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opencc-zeroDec 2014View details →

Data from: Static allometry of unicellular green algae: scaling of cellular surface area and volume in the genus Micrasterias (Desmidiales)

The surface area-to-volume ratio of cells is one of the key factors affecting fundamental biological processes and, thus, fitness of unicellular organisms. One of the general models for allometric increase in surface-to-volume scaling involves fractal-like elaboration of cellular surfaces. However, specific data illustrating this pattern in natural populations of the unicellular organisms have not previously been available. This study shows that unicellular green algae of the genus Micrasterias (Desmidiales) have positive allometric surface-to-volume scaling caused by changes in morphology of individual species, especially in the degree of cell lobulation. This allometric pattern was also detected within most of the cultured and natural populations analysed. Values of the allometric S:V scaling within individual populations were closely correlated to the phylogenetic structure of the clade. In addition, they were related to species-specific cellular morphology. Individual populations differed in their allometric patterns, and their position in the allometric space was strongly correlated with the degree of allometric S:V scaling. This result illustrates that allometric shape patterns are an important correlate of the capacity of individual populations to compensate for increases in their cell volumes by increasing the surface area. However, variation in allometric patterns was not associated with phylogenetic structure. This indicates that the position of the populations in the allometric space was not evolutionarily conserved and might be influenced by environmental factors.

opencc-zeroDec 2016View details →

Data from: Root volume distribution of maturing perennial grasses revealed by correcting for minirhizotron surface effects

Aims: Root architecture drives plant ecology and physiology, but current detection methods limit understanding of root placement within soil profiles. We developed a statistical model of root volume along depth gradients and used it to infer carbon storage potential of land-use changes from conventional agriculture to perennial bioenergy grasses. Methods: We estimated root volume of maize-soybean rotation and three perennial grass systems (Miscanthus × giganteus, Panicum virgatum, tallgrass prairie mix) by Bayesian modeling from minirhizotron images, correcting for small images and near-surface underdetection. We monitored seasonal and inter-annual changes in root volume distribution, then validated our estimates against root mass from core samples. Results: The model explained 29% of root volume variation and validated well against core mass. Seventh-year perennials had greater belowground biomass than maize-soybean both in total (11-16×) and throughout the profile (2-17× at every depth < 120 cm). Perennials' relative depth allocations were stable over time, while total root volume increased through five years. In 2012 a historically hot, dry summer damaged maize while perennials appeared resilient, suggesting their large-deep root systems aid drought resistance. Conclusions: Perennial root systems are large, deep, and persistent. Converting row crops to perennial bioenergy grasses likely sequesters carbon in a large, potentially very stable, soil pool.

Data from: Gray matter volume modifications in migraine: a cross-sectional and longitudinal study

Objective. To explore cross-sectional and longitudinal gray matter (GM) volume changes in migraine patients and their association with patients' clinical characteristics and disease activity. Methods. Brain T2-weighted and 3D T1-weighted scans were acquired from 73 episodic migraineurs and 46 age- and sex-matched non-migraine controls at baseline. Twenty-four migraineurs and 25 controls agreed to be re-examined after a mean follow-up of 4 years. Using a general linear model and SPM12, a whole-brain analysis was performed to assess GM volume modifications. Results. At baseline, compared to controls, migraine patients showed lower cerebellar GM volume and higher volume of regions of the fronto-temporal lobes. At follow-up, migraineurs were significantly older than controls. Over the follow-up, migraineurs developed an increased volume of fronto-temporo-parietal regions, which was more prominent in patients with a higher baseline disease activity: long disease duration and high attack frequency. Migraineurs also developed decreased GM volume of visual areas, which was related to higher pain severity. Patients with an increased attack frequency at follow-up experienced both increased and decreased volume of nociceptive regions. In migraineurs, reduced GM volume of extrastriate visual areas during the follow-up was significantly correlated to baseline disease activity: shorter disease duration and lower attack frequency. Conclusion. In this cohort, the migraine brain changes dynamically over time and different pathophysiological mechanisms can occur in response to patients' disease severity. The interaction between predisposing brain traits and experience-dependent responses might vary across different nociceptive and visual areas, thus leading to distinct patterns of longitudinal GM volume changes.

Data from: Cough frequency during treatment associated with baseline cavitary volume and proximity to the airway in pulmonary TB

Background: Cough frequency, and its duration, is a lab-free biomarker that can be used in low-resource settings and has been associated with transmission and treatment response. Radiological characteristics associated with increased cough frequency may be important in understanding transmission. The relationship between cough frequency and cavitary lung disease has never been studied. Methods: We analyzed 41 human immunodeficiency virus-negative adults with culture-confirmed, drug-susceptible pulmonary tuberculosis throughout treatment. Cough recordings were based on the Cayetano Cough Monitor and sputum samples were evaluated using microscopic-observation drug susceptibility broth culture, among culture-positive samples bacillary burden was assessed by time to positivity. Computerized tomography scans were analyzed by a U.S. board-certified radiologist and an automated-computer algorithm. The algorithm evaluates cavity volume and cavitary proximity to the airway. Computerized tomography scans were taken within one month of treatment initiation. We compared small cavities (≤7-mL) versus large cavities (>7-mL) and cavities located closer to (≤10-mm) and farther (>10-mm) from the airway to cough frequency and cough cessation until treatment day 62. Results: Cough frequency during treatment was two-fold higher in participants with large cavity volumes (Rate Ratio [RR]=1.98, p=0.01) and cavities located closer to the airway (RR=2.44, p=0.001). Comparably, cough ceased three times faster in smaller cavities (adjusted hazard ratio [HR]=2.89, p=0.06) and those farther from the airway (adjusted HR=3.61, p=0.02). Similar results are found for bacillary burden and culture conversion during treatment. Conclusions: Cough frequency during treatment is greater and lasts for longer in patients with larger cavities, especially those closer to the airway.

Data from: Current and projected cumulative impacts of fire, drought and insects on timber volumes across Canada

Canada's forests are shaped by disturbances such as fire, insect outbreaks and droughts that often overlap in time and space. The resulting cumulative disturbance risks and potential impacts on forests are generally not well accounted for by models used to predict future impacts of disturbances on forest. This study aims at projecting future cumulative effects of four main natural disturbances – fire, mountain pine beetle, spruce budworm and drought - on timber volumes across Canada's forests using an approach that accounts for potential overlap among disturbances. Available predictive models for the four natural disturbances were used to project timber volumes at risk under aggressive climate forcing up to 2100. Projections applied to the current vegetation suggest increases of volumes at risk related to fire, mountain pine beetle and drought over time in many regions of Canada, but a decrease of the volume at risk related to spruce budworm. When disturbance effects are cumulated, important changes in volumes at risk are projected to occur as early as 2011-2041, particularly in central and eastern Canada. In our last simulation period covering 2071 to 2100, nearly all timber volumes in most of Canada's forest regions could be at risk of being affected by at least one of the four natural disturbances considered in our analysis, a six-fold increase relative to the baseline period (1981-2010). Tree species particularly vulnerable to specific disturbances (e.g., trembling aspen to drought) could suffer disproportionate increases in their volume at risk with potential impacts on forest composition. By 2100, estimated wood volumes not considered to be at risk could be lower than current annual timber harvests in central and eastern Canada. Current level of harvesting could thus be difficult to maintain without the implementation of adaptation measures to cope with these disturbances.

Data from: Combining micro-volume isotope analysis and numerical simulation to reproduce fish migration history

1. Tracking the movement of migratory fish is of great importance for efficient conservation, although this has been technically difficult to achieve in small fish to which artificial tags cannot be attached. 2. We show that migration history can be reproduced by combining high-resolution otolith stable oxygen isotope ratio (δ18O) analysis and numerical simulation. 3. High-precision micro-milling and micro-volume carbonate analysing systems had the remarkable capability of extracting the otolith δ18O profiles with 10–30 days resolution. Furthermore, reasonable movements were reproduced by searching the routes consistent with the otolith δ18O profile, using an individual-based model with random swimming behaviour. 4. This method will be a valuable alternative to tagging and electronic loggers for revealing migration routes in early life stages, thereby providing crucial information to understand population structures and the environmental cause of recruitment variabilities, and to validate and improve fish movement models.

opencc-by-nc-4.0Jul 2016View details →

Could Google Trends be used to predict methamphetamine-related crime? An analysis of search volume data in Switzerland, Germany, and Austria

Data for paper submitted to PLoS One on 2016-07-08. Title: Could Google Trends be used to predict methamphetamine-related crime? An analysis of search volume data in Switzerland, Germany, and Austria Authors: Alex Gamma, Roman Schleifer, Wolfgang Weinmann, Anna Buadze, Michael Liebrenz Format: ZIP-file Contains: - Two datafiles, each as .csv and .dta (Stata version 11) file. - README file with instructions

FIGURE 21 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 21. Comparison of (a) surface and (b) volume rendering of the same skeletal region of the same specimen; the acetabulum of Rhombophryne serratopalpebrosa (MNHN 1975.24). The surface rendering is that used in Scherz et al. (2014). The volume rendering was produced for this study. Note particularly the unossified state of the pubis in (b) compared to that reproduced in (a). The arrow indicates the end of the urostyle, which gradually thins towards its tip, but is shown to end abruptly in surface rendering due to the on/off characteristic of meshes.

FIGURE 17 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 17. Forelimb anatomy of the R. serratopalpebrosa species group showing (a) left manus in ventral view, (b) left radioulna in dorsal view, and left humerus in (c) lateral, (d) ventral, and (e) medial view. Abbreviations: cpl(s) = carpal(s), cr.lat = crista lateralis, cr.ven = crista ventralis, e.cap = eminentia capitata, ep.ul = epicondylus ulnaris.

FIGURE 16 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 16. The pectoral girdle of the R. serratopalpebrosa species group in ventral view, articulated (left) and laid flat (right). Abbreviations: scap.pa = scapula pars acromialis, scap.pg = scapula pars glenoidalis.

FIGURE 13 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 13. Terminology of skull osteology in dorsal view (left) and ventral view (right). Abbreviations: col = columella, exoc = exoccipital, exoc.oc = occipital condyle of exoccipital, fpar = frontoparietal, fpar.lf = frontoparietal lateral flange, max = maxilla, max.pf = maxillary pars fascialis, max.parspal = maxillary pars palatina, nasal.mp = maxillary process of nasal, neopal = neopalatine, pmx.ap = premaxilla alary process, pmx.lp = premaxilla lateral process, pmx.palproc = premaxilla palatine process, povom = postchoanal vomer, proot = prootic, prvom = prechoanal vomer, prsph.cp = parasphenoid cultriform process, prsph.al = parasphenoid alae, pter.ar = pterygoid anterior ramus, pter.mr = pterygoid medial ramus, pter.vr = pterygoid ventral ramus, qj = quadratojugal, qj.pvp = quadratojugal posteroventral process, smax = septomaxilla, spheth = sphenethmoid, sq.or = squamosal otic ramus, sq.vr = squamosal ventral ramus, sq.zr = squamosal zygomatic ramus.

FIGURE 12 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 12. Osteology of Rhombophryne diadema sp. nov. (ZSM 1629/2012). Full skeleton in (a) dorsal, (b) ventral, and (c) lateral view; skull in (d) dorsal, (e) ventral, and (f) lateral view. Abbreviations as in Fig. 7.

FIGURE 9 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 9. Rhombophryne regalis sp. nov. in life, showing the holotype (MRSN A4602) in (a) dorsal and (b) ventral view; paratype MRSN A4603 in (c) dorsolateral and (d) ventral view; and (e) an individual from Ambolokopatrika in dorsolateral view (assignment to field and collection numbers unknown).

FIGURE 8 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 8. Map of the north of Madagascar showing the collection localities of specimens of the focal species of this paper, Rhombophryne guentherpetersi, R. regalis sp. nov., and R. diadema sp. nov. Basemap from www.vegmad.org. Hashing indicates protected areas; note that the full extent of Tsaratanana Strict Nature Reserve is not shown.

FIGURE 6 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 6. Rhombophryne guentherpetersi in life. (a–c) ZSM 607/2014 in (a) dorsolateral (with inset showing superciliary spines), (b) dorsal, and (c) ventral view; and (d, e) other specimens in dorsolateral view (assignment to field and collection numbers unknown).

FIGURE 11 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 11. Rhombophryne diadema sp. nov. in life, showing the holotype ZSM 1629/2012 in (a) dorsal and (b) ventral view; paratype ZSM 1628/2012 in (c) lateral and (d) ventral view; and paratype UADBA-A 60289 in (e) lateral and (f) ventral view.

FIGURE 15 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 15. The vertebral column of the R. serratopalpebrosa species group shown in dorsal (left) and lateral (right) view. Abbreviations: I–VIII = presacral numbers, S = sacrum, S.d = sacral diapophysis, U = urostyle, U.dr = urostyle dorsal ridge, tp = transverse processes, mr = medial ridge, na = neural arch, ns = neural spine.

FIGURE 4 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 4. Photographs of the holotypes of the species treated in this manuscript, in dorsal (top row) and ventral (bottom row) views.

FIGURE 3 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 3. Majority-rule consensus tree of the Rhombophryne serratopalpebrosa species group and its sister clade, obtained by partitioned BI analysis, based on 2491 nucleotide characters of two mitochondrial and one nuclear gene (16S, cox1, sacs). Asterisks indicate Bayesian posterior probability values (*0.95–0.98, **0.99–1.0; not shown if <0.95). Stumpffia psologlossa and other species of Rhombophryne were used as hierarchical outgroups and are here excluded from the figure as they are not the subject of this study. Members of the R. serratopalpebrosa species group are depicted in life, not to scale.

FIGURE 19 in A review of the taxonomy and osteology of the Rhombophryne serratopalpebrosa species group (Anura: Microhylidae) from Madagascar, with comments on the value of volume rendering of micro-CT data to taxonomists

FIGURE 19. Hindlimb anatomy of the R. serratopalpebrosa species group showing the right femur in (a) medial and (b) lateral view, the right tibiofibula in (c) ventral and (d) dorsal view, and (e) the right pes and tibiale-fibulare in ventral view. Abbreviations: tf.si = sulcus intermedius of tibiofibula, tsl(s) = tarsal(s).