Scale Tip Research Articles

Efficacy of Intra-Articular Corticosteroid Injection for Nonsurgical Management of Trapeziometacarpal Osteoarthritis: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

As osteoarthritis (OA) of the trapeziometacarpal (TMC) joint leads to a high degree of disease burden with compromises in rudimentary and fine movements of the hand, intra-articular injections may be a desirable treatment option. However, because there are no evidence-based guidelines, the choice of intra-articular injection type is left to the discretion of the individual surgeon in collaboration with the patient. The purpose of our study was to perform a systematic review and meta-analysis using level I studies to compare outcomes following corticosteroid and alternative methods of intra-articular injections for the management of TMC OA. Our hypothesis was that intra-articular corticosteroid injections were no more effective than other methods of intra-articular injections for the management of TMC OA. A systematic literature search was performed. Eligible for inclusion were randomized control trials reporting on intra-articular corticosteroid injection for the management of TMC OA. Clinical outcomes were recorded. The 10 included studies comprised 673 patients. The mean age was 57.8 ± 8.3 years, with a mean follow-up of 6.4 ± 2.7 months. There was no significant difference in visual analog scale scores, grip strength and tip pinch strength between corticosteroids and hyaluronic acid at short- and medium-term follow-up. Further, there was no difference in visual analog scale pain scores at rest at medium-term follow-up between corticosteroids and platelet-rich plasma. Despite short-term improvement with intra-articular corticosteroid injections, there was no significant difference in pain and functional outcomes following intra-articular corticosteroid injections compared to hyaluronic acid or platelet-rich plasma administration. Given the affordability, ease of administration, and efficacy associated with corticosteroids, they are a favorable option when considering the choice of intra-articular injection for the management of TMC OA. Therapeutic II.

Multi-institutional intervention to improve patient perception of physician empathy in emergency care

BackgroundPhysician empathy has been linked to increased patient satisfaction, improved patient outcomes and reduced provider burnout. Our objective was to test the effectiveness of an educational intervention to improve physician...

Resin Nano-Ceramic Material Surface Roughness, Color Stability, and Bacterial Adhesion Evaluation After Different Scaling Methods

Objectives: The study evaluated in vitro the changes in roughness, color stability, and bacterial count of a CAD/CAM Resin Nano-Ceramic material surface treated by various scaling procedures. Material and Methods: 70 disks (5mm diameter, 0.5 mm thickness) of Resin Nano-Ceramic (Lava ™Ultimate, 3M, ESPE) material were cemented in standardized cavities prepared in bovine teeth. A custom-made scaling apparatus of a double pan balance was used for different scaling methods, simulating standard clinical conditions. The specimens were assigned to three main groups: no scaling(C), ultrasonic scaling (U), and manual scaling (M). Each group was then divided into three subgroups according to scaling tip material; stainless steel tip (St), plastic tip (P), and titanium tip (Ti). The surface texture was analyzed quantitatively and qualitatively with a tactile profilometer and atomic force microscopy. A spectrophotometer was used for color measurement. Streptococcus mutans were counted in a colony counter. All the data were tabulated and statistically analyzed. Results: Two-way ANOVA was used to study the effect while One-way ANOVA was performed to compare between study groups. The significance level was set at p 0.05. The ultrasonic titanium tip(UTi) revealed the significant highest mean value of alterations (p < 0.001). The integrity of the material surface was altered in the form of deep scratches on the ultrasonically scaled surfaces and numerous smaller scratches on the hand-scaled surfaces. Conclusion: The plastic instrument would appear to be the instrument of choice during a routine maintenance procedure for Resin Nano-Ceramic materials. Keywords Bacterial biofilm; Dental ceramics; Color stability; Scaling; Surface roughness.

The Battle for Backdoors and Encryption Keys

This paper argues that the use of backdoors in software is inherently counterproductive and leads to invasion of privacy, either by federal or state governments or by intrusive hackers. The essay outlines encryption’s nature, pointing out that a software backdoor is a secret means of ignoring data authentication. Several examples of known backdoors known to terrorists, criminals, and governments alike are highlighted. Arguments in favor and opposing backdoors are provided, where the Apple Computer, Inc. v. FBI controversy is discussed. Finally, the balancing of harms test as proposed by John Stuart Mill is introduced, where the article concludes that when balancing the opposing positions, the scale tips toward data encryption because an innocent party would suffer the most harm from the existence of a software backdoor.

An in vitro evaluation of surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic after prophylactic periodontal treatment

Objective: to evaluate the effect of scaling procedures using different ultrasonic tips on the surface roughness, color stability and bacterial accumulation of lithium disilicate ceramic. Material and Methods: Scaling procedure was carried out using ultrasonic scaler (Satalec, Acteon, North America) with stainless-steel tip (US), titanium tip (UT) and plastic tip (UP), on disc shaped lithium disilicate samples cemented into a cavity prepared onto the labial surface of freshly extracted bovine teeth (10 samples per group). The samples were stored in coffee solution in an incubator at 37°C for 12 days, which is equivalent to 1 year of coffee consumption. The surface roughness was measured before and after the scaling procedure using a profilometer and atomic force microscopy. The color parameters were measured before and after scaling and staining procedures using VITA Easyshade Advance 4.0 according to the CIE L*a*b* color order system. The samples were then incubated with Streptococcus mutans (S. mutans) suspension. After incubation, the plates with 30 to 300 typical colonies of S. mutans were counted in a colony counter and mean values of colony forming units were obtained (CFU/mL). Results: The titanium scaling tip showed a statistically significant higher mean values of change in surface roughness Ra and bacterial count than the plastic scaling tip. Color changes (E) were not a statistically significant among the groups. The results showed a statistically significant positive (direct) correlation between surface roughness and color change (p = 0.012) and also between surface roughness and bacterial count (p = 0.00). Conclusion: Within the limitations of this study, titanium scaling instruments cause irreversible surface alterations of lithium disilcate ceramics which was in direct correlation to the color changes and bacterial accumulation; therefore, dentists should proceed with caution when scaling lithium disilicate surfaces. The findings of the current study may indicate the need for instruments or equipment that can remove plaque and calculus without causing surface damage. Keywords Surface properties; Color; Bacterial adhesion; Ultrasonics; Dental scaling; Ceramics.

Will Transaction Costs and Economies of Scale Tip the Balance in Farm Size in Industrial Agriculture? An Illustration for Non-Food Biomass Production in Germany

The study investigates how the agricultural sector can respond to a growing non-food biomass demand. Taking Germany as an example, a stylized case of biomass production under conditions of technological advance and constantly growing demand is modelled. It is argued that biomass producers might seek to adjust their farm size by simultaneously optimizing benefits from the production scale and transaction cost savings, where transaction costs are measured using Data Envelopment Analysis. The results extend the debate on transaction costs and structural change in agriculture by revealing a possible synergy and trade-off between transaction cost savings and benefits from (dis)economies of scale. They show that if larger farms cannot economize on transaction costs, then investments in land and labor, needed to adjust to higher biomass demand, partly compromise the returns to scale, which decelerates the farm size growth. A higher degree of asset specificity gives rise to transaction costs and reduces the rate at which the farm size decreases. Smaller producers may disproportionally benefit from their higher potential of transaction cost savings, if advanced technologies can offset the scale advantage of larger farms. The findings inform policymakers to consider this complex effect when comparing the opportunities of smaller and larger agricultural producers in the bioeconomy.

Modeling Green's function measurements with two-tip scanning tunneling microscopy

A double-tip scanning tunneling microscope with nanometer scale tip separation has the ability to access the single electron Green's function in real and momentum space based on second order tunneling processes. Experimental realization of such measurements has been limited to quasi-one-dimensional systems due to the extremely small signal size. Here we propose an alternative approach to obtain such information by exploiting the current-current correlations from the individual tips, and present a theoretical formalism to describe it. To assess the feasibility of our approach we make a numerical estimate for a $\sim$ 25 nm Pb nanoisland and show that the wavefunction in fact extends from tip-to-tip and the signal depends less strongly on increased tip separation in the diffusive regime than the one in alternative approaches relying on tip-to-tip conductance.

Evolutionary diversification of taiwanioid conifers: evidence from a new Upper Cretaceous seed cone from Hokkaido, Japan

A single cylindrical seed cone 2 cm long, 1.1 cm wide has been found preserved in a calcium carbonate marine concretion from the Hakobuchi Formation (late Campanian-early Maastrichtian) of Hobetsu, Hokkaido, Japan. The cone, attached to a bent peduncle lacking leaves, has helically arranged bract/scale complexes that arise at right angles from the cone axis in the middle of the cone. The cone axis, ca. 1 mm wide, has a broad cylinder of secondary vascular tissue, and lacks a continuous resin canal system. Bract-scale complexes are laminar, cordate-orbiculate, and upturned distally, consisting primarily of bract tissue with no visible scale tip. The vascular trace to the bract/scale complex originates as a rod that divides laterally into several traces at the level of seed attachment. A single resin canal originates at the base of the bract-scale complex abaxial to the vascular strand, but more distally there are up to ca. 15 large resin canals that form a single row. Two to three inverted winged seeds are attached adaxially near the cone periphery. Cone structure and vascularization are most similar to those in the Cupressaceae, Subfamily Taiwanioideae, differing from living Taiwania cryptomerioides by having up to three seeds/scale rather than two, an abruptly upturned bract tip, in details of bract/scale vasculature, and a cone peduncle lacking leaves. This cone is described as Mukawastrobus satoi Stockey, Nishida and Rothwell. Together with previously described Early to Late Cretaceous taiwanioid seed cones from Mongolia and Hokkaido the new species demonstrates that the taxonomically diagnostic characters of such conifers are as subtle as those of Cretaceous and Cenozoic sequoioid Cupressaceae. This realization emphasizes that evolutionary diversification and turnover among taiwanioid conifers during the Cretaceous and Paleogene are probably far greater than currently recognized.

Divergence study and emittance measurements for the electron beam emitted from a diamond pyramid

This paper reports the results of a divergence study and emittance measurements for an electron beam emitted from a single diamond pyramid in a sparse diamond field-emitter array (DFEA) cathode. DFEA cathodes are arrays of micrometer scale diamond pyramids with nanometer scale tips. A single diamond pyramid produces currents as high as 10 μA from a small surface area. DFEA cathodes are expected to be a good beam source for compact dielectric laser accelerators. For the electron beam divergence experiment, we have designed and assembled a test stand consisting of a DFEA cathode, a mesh anode, and a screen. We measured current and the size of the beam on the screen as functions of the distance between the cathode and the anode, the size of a pyramid’s base, and applied voltage on the cathode. In order to perform beam emittance measurements, we designed and fabricated a magnetic lens to be placed between the mesh and the screen. By measuring the size of the beam for different distances between the lens and the screen, we estimate the beam’s emittance. We also simulated the electron beam dynamics with Computer Simulation Technology Studio and General Particle Tracer codes. Experimentally measured divergence angles and normalized transverse emittance show good agreement with simulations.

Ultra compact electrochemical metallization cells offering reproducible atomic scale memristive switching

Here we show electrochemical metallization cells with compact dimensions, excellent electrical performance, and reproducible characteristics. An advanced technology platform has been developed to obtain Ag/SiO2/Pt devices with ultra-scaled footprints (15 × 15 nm2), inter-electrode distances down to 1 nm, and a transition from the OFF to ON resistance state relying on the relocation of only few atoms. This technology permits a well-controlled metallic filament formation in a highly confined field at the apex of an atomic scale tip. As a consequence of this miniaturization process, we achieve set voltages around 100 mV, ultra-fast switching times of 7.5 ns, and write energies of 18 fJ. Furthermore, we demonstrate very good cell-to-cell uniformity and a resistance extinction ratio as high as 6 · 105. Combined ab-initio quantum transport simulations and experiments suggest that the manufactured structures exhibit reduced self-heating effects due to their lower dimensions, making them very promising candidates as next-generation (non-)volatile memory components.

Must We Eat Fish?

Must We Eat Fish? Ian Buchanan (bio) If only I could reason with those who deliberately slaughtered the societies of great whales! If only the last Great Auks and Stellar's sea cows and Atlantic walruses had not been killed! Perhaps other choices would have been made, if only the dire consequences of draining wetlands, cutting primeval forests, polluting rivers, filling productive bays, had been known to those who forever closed options for me, for all those who share the present, and for all who will come in the future. —Sylvia Earle (1995, 321) Art, Deleuze argues in his books on cinema, has the task not of addressing a people, "which is presupposed already there, but of contributing to the invention of a people" (1989, 217). Art has the unenviable and perhaps impossible task of helping to create the conditions in which a certain kind of politics becomes possible. The people it must invent, the people who are presently lacking, are people capable of hearing and acting on its message. I was reminded of this passage in Deleuze as I read Elspeth Probyn's Eating the Ocean because from the opening pages it was apparent it was going to be an extended argument in favour of maintaining the status quo, something all marine scientists agree would be a disaster for the ocean. We cannot have our ocean and eat it too. Today, as we face up to the devastation humans have wrought on this planet, we must acknowledge the deep truth and uncanny prescience of Walter Benjamin's insight that preserving the status quo is literally the last thing we should be trying to do. As Benjamin put it, the "'status quo' is the catastrophe" (2003, 184). Once a species disappears we cannot bring them back and unless we act now generations into the future will be asking us the kinds of questions Sylvia Earle wants to ask the people of the past. Probyn says she wants to find ways for us to care more about the ocean, which one can but applaud, but it is uncertain whether what she has in mind is palliative care or critical care, is she concerned to save a life or help ease one into the final darkness. Moreover as the scale tips toward extinction for countless species, it is no longer enough to talk about conservation, we need to act urgently for the sake of preservation of what remains. "Again and again through this book," Probyn writes, "I wonder how we can care a bit more, or a bit better, for the entire entangled marine elements [End Page 79] that we devour when we eat the ocean" (2016, 7). I imagine that Probyn frames her ambitions in this bitty way out of modesty, which is doubtless commendable enough in an era of overblown claims, but it has the unfortunate effect of diminishing both the scale of the problem of overfishing and marine species loss and the need for urgency in responding to these problems. If one reads Probyn alongside the work of marine biologists like Sylvia Earle or Callum Roberts, the contrast between their positions is absolute, not because their view is more complex—if anything their position is even simpler than Probyn's. Where Probyn asserts that "we" cannot afford not to eat fish, they say "we" cannot afford not to stop eating fish. In contrast to Earle and Roberts, Probyn treats the dire situation of the ocean today as something that can be remedied by a few minor adjustments to the way we do things. The reality is in fact very different, as Probyn herself fleetingly acknowledges. Somewhat tongue-in-cheek, she notes that "we are at risk of eating it up, devouring it until there's nothing left except the not-so-apocryphal jellyfish-and-chips" (2). One might expect then that her argument would be that humans must act now to save the ocean from human predation. But that is not the course she takes, her argument pivots in precisely the opposite direction. Can the ocean help feed humanity? (7). That is her question and her answer is that it must! This is an argument for the status quo...

Tip-Based Nanofabrication for Scalable Manufacturing

Tip-based nanofabrication (TBN) is a family of emerging nanofabrication techniques that use a nanometer scale tip to fabricate nanostructures. In this review, we first introduce the history of the TBN and the technology development. We then briefly review various TBN techniques that use different physical or chemical mechanisms to fabricate features and discuss some of the state-of-the-art techniques. Subsequently, we focus on those TBN methods that have demonstrated potential to scale up the manufacturing throughput. Finally, we discuss several research directions that are essential for making TBN a scalable nano-manufacturing technology.

European Bioeconomy in Figures

Industrial BiotechnologyVol. 12, No. 2 Industry ReportEuropean Bioeconomy in FiguresStephan Piotrowski, Michael Carus, and Dirk CarrezStephan Piotrowskinova-Institute GmbH, Hürth, GermanySearch for more papers by this author, Michael Carusnova-Institute GmbH, Hürth, GermanySearch for more papers by this author, and Dirk CarrezBiobased Industries Consortium, Brussels, BelgiumSearch for more papers by this authorPublished Online:5 Apr 2016https://doi.org/10.1089/ind.2016.29030.spiAboutSectionsView articleView Full TextPDF/EPUB ToolsPermissionsDownload CitationsTrack CitationsAdd to favorites Back To Publication ShareShare onFacebookTwitterLinked InRedditEmail View articleFiguresReferencesRelatedDetailsCited byXylose Metabolism in Bacteria—Opportunities and Challenges towards Efficient Lignocellulosic Biomass-Based Biorefineries31 August 2021 | Applied Sciences, Vol. 11, No. 17Efficiency drivers in harvesting operations in mixed Boreal stands: a Norwegian case study17 June 2020 | International Journal of Forest Engineering, Vol. 32, No. sup1Will Transaction Costs and Economies of Scale Tip the Balance in Farm Size in Industrial Agriculture? An Illustration for Non-Food Biomass Production in Germany13 January 2021 | Sustainability, Vol. 13, No. 2A Bio-Based Resin for a Multi-Scale Optical 3D Printing16 June 2020 | Scientific Reports, Vol. 10, No. 1Innovation types in the bioeconomyJournal of Cleaner Production, Vol. 266Bioeconomy as a Circular and Integrated System7 March 2020Collective stakeholder representations and perceptions of drivers of novel biomass-based value chainsJournal of Cleaner Production, Vol. 200Markets, Sustainability Management and Entrepreneurship13 December 2017Sustainability Aspects of Biokerosene15 August 2017Tropicalizing Sustainable Bioeconomy: Initial Lessons from Ecuador21 January 2018Revitalisation of Agricultural Biomass for an Industrial Bio-economy, Case Studies on South Africa and Netherlands Bio-economy21 January 2018Towards a sustainable innovation system for the German wood-based bioeconomy: Implications for policy designJournal of Cleaner Production, Vol. 172Use of vegetal biomass for biofuels and bioenergy. Competition with the production of bioproducts and materials?Comptes Rendus Physique, Vol. 18, No. 7-8Understanding value chains in industrial biotechnologyAnnales des Mines - Réalités industrielles, Vol. Février 2017, No. 1Die Bioökonomie als Kreislauf- und Verbundsystem28 April 2017 Volume 12Issue 2Apr 2016 InformationCopyright 2016, Mary Ann Liebert, Inc.To cite this article:Stephan Piotrowski, Michael Carus, and Dirk Carrez.European Bioeconomy in Figures.Industrial Biotechnology.Apr 2016.78-82.http://doi.org/10.1089/ind.2016.29030.spiPublished in Volume: 12 Issue 2: April 5, 2016PDF download

Directly interrogating single quantum dot labelled UvrA2 molecules on DNA tightropes using an optically trapped nanoprobe.

In this study we describe a new methodology to physically probe individual complexes formed between proteins and DNA. By combining nanoscale, high speed physical force measurement with sensitive fluorescence imaging we investigate the complex formed between the prokaryotic DNA repair protein UvrA2 and DNA. This approach uses a triangular, optically-trapped “nanoprobe” with a nanometer scale tip protruding from one vertex. By scanning this tip along a single DNA strand suspended between surface-bound micron-scale beads, quantum-dot tagged UvrA2 molecules bound to these ‘”DNA tightropes” can be mechanically interrogated. Encounters with UvrA2 led to deflections of the whole nanoprobe structure, which were converted to resistive force. A force histogram from all 144 detected interactions generated a bimodal distribution centered on 2.6 and 8.1 pN, possibly reflecting the asymmetry of UvrA2’s binding to DNA. These observations successfully demonstrate the use of a highly controllable purpose-designed and built synthetic nanoprobe combined with fluorescence imaging to study protein-DNA interactions at the single molecule level.

Middle Jurassic evidence for the origin of Cupressaceae: A paleobotanical context for the roles of regulatory genetics and development in the evolution of conifer seed cones.

Triassic and Jurassic fossils record structural changes in conifer seed cones through time, provide the earliest evidence for crown-group conifer clades, and further clarify sister-group relationships of modern conifer families. A new and distinct seed-cone from the Isle of Skye in western Scotland provides the oldest detailed evidence for the ancestral morphology of the phylogenetically contentious family Cupressaceae. A single isolated cone was prepared as serial sections by the cellulose acetate peel technique, mounted on microscope slides, and viewed and photographed using transmitted light. The three-dimensional structure of the cone was first reconstructed from the serial sections and then refined through imaging with x-ray microtomography. Scitistrobus duncaanensis, gen. et sp. nov., is a 7.5 mm-diameter cylindrical seed cone with helically arranged bract-scale complexes in which three scale tips separate from a large bract, each tip bearing one adaxial seed. Seeds are near-inverted, show 180° rotational symmetry, and have a diminutive wing in the major plane. Scitistrobus duncaanensis extends the fossil record for anatomically preserved seed cones of the Cupressaceae backward from the Upper Jurassic to the Aalenian Stage of the Middle Jurassic. The cone displays a previously unknown combination of characters that we regard as diagnostic for seed cones of early-divergent Cupressaceae and helps to clarify the sequence of structural changes that occurred during the transition from ancestral voltzialean conifers to morphologically recognizable Cupressaceae. Hypotheses of homology underpinning such transformational series can be tested by ongoing reciprocal illumination between the morphology of fossil taxa and the morphogenesis and developmental genetics of their extant crown-group relatives.

Prospects for Lone Wolf and SIMAD terrorism

The recent terror events committed by individuals in the streets of Jerusalem, the Canadian Parliament and in New York have raised attention to the phenomena of Lone Wolf terrorism.While there is no internationally-agreed upon definition, generally a lone wolf (LW) is described as a single individual acting essentially alone who kills or injures people or significantly damages infrastructure to bring about political, religious, or ideological aims, to right perceived wrongs, to gain recognition or in response to schizophrenic aberrations or other insane impulses. We call a LW with intent to use weapons of mass destruction resulting in a high number of casualties “SIMAD” standing for “Single Individual Massively Destructive.” A new kind of arms race is developing. On the one hand, massively lethal weapons are becoming available to individuals who intend to use them, and on the other hand, methods of mass surveillance and for apprehending such individuals are increasing as well. Will the methods of detection be adequate and timely enough to avoid catastrophe? The outcomes of this race are important because weapons that become available to LWs will have enormous destructive power, and interdiction in their acquisition may involve new and repressive social constraints. No matter which way the scale tips, the world changes.To reach a broader understanding of this threat, the Israel Node of The Millennium Project initiated a Real-Time Delphi study of prospects for LW terrorism with the participation of some 60 worldwide experts in the field of security and other related specialties. The participants generally had high confidence in their answers, but there were some sharp and important disagreements. We have early warning about this issue; we should use this time to better understand it, and take steps to mitigate or avoid its threats.

Hubbardiastrobus cunninghamioides gen. et sp. nov., Evidence for a Lower Cretaceous Diversification of Cunninghamioid Cupressaceae

Premise of research. The occurrence of six ovulate cones and six leafy branching systems, two of which show attachment of the ovulate cone, reveals a new cunninghamioid fossil conifer from the Cretaceous Apple Bay locality of Vancouver Island, Canada. This anatomically preserved plant expands our understanding of basal Cupressaceae in the fossil record. Methodology. Specimens were studied from anatomical sections prepared by the classic cellulose acetate peel technique. Pivotal results. Vegetative shoots have helically arranged Cunninghamia-like leaves with a single vascular bundle and one to three resin canals. Ovulate cones consist of numerous helically arranged bract/scale complexes with a large bract and a small ovuliferous scale with three separate tips. There are three inverted seeds/ovules attached adaxially, immediately proximal to the free scale tips. Conclusions. This discovery reveals the presence of a new genus and species of basal Cupressaceae, Hubbardiastrobus cunninghamioides, in the Early Cretaceous (Valanginian; ∼136 Ma) of the Northern Hemisphere. These data expand the species richness of fossil Cupressaceae and further document the Cretaceous evolutionary radiation of subfamily Cunninghamioideae.

Microelectrode for energy and current control of nanotip field electron emitters

Emerging experiments and applications in electron microscopy, holography, and diffraction benefit from miniaturized electron guns for compact experimental setups. We present a highly compact microelectrode integrated field emitter that consists of a tungsten nanotip coated with a few micrometers thick polyimide film followed by a several nanometers thick gold film, both positioned behind the exposed emitter apex by approximately 10–30 μm. The control of the electric field strength at the nanometer scale tip apex allows suppression, extraction, and energy tuning of field-emitted electrons. The performance of the microelectrode is demonstrated experimentally and supported by numerical simulations.

Combined short scale roughness and surface dielectric function gradient effects on the determination of tip-sample force in atomic force microscopy

The contribution of tip roughness to the van der Waals force between an atomic force microscopy probe tip and the sample is calculated using the multilayer effective medium model, which allows us to consider the relevant case of roughness characterized by correlation length and amplitude in the nanometer scale. The effect of the surface dielectric function gradient is incorporated in the tip-sample force model. It is concluded that for rms roughness in the few nanometers range the effect of short scale tip roughness is quite significant.

Seed cone anatomy of Cheirolepidiaceae (Coniferales): Reinterpreting Pararaucaria patagonica Wieland

Seed cone morphology and anatomy reflect some of the most important changes in the phylogeny and evolutionary biology of conifers. Reexamination of the enigmatic Jurassic seed cone Pararaucaria patagonica reveals previously unknown systematically informative characters that demonstrate affinities with the Cheirolepidiaceae. This paper documents, for the first time, internal anatomy for seed cones of this important extinct Mesozoic conifer family, which may represent the ghost lineage leading to modern Pinaceae. Morphology and anatomy of cones from the Jurassic La Matilde Formation in Patagonia are described from a combination of polished wafers and thin section preparations. New photographic techniques are employed to reveal histological details of thin sections in which organic cell wall remains are not preserved. Specific terminology for conifer seed cones is proposed to help clarify hypotheses of homology for the various structures of the cones. Specimens are demonstrated to have trilobed ovuliferous scale tips along with a seed enclosing pocket of ovuliferous scale tissue. Originally thought to represent a seed wing in P. patagonica, this pocket-forming tissue is comparable to the flap of tissue covering seeds of compressed cheirolepidiaceous cones and is probably the most diagnostic character for seed cones of the family. Pararaucaria patagonica is assigned to Cheirolepidiaceae, documenting anatomical features for seed cones of the family and providing evidence for the antiquity of pinoid conifers leading to the origin of Pinaceae. A list of key morphological and anatomical characters for seed cones of Cheirolepidiaceae is developed to facilitate assignment of a much broader range of fossil remains to the family. This confirms the presence of Cheirolepidiaceae in the Jurassic of the Southern Hemisphere, which was previously suspected from palynological records.