Opaque Contents Research Articles

Use of cardiac gated computed tomography in the diagnosis of a rare congenital cardiovascular anomaly in an adult alpaca.

A 5-year-old female alpaca was presented with respiratory distress and lethargy. Thoracic radiographs revealed a cranioventrally distributed alveolar pattern, caudodorsal bronchial pattern, cardiomegaly, increased soft tissue opaque content in the ventral thorax, and rounded soft tissue opaque structures craniodorsal to the carina. Cardiac gated CT demonstrated a patent ductus arteriosus, ventricular septal defect, complete left atrioventricular valve atresia, partial anomalous venous connections from the cranial pulmonary veins to the azygous and cranial vena cava, severe right-sided cardiomegaly, pleural and peritoneal fluid, and severe hepatic congestion. These findings were confirmed with necropsy.

Protocupressinoxylon baii sp. nov., a gymnospermous fossil trunk from the Upper Shihhotse Formation (Permian) of Yangquan City, Shanxi Province, North China

A new permineralized gymnospermous fossil trunk with only secondary xylem being preserved, Protocupressinoxylon baii sp. nov., is described from the Upper Shihhotse Formation (Permian) in Yangquan City, Shanxi Province, North China. The pith, primary xylem, and bark are not preserved. The wood is pycnoxylic, composed of tracheids, rays, and axial parenchyma. True growth rings are absent. However, growth interruptions are well-developed. In cross section, tracheids in the growth interruption vary gradually in diameter from thin-walled, larger cells to thick-walled, smaller cells, and change at an opposite direction, forming a symmetrical boundary. Radial tracheidal pitting is uni- to biseriate. When uniseriate, pits are contiguous or separately arrayed. When biseriate, pits are mostly alternately arranged. Rims of Sanio and tangential pits are absent. The percentage of abietinean pitting of current fossil wood is 23.6%, and the araucarian pitting is 76.4%. Axial parenchymatous cells are irregularly distributed among the xylem tracheids with opaque contents. Rays are homogeneous, commonly uniseriate, and are 1–24 cells high. The cross-field pitting is mainly of the cupressoid type, and there are commonly 1–2, rarely 3–4 pits in each cross-field unit. The fossil trunk represents the first record of Protocupressinoxylon Eckhold from the Permian of the Cathaysia. Fungal hyphae present in tracheids and rays, demonstrating the association between the current trunk and fungi. The absence of true growth rings, and the presence of growth interruptions suggest suitable climatic conditions with episodic drought for the flourishing of plants during the time when the Upper Shihhotse Formation was deposited in the Permian.

CRUISING TIKTOK: USING ALGORITHMIC FOLK KNOWLEDGE TO EVADE CISHETERONORMATIVE CONTENT MODERATION

This paper examines crackdowns on queer content on TikTok and creative responses of content creators to circumvent biased content moderation and cisheteronormative censorship. The first portion of the paper demonstrates TikTok’s recurrent cisheteronormative biases in content moderation decisions and examines select instances of LGBTQ+ content that has been censored on the platform. It also works to situate this within a broader trend of LGBTQ+ censorship across internet platforms. The second portion of the paper examines how LGBTQ+ TikTok users have built up folk knowledges and intuitive understandings of TikTok’s blackboxed algorithms and opaque content moderation policies, situating this discussion within theories of the ‘algorithmic imaginary’. It catalogs the myriad ways that TikTok users work to circumvent LGBTQ+ censorship on the platform (e.g. by tactically obscuring key words in both speech and text and obscuring body parts and scenes). In the final portion of the paper, I draw on the concept of ‘cruising’ and other constitutive silences of LGBTQ+ existence to show how LGBTQ+ users are particularly well suited to producing folk knowledge about blackboxed algorithms. In closing, I examine the affordances and the limitations of LGBTQ+ users’ approach to navigating platform governance – and content moderation practices more specifically – as well as call for more organized and collective action in search of more permanent changes towards LGBTQ+-friendly platforms.

‘To say report it, well, it seems a little useless’: Evaluating Australians' expectations of online service providers and reducing online child sexual exploitation

AbstractOnline service providers (OSPs) provide a range of opportunities for individuals to engage in online child sexual exploitation, including the production and distribution of child sexual abuse material. As the failings of opaque content moderation systems have become apparent, a range of states have proposed or implemented new regulatory measures, amidst ongoing debates over the legitimacy of state intervention in online communication. This paper presents the findings of a survey of 482 Australian adults regarding their expectations of technology companies and governments in relation to key issues of online child protection. The results suggest strong demands for greater action by OSPs against sexual exploitation, and for governments to legally enshrine some obligations for OSPs, as well as concern about the privacy of innocent users and about the data handling and cybersecurity of governments and technology companies. These findings indicate that governments and OSPs which are seeking to construct meaningful action against online child sexual exploitation might find significant support among the general public for such measures. Equally, these are very sensitive areas of governance for many. Governments and companies would draw significant assistance from understanding the views of users when navigating these challenging issues and ensuring that their measures are carefully calibrated to their legitimate concerns.

An investigation of social media labeling decisions preceding the 2020 U.S. election.

Since it is difficult to determine whether social media content moderators have assessed particular content, it is hard to evaluate the consistency of their decisions within platforms. We study a dataset of 1,035 posts on Facebook and Twitter to investigate this question. The posts in our sample made 78 misleading claims related to the U.S. 2020 presidential election. These posts were identified by the Election Integrity Partnership, a coalition of civil society groups, and sent to the relevant platforms, where employees confirmed receipt. The platforms labeled some (but not all) of these posts as misleading. For 69% of the misleading claims, Facebook consistently labeled each post that included one of those claims-either always or never adding a label. It inconsistently labeled the remaining 31% of misleading claims. The findings for Twitter are nearly identical: 70% of the claims were labeled consistently, and 30% inconsistently. We investigated these inconsistencies and found that based on publicly available information, most of the platforms' decisions were arbitrary. However, in about a third of the cases we found plausible reasons that could explain the inconsistent labeling, although these reasons may not be aligned with the platforms' stated policies. Our strongest finding is that Twitter was more likely to label posts from verified users, and less likely to label identical content from non-verified users. This study demonstrates how academic-industry collaborations can provide insights into typically opaque content moderation practices.

Physical properties and average atomic numbers of chondrules using computed tomography

Micro-computed tomography is a fast and essentially non-destructive technique for studying 3D properties of solid objects. This study explores the use of a micro-CT technique to determine the physical properties and average atomic numbers of 44 chondrules from unequilibrated (petrologic type 3.00 to 3.6) ordinary, carbonaceous, and enstatite chondrites. Many chondrules deviate from a spherical geometry, implying that they were affected by strain during cooling and prior to complete solidification. The porosity of the studied chondrules ranges from 0.04 vol% to 5.3 vol%. Chondrules from carbonaceous chondrites show the highest porosity and the largest voids. The high porosity could be caused by the presence of oxidized precursors in the chondrule melt that escaped as a gas during high temperature processing and crystallization of the melt. In some chondrules, pores are associated with opaque phases, suggesting their formation either during solidification of metal phases and/or during aqueous alteration. The average atomic numbers of chondrules range from 35 ± 4 to 22 ± 2, independently of porosity and opaque content and is likely controlled by the variation of Mg/Fe in chondrule silicates. The absence of a consistent variation between the degree of deformation, chondrule diameter, and porosity among the studied chondrules from different groups, suggests that the processes responsible for the different physical properties of the chondrules are decoupled from each other and are likely universal to all chondrules.

You Can (Not) Say What You Want: Using Algospeak to Contest and Evade Algorithmic Content Moderation on TikTok

Social media users have long been aware of opaque content moderation systems and how they shape platform environments. On TikTok, creators increasingly utilize algospeak to circumvent unjust content restriction, meaning, they change or invent words to prevent TikTok’s content moderation algorithm from banning their video (e.g., “le$bean” for “lesbian”). We interviewed 19 TikTok creators about their motivations and practices of using algospeak in relation to their experience with TikTok’s content moderation. Participants largely anticipated how TikTok’s algorithm would read their videos, and used algospeak to evade unjustified content moderation while simultaneously ensuring target audiences can still find their videos. We identify non-contextuality, randomness, inaccuracy, and bias against marginalized communities as major issues regarding freedom of expression, equality of subjects, and support for communities of interest. Using algospeak, we argue for a need to improve contextually informed content moderation to valorize marginalized and tabooed audiovisual content on social media.

From trash to cash: the effect of product construal and benefit appeals on consumer evaluations of rescued meals

PurposeHospitality companies increasingly sell their unsold, or so-called rescued meals, on food waste reduction applications (e.g. Too Good To Go [TGTG]). The purpose of this research is to explore the influence of product construal and benefit appeals on consumer evaluations.Design/methodology/approachStudy 1 (N = 277 participants) is an online experiment with a 2 × 3 between subject design analyzed using ANOVA and planned contrast analysis. Study 2 is a 2 × 2 field experiment (N = 147 sold rescued food boxes) using chi-square tests for the main analysis.FindingsThis study finds that an abstract product description (e.g. a magic box with an opaque content) matched with an environmental benefit appeal renders significantly higher consumer evaluations in comparison to when the same product is paired with financial benefits. In contrast, a concrete product presentation featuring financial benefits as opposed to environmental benefits increases consumer purchase intentions and willingness to pay.Research limitations/implicationsWe empirically show how the interaction and congruency between product construal and benefit appeals affect evaluations in a last-minute purchase context.Originality/valueTo the best of the authors’ knowledge, this is the first study to look at the interactive effect between product construal and benefit appeals in a food waste and technology context.

Glandular Cells in Sea Star Lymphoïd Organ: Axial Organ Tem Observations

We recall, in this work, the presence of an epithelio-neural system in the sea star axial organ and a glandular one. Many vesicles (from 100 to 500 angstroms) with a more or less opaque content in electron microscopy, appear in these last cells

Gabbros versus granites of the subduction regime of South Sinai, Egypt: discrimination and geochemical modelling

The Arabian–Nubian Shield of South Sinai, Egypt, comprises older granite (OG) and metagabbro–diorite complex (MG) outcrops pertaining to the island arc regime. The study aims to throw some light on the role played by these rocks during the tectonic evolution of the Sinai, Egypt. Three selected areas via Nesyrin, El-Fringa-Minader and Shahera outcrops are selected as case example. Field, petrography, geochemistry and thermobarometric studies are considered to elucidate discriminations and genetic variations. The OG compositions are tonalite and granodiorite, whereas MG constitutes hornblende–metagabbros, hornblende–leucogabbro and diorite. Opaque mineral contents are relatively enriched in the MG and represented by magnetite, hematite and ilmenite with few sulphides. Geochemically, the OG rocks are peraluminous, calc-alkaline and I-type and belong to syncollision volcanic arc. The MG varieties exhibit transitional calc-alkaline/tholeiite magma types and are comparable to rocks of island arc setting. Amphiboles of MG are calcic-type (actinolite, actinolite hornblende and subordinate of magnesia-hornblende). Rocks are crystallised under medium (El-Fringa-Minader and Shahera) to low (Nesyrin) pressure. Amphiboles from the OG have the composition of actinolitic hornblende (Shahera area), ferroedenite to ferroedenitic hornblende (Nesyrin area). They are formed under low pressure. Plagioclase ranges in composition from oligoclase to andesine. Biotite of the OG is Mg-rich (Shahera area), Fe-rich (Nesyrin area) and lepidomelane. OG rocks exhibit calc-alkaline magma affinity. The thermobarometric study indicates that MG rocks are formed at a temperature between 600 and 730 °C and the pressure of emplacement varies from 2 to 4 kbar. OG rocks gave a temperature of 648–717 °C and an emplacement pressure of 1–4 kbar. Both modelling and thermobarometric calculations prove that magmas are generated at a depth of about 30 km for OG and from 15 to 35 km for MG. Geochemical modelling favours that MG is derived from 40% partial melting of the lower crust followed by 15% to 35% fractional crystallisation. Granodiorite is derived through the 25% to 45% fractional crystallisation of MG.

Squamous Pulmonary Neoplasia Grafted on Lesions of Pulmonary Tuberculosis Sequelae.

Clinical symptoms of hemoptysis, chest pain, dyspnea, night sweats and weight loss seen in a patient known for 14 years with pulmonary tuberculosis with sequelae lesions, will always guide the diagnose to a reactivated pulmonary tuberculosis. Yet, in this case, the latest pulmonary radiography revealed newly emerging bilateral lesions with the appearance of a macronodular opacity of medium intensity, discreetly non-homogeneous, located apical-sub-clavicular on the right side, but also with an apical-sub-clavicular cavity lesion on the left side, well defined, with uniform opaque content, and clear-cut outline. Complementary examinations, computed tomography and biopsy bronchoscopy, confirmed the diagnosis of upper right lobe pulmonary tumor with suspicion of aspergilloma in the upper left lobe.

The ultrastructure of the integument and proventriculus in the raptorial rotifer Cupelopagis vorax (Monogononta: Collothecaceae: Atrochidae)

AbstractMembers of the sessile rotifer species Cupelopagis vorax are unusual ambush predators that live permanently attached to submerged freshwater plants. Previous light microscopical research has revealed several uncommon features in this species including a stellate‐patterned integument and an expansive foregut region called the proventriculus. In this study, we apply transmission electron microscopy to explore the ultrastructure of both the integument and foregut to determine how they differ from other rotifers. Our results reveal that the integument is covered by a thick glycocalyx and is patterned with tubercles that originate from the intracytoplasmic lamina (ICL) within the syncytial epidermis. The ICL forms an apical layer within the syncytium, is electron dense and mostly amorphous, and forms tubercles up to 2.3 μm; these tubercles probably account for the patterned appearance of the integument and are similar to what has been found in other gnesiotrochan rotifers. The basal cytoplasm is highly granular and contains two types of membrane‐bound vesicles: large ovoid vesicles (320–411 nm) with amorphous, opaque contents, and secretory bulbs (110–264 nm) with electron‐lucent cores and occasionally electron‐dense contents. Only the secretory bulbs were observed to form connections to the apical plasmalemma, and so are probably exocytotic. Internally, the proventriculus is a large distensible sack that connects the anterior pharyngeal tube to the posterior mastax. The proventricular epithelium is a thin syncytium mostly covered with a dense glycocalyx and a strong brush border of microvilli underlain by a thin terminal web. The cytoplasm contains few organelles and there is no evidence that it is either secretory or has features (e.g., ICL) that might aid in maceration. We hypothesize that the thick glycocalyx might serve a protective function against the movements of live prey and/or against enzymes released from the rotifer's gastric glands that become regurgitated during feeding.

Explainable Agency for Intelligent Autonomous Systems

As intelligent agents become more autonomous, sophisti- cated, and prevalent, it becomes increasingly important that humans interact with them effectively. Machine learning is now used regularly to acquire expertise, but common techniques produce opaque content whose behavior is difficult to interpret. Before they will be trusted by humans, autonomous agents must be able to explain their decisions and the reasoning that produced their choices. We will refer to this general ability as explainable agency. This capacity for explaining decisions is not an academic exercise. When a self-driving vehicle takes an unfamiliar turn, its passenger may desire to know its reasons. When a synthetic ally in a computer game blocks a player’s path, he may want to understand its purpose. When an autonomous military robot has abandoned a high-priority goal to pursue another one, its commander may request justification. As robots, vehicles, and synthetic characters become more selfreliant, people will require that they explain their behaviors on demand. The more impressive these agents’ abilities, the more essential that we be able to understand them.

Glandular trichomes of Tussilago Farfara (Senecioneae, Asteraceae).

The glandular trichomes are developed on the aerial organs of Tussilago farfara ; they produce phenols and terpenoids. Smooth endoplasmic reticulum and leucoplasts are the main organelles of the trichome secretory cells. The aim of this study was to characterise the morphology, anatomy, histochemistry and ultrastructure of the trichomes in Tussilago farfara as well as to identify composition of the secretory products. Structure of trichomes located on the peduncles, bracts, phyllaries, and leaves were studied by light and electron microscopy. The capitate glandular trichomes consist of a multicellular head and a biseriate long stalk. Histochemical tests and fluorescence microscopy reveal phenols and terpenoids in the head cells. During secretory stage, the head cells contain smooth and rough endoplasmic reticulum, Golgi apparatus, diversiform leucoplasts with opaque contents in lamellae, chloroplasts, mitochondria, and microbodies. In the capitate glandular trichomes of T. farfara subcuticular cavity is absent, unlike glandular trichomes in other Asteraceae species. For the first time, content of metabolites in the different vegetative and reproductive organs as well as in the isolated capitate glandular trichomes was identified by GC-MS. Forty-five compounds, including organic acids, sugars, polyols, phenolics, and terpenoids were identified. It appeared that metabolite content in the methanol extracts from peduncles, bracts and phyllaries is biochemically analogous, and similar to the metabolites from leaves, in which photosynthesis happens. At the same time, the metabolites from trichome extracts essentially differ and refer to the above-mentioned secondary substances. The study has shown that the practical value of the aerial organs of coltsfoot is provided with flavonoids produced in the capitate glandular trichomes.

Morphological characterisation of vesicular structures in the canine ejaculate

Membrane vesicles (MV) have been identified in seminal plasma from various species and they are thought to have a significant impact on semen quality and fertilisation. Although recently presence of MV has been also described in the canine ejaculate, detailed knowledge on their morphology is missing by now. This is, however, needed to provide a basis for detailed biochemical and functional studies as it is generally assumed that different MV populations are responsible for distinct tasks. MV were prepared for light (LM) and transmission electron microscopy (TEM) analysis using samples from normospermic dogs (n=15), hypokinozoospermic dogs (n=2, h) and one castrated azoospermic dog (a). For TEM, a new preparation protocol was used resulting in a higher MV retrieval rate. Using fractionated semen samples, most MV were identified in the second (sperm-rich) fraction in LM. Using pooled ejaculates, three different MV types could be identified in LM: (1) large MV with a marginal accumulation of opaque, granulated material, (2) medium- to small size MV with dense, opaque content and (3) small MV with no further defined contents. No direct contact between sperm and MV could be visualised. In TEM, 11 different MV types were identified based on diameter, structure, contents and electron density of contents as well as presence, number and size of smaller MV inside the MV itself. In normospermic males, secondary vesicles (type i, H, K1/2) included smaller vesicles and had a weighted mean diameter of 409.46nm; hereof types i, H and K1 were smaller (mean: 287.55nm, range: 51.25–994.86nm) and type K2 was larger (mean: 1746.43nm, range: 1003.66–3289.34nm). Primary vesicles (mean diameter: 135.29nm) – without vesicles inside – were differentiated into larger MV (A, B, C1/2) with a mean diameter of 219.63nm (range: 39.08–1300.13nm) and small primary MV (F, G) with a mean diameter of 66.12nm (range: 24.62–99.84nm). Whereas all mentioned MV were round to oval and mostly double-, rarely multiple-membrane surrounded, one longish primary MV type (L) was identified. In general, small primary vesicles were most common independent of semen quality, but distribution frequency of vesicle types differed between normospermic, pathospermic dogs and the castrated male. Mean weighted diameter of MV was 195.14nm (range: 24.62–3289.34nm) in normospermic males with the maximum diameter being smaller in the other dogs (h: 2096.78nm; a: 1314.06nm). Our results provide new information about ultrastructure and distribution frequency of canine MV in normospermic males and point to possible differences in MVs depending on semen quality. They provide the basis for further detailed functional analysis of MV subpopulations. Furthermore, the presence of MV in the castrated azoospermic male confirms an at least partly prostatic origin of canine MV.

Mo1591 Usefulness of Flexible Spectral Imaging Color Enhancement (FICE) in the Evaluation of Subtle Small Bowel Ulcerative Mucosal Lesions Detected by Videocapsule Endoscopy

and rating the usefulness of each of these pre-sets. The comparison of accuracies in correctly categorizing the images was performed between the two readings (McNemar’s test). Results: Between the first (WLI only) and the second (chromoendoscopy-aided) reading, in terms of accuracy there was a global 16.5% [95% CI:13.6 - 19.4%] improvement (p!0.001), derived from 22% [95% CI: 18.9 - 25.1%] improvement in the evaluation of true ulcerative images (p!0.001), and 11% [95% CI: 4.1 - 17.7%] decrease in the evaluation of faked ones (p Z 0.003), results reproduced for each of the four readers. FICE 1 and 2 pre-sets were rated as most useful. Conclusions: The use of FICE pre-sets 1 and 2 may be clinically meaningful in order to better categorize difficult to interpret small bowel mucosal ulcerative lesions. These pre-sets seem to provide a high level of visibility by transparent-‘izing’ opaque luminal content or enhancing the color differences associated with ulcerated mucosa. However, care must be taken, and individual images should only be evaluated as part of a succession in a recording, as the technology could also misguide the interpretation of artifacts as ulcerative lesions, extra caution being necessary under poor bowel preparation. Acknowledgement: The work has been funded by the Sectoral Operational Programme Human Resources Development 2007-2013 of the Ministry of European Funds through the Financial Agreement POSDRU/159/1.5/ S/132395.

To what adaptive problems is human teaching a solution?

We welcome Kline's systematic overview of teaching from a functional evolutionary perspective. However, Kline's framework does not provide satisfying characterization of the adaptive problems driving the evolution of teaching through communication found in humans, where the key function is better characterized in terms of licensing inferences to opaque generic content than in terms of overcoming shortages of access and attention.

Microspore wall organisation and ultrastructure in two species of Selaginella (Lycophyta) producing permanent tetrads

Spore morphology and ultrastructural features of the permanent microspore tetrads of Selaginella convoluta and S. lepidophylla were studied with light microscopy, scanning and transmission electron microscopy. The four members of each tetrad in S. convoluta are linked together through a common envelope and form an unbroken complex system of alveoli that connects the equatorial and distal regions of the microspores. In the proximal exospore of microspores, no differentiation referable to an apertural fold was observed but an interruption of the exospore is evident in that area in germinating microspores. The distal exospore is composed of three strata: inner zone, intermediate zone and outer alveolar. In S. lepidophylla tetrads, the four microspores are assembled within a common tetrad envelope and are equatorially connected by a prominent ridge. The distal regions of the microspores are free. In the proximal exospore of microspores, no differentiation referable to an apertural fold was observed. The tetrad envelope appears as a wide common coat, which, on the surface and depending on the regions, is granular or alveolate, centrally perforated and, in section, consists of a single layer or forms a two-layered, more or less intricate, network. This envelope has the same contrast as the exospore outer layer and shows, in its median zone, cavities with opaque contents, quite similar to those of the microspore exospore layer. These two different types of tetrads emphasise the outstanding structural diversity of the microspore sporoderm in living Selaginellaceae.

Estimation of wear rate on diamond beads during cutting with diamond wire by using multiple linear regression techniques

The effects of mechanical, textural, and compositional properties of rocks on the bead wear during the cutting operation of marble blocks were evaluated in depth by multivariate statistical methods in this study. Moreover, the concept of texture coefficient (TC), which is a result of textural rock properties, was investigated and the effect of the textural coefficient on the marble and limestone cutting with diamond wire was examined. During the investigation, using statistical software called SPSS 10.0, stepwise multiple linear regression models of the wear rate for limestone and marble were developed based on the data obtained from field and laboratory studies. The results showed that wear on diamond beads increases as the cutting rate decreases. Wear rate increases as the quartz and opaque mineral content and TC increases while the average grain size decreases in limestone. Moreover, a weak correlation was detected between the cutting rate and TC, whereas no statistically significant relationship was found between the TC and wear rate in marble. As a result of this study, estimated values from the model equation are closely correlated with the values measured in the field; because of this, developed models could be used for determining the wear rate before starting the cutting operations of marble and limestone.

Spore morphology and wall ultrastructure of Hymenophyllaceae Link (Pteridophyta) from north-west Argentina

The family Hymenophyllaceae is represented in the study area by six species in two genera, Hymenophyllum J. E. Smith and Trichomanes L. The study was based on herbarium material and spores were studied under light microscope (LM), scanning electron microscope (SEM) and transmission electron microscope (TEM). Both genera have trilete spores, 23 to 45 μm in equatorial diameter, with an ornamentation of echinulae and cones in Hymenophyllum and of verrucae, gemmae and granules in Trichomanes. Mature spores have a sporoderm composed of a perispore, an exospore and a fibrillar endospore; the exospore is 0.5 to 2.5 μm thick, compact and with an irregular margin. In some cases radial channels and other channels associated with the middle and inner parts of the laesurae were evident. A series of cavities filled with an opaque content line the inner margin of the exospore. The perispore is 20 to 400 nm thick and unevenly differentiated along the surface of a same spore. Under TEM, two main differentially contrasted portions could be distinguished: a dark massive portion with structural components could not be distinguished, and a light portion with several plates arranged in piles. The inner surface of the perispore exhibit short scales. Globules are immersed within the perispore at some depth from the perispore surface and others connected to it by structural threads. The spore characters observed including shape, ornamentation, laesurae length and wall structure are useful in distinguishing the two genera studied, but less useful in differentiation at the species level.