Narrower Body Research Articles

Morphospace of lanternfish larvae and their interplay with oceanographic conditions from the southeastern Pacific Ocean

Lanternfish larval morphology is highly variable probably due to their adaptations to highly variable environmental conditions throughout ontogeny. To study the morphological variability of the larval stage of lanternfishes, samples were collected from the southeast Pacific Ocean between 2014 and 2022. Of the 24 species, nine belonged to the subfamily Lampanyctinae, two to the subfamily Diaphinae, one to the subfamily Notolychinae, one to the subfamily Gymnoscopelinae and 11 to the subfamily Myctophinae. A principal component analysis indicated the presence of body shapes varying from a slender and curved body, and upper jaw oriented downwards, with relatively rounded eyes, to taxa with robust bodies, particularly both the head and trunk, and elongated eyes in a dorsal-ventral plane (PC1 33%). Also, specimens varied from having short jaw, short snout, and slender body, to specimens with larger jaw (reaching behind the eye) and taller snout and trunk (PC2, 23%). Allometric effects were related to variations in body curvature and thickness (Diaphus theta, 12.9%), the curvature of the body and position of the eyes (Lampanyctodes hectoris, 25.1%), lengthening of the jaw and increase in eye size (Diogenichthys atlanticus, 24.6%), and a narrower body and smaller eyes (Hygophum bruuni, 20.5%). Four of the five subfamilies showed covariation between morphometrics and environmental conditions. Diaphinae, Gymnoscopelinae and Lampanyctinae body shape covaried with mean sea temperature of the water column, while Myctophinae larval shape covaried with mean salinity. In conclusion, this study quantifies shape variations during early lanternfish ontogeny from the southeastern Pacific Ocean, identifying main differences and allometric changes between the subfamilies belonging to Myctophidae, with a covariation between the shape of most lanternfish larvae and the environmental conditions experienced by myctophid early stages.

Seasonal dimorphism as an expression of sexual dimorphism: Influence of gonad maturity on the body shape of a rocky intertidal polyplacophoran

Seasonal dimorphism in the body shape of marine invertebrates has been poorly explored compared to vertebrates. We aim to investigate through traditional (body length/width ratio, dorsal elevation ratio and angle of elevation) and geometric (centroid size and shape geometric configurations) morphometrics the effect of gonad maturity (via the gonadosomatic index [GSI] and gonad development stages [GDS]) on changes in body shape in males and females of two latitudinally different populations of the broadcast-spawning intertidal mollusc Chiton articulatus. We confirmed that C. articulatus does not present external sexual dimorphism since sex does not have a significant effect on body shape (1%); instead, dimorphism was seasonal and related to the reproductive season, and varied across populations, probably because in the subtropical zone additional energy is invested in shell (scleritome) bending at the same time as the gonad matures, which is opposite of what occurs in the tropical zone. C. articulatus shows a narrower body shape (i.e., diminished body width) during its gonad maturity compared to the rest of the GDS and is corroborated by a body length/width ratio that contributes the greatest variation in the geometric shape descriptors (18%), just below the centroid size (24%). The expression of centroid size differences shows a correspondence with the change in body dimensions expressed by the three morphometric ratios during gonad maturity. The use of traditional body ratios over time may be useful in polyplacophoran molluscs as a proxy tool to estimate gonad maturity and to provide a reliable indication of the reproductive season.

New Scheloribates (Acari, Oribatida, Scheloribatidae) from Ethiopia

Four new species of the genus Scheloribates (Oribatida, Scheloribatidae)—S. (Scheloribates) flexibilis Ermilov sp. nov., S. (S.) monosetosus Ermilov sp. nov., S. (S.) triangulus Ermilov sp. nov., S. (Topobates) tredecim Ermilov sp. nov.—are described, based on adults collected from litter in the afroalpine and bamboo locations in Ethiopia. Scheloribates (S.) flexibilis differs from the related species S. (S.) longisetosus by the length of aggenital, anal and adanal setae and the morphology of setal bothridial head and anterodorsal part of the leg tibia II. Scheloribates (S.) monosetosus differs from the related species S. (S.) concentricus by the length of anal and adanal setae and translamellar line, and the morphology of the setal bothridial head. Scheloribates (S.) triangulus differs from the related species S. (S.) monosetosus by the morphology of ventrodistal part of the leg femora II–IV, number of setae on the leg genu II, the length of the prolamella, and the development of the notogastral seta p1. Scheloribates (T.) tredecim differs from the related species S. (T.) scheloribatoides by the absence of the prolamella, distinctly longer aggenital, anal and adanal setae, and narrower body.

A new species of the genus Xerodelphax Korotyaev, 1992 (Coleoptera: Curculionidae) from Kazakhstan

A new species, Xerodelphax ivanovi sp. n., of the subtribe Tanymecina (Tanymecini, Entiminae) is described and illustrated from the Ayagoz District of the Abai Region, Kazakhstan. The new species is similar to Xerodelphax parthicus Korotyaev, 1992 from Turkmenistan but differs in the pointed apex of the aedeagus, a broader pronotum anterior to and a narrower body. It is the first record of the genus Xerodelphax from Kazakhstan.

Differentiation of Bulinussenegalensis and Bulinusforskalii Snails in West Africa Using Morphometric Analysis

PurposeAccurate identification of medically important intermediate host and vector species is crucial for understanding disease transmission and control. Identifying Bulinus snails which act as intermediate host species for the transmission of schistosomiasis is typically undertaken using conchological and genital morphology as well as molecular methods.MethodsHere, a landmark-based morphometric analysis of shell morphology was undertaken to determine its utility to distinguish the closely related and morphologically similar sister species Bulinus senegalensis and Bulinus forskalii. The method was developed to increase the accuracy of conchological morphology methods to identify Bulinus species in the field. Both species are found in West Africa, but only B. senegalensis is implicated in the transmission of urogenital schistosomiasis.ResultsWe found when scaled down to the same length, 3-whorl and 4-whorl (juvenile) B. senegalensis shells had a longer spire, narrower body whorl and shorter aperture than B. forskalii. In contrast, 5-whorl (adult) B. senegalensis had a shorter spire, but still had a shorter aperture and narrower body whorl than B. forskalii. Canonical Variate Analysis (CVA) showed minimal overlap between B. senegalensis and B. forskalii for 3-whorl and 4-whorl shells, with a clear separation for 5-whorl shells. Overall, B. senegalensis had a consistently shorter aperture size and narrower body whorl than B. forskalii for all development stages. Spire length was variable depending on the stage of development, with 3-whorl and 4-whorl shells having the opposite trends of adult shells.ConclusionsOur study demonstrates the applicability of landmark-based morphometrics in distinguishing the medically important, Bulinus senegalensis from its morphologically similar sister species, Bulinus forskalii. We recommend using measurements based on spire length, penultimate whorl length, body whorl width and aperture size to differentiate B. senegalensis and B. forskalii, when used with the appropriate information for each shell’s development stage.

Secular Trends in the Size and Shape of the Scapula among the Portuguese between the 19th and the 21st Centuries.

Potential secular changes in the human scapula are fundamentally unbeknownst, with most of the preceding anatomical studies focusing on long-term changes in the long bones and the skull. As such, the cardinal purpose of this study pertains to the evaluation of secular trends on the shape and size of the scapula in a time period spanning from the 19th to the early 21st centuries. The study sample included 211 individuals (100 males and 111 females) from the Coimbra Identified Skeletal Collection and the 21st Century Identified Skeletal Collection. The size and shape of the scapula were evaluated using geometric morphometrics. Results show secular changes over a relatively short period of time in both the shape and size of the scapula in Portuguese nationals. Shape changes were observed in both sexes but expressed minimally, while a significant negative trend in the size of the scapula was detected in males. Scapular size decrement in males conceivably echoes general trends of the overall anatomy towards a narrower body associated with higher standards of living that include enhanced nutrition and universal healthcare, among other factors.

Testing trade‐offs in amphibian metamorphic traits: Swimming performance and selection across metamorphic stages in the aquatic frog Xenopus laevis

Abstract As frogs undergo metamorphosis from tadpole to adult, they may be susceptible to decreases in locomotor performance and survival during stages in which the tail and limbs are both present. Because these alternative axial and appendicular propulsive systems might interfere with each other, performance might be better when only one or the other system predominates. This framework, termed the ‘adaptive peak hypothesis’ emerged from studies of generalist anuran taxa with biphasic life histories in which aquatic larvae transition to terrestrial adults. However, it is not clear that such patterns apply to taxa with different patterns of ontogenetic environmental transitions. We evaluated the relationship between morphology, locomotor performance and survival versus predators across metamorphic stages of a fully aquatic frog, the pipid Xenopus laevis. We measured escape performance from individuals of four developmental stages spanning possession of just a tail, the presence of both tail and legs and resorption of the tail, and then conducted selection trials in which equal numbers of individuals of all stages were exposed to an aquatic predator (cichlid fish). After collecting survivors from these trials, we calculated linear and nonlinear selection gradients for a suite of morphological traits. Unlike generalist frogs, we found that both locomotor performance and survival increased across metamorphic stages of X. laevis. Linear selection gradients favoured tadpoles with longer hindlimbs, longer and narrower bodies, and shorter tails—patterns that generally parallel trends during metamorphic growth. Nonlinear selection showed that longer hindlimbs were favoured as body length increased and the positive effect of forelimb length was reduced as tail length increased. The relationship between hindlimb and body length aligns with expected changes in growth postmetamorphosis where postmetamorphic individuals are expected to have greater survival. However, longer forelimbs are generally associated with decreased locomotor performance, suggesting that alternative mechanisms of selection may be acting on the forelimbs of Xenopus through development. Overall, our results indicate that the generality of the adaptive peak framework, as applied to amphibian metamorphosis, can be impacted by specifics of life history patterns across species. Read the free Plain Language Summary for this article on the Journal blog.

Does atrazine induce changes in predator recognition, growth, morphology, and metamorphic traits of larval skipper frogs (Euphlyctis cyanophlyctis)?

Atrazine, an info disruptor, interferes with the olfaction of aquatic organisms by impairing the chemosensory system. Consequently, it affects behavior, physiology, and growth increases mortality and infections, and suppresses the immune system of aquatic animals. In this study, we wanted to determine the sensitivity of larval Euphlyctis cyanophlyctis to different concentrations of atrazine by assessing their antipredator behavior, growth, morphology, and metamorphic traits. The results indicate that exposure to atrazine did not affect the survival of tadpoles. However, it caused retarded growth at higher concentrations. Interestingly, the antipredator behavior of tadpoles toward conspecific alarm cues decreased in a dose-dependent manner with an increase in the concentration of atrazine. Tadpoles exposed to low concentrations of atrazine had deeper, wider bodies and tails while those exposed to higher concentrations had shallower and narrower bodies with shallower tail muscles. However, at low and moderate concentrations atrazine did not affect size at metamorphosis, it extended the larval duration at higher concentrations.

First Report of Beech Leaf Disease, Caused by Litylenchus crenatae mccannii, on American Beech (Fagus grandifolia) in Virginia.

Beech leaf disease (BLD) was first reported in 2012 in Lake County, Ohio on American beech trees (Fagus grandifolia Ehrh.). Since then, it spread across the Northeastern United States and has been reported from Ohio, Pennsylvania, New York, New Jersey, Connecticut, Rhode Island, Maine, West Virginia, and Ontario, Canada (Carta et al. 2020; Mara and LaMondia 2020, Reid et al. 2020). The symptoms of BLD are characterized by dark interveinal banding of leaves appearing soon after spring flush that become chlorotic and necrotic through autumn, resulting in canopy thinning in advanced stages, followed in some young trees by death. Litylenchus crenatae mccannii has similar morphological characteristics with Litylenchus crenatae (Kanzaki et al. 2019) reported on Fagus crenata from Japan. However that beech species has not shown BLD symptoms or yielded any L. crenatae mccannii in North America. There are several morphological differences between the two. The North American subspecies have shorter post-uterine sac, narrower body width in mature females, shorter tail in immature females, longer tail in mature females, and longer stylet in males when compared to the Japanese subspecies (Carta et al. 2020). BLD symptoms were found on American beech trees in Prince William Forest Park, Prince William County, Virginia in June, 2021. The affected leaves contained females, males, and juveniles with morphometrics consistent with L. crenatae mccannii (Carta et al. 2020). The crude genomic DNA from a live single Litylenchus was prepared with freeze-thaw lysis (Carta and Li, 2019). The ITS PCR were performed by using the procedures and primer set, ITS-CL-F2 and 28S-CL-R described in the previous study (Carta and Li, 2020). The visualization, the cleanup and the direct DNA sequencing of the PCR products were performed by using the procedures described in the previous studies (Carta and Li, 2018 and 2019). Sequences were submitted to GenBank as accessions MZ611855 and MZ611856. This represents the first report of BLD in Virginia. It is also approximately 300 miles south of the 2020 detection of BLD from New Cumberland, WV, and represents the southernmost detection of the disease and nematode in North America. The author(s) declare no conflict of interest. References Carta, L.K., Li, S. 2018. Improved 18S small subunit rDNA primers for problematic nematode amplification. Journal of Nematology. 50, 533-542. Carta, L.K., Li, S. 2019. PCR amplification of a long rDNA segment with one primer pair in agriculturally important nematodes. Journal of Nematology. 51, e2019-26. Carta, L.K., Li, S. 2020. Improvement of long segment ribosomal PCR amplification for the molecular taxonomic identification of Litylenchus crenatae mccannii in beech trees with beech leaf disease. Journal of Nematology. 52, e2020-016. Kanzaki, N., Ichihara, Y., Aikawa, T., Ekino, T., Masuya, H. 2019. Litylenchus crenatae n. sp. (Tylenchomorpha: Anguinidae), a leaf gall nematode parasitising Fagus crenata Blume Nematology 21 (1), 5-22. http://www.brill.com/nematology doi: 10.1163/15685411-00003190 Marra, R.E., LaMondia, J. 2020. First report of beech leaf disease, caused by the foliar nematode, Litylenchus crenatae mccannii, on American beech (Fagus grandifolia) in Connecticut. Plant Disease (early view). https://doi.org/10.1094/PDIS-02-20-0442-PDN Reed, S. E., Greifenhagen, S., Yu, Q., Hoke A., Burke D. J., Carta L. K., Handoo Z.A., Kantor, M.R., Koch, J. 2020. Foliar nematode, Litylenchus crenatae ssp. mccannii, population dynamics in leaves and buds of beech leaf disease-affected trees in Canada and the US. Forest Pathology 50 (3), e12599.

Changes in the perceived size of the body following exposure to distorted self-body images.

Inaccurate perceptions, such as under- or over-estimation of body size are often found in clinical eating disorder populations but have recently been shown also in healthy people. However, it is not yet clear how body size perception may be affected when the internal body representation is manipulated. In this study, visual adaptation was used to investigate whether exposure to distorted visual feedback alters the representation of body size and how long any such effects might last. Participants were exposed for five minutes to a distorted life-size image of themselves that was either 20% wider or 20% narrower than their normal size. Accuracy was measured using our novel psychophysical method that taps into the implicit body representation. The accuracy of the representation was assessed at 6, 12 and 18 min following exposure to adaptation. Altered visual feedback caused changes in participants' judgements of their body size: adapting to a wider body resulted in size overestimation whereas underestimations occurred after adapting to a narrower body. These distortions lasted throughout testing and did not fully return back to normal within 18 min. The results are discussed in terms of the emerging literature indicating that the internal representation of the body is dynamic and flexible.

Body shape variation of Garra rufa (Teleostei, Cyprinidae) populations in the Tigris basin in Iran using geometric morphometric analysis

Geometric morphometric method was used to examine the body shape variations among the six populations of Garra rufa , in Iranian part of Tigris basin. A total of 15 landmark-points was used for 170 specimens to hypothesize population differentiation of G. rufa in the six rivers and reservoir. In discriminant function analysis, 85.9% of original grouped cases correctly classified. Principal component analysis (PCA) and canonical variates analysis (CVA) confirmed the significant difference between the populations. The results revealed that the studied populations are divided into three clades based on differences in body depth, caudal peduncle length, backward moving of anal fin. Caudal peduncle showed shortening trend in five populations. Narrower body shape was dominated among specimens of four regions. Studies on body shape provide supporting data on fisheries, stock management, and conservative programs.

A Side-Viewing Endoscopic Probe With Distal Micro Rotary Scanner for Multimodal Luminal Imaging and Analysis

This paper reports a novel micro electromagnetic actuator serving as the distal rotary scanner of an endoscopic probe developed for side-viewing luminal tissue screening and analysis enabled through different endoscopic modalities. The micro rotary optical scanner, for the first time, offers stepwise, low-speed, and high-speed rotational motions to be compatible with endoscopic optical coherence tomography (OCT) and Raman spectroscopy. In comparison with preceding designs, this rotary scanner is shown to provide up to 125× higher revolution speeds per power via a ~50% narrower body while limiting its operation temperature within a biologically safe level for in-vivo scanning purposes. A preliminary experiment on human skin tissues is performed using the prototyped side-viewing OCT endoscopic probe equipped with the developed distal scanner. The results demonstrate the probe's ability for real-time 360° imaging of live tissue with both high speed and high resolution. These results pave the path for further testing on human internal lumens.

Biological Parameters of the Bark Beetle, Xylosandrus crassiusculus (Motschulsky) Under Controlled Laboratory Conditions

Biological parameters of the bark beetle, Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae: Scolytinae) was investigated under different temperature regimes (27, 29, 31 and 35ºC). The females reared at 29°C, lived 30.93±2.36 days for oviposition. The female laid a maximum of 6.71±1.89 eggs per day and a maximum of 6.99±1.33 batches per female. Each batch had an average of 13.78±2.01 eggs. The mean total fecundity recorded was 67.8±4.25 eggs, with a shortest egg incubation period. At 29°C, the duration of the larval stage was 20.17±2.89 days, the pupal stage 5.03±1.11 days, and the life span of the adult insect was 29.44±3.19 days. Significant differences (P<0.05) were noted when the duration of the different life stages under 29 and 35ºC were compared, with longer duration at 29°C. Insects reared at 35°C had narrower bodies and smaller sizes. Furthermore, the developmental stages period, including the ovipositional period (days) were negatively correlated with temperature. Keywords: Xylosandrus crassiusculus, bark beetle, biological parameters, temperature regimes.

Phenotypic, ecological, and genomic variation in common bully (Gobiomorphus cotidianus) populations along depth gradients in New Zealand’s southern Great Lakes

Depth gradients in lakes are often key drivers of population divergence and speciation in fishes. New Zealand has many deep lakes but no known profundal specialist fishes or cases of intralacustrine speciation. We sampled a native benthic fish, the common bully (Gobiomorphus cotidianus), from 5 to 90 m depth in four South Island lakes to test for morphological, ecological, or genetic differentiation associated with depth. Deeper fish consistently had narrower bodies, while other morphological traits showed variable relationships with depth. Carbon and nitrogen stable isotope values of fish increased with depth, largely tracking isotopic trends with depth of benthic invertebrate prey. Genotyping-by-sequencing showed some genome-wide differentiation between two of the lakes, but no evidence for within-lake genetic structuring along depth gradients. These results indicate that individual bullies associate with shallower or deeper habitats within their lifetimes, but we found no evidence of progress toward genetic divergence within lakes. The apparent lack of intralacustrine genetic divergence in New Zealand’s fishes may be explained by a combination of environmental factors and constraints intrinsic to its marine-derived freshwater fish fauna.

Cockroach Stavba jarzembowskii sp. nov. (Blattaria: Liberiblattindae) from mid-Cretaceous Burmese amber

The family Liberiblattinidae is a small but phylogenetically most important group of Blattaria (cockroaches), comprising 17 Mesozoic genera and 20 species. The genus Stavba Vršanská et Vršanský in Vršanský et al. (2019c) of this family consists of two known species. Stavba jarzembowskii sp. nov. is described and figured based on an exceptionally preserved male individual in mid-Cretaceous amber from Myanmar. It is distinguished from the other two species by having more round eyes, a narrower body, broader wings with broader costal area and less crossveins in the radial sector and medial field, and relatively uncurved A veins. Our new find further adds the diversity within this genus and of the cockroaches in 99 Ma tropical forests of Burmese amber.

Scolopsislacrima, a new species of monocle bream (Teleostei, Perciformes, Nemipteridae) from New Caledonia.

The new monocle bream Scolopsislacrimasp. nov. is described from a single specimen (213.6 mm standard length) collected from Grande-Terre Island, New Caledonia. The new species closely resembles S.meridiana, both species having the upper part of the pectoral-fin base with reddish blotch when fresh, two bands across the top of the snout, a dorsal scaled area on the head reaching anteriorly to between the anterior margin of the eye and anterior nostril, a similar number of lateral-line scales, and absence of a small antrorse spine below the eye. However, S.lacrimasp. nov. is distinguished from S.meridiana by having diagonal lines on the body absent (vs. 18–20 diagonal lines in the latter), a dark longitudinal band below the lateral line (vs. longitudinal lines absent), the caudal fin central area not patterned (vs. with several dark horizontal lines), a narrower body and shallower caudal peduncle.

Tadpoles of three western African frog genera: Astylosternus Werner, 1898, Nyctibates Boulenger, 1904, and Scotobleps Boulenger, 1900 (Amphibia, Anura, Arthroleptidae)

Herein, we describe the tadpoles of six Astylosternus species, A.fallax, A.cf.fallax, A.laurenti, A.montanus, A.perreti, A.ranoides, and Scotoblepsgabonicus, and redescribe the tadpoles of A.batesi, A.diadematus, A.laticephalus, A.occidentalis, A.rheophilus, and Nyctibatescorrugatus. All Astylosternus tadpoles are adapted to torrent currents and share a long, oval body, slightly flattened in lateral view, with very long muscular tails with narrow fins. The jaws are massive, serrated, and often show a tooth-like medial projection (fang) in the upper jaw. Body proportions of Astylosternus tadpoles are extremely similar. The best characters to distinguish species might be life coloration and potentially the shape of labial papillae. The tadpole of Scotoblepsgabonicus is similar to Astylosternus and differs only slightly by a narrower body with a shorter and rounder head. The upper jaw of Scotobleps carries two or three lateral fangs instead of one medial one. The tadpole of Nyctibatescorrugatus is easily distinguishable from the other two genera on the basis of their very long, eel-shaped body and tail and the bluish-black color.

(Invited) Next Generation CMOS Devices: Transistor Module Challenges and Opportunities

In this presentation, we first review the overall trends for advanced CMOS devices in terms of scalability and performance. To carry on Moore’s law, devices need to be scaled from node to node. To enable this scaling, taller, more rectangular FinFETs with narrower body width at scaled pitches has been demonstrated. However this leads to several key process and integration challenges such as Fin integrity, capacitance increase, channel mobility, sub-fin isolation, and sidewall doping as well as contact resistance reduction. Next, we review the challenges of increasing FinFET device performance (e.g., mobility boost, Rexternal reduction) such as fin smoothing, epi Source Drain proximity or contact resistance reduction. Regarding alternate channel material, SiGe p-channel FinFET has gained quite a lot of attention in the past several years. Several SiGe integration approaches have been reported in the literature and will be briefly discussed. Consideration of the entire process flow is critical to ensure maximum strain is achieved in the channel with very low defectivity – two critical requirements for High Volume Manufacturing of high performance, low power devices. These topics will be explored for several of the integration approaches mentioned above. Finally, we will discuss the potentially disruptive transition to new device architecture – the Gate-All-Around (GAA) transistor - and discuss process requirements and challenges for this novel device type.

Molecular characterisation of four echinostomes (Digenea: Echinostomatidae) from birds in New Zealand, with descriptions of Echinostoma novaezealandense n. sp. and Echinoparyphium poulini n. sp.

Morphological and molecular characterisation of echinostome specimens (Digenea: Echinostomatidae) recovered in one Anas platyrhynchos L. and one Cygnus atratus (Latham) (Anseriformes: Anatidae) from New Zealand revealed the presence of two known species, Echinostoma miyagawai Ishii, 1932 and Echinoparyphium ellisi (Johnston & Simpson, 1944) and two species new to science. Comparative morphological and phylogenetic analyses supported the distinct species status of Echinostoma novaezealandense n. sp. ex Branta canadensis (L.), A. platyrhynchos and C. atratus, and Echinoparyphium poulini n. sp. ex C. atratus. Echinostoma novaezealandense n. sp., a species of the "revolutum" species complex characterised by the possession of a head collar armed with 37 spines, keyed down to E. revolutum but was distinguished from the latter in having a much narrower body with almost parallel margins, longer oesophagus, wider cirrus-sac, larger seminal vesicle, much smaller ventral sucker, ovary, Mehlis' gland and testes, more anteriorly located ovary and testes, and distinctly smaller eggs (81-87×42-53 vs 106-136×55-70µm). This new species appears similar to Echinostoma acuticauda Nicoll, 1914 described in Australia but differs in having a longer forebody, more posteriorly located ovary and testes, and much smaller eggs (81-87×42-53 vs 112-126×63-75µm). Echinoparyphium poulini n. sp. is differentiated from the four species of Echinoparyphium possessing 37 collar spines considered valid as follows: from E. chinensis Ku, Li & Chu, 1964 in having a much smaller body, four (vs five) angle spines and simple seminal vesicle (vs bipartite); from E. schulzi Matevosyan, 1951 in having a less robust body at a comparable body length, much smaller ventral sucker, ovary and testes, and longer but narrower eggs (87-109×50-59 vs 70-85×60-84µm); and from the two smaller forms, E. serratum Howell, 1968 and E. aconiatum Dietz, 1909, in a number of additional metrical features correlated with body size and especially in the possession of much larger collar spines. Partial fragments of the mitochondrial nad1 and 28S rRNA genes were amplified for representative isolates of the four species and analysed together with sequences for Echinostoma spp. and Echinoparyphium spp. available on GenBank. Phylogenetic analyses based on the mitochondrial nad1 gene revealed congruence between the molecular data and species identification/delineation based on morphology; this was corroborated by the 28S rDNA sequence data.

(Invited) Group IV Epitaxy Applications for Enabling Advanced Device Scaling

In the past decade, the surge of demand for mobile devices has been tremendous, and has been a key growth engine for the semiconductor market. These novel devices have all capabilities for sophisticated mobile communication, as well as capabilities for gaming, computing, etc. To address the stringent requirements in terms of battery lifetime, device speed, and scaling, the design and manufacturing processes of mobile devices needs constant innovation. Historically, Group IV epitaxial processes such as e-SiGe source/drain have played a critical role in meeting the needs for device scaling and performance in planar devices. One dramatic change that has taken place to address device scalability is the move to the multigate architecture of the FinFET (Fin Field Effect Transistor), which enables the virtual increase of the gate length and dramatically improved electrostatic performance. Beyond FinFET, the GAA (Gate All around Transistors) device structure is one of the most promising paths for offering another disruptive leap in device scaling. This paper discusses the increasingly critical role of epitaxy applications for enabling both of these new device architectures, which have much more complex integration schemes and tighter process control requirements than planar devices. We first review the overall trends for advanced CMOS devices in terms of scalability and performance. To carry on Moore’s law, devices need to be scaled from node to node. To enable this scaling, taller, more rectangular FinFETs with narrower body width at scaled pitches has been demonstrated. However this leads to several key process and integration challenges such as Fin integrity, capacitance increase, Channel mobility, sub-fin isolation, sidewall doping as well as contact resistance reduction. Next, we review the challenges of increasing FinFET device performance (e.g., mobility boost) by using SiGe p-channel FinFET, which has gained quite a lot of attention in the past several years. Several SiGe integration approaches have been reported in the literature, all which are enabled by new epitaxy applications. Examples of these SiGe channel integration approaches include SiGe replacement channel, STI last SiGe formation, cladded SiGe and SiGe condensation. There are significant integration challenges for each of these approaches from the perspective of epitaxial growth and related processes. For example, each of SiGe channel formation schemes have some specific requirements not only on the pre-clean and/or epi growth but also on the overall CMOS integration scheme (alleviation of SiGe oxidation, recess, Fin shaping, junction formation etc.). Consideration of the entire process flow is critical to ensure maximum strain is achieved in the channel with very low defectivity – two critical requirements for High Volume Manufacturing of high performance, low power devices. These topics will be explored in detail for several of the integration approaches mentioned above. Finally, we will discuss the potentially disruptive transition to a new device architecture – the Gate-All-Around (GAA) transistor - and discuss new epitaxy opportunities, requirements and challenges for this new device type.