RecruitNet: A global database of plant recruitment networks

Plant recruitment interactions (i.e., what recruits under what) shape the composition, diversity, and structure of plant communities. Despite the huge body of knowledge on the mechanisms underlying recruitment interactions among species, we still know little about the structure of the recruitment networks emerging in ecological communities. Modeling and analyzing the community-level structure of plant recruitment interactions as a complex network can provide relevant information on ecological and evolutionary processes acting both at the species and ecosystem levels. We report a data set containing 143 plant recruitment networks in 23 countries across five continents, including temperate and tropical ecosystems. Each network identifies the species under which another species recruits. All networks report the number of recruits (i.e., individuals) per species. The data set includes >850,000 recruiting individuals involved in 118,411 paired interactions among 3318 vascular plant species across the globe. The cover of canopy species and open ground is also provided. Three sampling protocols were used: (1) The Recruitment Network (RN) protocol (106 networks) focuses on interactions among established plants ("canopy species") and plants in their early stages of recruitment ("recruit species"). A series of plots was delimited within a locality, and all the individuals recruiting and their canopy species were identified; (2) The paired Canopy-Open (pCO) protocol (26 networks) consists in locating a potential canopy plant and identifying recruiting individuals under the canopy and in a nearby open space of the same area; (3) The Georeferenced plot (GP) protocol (11 networks) consists in using information from georeferenced individual plants in large plots to infer canopy-recruit interactions. Some networks incorporate data for both herbs and woody species, whereas others focus exclusively on woody species. The location of each study site, geographical coordinates, country, locality, responsible author, sampling dates, sampling method, and life habits of both canopy and recruit species are provided. This database will allow researchers to test ecological, biogeographical, and evolutionary hypotheses related to plant recruitment interactions. There are no copyright restrictions on the data set; please cite this data paper when using these data in publications.

Implant Placement After Marsupialization of a Dentigerous Cyst

This paper presents a case of a dentigerous cyst accompanied by a history of inflammation, resorption of the roots of the first molar and the lingual aspect of the distal root of the second molar, and devitalization of the 2 premolars. The treatment option chosen was marsupialization of the cyst, extraction of the involved teeth, endodontic treatment of both premolars, and implant insertion in the area of the first mandibular molar at a later stage. Twelve months postsurgery the area of interest was almost flattened and the radiographic examination revealed total disappearance of the radiolucency. An implant of 15 × 4 mm was inserted in the area of the first mandibular molar. Despite the excellent implant stability achieved, a thin central zone of the defect remained void of bone. After complete excision of soft tissue the defect was filled with an alloplastic bone substitute. Eight months later (20 months postsurgery), the implant was uncovered and the restorative procedure completed. The implant and the crown have been functioning sign and symptom free for 48 months. Marsupialization was preferred instead of enucleation due to (1) proximity of the cyst to the mandibular canal; (2) need for apicectomy of both premolars to gain good access for enucleation; (3) refusal of the patient to undergo a second surgery for bone harvesting; (4) lower probability for postoperative contamination; (5) need of small quantity of bone substitute; (6) easier extraction of the impacted second molar due to its coronal movement. The disadvantages of the treatment were the long healing period and the discomfort of the patient at the early stages of marsupialization. It was judged that the advantages outweighed the disadvantages in this case. We discuss the findings of other authors who support the conservative approach to jaw cysts in a young population, and the concerns that exist in the literature about the ability of osseoconductive graft materials to generate vital bone and achieve implant-to-bone contact.

Conventional radiographsvsdigitized radiographs: image quality assessment

OBJECTIVES

The aim of this study was to compare image quality characteristics of conventional radiographs and their digital counterparts.

METHODS

100 conventional radiographs (E-speed) were used for the evaluation of density and contrast. The radiographs were made using a range of exposures under standardized conditions and were compared with digital images that resulted from scanning the above radiographs with a commercially available scanner. Resolution was evaluated with an experiment using 50 film packets and a resolution target exposed with different exposure times, using both the original radiographs and their scanned equivalents.

RESULTS

The digitized radiographs appeared to be of higher density than the conventional ones. Moreover, they demonstrated a narrower density range. Resolution was similar for both types of images.

CONCLUSIONS

Although there is an agreement with the literature that the digitized radiographs are of higher density, further investigation is required to detect the various factors that may have an effect on the quality of the digitized images.

Determination of benzodiazepines in forensic samples by HPLC with photo-diode array detection

A high-performance liquid chromatographic (HPLC) method has been developed for the analysis of several benzodiazepines and some of their metabolites in blood, plasma and urine. The method included a liquid-liquid extraction with n-hexane:ethylacetate, a gradient elution on a C8 reversed phase column with a non-electrolyte eluent and a photo diode array detection. This allowed a rapid detection, a purity check, and identification as well as quantitation of the eluting peaks. The detection limit was 10 to 30 ng and the limit of quantitation was 0.05 microgram/mL, using 1 mL of blood, plasma or urine. The procedure is applied routinely in forensic toxicological analyses involving blood, stomach content, urine and organ samples. About 30 positive cases are reported. The avoidance of the use of an electrolyte buffer in the eluent resulted in a robust procedure, free of technical problems and of long rinsing periods, suitable for routine use in forensic toxicology analysis involving blood, urine, stomach content and tissue samples.

Simultaneous determination of flunitrazepam and its metabolites in plasma and urine by HPLC/DAD after solid phase extraction

A high performance liquid chromatography (HPLC) assay was developed for the determination of flunitrazepam (FNZ) and its metabolites in urine and plasma. The analytes and the internal standard (triazolam, TRZ) were extracted by Sep-Pak C18 SPE-cartridge and separated utilizing a 5 microm ChromSpher C8 glass column with a gradient mobile phase containing methanol and 0.125% (v/v) of isopropylamine in water. Diode array detection (DAD) was carried out at a monitoring wavelength of 240 nm and a reference wavelength of 550 nm. Standard curves were linear from their quantitation limits until 200 ng ml(-1) urine or 250 ng ml(-1) plasma for 7-amino-desmethyl-flunitrazepam (ADF), 7-amino-flunitrazepam (AF), 7-acetamino-flunitrazepam (ACF) and until 400 ng ml(-1) urine or 500 ng ml(-1) plasma for FNZ, 1-desmethyl-flunitrazepam (DF), and 3-hydroxyl-flunitrazepam (HF). The intraday and interday coefficients of variation ranged from 2.04 to 9.07% and from 2.64 to 14.10%, respectively in urine and from 5.13 to 8.60% and from 7.27 to 10.46%, respectively in plasma. The developed method is used in forensic toxicology and is also applicable to pharmacokinetic studies in man.

Radiopacity of elastomeric impression materials

The purpose of this study was to measure and classify the radiopacity of various elastomeric impression materials available on the open market and to compare their appearance in radiographs of the oral tissues. In order to measure and classify their radiopacity, twenty-eight specimens of various materials were placed and exposed on film together with an aluminium stepwedge. A dummy head was used to investigate the radiographic density of the above specimens in comparison with that of simulated oral tissues.

Nuchal nevus flammeus as a skin marker of prognosis in alopecia areata

In this work, the incidence of nuchal nevus flammeus was studied in 205 patients suffering from various forms of alopecia areata, as well as in a group of 555 volunteers without alopecia areata examined in our outpatient clinic. The incidence of nuchal nevus flammeus in the totalis-universalis form of alopecia areata was 58.2% (examined patients, n = 79), in ophiasis-extensive forms 22.8% (examined patients, n = 70) and in simple forms of alopecia areata 3.6% (examined patients, n = 56). In the group of 555 volunteers without alopecia areata the incidence of nuchal nevus flammeus was 4.5%. Our results show that nuchal nevus flammeus could be a valuable skin marker indicating a more severe course of alopecia areata.

CH50 and C3 component of complement in Hansen's disease

Although a variety of complement values have been reported in leprosy, we found no difference in the CH50 and C3 in the sera of 30 normal persons and 233 lepromatous patients. No statistically significant difference was observed in CH50 and C3 values between healthy controls and lepromatous patients taken as a whole or separated into the different types of the disease spectrum (P greater than 0.1). A statistical difference in C3 titers was found between health controls and borderline patients (P less than 0.05 greater than 0.01) but the sample number is too small to be valid. An important number of sera tested had low and an equally important number had high complement values. Sera with high and low values are important because high values are found in acute inflammatory reactions and low values demonstrate complement activation. Discrepancies in reported results are probably due not only to differences in the methods used, storage and limited number of sera tested, but mainly to the stage of the disease and the drug's administration.