Reproductive Phenology of the Brown Alga Analipus japonicus in Peter the Great Bay (Sea of Japan)

The alga Analipus japonicus (Harv.) Wynne displays a distinct seasonal pattern in its development in Peter the Great Bay (Sea of Japan). In winter and spring, it occurs only in the form of basal crusts, and vertical axes develop in the summer–autumn period. It reproduces mostly asexually from July to November. Algae with unilocular sporangia occur very seldom, only in June and July.     

Structural Insights into the Mechanism of Base Excision by MBD4

DNA glycosylases remove damaged or modified nucleobases by cleaving the N-glycosyl bond and the correct nucleotide is restored through subsequent base excision repair. In addition to excising threatening lesions, DNA glycosylases contribute to epigenetic regulation by mediating DNA demethylation and perform other important functions. However, the catalytic mechanism remains poorly defined for many glycosylases, including MBD4 (methyl-CpG binding domain IV), a member of the helix-hairpin-helix (HhH) superfamily. MBD4 excises thymine from G·T mispairs, suppressing mutations caused by deamination of 5-methylcytosine, and it removes uracil and modified uracils (e.g., 5-hydroxymethyluracil) mispaired with guanine. To investigate the mechanism of MBD4 we solved high-resolution structures of enzyme-DNA complexes at three stages of catalysis. Using a non-cleavable substrate analog, 2′-deoxy-pseudouridine, we determined the first structure of an enzyme-substrate complex for wild-type MBD4, which confirms interactions that mediate lesion recognition and suggests that a catalytic Asp, highly conserved in HhH enzymes, binds the putative nucleophilic water molecule and stabilizes the transition state. Observation that mutating the Asp (to Gly) reduces activity by 2700-fold indicates an important role in catalysis, but probably not one as the nucleophile in a double-displacement reaction, as previously suggested. Consistent with direct-displacement hydrolysis, a structure of the enzyme-product complex indicates a reaction leading to inversion of configuration. A structure with DNA containing 1-azadeoxyribose models a potential oxacarbenium-ion intermediate and suggests the Asp could facilitate migration of the electrophile towards the nucleophilic water. Finally, the structures provide detailed snapshots of the HhH motif, informing how these ubiquitous metal-binding elements mediate DNA binding.     

Group versus population level demographics: An analysis of comparability using long term data on wild white‐faced capuchin monkeys (Cebus capucinus imitator)

Primates have long been used as indicator species for assessing overall ecosystem health. However, area‐wide census methods are time consuming, costly, and not always feasible under many field conditions. Therefore, it is important to establish whether monitoring a subset of a population accurately reflects demographic changes occurring in the population at large. Over the past 35 years, we have conducted 15 area‐wide censuses in Sector Santa Rosa, Costa Rica. These efforts have revealed important trends in population growth patterns of capuchin monkeys following the protection and subsequent regeneration of native forests. During this same period, we have also intensively studied a subset of the capuchin groups. Comparing these two datasets, we investigate whether the population structures of the closely monitored groups are reliable indicators of area‐wide demographic patterns. We compare the overall group size and the individual age/sex class compositions of study groups and nonstudy groups (i.e., those contacted during area‐wide censuses only). Our study groups contained more individuals overall with a larger proportion of infants, and there were indications that the proportion of adult and subadult males was lower. These differences can be ascribed either to sampling errors or real differences attributable to human presence and/or better habitat quality for the study groups. No other sex/age classes differed, and major demographic changes were simultaneously evident in both study and nonstudy groups. This study suggests that the Santa Rosa capuchin population is similarly impacted by large‐scale ecological patterns observable within our study groups.     

Role of electrostatics in the binding of charged metallophthalocyanines to neutral and charged phospholipid membranes

Binding of the cationic tetra(tributylammoniomethyl)-substituted hydroxoaluminum phthalocyanine (AlPcN₄) to bilayer lipid membranes was studied by fluorescence correlation spectroscopy (FCS) and intramembrane field compensation (IFC) methods. With neutral phosphatidylcholine membranes, AlPcN₄ appeared to bind more effectively than the negatively charged tetrasulfonated aluminum phthalocyanine (AlPcS₄), which was attributed to the enhancement of the coordination interaction of aluminum with the phosphate moiety of phosphatidylcholine by the electric field created by positively charged groups of AlPcN₄. The inhibitory effect of fluoride ions on the membrane binding of both AlPcN₄ and AlPcS₄ supported the essential role of aluminum-phosphate coordination in the interaction of these phthalocyanines with phospholipids. The presence of negative or positive charges on the surface of lipid membranes modulated the binding of AlPcN₄ and AlPcS₄ in accord with the character (attraction or repulsion) of the electrostatic interaction, thus showing the significant contribution of the latter to the phthalocyanine adsorption on lipid bilayers. The data on the photodynamic activity of AlPcN₄ and AlPcS₄ as measured by sensitized photoinactivation of gramicidin channels in bilayer lipid membranes correlated well with the binding data obtained by FCS and IFC techniques. The reduced photodynamic activity of AlPcN₄ with neutral membranes violating this correlation was attributed to the concentration quenching of singlet excited states as proved by the data on the AlPcN₄ fluorescence quenching.     

ACE/ACE2 Ratio and MMP-9 Activity as Potential Biomarkers in Tuberculous Pleural Effusions

Objective: Pleural effusion is common problem, but the rapid and reliable diagnosis for specific pathogenic effusions are lacking. This study aimed to identify the diagnosis based on clinical variables to differentiate pleural tuberculous exudates from other pleural effusions. We also investigated the role of renin-angiotensin system (RAS) and matrix metalloproteinase (MMPs) in the pathogenesis of pleural exudates.Experimental design: The major components in RAS and extracellular matrix metabolism, including angiotensin converting enzyme (ACE), ACE2, MMP-2 and MMP-9 activities, were measured and compared in the patients with transudative (n = 45) and exudative (n = 80) effusions. The exudative effusions were come from the patients with tuberculosis (n = 20), pneumonia (n = 32), and adenocarcinoma (n = 28).Results: Increased ACE and equivalent ACE2 activities, resulting in a significantly increased ACE/ACE2 ratio in exudates, were detected compared to these values in transudates. MMP-9 activity in exudates was significantly higher than that in transudates. The significant correlation between ACE and ACE2 activity that was found in transudates was not found in exudates. Advanced analyses showed significantly increased ACE and MMP-9 activities, and decreased ACE2 activity in tuberculous pleural effusions compared with those in pneumonia and adenocarcinoma effusions. The results indicate that increased ACE and MMP-9 activities found in the exudates were mainly contributed from a higher level of both enzyme activities in the tuberculous pleural effusions.Conclusion: Interplay between ACE and ACE2, essential functions in the RAS, and abnormal regulation of MMP-9 probably play a pivotal role in the development of exudative effusions. Moreover, the ACE/ACE2 ratio combined with MMP-9 activity in pleural fluid may be potential biomarkers for diagnosing tuberculous pleurisy.     

Infradian Rhythmicity in Sleep/Wake Ratio in Developing Infants

Although there are several reports on ultradian and circadian rhythms in newborns, we found only one report in which infradian periodicities are described for heart-rate measurements in the early stages of human development. Here, we report infradian rhythms in the monthly range in the sleep/wake cycle of four infants studied along 24 consecutive weeks. Our procedure was applied to sleep diary records from four healthy newborns. The data were arranged in binary time series representing sleep (?1) or wake (1) states. These time series were integrated in order to obtain the cumulative sleep/wake time. A measure of the sleep/wake ratio (SWR) was obtained by computing the average slope of the cumulative sleep/wake time. To extract periodicities we applied the Fourier periodogram to the temporal course of the SWR. We found a notorious difference in the SWR pattern among infants. In two infants the SWR showed a marked linear decay, spending more time asleep than awake, while in the two other infants oscillated near zero. We found robust oscillations in all children. In all cases the Fourier periodogram results present significant power in the infradian range. From these results, we suggest that sleep and wake durations are probably modulated by some internal stimuli.     

Structure–antimicrobial activity of some natural isocoumarins and their analogues

Three naturally occurring isocoumarins (paepalantine, paepalantine 9-O-beta-D-glucopyranoside and paepalantine 9-O-beta-D-allopyranosyl(1 --> 6) glucopyranoside) and two semi-synthetic analogues, 9,10-acylated compound and 9-OH-10-methylated compound, structurally similar to paepalantine, were evaluated for antimicrobial activity using a spectrophotometric microdilution technique. The paepalantine was active against S. aureus, S. epidermidis, and E. faecalis while the other four compounds proved ineffective against all microorganisms tested at concentrations of 500 microg/ml. Variations in phenolic substitution at OH-9 and/or OH-10 in the paepalantine molecule resulted in compounds without antimicrobial activity. A combination of structural features, two phenolic groups as cathecolic system, forms an oxygenated system arrangement that may reflect the potentially antimicrobial properties of paepalantine.     

Re-making the majority? Ethnic New Zealanders in the 2006 census

Abstract

The national census is often seen as a site of struggle for minorities seeking recognition and equality. Much less is known about the conditions under which ethnic majorities are galvanized to stake identity claims in the census. This article examines recent trends in New Zealand where an increasing number of people from the dominant New Zealand European group are redefining themselves as ethnic New Zealanders. Drawing from the literature on ethnic boundaries, we theorize the factors underlying the surge in New Zealander identification, and present census data to demonstrate its selective appeal. We also review patterns of national naming in North America and Australia to show that the New Zealander phenomenon reflects a broader shift by settler state majorities to reimagine their identities. The implications for ethnic counting in other contexts are briefly considered.