cm FL at recapture. Modal length–frequency data were used to verify the first four age classes. Growth curves were fit using both von Bertalanffy and Gompertz models. The 3-parameter version of the von Bertalanffy growth function produced the most biologically reasonable values for males, based on observed data (L _∞  = 253 cm FL, K = 0.125 year^?1 (estimated longevity = 21 year), and L ₀ = 72 cm). The 3-parameter version of the Gompertz growth function produced the most biologically reasonable estimates, for females (L _∞  = 366 cm FL, K = 0.087 year^?1 (estimated longevity = 38 year) and L ₀ = 88 cm. Males and females were aged to 29 (260 cm FL) and 32 years (335 cm FL), respectively. Both sexes grew similarly to age 11 (207 cm FL, 212 cm FL for males and females, respectively) when the curve leveled in males and continued to rise in females. Age at 50% maturity was estimated at 8 years for males (185 cm FL) and 18 years for females (275 cm FL). The species grows slower, matures later and has a longer life span than previously reported in North Atlantic waters.     

Out with the old,in with the new? Comparing methods for measuring protein degradation

Protein degradation is a critical factor in controlling cellular protein abundance. Here, we compare classical methods for determining protein degradation rates to a novel GFP (green fluorescent protein) fusion protein based method that assesses the intrinsic stability of cloned cDNA library products by flow cytometry [Yen et al. (2008) Science 322, 918]. While no method is perfect, we conclude that chimeric gene reporter approaches, though powerful, should be applied cautiously, due principally to GFP (or other reporter tag) interference with protein organelle targeting or incorporation into macromolecular assemblies, both of which cause spuriously high degradation rates.     

Alternate Positions for the Sulphydryl Group in β-Lactoglobulin: the Significance for Sulphydryl Location in Other Proteins

EARLIER studies of the location of the single cysteine residue and the two disulphide bridges in bovine β-lactoglobulins A and B¹, for each of which the monomer is a single chain of 162 residues and 18,000 molecular weight^2,3, led to the conclusion that the sulphydryl group is at position 69 and that the disulphides bridge positions 123 to 160 and 57 to 70. These results were based on diagonal peptide studies⁴ and on the composition of peptides in which the sulphydryl group had been labelled with ¹⁴C-iodoacetamide, the disulphide bridges being left intact. Use was made of the partial amino-acid sequence given by Frank and Braunitzer⁵ and the reasonable assumption was made that the sulphydryl occurred in only one position. Subsequently, Shaw⁶ has shown that the sequence of Frank and Braunitzer⁵ showing Cys residues adjacent at positions 69 and 70 is incorrect and that they are separated by a glutamine, the sequence for positions 67 to 71 for the Bvariant being Ala.Cys.Gln.Cys.Leu. Autoradiography of the dansyl amino-acid derivatives formed during the sequence determination of this pentapeptide indicated that both residues 68 and 70 seemed to have been labelled and so we have given further consideration to the sulphydryl location. It has been found that although it does occur at 68, with 57 and 70 disulphide bridged, there is also an equal amount of protein present with the sulphydryl at 70, with 57 and 68 disulphide bridged. We discuss this additional finding here and the significance for the determination of the location of sulphydryl groups in other proteins.     

Irrigators’ attitudes towards environmental flows for wetlands in the Murrumbidgee, Australia

In Australia and many countries worldwide environmental flows are becoming an increasingly popular tool for reducing the negative impacts of river regulation. However, there are many factors that restrict the effectiveness of these flows such as thermal pollution, existing physical infrastructure and the limited volume of water available. Since environmental flows result in reduced water allocations for irrigators, the aim of the present study was to investigate whether irrigators’ attitudes towards environmental flows for wetlands are influenced by the effectiveness of these flows. Three focus groups were used to engage with farmers in the Murrumbidgee Catchment, eastern Australia. A simulation model of the Murrumbidgee River was created to provide focus groups with a tool for examining the effectiveness of wetland-watering releases and exploring alternative management scenarios. The results showed that participants support the principle of environmental flows for wetlands. However, they believed that the flows could be more effective if the restrictions imposed by physical infrastructure were removed. They also suggested that the volume of translucency releases should be lowered, as these flows reduce the amount of water available for wetlands and lower early season allocations for general-security water users. The participants provided numerous suggestions for altering the management of water resources so that both the Mid Murrumbidgee Wetlands and farmers would benefit.

Barrels, stripes, and fingerprints in the brain—Implications for theories of cortical organization

In the last decade improvements in the histological processing of cortical tissue in conjunction with the investigation of additional mammalian species in comparative brain studies has expanded the information available to guide theories of cortical organization. Here I review some of these recent findings in the somatosensory system with an emphasis on modules related to specializations of the peripheral sensory surface. The diversity of modular representations, or cortical “isomorphs” suggest that information from the sensory sheet guides many of the features of cortical maps and suggest that cortex is not constrained to form circular units in the form of a traditional cortical column.     

Is the PRC for Dark Pulses in LL a Mirror Image of the PRC for Light Pulses in DD in Mice?

The phase-response curves (PRC) for light pulses in continuous darkness (DD) have been described in many mammals, especially in nocturnal rodents. The PRC for dark pulses in continuous light (LL), however, has been described in a few mammals only, in nocturnal for bat and for hamster and in diurnal for Octodon degus, suggesting that this PRC is mirror imaging the PRC for light pulses. Therefore, the effect of 1-h and 3-h lasting dark pulses on the circadian wheel-running activity rhythm of mice in continuous light was investigated and then the PRC for dark pulses in LL was drawn up. For comparison, the effect of 1-h lasting light pulses on the circadian wheel-running activity rhythm of mice in DD was examined and the PRC for light pulses in DD was constructed. It appeared that the PRC for dark pulses, to a certain degree, represents a mirror image of the PRC for light pulses in mice. However, the advance region of this PRC is longer than that of delay. The mechanism of dark pulses action is discussed.     

Is the PRC for Dark Pulses in LL a Mirror Image of the PRC for Light Pulses in DD in Mice?

The phase-response curves (PRC) for light pulses in continuous darkness (DD) have been described in many mammals, especially in nocturnal rodents. The PRC for dark pulses in continuous light (LL), however, has been described in a few mammals only, in nocturnal for bat and for hamster and in diurnal for Octodon degus, suggesting that this PRC is mirror imaging the PRC for light pulses. Therefore, the effect of 1-h and 3-h lasting dark pulses on the circadian wheel-running activity rhythm of mice in continuous light was investigated and then the PRC for dark pulses in LL was drawn up. For comparison, the effect of 1-h lasting light pulses on the circadian wheel-running activity rhythm of mice in DD was examined and the PRC for light pulses in DD was constructed. It appeared that the PRC for dark pulses, to a certain degree, represents a mirror image of the PRC for light pulses in mice. However, the advance region of this PRC is longer than that of delay. The mechanism of dark pulses action is discussed.     

Mushrooms for Life among the Jotï in the Venezuelan Guayana

Mushrooms for Life among the Jotï in the Venezuelan Guayana. This paper explores the relevance of mushrooms in mythology and daily life among the Jotï, an indigenous group inhabiting the rain forests of the Venezuelan Guayana. It is reported here how a personal experience of the author in the field stimulated deeper research into the religious symbolism surrounding mushrooms and their role in Jotï cosmology, ritual, and life dynamics. Different categories of mushroom usage are described, including edible, medicinal, and ritual uses. Mushrooms seem to be more important to the Jotï than to most Amazonian groups. Most significantly, certain species of mushrooms are key ingredients in medicinal and ritual preparations used throughout the Jotï life cycle in ways that reflect their worldview and mythology.     

Proposal for the Establishment of the Core Zones in the Biosphere Reserve of Tehuacán-Cuicatlán, Mexico

This work proposes the establishment of core zones in the Biosphere Reserve of Tehuacán-Cuicatlán (BRTC), based on plant species richness and endemism. A total of 561 species of the four most important plant families in the region (Asteraceae, Cactaceae, Leguminosae and Poaceae) as well as 174 endemic species of these and other families were used in the analyses. Distribution of these taxa was analyzed using two different iterative complementarity methods. Significant correlations were found between patterns of species richness and endemic plants distribution in the study area. These results were combined with other analysis where two different indices (species richness index and human population index) were used. The results suggest the delimitation of four core zones within the Biosphere Reserve, covering a total area of 105,300 ha. The core zones represent 21.8% of the area, and would protect 72.54% of the species from the selected plant families and 67.8% of endemic species.     

Comparison of the Kato-Katz and Helmintex methods for the diagnosis of schistosomiasis in a low-intensity transmission focus in Bandeirantes, Paraná, southern Brazil

The diagnosis of schistosomiasis is problematic in low-intensity transmission areas because parasitological methods lack sensitivity and molecular methods are neither widely available nor extensively validated. Helmintex is a method for isolating eggs from large faecal samples. We report preliminary results of a comparative evaluation of the Helmintex and Kato-Katz (KK) methods for the diagnosis of schistosomiasis in a low-intensity transmission area in Bandeirantes, Paraná, southern Brazil. Eggs were detected by both methods in seven patients, whereas only Helmintex yielded positive results in four individuals. The results confirm the previously demonstrated higher sensitivity of the Helmintex method compared with the KK method.     

New Empirical Equation for the Atomic Form Factor Function in the Momentum Transfer Range,q?=?0–50 ??1 for the Elements in the Range 1≤ Z ≤30

The importance of Atomic Form Factors (f) is well-known to the scientific community. Tabulated values for f are mostly used in calculating cross-sections and Monte Carlo sampling for the coherent scattering of photons. The uses of these values are subjected to different approximations and interpolation techniques because the available data points for f in the literature for specified momentum-transfer-grids are very limited. In order to make it easier to accurately use the tabulated data, a mathematical expression for f functions would be a great achievement. Therefore, the current study was designed to suggest an empirical expression for the f functions. In the results, an empirical equation for Hubbell''s tabulated data for f is created in the momentum transfer range, q = 0–50 Å⁻¹ for the elements in the range 1≤ Z ≤30. The number of applied parameters was seven. The fitting to f showed that the maximum deviation was within 3%, 4% and 5% for the element having, Z = 1–11, Z = 12–22 and Z = 23–30, respectively, while the average deviations were within 0.3–2.25% for all elements (i.e., Z = 1–30). The values generated by the analytical equation were used in the Monte Carlo code instead of Hubbell’s tabulated values. The statistical noise in the Probability Distribution Functions of coherently scattered photons was efficiently removed. Furthermore, it also reduced the dependence on different interpolation techniques and approximations, and on the use of large tabulated data for f with the specified elements.     

ROS signaling in the hypersensitive response: When,where and what for?

Plants generally react to the attack of non-host and incompatible host microorganisms by inducing pathogenesis-related (PR) genes and localised cell death (LCD) at the site of infection, a process collectively known as the hypersensitive response (HR). Reactive oxygen species (ROS) are generated in various sub-cellular compartments shortly after pathogen recognition, and proposed to cue subsequent orchestration of the HR. Although apoplast-associated ROS production by plasma membrane NADPH oxidases have been most thoroughly studied, recent observations suggest that ROS are generated in chloroplasts earlier in the response and play a key role in execution of LCD. A model is presented in which the initial outcome of successful pathogen detection is ROS accumulation in plastids, likely mediated by mitogen-activated protein kinases and caused by dysfunction of the photosynthetic electron transport chain. ROS signaling is proposed to spread from plastids to the apoplast, through the activation of NADPH oxidases, and from there to adjacent cells, leading to suicidal death in the region of attempted infection.Key words: biotic stress, chloroplasts, flavodoxin, hypersensitive response (HR), reactive oxygen species (ROS), ROS signaling     

The requirement for the protonated α-amino group for the transport of peptides in Escherichia coli

Many glycine peptides support growth of a glycine auxotroph of Escherichia coli. If the alpha-amino group of these peptides is methylated, the products are still utilized for growth, and also retain comparable ability with the unsubstituted peptides to compete with natural peptides for transport into the cell. In contrast, glycine peptides devoid of an alpha-amino group, or that have the alpha-amino group substituted by one of a number of acyl groups are not utilized, although E. coli possesses intracellular enzymic activity able to release glycine from such compounds; further, these derivatives do not compete with natural peptides for transport into the cell.     

Cytoplasmatic domain of Na,K-ATPase α-subunit is responsible for the aggregation of the enzyme in proteoliposomes

We studied the thermal dependence of amide I′ infrared absorption and fluorescence emission of Trp residues in the Na,K-ATPase of rabbit kidney. We studied the whole enzyme solubilized with detergent, the whole enzyme reconstituted in proteoliposomes and the protein fraction that remained in the lipid membrane after the trypsin digestion of the proteoliposomes. Cooperative unfolding and aggregation with increasing temperature were observed in the whole protein, whether solubilized or reconstituted, but not in the fraction remaining after trypsinization. The protein influenced the physical state of the lipid, decreasing the temperature of the gel to liquid-crystalline phase transition and the degree of cooperativity. This study provides new information for the understanding of the processes controlling the association mechanisms that are important for enzyme function in natural membranes.