Mouth Tube Research Articles

The impact of chronotype on VO2max in university students at two different times of the day

Background and Study Aim. To choose the ideal training or performance times, it is crucial to assess VO2 max performance across different time-of-day particular chronotypes. This study aimed to investigate the differences in VO2 max between the chronotype of university students during the morning and evening time of the day. Material and Methods. Fifty-two university students (26 morning type and 26 evening type) with mean age 23.05± 2.07 years, weight 66.71±4.31Kg and height of 170.90±5.18 cm and BMI of 22.75±1.91kg/m2 were recruited based on the results of the Horne-Ostberg Morningness- Eveningness Questionnaire (MEQs) participated in this Cross-over study. VO2 max was measured directly by gas collected using mouth tube breath to breath through the use of the gas analyzer the AD instrument (model-ML206) with an incremental graded maximal exercise test done on the treadmill. Results. The morning type group's VO2 max was significantly better in the morning hour than it was in the evening (p=.013), and when the VO2 max of the evening type group was measured in the morning and evening hours and compared, there was a statistically significant difference in favour of the evening hours (p=.004). Additionally, there is no discernible difference between the VO2 max of the morning type and the evening type group either in the morning hours or the evening hours, but trends indicate that the morning type group has a higher VO2max in the morning hour and the same is true for the evening type group in the evening hour. Conclusion. The findings of this study showed an interaction between chronotype and time of the day in VO2 max. For endurance training, trainers should consider the individual's chronotype and time of the day for exercise prescription.

Estimating SpO2 with Deep Oxygen Desaturations from Facial Video Under Various Lighting Conditions: A Feasibility Study.

This paper presents a feasibility study to collect data, process signals, and validate accuracy of peripheral oxygen saturation (SpO2) estimation from facial video in various lighting conditions. We collected facial videos using RGB camera, without auto-tuning, from subjects when they were breathing through a mouth tube with their nose clipped. The videos were record under four lighting conditions: warm color temperature and normal brightness, neutral color temperature and normal brightness, cool color temperature and normal brightness, neutral color temperature and dim brightness. The air inhaled by the subjects was manually controlled to gradually induce hypoxemia and lower subjects' SpO2 to as low as 81%. We first extracted the remote photoplethysmogram (rPPG) signals from the videos. We applied the principle of pulse oximetry and extracted the ratio of ratios (RoR) for two color combinations: Red/Blue and Red/Green. Next, we assessed SpO2 estimation accuracy against the ground truth, a Transfer Standard Pulse Oximeter. We have achieved an RMSE of 1.93% and a PCC of 0.97 under the warm color temperature and normal brightness lighting condition using leave-one-subject-out cross validation between two subjects. The results have demonstrated the feasibility to estimate SpO2 remotely and accurately using consumer level RGB camera with suitable camera configuration and lighting condition.Clinical Relevance- This work demonstrates that SpO2 can be estimated accurately using an RGB camera without auto-tuning and under warm color temperature, enabling continuous SpO2 monitoring applications that require noncontact sensing.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 33.

Abstracts from The Aerosol Society Drug Delivery to the Lungs 33.

A new genus and species of Loricifera (Nanaloricida: Pliciloricidae) from the deep waters of Japan

In this paper, we describe Wataloricus japonicus gen. et sp. nov. (phylum Loricifera), based on specimens collected during surveys of Japanese waters in the Northwest Pacific conducted onboard the TR/Vs TOYOSHIO MARU and SEISUI MARU. This new loriciferan is placed in the family Pliciloricidae based on the morphology of the adult lorica and Higgins larval internal armature, setae, and toes. It is readily distinguished from other pliciloricid genera by the following combination of characters: adult with a long rigid mouth tube bearing an umbrella-like membrane that extrudes from the mouth opening; a double organ consisting of two untransformed separate spinoscalids; 15 single trichoscalids; and approximately 46 longitudinal folds in the lorica and anal field; and Higgins larva with clavoscalids characterized by ventral swelling and spine-like tip; short unsegmented spinoscalids of the second scalid row; indistinct collar, heavily wrinkled thorax; two pairs of anterior setae; two pairs of posterior setae; and slender toes with sub-terminal swelling. The new genus described herein appears to be synonymous with a previously reported undescribed genus sensu Heiner and Neuhaus (2007) from the Galapagos Spreading Centre, thereby indicating that the geographical distribution of the new genus may at least span the entire Pacific region.

Histological and histochemical characterisation of glands associated with the feeding appendages of Argulus foliaceus (Linnaeus, 1758)

Argulus foliaceus (Linnaeus, 1758) is a member of the branchiuran family Argulidae, a group comprising parasitic “fish lice”. A. foliaceus is distributed worldwide and causes major economic impacts for cultured freshwater fish globally. The work described in this study was undertaken with the objective of identifying, describing and characterising glands associated with feeding in A. foliaceus. From structural and ultrastructural microscopic studies of A. foliaceus, three types of gland were determined to be associated with the pre-oral spine and mouth tube and were suggested to be involved in feeding activities. Two of these glands, the labial glands and the proboscis glands, appeared to secrete their products via the mouth tube and a third, the spinal gland, was connected directly to the pre-oral spine. The current study confirmed that the pre-oral spine delivers active secretions from the spinal gland, which may aid in immunomodulation, while the tubular labial spines and proboscis glands openings within the mouth tube may serve to enhance the feeding process by delivering salivary components to aid pre-digestion and immune-modulate the host. The suggested functions are supported by histological and histochemical staining, coupled with fluorescent lectin-binding assays, which enabled characterisation of the carbohydrate moieties associated with these glandular tissues.

Discovery of the male of the rare caligiform copepod Kabataia Kazachenko, Korotaeva & Kurochkin, 1972 (Copepoda: Siphonostomatoida), with a reconsideration of its phylogenetic affinities.

We report the discovery of the male of the rare caligiform copepod Kabataia ostorhynchi Kazachenko, Korotaeva & Kurochkin, 1972 on the gills of the type-host Oplegnathus woodwardi (Waite, 1900) captured in the Southern Ocean, off Australia. Light and scanning electron microscopy confirmed the unusual body plan of Kabataia Kazachenko, Korotaeva & Kurochkin, 1972, where only the first pedigerous somite is incorporated into the cephalothorax and the second and third pedigerous somites are fused to form a double-somite, visible both dorsally and ventrally. The adult female carries paired dorsal plates originating from the second pedigerous somite within this double-somite. In the male the second and third pedigerous somites are free and paired dorsal plates are present on the former. Kabataia exhibits sexual dimorphism in an unusually wide range of limbs. Most remarkable is the tubular extension from the exit pore of the maxillary gland at the base of the maxilla which reaches beyond the anterior margin of the mouth tube; this is present in the male only. Kabataia exhibits a functional articulation between the first and second pedigerous somites and thus lacks the diagnostic apomorphy of the family Trebiidae (incorporation of both first and second pedigerous somites into the cephalothorax). We propose to transfer Kabataia to the Pandaridae, since it shares the key synapomorphies of this family. Furthermore, we propose to transfer Innaprokofevnas Kazachenko, 2001 to the Dissonidae, which leaves Trebius Krøyer, 1838 as the only genus within the Trebiidae. The correct spelling of Philorthragoriscus Horst, 1897 is noted.

Life Cycle and Morphology of a Cambrian Stem-Lineage Loriciferan

Cycloneuralians form a rich and diverse element within Cambrian assemblages of exceptionally preserved fossils. Most resemble priapulid worms whereas other Cycloneuralia (Nematoda, Nematomorpha, Kinorhyncha, Loricifera), well known at the present day, have little or no fossil record. First reports of Sirilorica Peel, 2010 from the lower Cambrian Sirius Passet fauna of North Greenland described a tubular lorica covering the abdomen and part of a well developed introvert with a circlet of 6 grasping denticles near the lorica. The introvert is now known to terminate in a narrow mouth tube, while a conical anal field is also developed. Broad muscular bands between the plates in the lorica indicate that it was capable of movement by rhythmic expansion and contraction of the lorica. Sirilorica is regarded as a macrobenthic member of the stem-lineage of the miniaturised, interstitial, present day Loricifera. Like loriciferans, Sirilorica is now known to have grown by moulting. Evidence of the life cycle of Sirilorica is described, including a large post-larval stage and probably an initial larva similar to that of the middle Cambrian fossil Orstenoloricusshergoldii .

Culexiregiloricus, a new genus of Nanaloricidae (Loricifera) from the deep sea of the Guinea Basin (Southeast Atlantic)

A postlarva of Nanaloricidae (Loricifera) was found in the deep sea of the Guinea Basin. This postlarva belongs to a new species, Culexiregiloricus trichiscalida, which also represents a new genus. It inhabits clayish sediments with a high amount of calcitic multi-chambered shells of recent planktonic foraminiferans of 0.25 to 1.5 mm in size. This is the third report of a species of Nanaloricidae from a deep-sea habitat. The postlarva is characterized by a mouth cone divided in a short basal section and being drawn out terminally in to a long and slim mouth tube as second section. It also has distinct filiform and delicate clavoand spinoscalis of the second and third rows all covered with minute trichoids, a lorica divided into eight plates (four broad and four narrow ones, some of which have two to eight transversal undulations) and eight wide intercalary plicae (six broad and two narrow ones, with distinct longitudinal folds), 14 lorica spikes of medium size along anterior rim of lorica. Other characters include eight dorsal papillated flosculi, of which six form clusters of three each on dorsolateral plates, and a caudal end with a broad ventral plate flanked longitudinally by massive elevated cuticular ridges. Together with the three species of the genus Armorloricus and one species of the genus Phoeniciloricus, the new species may form a specific species-group within Nanaloricidae, which is characterized by a long and slim mouth tube as the most obvious character.

Nauplii of Tegastes falcatus (Norman, 1869) (Harpacticoida, Tegastidae), a Copepod with an Unusual Naupliar Mouth and Mandible

There are six stages in the naupliar phase of development of Tegastes falcatus (Norman, 1869). The labrum is expressed as a simple fold which does not cover the mouth. A poorly-sclerotized mouth tube was observed on some specimens of all stages except NI (= naupliar stage 1); NI and NII are the only stages without an anus and presumably do not feed. The antennal endopod is a subchela against itself at NII; its distal endopodal segment becomes bifurcate at NIII. A chela on the naupliar mandible consists of the endopod opposite a distoventral attenuation of the basis on NII-NVI. The segmental elements of a chela are present at NI, although the endopod does not oppose the basis at this stage. The maxillule is a unilobe bud with one seta at NIII that gains a second seta at NV and is transformed into a simple bilobe bud with three setae at NVI. The maxilla and maxilliped are each an asetose, ventral attenuation at NVI. Naupliar stages, found in large numbers along with all six copepodid stages of T. falcatus, apparently feed on suctorian ciliates growing on colonies of the bryozoan Flustra foliacea (Linnaeus, 1758). This is the first description of six naupliar stages for a species of Tegastidae Sars, 1904.

Nauplii of Tegastes Falcatus (Norman, 1869) (Harpacticoida, Tegastidae), a Copepod with an Unusual Naupliar Mouth and Mandible

There are six stages in the naupliar phase of development of Tegastes falcatus (Norman, 1869). The labrum is expressed as a simple fold which does not cover the mouth. A poorly-sclerotized mouth tube was observed on some specimens of all stages except NI (= naupliar stage 1); NI and NII are the only stages without an anus and presumably do not feed. The antennal endopod is a subchela against itself at NII; its distal endopodal segment becomes bifurcate at NIII. A chela on the naupliar mandible consists of the endopod opposite a distoventral attenuation of the basis on NII-NVI. The segmental elements of a chela are present at NI, although the endopod does not oppose the basis at this stage. The maxillule is a unilobe bud with one seta at NIII that gains a second seta at NV and is transformed into a simple bilobe bud with three setae at NVI. The maxilla and maxilliped are each an asetose, ventral attenuation at NVI. Naupliar stages, found in large numbers along with all six copepodid stages of T. falcatus, apparently feed on suctorian ciliates growing on colonies of the bryozoan Flustra foliacea (Linnaeus, 1758). This is the first description of six naupliar stages for a species of Tegastidae Sars, 1904.

Ciliary receptors associated with the mouth and pharynx of Acoela (Acoelomorpha): a comparative ultrastructural study

AbstractThe ultrastructure and distribution of receptor cells near the mouth and (where present) the pharynx of Hofstenia miamia, Proporus bermudensis, Conaperta thela, and Convoluta convoluta (Acoela) were investigated by transmission electron microscopy and confocal laser scanning microscopy of specimens stained with a fluorescence marker for actin. Five types of monociliary receptors were identified: (1) non‐collared receptors with a single long and narrow ciliary rootlet; (2) non‐collared receptors with a wide main ciliary rootlet and a smaller posterior rootlet; (3) non‐collared receptors with a single wide and hollow ciliary rootlet with a granulated core; (4) Collar (?) receptors with obliquely radial filament bundles in the cell apex and with a single hollow ciliary rootlet composed of numerous strand‐like elements; and (5) Collar receptors lacking a striated rootlet but with a granular body (swallow's nest rootlet). While H. miamia bears the first two receptor types, P. bermudensis has receptors of type 1, 3 and 5, and Cona. thela and Conv. convoluta have receptors of type 3, 4 and 5. The density of receptors is generally highest at the anterior body tip, regardless of where the mouth is located. Most receptor types occur scattered over the whole body but type 2 receptors of H. miamia are restricted to the pharynx and mouth region. The lack of a common receptor type specific for the mouth and pharynx of the investigated species points to an independent origin of the pharynges in Hofsteniidae and in Proporidae and of the mouth tube in Convolutidae. Moreover, the homology of the so‐called collar receptors in Acoela with typical collar receptors in other invertebrates is questioned.

The Mouth Cone and Mouth Ring of Echiniscus viridissimus Peterfi, 1956 (Heterotardigrada) with Comparisons to Corresponding Structures in Other Tardigrades

The mouth cone and mouth ring of the tardigrade Echiniscus viridissimus are described and their primary homology is assessed by comparing them to structures considered to be homologous in other heterotardigrades, eutardigrades, and ecdysozoans. In E. viridissimus the mouth cone is divided into anterior and posterior regions that differ in the ultrastructure of their cuticle. The mouth ring of the buccopharyngeal apparatus lies just anterior to the buccal tube. It is connected to it by a narrow flange or ridge of cuticle that allows the rostral end of the mouth tube to telescope part way into the mouth ring. Sensilla innervating the mouth cone and mouth ring in E. viridissimus correspond to sensilla of the circumoral and suboral sensory regions described for eutardigrades. The sensory fields, of both the mouth cone and mouth ring, exhibit two planes of mirror image or biradial symmetry. Although the relative dimensions of mouth ring differ markedly between E. viridissimus and eutardigrades, homologous areas can be identified easily. For example, the supporting rods of the mouth ring in E. viridissimus appear to be homologous to the supporting plates in the lamellae of eutardigrades. The widespread occurrence of the mouth cone and mouth ring in hetero- and eutardigrades suggests that these structures were present in the last common ancestor of all tardigrades. Expression of these characters in other ecdysozoans is more problematic. Tentatively the mouth cone and mouth ring are considered to be homologous to the circumoral plates of onychophorans and the ring of radiating plates found in the ‘Peytoia’ apparatus of Cambrian arthropods. These structures are not thought to be homologous to the introverts of scalidophorans or the circumoral structures of nematodes or nematomorphs, and are considered to be absent in these taxa. Thus, the mouth cone and mouth ring are potentially key synapomorphies for Panarthropoda.

NEW ORAL LINGUIFORM PROJECTIONS AND THEIR ASSOCIATED NEURONS IN THE THIRD-STAGE INFECTIVE LARVA OF THE PARASITIC NEMATODE OESOPHAGOSTOMUM DENTATUM

The infective larvae (L3i) of the nematode parasite of swine, Oesophagostomum dentatum, are passively ingested by their hosts. The L3i exhibit certain behaviors that are probably selected to increase the likelihood of ingestion, by strategic positioning in the environment. The larvae show positive geotactic behavior and respond to temperature variations in their environment, as shown by their behavior on a thermal gradient. To investigate neuronal control of this behavior, we initiated a study of the structure of the amphidial neurons of this parasite. The same number and types of neuronal dendritic processes are found in the amphids of the O. dentatum L3i as in those of its close relatives Haemonchus contortus and Ancylostoma caninum. Well-developed dendritic processes of wing cells are located in the amphidial sheath cells, these being similar to wing cells AWA in the free-living nematode Caenorhabditis elegans but actually more extensive. Similar to its close relatives just mentioned, and C. elegans as well, O. dentatum L3i has prominent finger cell processes, the finger cell neurons being the thermoreceptors in all 3 of the preceding species. However, unlike the arrangement seen in H. contortus and A. caninum, where the microvilli-like "fingers" of these neurons lie dorsal to the amphidial channel and occupy a very large portion (>50%) of the anterior end of the larva, the dendritic process of the finger cells in O. dentatum extends into unusual linguiform projections that, in turn, extend into the lumen of the mouth tube, a complex structural arrangement that has not been described for any other nematode.

A new genus of Nanaloricidae (Loricifera) from deep-sea sediments of volcanic origin in the Kilinailau Trench north of Papua New Guinea

A new genus and species of Nanaloricidae (Loricifera), Phoeniciloricus simplidigitatus, is described inhabiting fine sand covered by a layer of volcanic ash at a water depth of 1,813 m in the New Ireland Basin near the Kilinailau Trench (north of Papua New Guinea). The described specimen is a postlarva enclosed in a larval exuvium. This is the first report of a species belonging to the Nanaloricidae from the deep sea. This occurrence is surprising, because Nanaloricidae are typical inhabitants of coarse sands in the intertidal or littoral zone. Preference for these shallow water habitats is reflected in many morphological features which characterize the Nanaloricidae, and are not normally found in Loricifera inhabiting fine-grained, clayish, deep-sea bottoms. The postlarva of the new species is characterized by a long narrow mouth tube, an urn-shaped lorica divided into ten plates, and 13 small lorica spikes. Distinguishing features of the Higgins-larva include short spinose toes lacking mucros but having small and slightly enlarged bases, short scalids on the introvert, many thoracic plates arranged in 6–8 rows, numerous small papillate flosculi in the collar and caudal regions, and three pairs of filiform, short locomotory appendages on the ventral side. Some features of the new species, especially of the Higgins-larva, are discussed as adaptations to the deep-sea environment.

Nasal Deposition of Ultrafine Particles in Human Volunteers and Its Relationship to Airway Geometry

ABSTRACT Very large and very small particles most often deposit in the nasal airways. Human volunteers have often been used in deposition studies using particles > 0.5 μm, whereas physical airway models have been used in studies of ultrafine particle deposition. Studies in airway models provide large data sets with which to evaluate the deposition mechanism, while in vivo deposition data are needed to validate results obtained with nasal models. Four adult male, nonsmoking, healthy human volunteers (ages 36–57 yr) participated in this study. Deposition was measured in each subject at constant flow rates of 4, 7.5, 10, and 20 L min −1. Monodisperse silver particles (5, 8, and 20 nm) and polystyrene latex particles (50 and 100 nm) were used. Each subject held his breath for 30–60 sec, during which time, the aerosol was drawn through the nasal airway and exhausted through a mouth tube. Aerosol concentrations in the intake and exhaust air were measured by an ultrafine condensation particle counter. The deposi...

Structure of the mouth tube of a parasitic copepod,Isobranchia appendiculata Heegaard, 1947 (Siphonostomatoida:Lernaeopodidae)

The structure and musculature of the mouth tube of the lernaeopodidIsobranchia appendiculata Heegaard is described in detail. Situated on the median eminence, the mouth tube appears to be lodged inside a median longitudinal groove on the ventral wall of the cephalothorax. The components of the mouth tube, the labrum and the labium are loosely held together along their lateral edges. The thin, transparent walls of both the labrum and the labium are reinforced by chitinous rods. The musculature of the mouth tube consists of two pairs ofretractores oris, four pairs ofcompressores labri and two pairs oflevatores labii. The mandibles are operated by a pair of antagonistic muscles, theroto adductor mandibulae androto abductor mandibulae. Like other lernaeopodids,I. appendiculata resorts to a browsing type of feeding.

A new species ofArgulus(Crustacea: Branchiura) from a bony fish in Algoa Bay, South Africa

The new species is characterized by the unique shape of the antennule, antenna and maxilla. In addition, huge scales are present on the mouth tube and smaller scales are present on the base of the mouth tube. A row of small spines is present inside the sucker rim of the maxillule. A round dimpled structure occurs ventral to the male gonopore and the unique accessory copulatoiy structures are described.

A new species of <i>Argulus</i> from Kosi Bay, South Africa and distribution records of the genus

A new species of the fish ectoparasite Argulus i.e. A. kosus is described from Kosi Bay in South Africa. This species is characterised by deep antero-lateral depressions of the dorsal carapace which delimit a pronounced frontal region, scales are present on the mouth tube, varying numbers of sclerites are present on the maxillae, no flagella occur on the swimming legs nor any scales on the antennae. The shape of the respiratory areas are also typical for this species. A table of the distribution of the genus in South Africa and a map showing the localities, is also included.

The fine structure and function of the cephalic appendages of the branchiuran parasite, Argulus japonicus Thiele

The fish parasite Argulus japonicus Thiele (Crustacea: Branchiura) has recently been introduced into Britain and is now established in the wild. A. japonicus , an ectoparasite attaching to, and feeding on, the skin of its host, is a potentially serious pathogen of native freshwater fishes. The anatomy of the attachment and feeding structures is described using light and electron microscopy. The primary attachment organs are the suckers derived from the maxillules. The extrinsic musculature of the suckers comprises two major muscle groups: the suction muscles which insert on the floor of the sucker and generate suction, and the cup muscles which control the orientation and movement of the sucker as a whole. The inner wall of the sucker cup comprises two hoops of thickened cuticle and provides the rigidity necessary to prevent the sucker from collapsing. These hoops are hinged to allow extra movement of the distal hoop plus its marginal m em brane when forming a seal onto the surface of the host. Numerous mucous glands are present in the floor of the sucker. The elongate mouth tube represents a ventral outgrowth of the head bearing a small labrum and labium distally. The homology of the labium is confirmed by the arrangement of its paired muscles, which originate on the undersurface of the ventral cephalic tendon and pass down through channels in the suboesophageal ganglion. The labrum lacks muscles. The ontogeny of the mouth tube, the adult m andibular musculature and the possible feeding mechanism are described. The preoral spine lies in the ventral midline of the body anterior to the mouth tube. It consists of a tapering spine carried on a long eversible sheath. When fully retracted the spine and sheath virtually disappear into the body. As the spine retracts the cuticle of the proximal sheath becomes inverted. The epithelium beneath this sheath cuticle is syncytial and is separated from the cuticle-lined, central duct of the spine by a fluid matrix which can be displaced as the spine is retracted. The fluid matrix appears to be secreted by the epithelial cells of the sheath cuticle. Retraction is by means of paired retractor muscles which originate dorsal to the midgut and pass down through the nerve ring. These muscles shorten to about 25% of their maximum length during extreme retraction.

Laboratory assessment of Laerdal mouth tube mask prototype resuscitation device.

Laboratory assessment of Laerdal mouth tube mask prototype resuscitation device.