Biogeography,ecology and conservation of Erebia oeme (Hübner) in the Carpathians (Lepidoptera: Nymphalidae: Satyrinae)

The European endemic Erebia oeme (Hübner [1804]) (Lepidoptera: Nymphalidae: Satyrinae) is discovered in the Carpathian Chain, from where it was considered to be absent. The single population found is situated in the southern part of the Romanian Carpathians (Retezat Mountains), where it flies sympatrically and synchronically with Erebia medusa ([Denis & Schiffermüller] 1775). The similar external morphology of these two species probably caused E. oeme to be overlooked in the Carpathians, leading to an unexpected information gap in the otherwise thoroughly studied European continent. The morphology of the Romanian specimens is compared to populations from the rest of the species’ range and to E. medusa. In addition, we tested DNA barcoding as a method to discriminate between these species and confirmed that it represents an effective identification tool for the taxa involved. The habitat of E. oeme, adults of both sexes and their genitalia are illustrated in comparison with E. medusa. Based on the study of several collections, we show that E. oeme is likely to be extremely local in the Carpathians and provide arguments to consider the species as vulnerable in Romania.     

The Photoperiodic Entrainment and Induction of Reproductive Rhythms in Male Blackheaded Buntings (Emberiza Melanocephala)

Groups of photosensitive, unstimulated or stimulated, male blackheaded buntings were subjected to photoregimes of 15 hr of green light of three intensities and 9 hr of dark per day. In some groups green light was interrupted with 90 min of bright fluorescent light at different times in the subjective day. While gonads did not develop or regressed in some groups, birds in others behaved as if exposed to long daylengths. The results besides suggesting the involvement of endogenous circadian rhythm during initiation and maintenance of gonadal growth indicate that the reproductive rhythms are entrained and induced by environmental photoperiod.     

Electrotactile stimulation on the tongue: Intensity perception,discrimination, and cross-modality estimation

Due to its high sensitivity and conductivity, electrotactile stimulation (ETS) on the tongue has proven to be a useful and technically convenient tool to substitute and/or augment sensory capabilities. However, most of its applications have only provided spatial attributes and little is known about (a) the ability of the tongue's sensory system to process electrical stimuli of varying magnitudes and (b) how modulation of ETS intensity affects subjects’ ability to decode stimulus intensity. We addressed these questions by quantifying: (1) the magnitude of the dynamic range (DR; maximal comfortable intensity/perception threshold) and its sensitivity to prolonged exposure; (2) subjects’ ability to perceive intensity changes; and (3) subjects’ ability to associate intensity with angular excursions of a protractor's handle. We found that the average DR (17 dB) was generally large in comparison with other tactile loci and of a relatively constant magnitude among subjects, even after prolonged exposure, despite a slight but significant upward drift (p < 0.001). Additionally, our results showed that as stimulus intensity increased, subjects’ ability to discriminate ETS stimuli of different intensities improved (p < 0.05) while estimation accuracy, in general, slightly decreased (increasing underestimation). These results suggest that higher ETS intensity may increase recruitment of rapidly adapting mechanoreceptor fibers, as these are specialized for coding stimulus differences rather than absolute intensities. Furthermore, our study revealed that the tongue's sensory system can effectively convey electrical stimuli despite minimal practice and when information transfer is limited by memory and DR drift.     

Rangewide landscape genetics of an endemic Pacific northwestern salamander

A species' genetic structure often varies in response to ecological and landscape processes that differ throughout the species' geographic range, yet landscape genetics studies are rarely spatially replicated. The Cope's giant salamander (Dicamptodon copei) is a neotenic, dispersal‐limited amphibian with a restricted geographic range in the Pacific northwestern USA. We investigated which landscape factors affect D. copei gene flow in three regions spanning the species' range, which vary in climate, landcover and degree of anthropogenic disturbance. Least cost paths and Circuitscape resistance analyses revealed that gene flow patterns vary across the species' range, with unique combinations of landscape variables affecting gene flow in different regions. Populations in the northern coastal portions of the range had relatively high gene flow, largely facilitated by stream and river networks. Near the southeastern edge of the species' range, gene flow was more restricted overall, with relatively less facilitation by streams and more limitation by heat load index and fragmented forest cover. These results suggested that the landscape is more difficult for individuals to disperse through at the southeastern edge of the species' range, with terrestrial habitat desiccation factors becoming more limiting to gene flow. We suggest that caution be used when attempting to extrapolate landscape genetic models and conservation measures from one portion of a species' range to another.     

二郎山小型兽类区系及分布格局

动物种类和数量在不同的山地或同一山地的不同垂直高度有很大的差异,正因如此,国际上和国内的研究者们一直在努力探讨动物在山地的分布规律和产生差异的原因(Merriam et al.,1890;鲍毅新等,1984;Heaney,2001;Rickart,2001;SánchezCordero,2001;张云智等,2002;李义明等,2003;马俊等,2010).横断山是中国最长、最宽和最典型的南北向山系,位于青藏高原东南部,通常为四川、云南两省西部和西藏自治区东部南北向山脉的总称.横断山是全球25个生物多样性热点地区之一,其生物多样性资源极其丰富(Myers et al.,2000).     

Movement patterns of Antillean manatees in Chetumal Bay (Mexico) and coastal Belize: A challenge for regional conservation

Information from 15 satellite‐tracked Antillean manatees (Trichechus manatus manatus) was analyzed in order to assess individual movements, home ranges, and high‐use areas for conservation decisions. Manatees were captured in Chetumal Bay, Mexico, and tagged with Argos‐monitored satellite transmitters. Location of the manatees and physical characteristics were assessed to describe habitat properties. Most manatees traveled to freshwater sources. The Maximum Area Size (MAS) for each manatee was determined using the observation‐area method. Additional kernel densities of 95% home range and 50% Center of Activity (COA) were also calculated, with manatees having 1–3 COAs. Manatees exhibited two different movement patterns: remaining in Chetumal Bay, and long‐distance (up to 240 km in 89 d). The residence time in Chetumal Bay was higher for females (89.6% of time) than for males (72.0%), but the daily travel rate (0.4–0.5 km/d) was similar for both sexes. Most of the COAs fell within Natural Protected Areas (NPA). However, manatees also travel for long distances into unprotected areas, where they face uncontrolled boat traffic, fishing activities, and habitat loss. Conservation of movement corridors may promote long‐distance movements and facilitate genetic exchange.     

Deriving how far structural information is transmitted through parallel homodimeric coiled‐coils: A correlation analysis of helical staggers

How local conformation is affected by local sequence is fairly well understood for alpha‐helical coiled‐coils, but less is known about how local conformation is influenced by distant features. Here, I describe an approach to detect such an effect, based on computing correlation coefficients of local out‐of‐register alignments, or so‐called “staggers” between the helices, as a function of the axial distance between the staggers. This approach requires parallel homodimers, in which each stagger can occur with two “signs,” where either one helix or the other is shifted towards the N terminus. The signs of such staggers separated by up to 12 residues are strongly correlated, indicating that the conformations of the ends of coiled‐coils are commonly influenced by attached structures. Thus, the structures of coiled‐coil residues aberrantly attached to alternative proteins, such as those resulting from leukemogenic chromosomal rearrangements, may be distinguishable from those in normal tissues, and in turn serve as targets of selective drug design. The signs of helical staggers separated by between 13 and 30 residues are moderately yet significantly correlated, indicating that some of the coiled‐coils transmit this conformational feature axially for at least 45 Å. A positive, albeit noisy, correlation also exists among tropomyosin coiled‐coils for signed staggers separated by the 40‐residue actin repeat distance, consistent with the semi‐flexible tropomyosin filament binding F‐actin and regulating skeletal muscle contraction in a partially cooperative manner. Communication of the signs of axial staggers is explained in part by minimization of main‐chain hydrogen bond deformations. © Proteins 2013. © 2012 Wiley Periodicals, Inc.     

Tertiary dinosaurs in South America? A reply to some of Van Valen's assertions

The discussion of the age of some South American Late Cretaceous fossil vertebrate localities by Van Valen led this author to admit the possible persistence of Dinosaurs at the base of the Paleocene. Van Valen's arguments resting on the selachians are reviewed and it can be asserted that the selachian‐bearing localities of the El Molino Formation of Bolivia are Cretaceous and not Tertiary.     

Book review

Fucoid macroalgae are important primary producers and habitat modifiers on North Atlantic intertidal rocky shores. With decreasing latitude, western European fucoid populations display reduced levels of abundance, biomass and recruitment, while experiencing higher levels of physical environmental stress during summer months. We hypothesized that such reduction in the south is accompanied by a detectable decline in fucoid reproductive capacity. To test this hypothesis, morphological and reproductive traits of core (Welsh) and marginal (Portuguese) populations of two common fucoid species, Fucus vesiculosus and F. spiralis (Ochrophyta, Fucales), were examined. Morphological measurements showed that for a given thallus length, both fucoid species had smaller thallus volume and lower biomass in the southerly marginal part of the range. Significantly lower biomass of reproductive tissue of F. vesiculosus and a smaller number of receptacles per individual on specimens of both species indicate that levels of reproductive output are probably lower in southern populations. Despite the differences in reproductive traits observed between regions, reproductive effort (measured as the percentage of total dry biomass represented by reproductive tissue) of both species remained similar, as algae from both regions made similar investments in reproduction. The results indicate that stressful conditions reduced growth and number of receptacles of both species and amount of reproductive biomass of F. vesiculosus in the south but do not seem to change the way these algal species invest their energy. The decline in mass and reproductive biomass of specimens from southern shores found in this study, when combined with the lower abundance of adults and lower recruitment levels previously observed, is a strong indication of fucoid populations with lower levels of propagule output. This is an important factor when considering responses of these populations to a changing environment.     

Effect of Molecular Characteristics on Cellular Uptake,Subcellular Localization,and Phototoxicity of Zn(II) N-Alkylpyridylporphyrins

Tetra-cationic Zn(II) meso-tetrakis(N-alkylpyridinium-2 (or -3 or -4)-yl)porphyrins (ZnPs) with progressively increased lipophilicity were synthesized to investigate how the tri-dimensional shape and lipophilicity of the photosensitizer (PS) affect cellular uptake, subcellular distribution, and photodynamic efficacy. The effect of the tri-dimensional shape of the molecule was studied by shifting the N-alkyl substituent attached to the pyridyl nitrogen from ortho to meta and para positions. Progressive increase of lipophilicity from shorter hydrophilic (methyl) to longer amphiphilic (hexyl) alkyl chains increased the phototoxicity of the ZnP PSs. PS efficacy was also increased for all derivatives when the alkyl substituents were shifted from ortho to meta, and from meta to para positions. Both cellular uptake and subcellular distribution of the PSs were affected by the lipophilicity and the position of the alkyl chains on the periphery of the porphyrin ring. Whereas the hydrophilic ZnPs demonstrated mostly lysosomal distribution, the amphiphilic hexyl derivatives were associated with mitochondria, endoplasmic reticulum, and plasma membrane. A comparison of hexyl isomers revealed that cellular uptake and partition into membranes followed the order para > meta > ortho. Varying the position and length of the alkyl substituents affects (i) the exposure of cationic charges for electrostatic interactions with anionic biomolecules and (ii) the lipophilicity of the molecule. The charge, lipophilicity, and the tri-dimensional shape of the PS are the major factors that determine cellular uptake, subcellular distribution, and as a consequence, the phototoxicity of the PSs.